bhushan steels report final
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Industrial Training Report (Bhushan Steels Pvt. Ltd.)
Name : VIVEK RAJ YADAVUniv. Roll No. : 0809140089Academic Session : 2008-2012
JSS ACADEMY OF TECHNICAL EDUCATION, NOIDAJSS MAHAVIDYAPEETHADEPARTMENT OF MECHANICAL ENGINEERING
1JSS MAHAVIDYAPEETHA
JSS ACADEMY OF TECHNICAL EDUCATIONDEPARTMENT OF MECHANICAL ENGINEERING
CONTENT
1.
0 Acknowledgement….………………………………………………………………3
2.0 Abstract …………………………………………………………………............... 4
3.0 Histry of the company…………………………………………………………......5
4.0 Company profile…………………………………………………………………...7
5.0 Vision of the company………..……………………………………………………8
6.0 Policies of company……………………………………………………………….9
7.0 List of departments visited in training………………………..…………………10
7.1 HR slitting………………………………………….………………………………11
7.2 Pickling…………………………………………………………………………….12
7.3 Rolling mills……...………………………………………………………………....14
7.4 Electrochemical cleaning……………………….……………………………….…17
7.5 Annealing………..……………………………………………………………….…20
7.6 Normalization……………..………………………………………………………..22
7.7 Skin pass mill…………………………………………………………………….…24
7.8 Cold roll stilling/Cut to length………...………………………………………..…25
7.9Qualitycontrol…………..…………………………………………………..…….…28
7.10 Research and development.……………………………………………………….29
7.11 Galvanising plant…………………..……………………………………………...32
7.12Rollgrindingmachine………………………………………………..………....37
7.13 Narrow plant………………….…………………………………………...……....41
8.0 Conclusion…………………………………………………………………………...42
9.0 References……………………………………………………………………….......43
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ACKNOWLEDGEMENT
I would wish to express my gratitude to my H.O.D Dr. C.V.Chandrashekhara for providing
me the opportunity to explore studies beyond academics. I am also thankful to BHUSHAN
STEELS Ltd for allowing me to undergo the SUMMER TRAINING PROGRAMME in their
organization. At last but not the least I extend my thanks to all the staff members for
providing valuable information regarding the plant and processes that formed the core of the
training.
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ABSTRACT
In 30 days of my industrial training I have learned about various processes
such as cold rolling slitting etc. I had a good exposure to these processes which added
more to my knowledge. I worked on ‘galvanising plants’ in which galvanization
process takes place,on steel.basically zinc or aluminium coating is done on the
steel,for increasing life of steel and making it suitable for use, but at Bhushan steel
they also coat steel with galume a mixture of 55% zinc + 43% aluminium + 2%
silicon. Its coating is very effective and useful.silicon is basically used just to improve
adhesion of the other two material on the steel. Other products of the industry are
colour coated coil, hard tempered coil, billets, sponge iron, tubes, etc.
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HISTRY OF THE COMPANY
Year events 1983 - The company was incorporated on 7thJanuary, under the name of Jawahar
Metal Industries Private Limited for the manufacture of cold rolled steel strips and steel
ingots at Sahibabad Industrial Area, District Ghaziabad.
1987 - On 14th January, Brij Bhushan Singal and his sons Sanjay Singal and Neeraj Singal
and associate companies took over the management of the company by acquiring the entire
share capital of the company.
1989 - The company undertook the setting up of a new plant for the manufacture of wide
width Cold Rolled Steel Strips with integrated plant facilities.
1992 - The name of the company was changed to the present name of Bhushan Steel & Strips
Limited and fresh Certificate of Incorporation was issued on 9th June.
1993 - The company made its maiden Public Issue of 22 lac equity shares of Rs.10 each at a
premium of Rs.55 share aggregating Rs. 1430 lacs in September/October.
1994 - The galvanising plant was commissioned in January. Presently the company has
facilities for the manufacture of 1,20,000 tonnes per' annum of wide width cold rolled steel
strips and 1,00,000 tonnes per annum of galvanised sheets.
1995 - The Cold Rolling Expansion the Company is installing state of the art 1600mm width
6HI combination Universal Crown Mill (UCM) of Hitachi, Japan with sophisticated features
for shape control and surface finish to cater to the requirements of the automobile and white
goods sector.
1996 - The Part B of 68,94,800 14% unsecured fully convertible Debentures aggregating Rs
8375 Lacs have been converted into Equity Shares w.e.f. 1st April.
1998 - With the commissioning of the new plant recently set up at company's existing site at
Sahibabad (UP), the company is now exploring further growth possibilities of setting up a
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modern Cold Rolling cum Galvanizing Unit at West Coast of the Country.
1999 - During the year, the company has set up a dedicated service centre for large OEM
customers at Sahibabad so as to ensure supplies to them on 'just in time' concept.
2000 - The Delhi-based Bhushan Steel and Strips' to set up a Rs 750 crore cold rolled steel
plant is likely to hit a road block.
2002-Strikes an important position in the market for cold rolled steel for automobiles, feeding
over 70% of demand for car bodies.
2003-Enters into a strategic alliance with Sumitomo Metal Industries of Japan under which,
the latter has further extended process know-how for the manufacture of automotive steel
sheets for a period of six years
2004-Bhushan Steel awards Rs 36 cr order for BHEL
2006-Bhushan Steel & Strips Ltd has informed that Sh. Sanjay Singal, has ceased to be a
Director of the Company w.e.f. October 18, 2006.
2007-Company name has been changed from Bhushan Steel & Strips Ltd to Bhushan Steel
Ltd
2008-Bhushan Steel Ltd has informed that w.e.f. September 23, 2008, Sh. B B Tandon has
been appointed as an Additional Director on the Board of the Company as a Independent
Non-Executive Director.
2009-Bhushan Steel buys Aussie exploration firm
2010- Bhushan Steel Ltd has informed that Life Insurance Corporation of India has appointed
Smt. Sunita Sharma, their representative as a Nominee Director on the Board of the
Company.
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COMPANY PROFILE
TYPE : PRIVATE
FOUNDED IN : 1987
HEADQAURTERS : INDIA
KEY PERSONS : Brij Bhushan Singhal (Chairperson) Neeraj Singhal (Managing Director)
INDUSTRY : STEEL
WEBSITE : www.bhushangroup.com
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VISION OF THE COMPANY
The vision of evolving into a totally Integrated Steel Producer by
committing to achieve the highest standards of Quality through
The key to Vision is to use rigorous conceptual framework and to understand how that framework connects to the underlying DNA of enduring great companies.
A well-conceived vision consists of two major components—“CORE IDEOLOGY” and an “ENVISIONED FUTURE”. A good vision builds on the interplay between these two complementary Yin-and-Yang forces; it defines “What we stand for and Why we exist” that does not change the Core Ideology and sets forth “What we aspire to become, to achieve.
It is true to say that most of our vision statements express an element of ambition.BSL’s vision of total integration is a lot closer to realization today. Through seamless backward integration, BSL is consolidating its position on the entire steel value chain from iron ore to specialized is surging ahead.
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POLICIES OF THE COMPANY
BHUSHAN STEEL LTD, SAHIBABAD
Integrated Quality, Environment, Occupational Health & Safety Management
System Policy
Bhushan Steel Ltd. commits to produce cold rolled and galvanized steel sheets of world class quality in a safe, healthy and clean environment by involving employees with continual improvements in system implementation, technological advancement, operational integration, prevention of pollution & hazards maintaining Legal compliance and satisfying needs & expectations of Customers.
For environment management system we have ISO 14001:2004 certification
For quality system we have ISO/TS 16949:2002 certification
For safety management system we have OHSAS 18001:2007 certification for
quality system we have ISO/TS 16949:2002 certification.
For Safety Management System we have OHSAS 18001:2007 Certification
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LIST OF DEPARTMENT VISITED IN TRAINING
1. HR SLITTING
2.HRS/PICKLING
3. ROLLING MILLS
4. ECL
5. ANNEALING
6. SKIN PASS MILL
7. CRS/CTL
8. QUALITY
9. R&D
10. UTILITY
11. GP
12. RGM
13. NARROW PLANT
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HR SLITTING
Roll slitting, also known as log slitting, is a shearing operation that cuts a large roll
of material into narrower rolls. The log slitting terminology refers back to the olden
days of saw mills when they would cut logs into smaller sections. They would also
use these saw mills to cut iron rods into smaller sections; see slitting mill. The
multiple narrower strips of material are known as mults (short for multiple) By today's
definition, slitting is a process in which a coil of material is cut down into a number of
smaller coils of narrower measure. Potential workpieces are selectively thin (0.001 to
0.215 in.) and can be machined in sheet or roll form. Slitting is considered a practical
alternative to other methods due to its high productivity and the versatility of
materials it can manage.
Soft materialsSeveral methods are available for soft materials like plastic films and paper. Razor
blades, straight, or circular blades are being used. Some blades cut through the
material while others crush the material against a hard roll. Those are similar to
knives and cut the material into narrow strips, which are called coils when being
rewound. The cutting blades can be set to a desired width. Some machines have
many blades to increase the options of cutting widths, others have just a single blade
and can be set to a desired location. The slit material is being rewound on paper or
plastic cores on the exit side of the machine.
Examples of materials that can be cut this way are: adhesive tape, foam, rubber,
paper products, foil, plastics (such as tarps and cling wrap), glass cloth,
fabrics, release liner and film.Hard materials
For harder materials, such as sheet metal, blades cannot be used. Instead a
modified form of shearing is used. Two cylindrical rolls with matching ribs and
grooves are used to cut a large roll into multiple narrower rolls. This continuous
production process is very economical yet precise; usually more precise than most
other cutting processes. However, the occurrence of rough or irregular edges known
as burrs are commonplace on slit edges.
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PICKLING
Pickling (metal)Pickling is a metal surface treatment used to remove impurities, such as stains,
inorganic contaminants, rust or scale from ferrous metals, copper,
and aluminum alloy. A solution called pickle liquor, which contains strong acids, is
used to remove the surface impurities. It is commonly used to descale or
clean steel in various steelmaking processes.
Process
Many hot working processes and other processes that occur at high temperatures
leave a discoloring oxide layer or scale on the surface. In order to remove the scale
the workpiece is dipped into a vat of pickle liquor.
The primary acid used is hydrochloric acid, although sulfuric acid was previously
more common. Hydrochloric acid is more expensive than sulfuric acid, but it pickles
much faster while minimizing base metal loss. The speed is a requirement for
integration in automatic steel mills that run production at high speed; speeds as high
as 800 ft/min (~243 metres/min) have been reported.
Carbon steels, with an alloy content less than or equal to 6%, are often pickled in
hydrochloric or sulfuric acid. Steels with an alloy content greater than 6% must be
pickled in two steps and other acids are used, such
as phosphoric, nitric andhydrofluoric acid. Rust- and acid-resistant chromium-nickel
steels are pickled in a bath of hydrochloric and nitric acid. Most copper alloys are
pickled in dilute sulfuric acid, but brass is pickled in concentrated sulfuric and nitric
acid mixed with sodium chloride and soot.[1]
In jewelry making, pickling is used to remove the oxidation layer from copper
surfaces, which occurs after heating. A diluted sulfuric acid pickling bath is used.
Sheet steel that undergoes acid pickling will oxidize (rust) when exposed to
atmospheric conditions of moderately high humidity. For this reason, a thin film of oil
or similar waterproof coating is applied to create a barrier to moisture in the air. This
oil film must later be removed for many fabrication, plating or painting processes.
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DisadvantagesAcid cleaning has limitations in that it is difficult to handle because of its
corrosiveness, and it is not applicable to all steels. Hydrogen embrittlement becomes
a problem for some alloys and high-carbon steels. The hydrogen from the acid
reacts with the surface and makes it brittle and causes cracks. Because of its high
reactance to treatable steels, acid concentrations and solution temperatures must be
kept under control to assure desired pickling rates.
Waste productsPickling sludge is the waste product from pickling, and includes acidic rinse waters,
metallic salts and waste acid.] Spent pickle liquor is considered a hazardous
waste by EPA.Pickle sludge from steel processes is usually neutralized with lime and
disposed of in a land fill. After neutralization the EPA no longer deems the waste a
hazardous waste. The lime neutralization process raises the pH of the spent acid
and makes heavy metals in the sludge less likely to leach into the
environment. Since the 1960s, hydrochloric pickling sludge is often treated in
a hydrochloric acid regeneration system, which recovers some of the hydrochloric
acid and ferric oxide. The rest must still be neutralized and disposed of in land
fills.The by-products of nitric acid pickling are marketable to other industries, such
as fertilizer processors
ROLLING MILLSCCR is lo
In metalworking, rolling is a metal forming process in which metal stock is passed
through a pair of rolls. Rolling is classified according to the temperature of the metal
rolled. If the temperature of the metal is above its recrystallization temperature, then
the process is termed as hot rolling. If the temperature of the metal is below its
recrystallization temperature, the process is termed as cold rolling. In terms of
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usage, hot rolling processes more tonnage than any other manufacturing process
and cold rolling processes the most tonnage out of all cold working processes.
There are many types of rolling processes, including flat rolling, foil rolling, ring
rolling, roll bending, roll forming, profile rolling, and controlled rolling.
Hot rolling is a metalworking process that occurs above the recrystallization
temperature of the material. After the grains deform during processing, they
recrystallize, which maintains an equiaxed microstructure and prevents the metal
from work hardening. The starting material is usually large pieces of metal, like semi-
finished casting products, such as slabs, blooms, and billets. If these products came
from a continuous casting operation the products are usually fed directly into the
rolling mills at the proper temperature. In smaller operations the material starts at
room temperature and must be heated. This is done in a gas- or oil-fired soaking
pit for larger workpieces and for smaller workpieces induction heating is used. As the
material is worked the temperature must be monitored to make sure it remains
above the recrystallization temperature. To maintain a safety factor a finishing
temperature is defined above the recrystallization temperature; this is usually 50 to
100 °C (122 to 212 °F) above the recrystallization temperature. If the temperature
does drop below this temperature the material must be re-heated before more hot
rolling.
Hot rolled metals generally have little directionality in their mechanical properties and
deformation induced residual stresses. However, in certain instances non-metallic
inclusions will impart some directionality and workpieces less than 20 mm (0.79 in)
thick often have some directional properties. Also, non-uniformed cooling will induce
a lot of residual stresses, which usually occurs in shapes that have a non-uniform
cross-section, such as I-beams and H-beams. While the finished product is of good
quality, the surface is covered in mill scale, which is an oxide that forms at high-
temperatures. It is usually removed via pickling or the smooth clean surface process,
which reveals a smooth surface. Dimensional tolerances are usually 2 to 5% of the
overall dimension.
Hot rolling is used mainly to produce sheet metal or simple cross sections, such
as rail tracks.
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Cold rolling
Cold workingCold rolling occurs with the metal below its recrystallization temperature (usually at
room temperature), which increases the strength via strain hardening up to 20%. It
also improves the surface finish and holds tighter tolerances. Commonly cold-rolled
products include sheets, strips, bars, and rods; these products are usually smaller
than the same products that are hot rolled. Because of the smaller size of the
workpieces and their greater strength, as compared to hot rolled stock, four-high or
cluster mills are used. Cold rolling cannot reduce the thickness of a workpiece as
much as hot rolling in a single pass.
Cold-rolled sheets and strips come in various conditions: full-hard, half-hard, quarter-
hard, and skin-rolled. Full-hard rolling reduces the thickness by 50%, while the
others involve less of a reduction. Quarter-hard is defined by its ability to
be bent back onto itself along the grain boundary without breaking. Half-hard can be
bent 90°, while full-hard can only be bent 45°, with the bend radiusapproximately
equal to the material thickness. Skin-rolling, also known as a skin-pass, involves the
least amount of reduction: 0.5-1%. It is used to produce a smooth surface, a uniform
thickness, and reduce the yield-point phenomenon (by preventing Luder bands from
forming in later processing). It is also used to breakup the spangles in galvanized
steel.[citation needed] Skin-rolled stock is usually used in subsequent cold-working
processes where good ductility is required.
Other shapes can be cold-rolled if the cross-section is relatively uniform and the
transverse dimension is relatively small; approximately less than 50 mm (2.0 in). This
may be a cost-effective alternative toextruding or machining the profile if the volume
is in the several tons or more. Cold rolling shapes requires a series of shaping
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operations, usually along the lines of: sizing, breakdown, roughing, semi-roughing,
semi-finishing, and finishing.
Processes
Flat rollingFlat rolling is the most basic form of rolling with the starting and ending material
having a rectangular cross-section. The material is fed in between two rollers,
called working rolls, that rotate in opposite directions. The gap between the two rolls
is less than the thickness of the starting material, which causes it to deform. The
decrease in material thickness causes the material to elongate. The friction at the
interface between the material and the rolls causes the material to be pushed
through. The amount of deformation possible in a single pass is limited by the friction
between the rolls; if the change in thickness is too great the rolls just slip over the
material and do not draw it in. The final product is either sheet or plate, with the
former being less than 6 mm (0.24 in) thick and the latter greater than; however,
heavy plates tend to be formed using a press, which is termed forming, rather than
rolling.
Oftentimes the rolls are heated to assist in the workability of the metal. Lubrication is
often used to keep the workpiece from sticking to the rolls. To fine tune the process
the speed of the rolls and the temperature of the rollers are adjusted.
Foil rollingFoil rolling is a specialized type of flat rolling, specifically used to produce foil, which
is sheet metal with a thickness less than 200 µm (0.0079 in) The rolling is done in
a cluster mill because the small thickness requires a small diameter rolls. [3] To
reduce the need for small rolls pack rolling is used, which rolls multiple sheets
together to increase the effective starting thickness. As the foil sheets come through
the rollers, they are trimmed and slitted with circular or razor-like knives. Trimming
refers to the edges of the foil, while slitting involves cutting it into several sheets
Aluminum foil is the most commonly produced product via pack rolling. This is
evident from the two different surface finishes; the shiny side is on the roll side and
the dull side is against the other sheet of foil.
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ELECTROCHEMICAL CLEANING
Electrochemical Cleaning (ECC)SM is a very effective process using the same physics, equipment, and chemicals we use in our proprietary "spot" electropolishing technique. Discovered when a customer had a product residue issue that looked like classic "rouge" yet when industry accepted de-rouging chemical applications were tried they proved completely ineffective. In an experiment we used the spot electropolish procedure whereby electrolyte was applied to the stained surface and the DC current was activated and the "hand tool" was applied to and moved over the surface the stain was removed immediately. Because of this discovery we were able to completely clean 5,10,15K GALLON & larger vessels in hours instead of days.
Once discovered this method has found several very cost effective applications where ECC can be used in place of more expensive and less effective chemical or manual processes while delivering a micro surface improvement to the area being cleaned where optional processes at best do nothing to improve and at worst can etch the micro surface.
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Applications
De-rouging: ECC has been found to be very effective for removing rouge for both electropolished and non-electropolished surfaces. An added benefit observed on items de-rouged using ECC is the rouge is very slow to return. Though conventional de-rouging and passivation methods would yield a clean product contact surface the rouge would begin to reform in a matter of hours. Equipment de-rouged using ECC has shown the rouge resisted returning for months and in some cases years.Grey Residue: On equipment with a sanded or mechanically polished stainless steel surface only it is common to find a grey residue present when the surface is wiped with an alcohol soaked cloth. In many instances the entire surface of a vessel, as an example, will be hand wiped for hours using "clean wipes" until all of the grey residue has appeared to have been removed. The vessel may then be passivated or cleaned in place and allowed to dry only to have the grey residue return at visibly the same concentration as observed before the cleaning operation.
It is believed this grey residue is made up of stainless steel powder created by the sanding process and electrostatically adhered to the mechanically polished surface (PIC). No amount of wiping or chemical cleaning has proven to completely remove this residue. Understandably Quality Control personnel find this condition unacceptable concerned if the grey residue can be wiped off, it stands to reason it can come loose during product processing and become an undesirable additive.
ECC can completely remove this grey residue in one application by electrolytic action as metal is removed ion by ion with the very outermost surface and any residue being removed. In dozens of applications this condition has successfully been treated in one application eliminating grey residue from the equation.
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Weld Scale and Discoloration: Prior to successful use as a de-rouging or surface contaminant removal process, ECC was developed specifically for removing weld discoloration directly on a weld or in the heat affected zones adjacent to the weld.
The process utilizes a mild acid electrolyte solution and DC current that when applied to a weld or heat affected zone (HAZ) very rapidly removes discoloration. On large construction projects utilizing austenitic, super-austenitic or nickel alloys, weld discoloration has historically been removed by mechanical polishing, blasting or a harsh chemical application, all of which alter the appearance when compared to untreated surrounding surfaces. The process has also been shown to improve corrosion resistance in these areas comparable to that of the surrounding base metal.
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ANNEALING
Annealing, in metallurgy and materials science, is a heat treatment wherein a
material is altered, causing changes in its properties such as strength and hardness.
It is a process that produces conditions by heating to above the recrystallization
temperature, maintaining a suitable temperature, and then cooling. Annealing is
used to induce ductility, soften material, relieve internal stresses, refine the structure
by making it homogeneous, and improve cold working properties.
In the cases of copper, steel, silver, and brass, this process is performed by
substantially heating the material (generally until glowing) for a while and allowing it
to cool. Unlike ferrous metals—which must be cooled slowly to anneal—copper,
silver and brass can be cooled slowly in air or quickly by quenching in water. In this
fashion the metal is softened and prepared for further work such as shaping,
stamping, or forming.
ThermodynamicsAnnealing occurs by the diffusion of atoms within a solid material, so that the
material progresses towards its equilibrium state. Heat is needed to increase the rate
of diffusion by providing the energy needed to break bonds. The movement of atoms
has the effect of redistributing and destroying the dislocations in metals and (to a
lesser extent) in ceramics. This alteration in dislocations allows metals to deform
more easily, so increases their ductility.
The amount of process-initiating Gibbs free energy in a deformed metal is also
reduced by the annealing process. In practice and industry, this reduction of Gibbs
free energy is termed "stress relief"..
The relief of internal stresses is a thermodynamically spontaneous process;
however, at room temperatures, it is a very slow process. The high temperatures at
which the annealing process occurs serve to accelerate this process.
The reaction facilitating the return of the cold-worked metal to its stress-free state
has many reaction pathways, mostly involving the elimination of lattice vacancy
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gradients within the body of the metal. The creation of lattice vacancies is governed
by the Arrhenius equation, and the migration/diffusion of lattice vacancies are
governed by Fick’s laws of diffusion.
Mechanical properties, such as hardness and ductility, change as dislocations are
eliminated and the metal's crystal lattice is altered. On heating at specific
temperature and cooling it is possible to bring the atom at the right lattice site and
new grain growth can improve the mechanical properties.
Stages
There are three stages in the annealing process, with the first being
the recovery phase, which results in softening of the metal through removal
of crystal defects (the primary type of which is the linear defect called a dislocation)
and the internal stresses which they cause. Recovery phase covers all annealing
phenomena that occur before the appearance of new strain-free grains. The second
phase is recrystallization, where new strain-free grains nucleate and grow to replace
those deformed by internal stresses. If annealing is allowed to continue once
recrystallization has been completed, grain growth will occur, in which the
microstructure starts to coarsen and may cause the metal to have less than
satisfactory mechanical properties.
Controlled atmospheresThe high temperature of annealing may result in oxidation of the metal’s surface,
resulting in scale. If scale is to be avoided, annealing is carried out in a special
atmosphere, such as with endothermic gas (a mixture of carbon monoxide, hydrogen
gas, and nitrogen gas).
The magnetic properties of mu-metal (Espey cores) are introduced by annealing the
alloy in a hydrogen atmosphere.
Setup and equipmentTypically, large ovens are used for the annealing process. The inside of the oven is
large enough to place the workpiece in a position to receive maximum exposure to
the circulating heated air. For high volume process annealing, gas fired conveyor
furnaces are often used. For large workpieces or high quantity parts Car-bottom
furnaces will be used in order to move the parts in and out with ease. Once the
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annealing process has been successfully completed, the workpieces are sometimes
left in the oven in order for the parts to have a controlled cooling process. While
some workpieces are left in the oven to cool in a controlled fashion, other materials
and alloys are removed from the oven. After being removed from the oven, the
workpieces are often quickly cooled off in a process known as quench hardening.
Some typical methods of quench hardening materials involve the use of media such
as air, water, oil, or salt.
Diffusion annealing of semiconductorsIn the semiconductor industry, silicon wafers are annealed, so that dopant atoms,
usually boron, phosphorus or arsenic, can diffuse into substitutional positions in the
crystal lattice, resulting in drastic changes in the electrical properties of the
semiconducting material.
NormalizationNormalization is an annealing process in which a metal is cooled in air after heating
in order to relieve stress.
It can also be referred to as: Heating a ferrous alloy to a suitable temperature above
the transformation temperature range and cooling in air to a temperature
substantially below the transformation range.
This process is typically confined to hardenable steel. It is used to refine grains
which have been deformed through cold work, and can improve ductility and
toughness of the steel. It involves heating the steel to just above its upper critical
point. It is soaked for a short period then allowed to cool in air. Small grains are
formed which give a much harder and tougher metal with normal tensile strength and
not the maximum ductility achieved by annealing. It eliminates columnar grains and
dendritic segregation that sometimes occurs during casting. Normalizing
improves machinability of a component and provides dimensional stability if
subjected to further heat treatment processes.Process annealing
Process annealing, also called "intermediate annealing", "subcritical annealing", or
"in-process annealing", is a heat treatment cycle that restores some of the ductility to
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a work piece allowing it be worked further without breaking. Ductility is important in
shaping and creating a more refined piece of work through processes such
as rolling, drawing, forging, spinning, extruding and heading. The piece is heated to
a temperature typically below the austenizing temperature, and held there long
enough to relieve stresses in the metal. The piece is finally cooled slowly to room
temperature. It is then ready again for additional cold working. This can also be used
to ensure there is reduced risk of distortion of the work piece during machining,
welding, or further heat treatment cycles.
The temperature range for process annealing ranges from 260 °C(500 °F) to 760
°C(1400 °F), depending on the alloy in question.
Full anneal
A full anneal typically results in the second most ductile state a metal can assume for
metal alloy. It creates an entirely new homogeneous and uniform structure with good
dynamic properties. To perform a full anneal, a metal is heated to its annealing point
(about 50°C above the austenic temperature as graph shows) and held for sufficient
time to allow the material to fully austenitize, to form austenite or austenite-cementite
grain structure. The material is then allowed to cool slowly so that
the equilibrium microstructure is obtained. In some cases this means the material is
allowed to air cool. In other cases the material is allowed to furnace cool. The details
of the process depend on the type of metal and the precise alloy involved. In any
case the result is a more ductile material that has greater stretch ratio and reduction
of area properties but a lower yield strength and a lower tensile strength. This
process is also called LP annealing for lamellar pearlite in the steel industry as
opposed to a process anneal which does not specify a microstructure and only has
the goal of softening the material. Often material that is to be machined, will be
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annealed, then be followed by further heat treatment to obtain the final desired
properties.
Short cycle anneal
Short cycle annealing is used for turning normal ferrite into malleable ferrite. It consists of heating, cooling, and then heating again from 4 to 8 hours.
Resistive heatingResistive heating can be used to efficiently anneal copper wire; the heating system
employs a controlled electrical short circuit. It can be advantageous because it does
not require atemperature-regulated furnace like other methods of annealing.
The process consists of two conductive pulleys (step pulleys) which the wire passes
across after it is drawn. The two pulleys have an electrical potential across them,
which causes the wire to form a short circuit. The Joule effect causes the
temperature of the wire to rise to approximately 400 °C. This temperature is affected
by the rotational speed of the pulleys, the ambient temperature, and the voltage
applied. Where t is the temperature of the wire, K is a constant, V is
the voltageapplied, r is the number of rotations of the pulleys per minute, and ta is
the ambient temperature:
The constant K depends on the diameter of the pulleys and the resistivity of the
copper.
Purely in terms of the temperature of the copper wire, an increase in the speed with
which the wire passes through the pulley system has the same effect as an increase
in resistance. Therefore, the speed with which the wire can be drawn through varies
quadratically as the voltage applied.
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SKIN PASS MILL
After annealing, coils may require a final rolling called a temper pass, skin pass or planish
pass. This involves a controlled light reduction to establish the final thickness, impart the
desired surface finish, flatten the strip to improve shape and create the required hardness or
temper of the material.
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COLD ROLL SLITTING / CUT TO LENGTH
Some customers require a steel to be of a particular thickness other than the
general increment sizes rolled in the hot mill or thinner than the minimum thickness
rolled in the mills. These steels are processed in the cold roll reduction mill. These
mills are capable of rolling steel to the precise thickness that the customer orders
and are a major part of the steel strip production process. The reduction mill in the
plant I worked had four rolls in the mill that were stacked upon each other. This
arrangement is known as a two high mill. There are two working rolls between which
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the strip is passed and two large back-up rolls, one on top of the working rolls and
one on the bottom. The back-up rolls apply the tremendous pressures required to
cold roll (reduce) the strip between the working rolls. The working rolls are usually
about two to three feet in diameter while the back-up rolls are about seven to eight
feet in diameter. The rolls are made of high alloy steel so they can withstand the
tremendous pressure they are under while rolling without deforming. Because of this
the rolls are ground in a large lathe using a very large grinding wheel on a movable
carriage. Depending on the surface finish required of the strip the working rolls will
either have a highly polished (mirror like) finish or a dull finish on them. All working
rolls are ground on the lathe in the mill to a highly polished surface periodically. The
rolls that have a dull finish on them are shot blasted after grinding to produce the
desired surface.
After grinding to a polished surface the rolls that need a dull finish are placed on a
large carriage which has a set of rubber rolls on it. The carriage then travels on a
small rail track into a large enclosure and the door is closed down. On top of this
enclosure is a large hopper filled with fine steel balls called shot. This shot is very
small in diameter (about half the size of a BB or smaller) and is very hard. It is fed
down a chute and using either compressed air or a impeller type system it is
accelerated to high speed (in excess of a hundred miles per hour) and blasted
against the surface of the roll. The rubber rolls on the carriage rotate causing the
steel roll to rotate so all its surface is exposed to the shot blast. The shot comes in a
variety of sizes and hardness grades and different types are used depending on the
type of surface finish required on the rolls. After a predetermined cycle time the roll is
removed from the Wheelabrator, as it is called and is ready to be used in the mill.
A saddle type conveyor runs along the side of the reduction mill. Steel coils are place
on this conveyor by overhead cranes using the same ‘C’ hook as at the entry and
exit ends of the pickle lines. This saddle conveyor moves the coils along to the
reduction mill where they are lowered onto a frame at the entry side of the mill. A
transfer saddle operated by the mill operator moves out to the frame and picks up
the coil and moves it back into the feed mandrel on the entry side. The operator cuts
the strap, freeing up the loose end of the coil. He opens a space between the work
rolls and feeds the end of the exit side. On the exit side is another expandable
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mandrel the same as the catcher mandrels of the hot mills and pickle line. The entry
operator feed the strip until the exit operator can catch the end in the open segment
of his mandrel, expanding it and trapping the end of the strip. The entry operator
then closes the gap in the working rolls down on the strip. Pressure (thousands of
tons) is applied by the back-up rolls by means of hydraulically operated screws, to
the working rolls and the reduction rolling process begins. If the thickness of the steel
needs to be greatly reduced, the strip will be passed back and forth between the rolls
a number of times with the rolls adjusted for each pass. Due to the great amount of
pressure exerted in the reduction process the steel strip becomes very hot. In order
to prevent the steel from becoming too hot and sticking to the work rolls, the rolls are
flooded with a coolant consisting of 95% water and the other 5% water soluble oil.
The end of the strip that is in the exit mandrel is not released in the multiple pass
process nor is it completely unwound from the entry mandrel. In the final pass
through the reduction mill, the portion that was not reduced from the entry end is
trimmed off in a set shears just before they enter the work rolls to the exit side. A
transfer saddle on the exit side then moves the coil back onto the conveyor that runs
beside the mill.
QUALITY CONTROL
Quality control is a process by which entities review the quality of all factors
involved in production. This approach places an emphasis on three aspect
1. Elements such as controls, job management, defined and well managed
processes, performance and integrity criteria, and identification of records
2. Competence, such as knowledge, skills, experience, and qualifications
3. Soft elements, such as personnel integrity, confidence, organizational
culture, motivation, team spirit, and quality relationships.
The quality of the outputs is at risk if any of these three aspects is deficient in any
way.
Quality control emphasizes testing of products to uncover defects, and reporting to
management who make the decision to allow or deny the release, whereas quality
assurance attempts to improve and stabilize production, and associated processes,
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to avoid, or at least minimize, issues that led to the defects in the first pun For
contract work, particularly work awarded by government agencies, quality control
issues are among the top reasons for not renewing a contract.
"Total quality control", also called total quality management, is an approach that
extends beyond ordinary statistical quality control techniques and quality
improvement methods. It implies a complete overview and re-evaluation of the
specification of a product, rather than just considering a more limited set of
changeable features within an existing product. If the original specification does not
reflect the correct quality requirements, quality cannot be inspected or manufactured
into the product. For instance, the design of a pressure vessel should include not
only the material and dimensions, but also operating,
environmental, safety, reliability and maintainability requirements, and
documentation of findings about these requirements.
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RESEARCH AND DEVELOPMENT
The phrase research and development (also R and D or, more often, R&D),
according to the Organization for Economic Co-operation and Development, refers to
"creative work undertaken on a systematic basis in order to increase the stock of
knowledge, including knowledge of man, culture and society, and the use of this
stock of knowledge to devise new applications".
Research and development is often scientific or towards developing
particular technologies and is frequently carried out as corporate or governmental
activity.
Overview
New product design and development is more often than not a crucial factor in the
survival of a company. In an industry that is changing fast, firms must continually
revise their design and range of products. This is necessary due to continuous
technology change and development as well as other competitors and the changing
preference of customers. Without an R&D program, the firm must rely on strategic
alliances, acquisitions, and networks to tap into the innovations of others.
A system driven by marketing is one that puts the customer needs first, and only
produces goods that are known to sell. Market research is carried out, which
establishes what is needed. If the development is technology driven then it is a
matter of selling what it is possible to make. The product range is developed so that
production processes are as efficient as possible and the products are technically
superior, hence possessing a natural advantage in the market place.
R&D has a special economic significance apart from its conventional association
with scientific and technological development. R&D investment generally reflects a
government's or organization's willingness to forgo current operations or profit to
improve future performance or returns, and its abilities to conduct research and
development.
The top eight spenders in terms of percentage of GDP
were Israel (4.53%), Sweden (3.73%), Finland (3.45%) Japan (3.39%), South
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Korea (3.23%), Switzerland (2.9%), Iceland (2.78%) and United States (2.62%).[2] The Commitment to Development Index ranks these countries, rewarding them for
research and development that support the creation and dissemination of
innovations of value to developing countries.
In general, R&D activities are conducted by specialized units or centers belonging
to companies, universities and state agencies. In the context of commerce,
"research and development" normally refers to future-oriented, longer-term activities
inscience or technology, using similar techniques to scientific research without
predetermined outcomes and with broad forecasts of commercial yield.
Statistics on organizations devoted to "R&D" may express the state of an industry,
the degree of competition or the lure of progress. Some common measures
include: budgets, numbers of patents or on rates of peer-reviewed publications. Bank
ratios are one of the best measures, because they are continuously maintained,
public and reflect risk.
In the U.S., a typical ratio of research and development for an industrial company is
about 3.5% of revenues. A high technology company such as a computer
manufacturer might spend 7%. Although Allergan (a biotech company) tops the
spending table with 43.4% investment, anything over 15% is remarkable and usually
gains a reputation for being a high technology company. Companies in this category
include pharmaceutical companies such as Merck & Co. (14.1%)
or Novartis (15.1%), and engineering companies like Ericsson (24.9%).[3] Such
companies are often seen as poor credit risks because their spending ratios are so
unusual.
Generally such firms prosper only in markets whose customers have extreme needs,
such as medicine, scientific instruments, safety-critical mechanisms (aircraft) or high
technology military armaments. The extreme needs justify the high risk of failure and
consequently high gross margins from 60% to 90% of revenues. That is, gross
profits will be as much as 90% of the sales cost, with manufacturing costing only
10% of the product price, because so many individual projects yield no exploitable
product. Most industrial companies get only 40% revenues.
On a technical level, high tech organizations explore ways to re-purpose and
repackage advanced technologies as a way of amortizing the high overhead. They
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often reuse advanced manufacturing processes, expensive safety certifications,
specialized embedded software, computer-aided design software, electronic designs
and mechanical subsystems.
Research has shown that firms with a persistent R&D strategy outperform those with
an irregular or no R&D investment programme
GALVANISING PLANT
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Metal protection
In current use, the term refers to the coating of steel or iron with zinc. This is done to
prevent galvanic corrosion (specifically rusting) of the ferrous item. The value of
galvanising stems from the relative corrosion resistance of zinc, which, under most
service conditions, is considerably less than those of iron and steel. The effect of this
is that the zinc is consumed first as a sacrificial anode, so that it cathodically protects
exposed steel. This means that in case of scratches through the zinc coating, the
exposed steel will be cathodically protected by the surrounding zinc coating, unlike
an item which is painted with no prior galvanising, where a scratched surface would
rust. Furthermore, galvanising for protection of iron and steel is favoured because of
its low cost, the ease of application, and the extended maintenance-free service that
it provides.
The term galvanizing, while correctly referring to the application of the zinc coating
by the use of a galvanic cell (also known as electroplating), sometimes is also used
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to refer to hot dip zinc coating (commonly incorrectly referred to as hot dip
galvanizing). The practical difference is that hot dip zinc coating produces a much
thicker, durable coating, whereas genuine galvanizing (electroplating) produces a
very thin coating. Another difference, which makes it possible to determine visually
which process has been used if an item is described as 'galvanized', is that
electroplating produces a nice, shiny surface, whereas hot dip zinc coating produces
a matte, grey surface. The thin coating produced by electroplating is much more
quickly consumed, after which corrosion turns to the steel or iron itself. This makes
electroplating unsuitable for outdoor applications, except in very dry climates. For
example, nails for indoor use are electroplated (shiny), while nails for outdoor use
are hot dip zinc coated (matte grey). However, electroplating and subsequent
painting is a durable combination because the paint slows down the consumption of
the zinc. Car bodies of some premium makes are corrosion protected using this
combination.
Nonetheless, electroplating is used on its own for many outdoor applications
because it is cheaper than hot dip zinc coating and looks good when new. Another
reason not to use hot dip zinc coating is that for bolts and nuts size M10 or smaller,
the thick hot-dipped coating uses up too much of the threads, which reduces
strength (because the dimension of the steel prior to coating must be reduced for the
fasteners to fit together). This means that for cars, bicycles and many other 'light'
mechanical products, the alternative to electroplating bolts and nuts is not hot dip
zinc coating but making the bolts and nuts from stainless steel (known by the
corrosion grades A4 and A2).
Electroplated steel is visually indistinguishable from stainless steel when new. To
determine whether a part is electroplated or stainless steel, apply a magnet. The
most common stainless steel alloys (including those used for bolts and nuts) are not
magnetic or only very slightly attracted to a magnet.
History
Originally, "galvanization" was the administration of electric shocks (in the 19th
century also termed Faradism, after Michael Faraday). It stemmed from Galvani's
induction of twitches in severed frogs' legs, by his accidental generation of electricity.
This archaic sense is the origin of the meaning of galvanic when meaning
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"affected/affecting, as if by a shock of electricity; startled". Its claims to health
benefits have largely been disproved, except for some limited uses in psychiatry in
the form of electroconvulsive therapy (ECT). Later the word was used for processes
of electrodeposition. This remains a useful and broadly applied technology, but the
term "galvanization" has largely come to be associated with zinc coatings, to the
exclusion of other metals.
Galvanic paint, a precursor to hot-dip galvanization, was patented by Stanislas Sorel,
of Paris, France in December, 1837.
The earliest known example of galvanizing of iron was found on the 30th September
1999 by the Royal Armouries Museum on a 17th century Indian armour in their
collection.
Zinc coatings
Zinc coatings prevent corrosion of the protected metal by forming a physical barrier,
and by acting as a sacrificial anode if this barrier is damaged. When exposed to the
atmosphere, zinc reacts with oxygen to form zinc oxide, which further reacts with
water molecules in the air to form zinc hydroxide. Finally zinc hydroxide reacts with
carbon dioxide in the atmosphere to yield a thin, impermeable, tenacious and quite
insoluble dull gray layer of zinc carbonate which adheres extremely well to the
underlying zinc, so protecting it from further corrosion, in a way similar to
the protection afforded to aluminium and stainless steels by their oxide layers.
Hot-dip galvanizing deposits a thick robust layer that may be more than is necessary
for the protection of the underlying metal in some applications. This is the case
in automobile bodies, where additional rust proofing paint will be applied. Here, a
thinner form of galvanizing is applied by electroplating, called "electrogalvanization".
The hot-dip process slightly reduces the strength of the base metal, which is a
consideration for the manufacture of wire rope and other highly-stressed products.
The protection provided by this process is insufficient for products that will be
constantly exposed to corrosive materials such as salt water. For these applications,
more expensive stainless steel is preferred. Some nails made today are electro-
galvanized.
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As noted previously, both mechanisms are often at work in practical applications. For
example, the traditional measure of a coating's effectiveness is resistance to a salt
spray. Thin coatings cannot remain intact indefinitely when subject to surface
abrasion, and the galvanic protection offered by zinc can be sharply contrasted to
more noble metals. As an example, a scratched or incomplete coating
of chromium actually exacerbates corrosion of the underlying steel, since it is less
electrochemically active than the substrate.
Galvanized surface with visible spangle
The size of crystallites in galvanized coatings is an aesthetic feature, known
as spangle. By varying the number of particles added for
heterogeneous nucleation and the rate of cooling in a hot-dip process, the spangle
can be adjusted from an apparently uniform surface (crystallites too small to see with
the naked eye) to grains several centimetres wide. Visible crystallites are rare in
other engineering materials. Protective coatings for steel constitute the largest use of
zinc and rely upon the galvanic or sacrificial property of zinc relative to steel.
Thermal diffusion galvanizing, a form of Sherardizing, provides a zinc coating on iron
or copper based materials partially similar to hot dip galvanizing. The final surface is
different than hot-dip Galvanizing; all of its zinc is alloyed. [4] Zinc is applied in a
powder form with "accelerator chemicals" (generally sand, [5] but other chemicals are
patented). The parts and the zinc powder are tumbled in a sealed drum while it is
heated to slightly below zinc's melting temperature. The drum must be heated
evenly, or complications will arise. Due to the chemicals added to the zinc powder,
the zinc/iron makes an alloy at a lower temperature than hot dip galvanizing. This
process requires generally fewer preparatory cleanings than other methods. The
dull-grey crystal structure formed by the process bonds stronger with paint, powder
coating, and rubber overmolding processes than other methods. It is a preferred
37
method for coating small, complex-shaped metals and smoothing in rough surfaces
on items formed with powder metal.
Eventual corrosion
Rusted corrugated steel roof
Although galvanizing will inhibit attack of the underlying steel, rusting will be
inevitable, especially due to natural acidity of rain. For example, corrugated
iron sheet roofing will start to degrade within a few years despite the protective
action of the zinc coating. Marine and salty environments also lower the lifetime of
galvanized iron because the high electrical conductivity of sea water increases the
rate of corrosion. Galvanized car frames exemplify this; they corrode much quicker in
cold environments due to road salt. Galvanized steel can last for many years if other
means are maintained, such as paintcoatings and additional sacrificial anodes.
ROLL GRINDING MACHINE
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Giant rollers still need intricate precision
A roll grinder has little in common with a precision tool at first glance. This is due on one
hand to its dimensions - the rollers for machining can be up to 400 tons, dead weight and up
to 10 m in length - and on the other hand due to the surroundings of the rolling mill where
thousands of tons of steel are being manoeuvred and processed. However, a second look
reveals the high-precision character of such a machine: in addition to several measuring axes,
a grinding machine has at least four machining axes, which are implemented by means of
Servo Drives:
W-axis: Spindle head turns the roller which is clamped centrally in a steady rest
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X-axis: Grinding wheel feeds vertical to the roller
Z-axis: Grinding wheel traverses parallel to the roller
C-axis: Grinding wheel microfeeds via a tilting axis
The roller to be ground is clamped in the spindle head and is driven by it. A high-precision incremental measuring instrument with two tactile measuring sensors traces the turning roller and determines the current form and diameter as well as detects any possible damage on the surface of the roller. The machine operator sets the parameters for cylindricity, final diameter, surface quality and structure or abrasion, depending on the required result. The control system calculates the grinding process from these parameters. Continuous measuring is carried out simultaneously in order to record the results of the grinding process and determine or correct the required values for the next travel.
Certain manufacturing processes in the steel and paper industries require a precisely defined roller form. These can be conical or spherical or - looked at from the longitudinal axis - display a sinusoidal or bottleneck form (CVC). These variations of form are not visible to the naked eye, as they are on the order of millimetres. The automotive industry, for example, has specific requirements for the surface structure of the sheet metal in order to have shine and reflective properties in the sprayed bodywork, which could not be achieved by spraying alone. The necessary grinding precision goes down to 1/1000 mm in concentricity and the same in geometrical accuracy. In order to do justice to this complex task, HCC KPM Electronics has produced a control system which can be applied with only minor adaptations to all kinds of machines - all on the PLC and Motion Control solution, TwinCAT PTP and NC I/CNC software.
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Synergy from customer expertise and an intelligent control concept
In order to utilize the benefits of a central control concept in terms of commissioning, maintenance and performance, the electrical design engineers at Herkules aimed to run as many functions as possible in software and decided in favour of TwinCAT. The open software structure and the dynamic functions for controlling axis movement that TwinCAT provides enabled Herkules to integrate the expertise acquired over many years of developing their own control system into the software PLC and create the "HCC/KPM 10" roll grinder control system.
Almost all the functionalities provided by TwinCAT are used:
3 PLC tasks in one run-time system with 1 or 10 ms interval time
1 NC task with up to 10 axes with 2 ms interval time
almost all programming languages (IL, FBD, ST, SFC) in the PLC projects
application of PTP axis functions and complex multi-table coupling for the grinding processes with correction parameters from the grinding current, grinding wheel wear and measured deviations from the required form to the actual form of the roller
communication with integrated visualization based on Visual Basic and operating guidance through the ADS DLL communication interfaces
TwinCAT NC I for interpolating functions e.g. to mill concentric grooves in the surface of the roller
Lightbus is used as the fieldbus to incorporate the peripheral Beckhoff Bus Terminals within the machine. For communication with the Servo Drives, the Ethernet- based EtherCAT bus system is predominantly used. A major
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benefit of EtherCAT on one hand is its real-time capability and high data throughput - with bus cycle times of less than 1 ms - and, on the other, simple handling using TwinCAT. Only one free network port is necessary in the control PC. The Servo Drives are connected via standard network cables.
NARROW PLANT
In narrow plant the width of the coils being passed is small ranging from 110-530 mm.
Rolling is performed by 4 rollers without any intermediate rollers. Here also annealing and ctl
facilties are available. Instead of electrochemical cleaning here rewinding operation is used.
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CONCLUSION
IT GIVES ME IMMENSE PLEASURE TO SAY THAT I HAVE SUCESSFULLY UNDERGONE 30 DAYS
OF INDUSTRIAL TRANING IN BHUSHAN STEEL LTD. IT WAS A LIFETIME EXPERIENCE . I
LEARNED A LOT OF NEW THINGS ,AND LOT OF NEW WAYS OF SOLVING A PROBLEM. I WANT
TO CONCLUDE MY REPORT ON A POSITIVE NOTE AND I HOPE THAT THE EXPERIENCE WHICH I
GOT WILL ALSO B FRUITFUL IN MY CAREER AHEAD.
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BIBLIOGRAPHY
1.www.bhushan-group.com
2. Wikipedia.com
3.Ghosh and Malik-Production Enginnering
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