automotive innovation of materials (1)

7/31/2019 Automotive Innovation of Materials (1)

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Innovations of Steel for

Automobiles

Group 2:

Corey Dixon, Matthew Edringston,

Mina Isak, & Shanaya Johnson


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Agenda

Introduction

Body Structure

Front Rail B-Pillar

Body Side Outer

Closures

Wheels


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Introduction

Innovation has taken place on automobiles to

fulfill regulations to protect pedestrians, meet

crash test standards , obtain customer

satisfactions, and for the vehicle to be easy to

repair.

These requirements often conflict which

makes it challenging to achieve.


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Body Structure

Vehicles skeleton

Body structure

Closures

Innovation from mildsteel

To meet stringent crash

requirements

Improvement on fuel

usage


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Front Rail

Provides structural

support for powertrain

components.

Important part for crashenergy absorption.

Reducing chances of

serious injuries to

passengers.


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B-Pillar

Made with advancehigh strength steels

Formability

Must meet side impact,side pole, and roof crushcrash requirements.

Sandwichesreinforcement

Inner & outer panels

Part of the body sideouter

ll l f h fl


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Metallurgical factors that influence

steel strip formability Arc furnace- A steel melting furnace in to

which heat is generated by an arc

between graphite electrodes and themetal. Both carbon and alloy steels areproduced in electric arc furnaces, andscrap rather than molten metal is used asthe base material.

Annealing - The cold rolling of steel striphardens the material. Although it can be

used in this condition (Known as hardbright), most strip requires annealing inorder to soften it for further processessuch as forming. The softening process orannealing, takes place in a furnace wherethe temperatures and the rates ofheating and cooling are carefullycontrolled. To avoid scaling it is necessary

to exclude oxygen from the furnacewhich is replaced with an atmospherecontaining nitrogen or hydrogen as thepredominant gas.


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Metallurgical factors that influence steel

strip formability

Austempering- heat treating process thatconsists of quenching a ferrous alloy fromtemperature above the transformationranges, in a medium having a rate of heatabstraction sufficiently high to prevent theformation of high-temperature

transformation products and in maintainingthe alloy, until transformation is complete,at a temperature below that of pearliteformations and above that of martensiteformation.

Ductility - The property of metals thatenables them to be mechanically deformed

when cold, without fracture. In steel,ductility is usually measured by elongationand reduction of area as determined in atensile test


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Geometrical factors that influence

formability of steel strip

Bend radius- The inside radius of

a formed feature. The bend radius

should be equal to, or greater

than, the material thickness. A

small bend radius can create

fracturing at the bend due to thenatural thinning that does occur

at the bend radius. Also called

inside radius.


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Corrosion protection options

Galvanizing - Coating steel with zinc and tin(principally zinc) for rustproofing purposes.Formerly for the purpose of galvanizing, cutlength steel sheets were passed singly through abath of the molten metal. Todays galvanizing

processing method consists of uncoiling andpassing the continuous length of successive coils

either through a molten bath of the metaltermed Hot Dipped Galvanizing or bycontinuously zinc coating the uncoiled sheetelectrolytic-ally

Hot dip galvanizing - The process of applying azinc coating to fabricated iron or steel materialby immersing the material in a bath consistingprimarily of molten zinc. The simplicity of the

galvanizing process is a distinct advantage overother methods of providing corrosion protection.The automotive industry depends heavily on thisprocess for the production of many componentsused in car manufacturing


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hot melt wax- are thermoplastic corrosion

prevention compounds. They have a solvent

or waterborne formulation. hot melt waxes

have been used extensively on underbody

structural components to provide corrosion

protection and enhance vehicle durability.Hot melt waxes are usually applied through

a dipping process. The wax is preheated to a

temperature between 125 and 195 degrees

C (257 and 383 degrees F). Following an

alkali cleaning and water rinsing operation,

parts are immersed in the molten wax. Thethickness determined by preheat and time

immersed. Parts then returned to ambient

temperature. Holt melt wax coating can

withstand up to 293 F.


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Electrocoating ( e-coat) -is the

process by which a metallic work

piece is submerged in a paint or

water bath and electricity is used

to deposit paint onto the work

piece. The electro depositionprocess is the most automatic,

controllable, and efficient

method for applying a corrosion

inhibiting primer to a metallic

work piece


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Powder Coating- is the technique ofapplying dry paint to a part. 2 maintechniques, The item is lowered into afluidized bed of the powder, which may ormay not be electrostatically charged, or Thepowdered paint is electrostatically chargedand sprayed onto the part The part is then

placed in an oven and the powder particlesmelt and coalesce to form a continuousfilm. There are two main types of powderavailable to the surface finisher,Thermoplastic powders that will remeltwhen heated, and Thermosetting powdersthat will not remelt upon reheating. Duringthe curing process (in the oven) a chemical

cross-linking reaction is triggered at thecuring temperature and it is this chemicalreaction which gives the powder coatingmany of its desirable properties.


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Body Side Outer

Made of 5 piece tailor

blanket

Tailor thickness &

strength of steel Greater efficiency and

weight reduction

Innovation of advance

strength steels


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Closures

Doors, decklids, hoods,

and hatches

Technical Issues

High quality finish forpaint application

Pleasing to the customers

eye

Dent resistant Effects warranty cost,

factory handling, and

customer satisfaction


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Joining Automotive Parts


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Resistance Welding

Commonly used to join two or moremetal parts together in a localizedarea by the application of heat andpressure.

The heat is produced by theresistance of the material to carry ahigh amperage current.

Types of resistance welding:

Flash welding

High-frequency resistance welding

Percussion welding

Projection welding Resistance seam welding

Resistance spot welding

Upset welding


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Steel Grade

Going by the standard18 gauge used, using 20gauge Dual Phase steelat a very thin gauge can

reduce mass by over25%. Dual Phase steelcontains ferrite andmartensite

microstructures, so it isvery strong.

Going by the currentaverage standard of 140microns, a thickness of100-105 microns of a

galvanized acrylicurethane coating. Ichose this coatingbecause it has a good

combination ofthickness, strength anddurability.


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Sheet Metal Thickness Gauges


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Wheels

What used to be

aluminum wheels are

made of steel for

performance reasons.Microalloy wheel

prototypes tested at

11% lighter and 18%

cheaper than itsaluminum counterparts.


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Recap

Reducing the mass of automotive components

is desirable to meet stringent crash

requirement,

When using thinner, higher strength steel strip

for auto body panels technical issues arise for

the surface to be Class A, high quality finish,

and be dent resistant.


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Recap

Many finishing process have been developed

to increase the life of the coating on the

automobile.

Steel grade and joining methods are also

important because most of the car is made of

steel so it affects alot; specifically cost!


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Conclusion

The challenging requirements have been

achieved using advanced high strength light

weight steel.

automotive innovation of materials (1)

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