building material building material palestine university chapter no.#4 steel

BUILDING MATERIALBUILDING MATERIAL

PALESTINE UNIVERSITY PALESTINE UNIVERSITY

chapter No.#4 chapter No.#4

SteelSteel

STEEL STEEL General General

Steel is a structural material Steel is a structural material which consists mostly of iron which consists mostly of iron and carbon. It can, however, and carbon. It can, however,

contain other additives which contain other additives which might change the steel's might change the steel's

properties. Steel can be hot properties. Steel can be hot rolled or cold formed into rolled or cold formed into

structural shapes, such as the structural shapes, such as the familiar "I" beam known familiar "I" beam known

today as a wide flange. Steel today as a wide flange. Steel has the same strength in has the same strength in

tension as it has in tension as it has in compression, unlike concrete.compression, unlike concrete.

STEELSTEELGeneral General

There are some tests for steel must be applied as :

tension test: this test used to measure the material

properties of a steel (or really any material, for that

matter),

Beam bending test: this test used to measure the

material properties of a specimen and the effectiveness

of the orientation of the beam.

STEELSTEELGeneral General

Some types of steel are specifically for use in Some types of steel are specifically for use in fabricating large structures. They are called ‘fabricating large structures. They are called ‘high-strength high-strength lowlow alloyalloy’ or ’ or HSLAHSLA steels. These steels are: steels. These steels are:

much stronger and tougher than ordinary carbon much stronger and tougher than ordinary carbon steels steels

ductile ductile highly formable highly formable weld able weld able Highly resistant to corrosion - which is important Highly resistant to corrosion - which is important

since the structure may be in place for a long time.since the structure may be in place for a long time.

STEELSTEEL Why HSLA Steels are Why HSLA Steels are Strong:- Strong:-

The starting point in achieving the desirable properties of The starting point in achieving the desirable properties of

structural steels is to get the composition of the alloy right. structural steels is to get the composition of the alloy right.

The extra strength can be achieved through various The extra strength can be achieved through various

combinations of alloying elements which means that there combinations of alloying elements which means that there

can be some choice in the other properties that the steel will can be some choice in the other properties that the steel will

have. have.

A typical HSLA steel will contain about 0.15% carbon, 1.65% A typical HSLA steel will contain about 0.15% carbon, 1.65%

manganese and low levels (under 0.035%) of phosphorous manganese and low levels (under 0.035%) of phosphorous

and sulphur and additions of other elements:and sulphur and additions of other elements:

STEEL STEEL Microstructure of HSLA steelsMicrostructure of HSLA steels

The strength of all steels, The strength of all steels, including including HSLAHSLA steels, steels, comes from their comes from their microstructure. Strength is microstructure. Strength is increased by: increased by: increasing the amount of increasing the amount of pearlite pearlite increasing the fineness increasing the fineness of the grains structure of the grains structure increasing the amount of increasing the amount of hard precipitate.hard precipitate.

STEEL STEEL Chemical Composition of Structural Chemical Composition of Structural

SteelsSteels The primary types of structural steel are usually classified The primary types of structural steel are usually classified

according to the following chemical composition according to the following chemical composition

categories:categories:

Carbon-manganese steelsCarbon-manganese steels

High-strength, low-alloy (High-strength, low-alloy (HSLAHSLA) steels) steels

High-strength quenched and tempered alloy steelsHigh-strength quenched and tempered alloy steels

STEELSTEELCarbon manganese Steels Carbon manganese Steels

whose primary chemical components are carbon andwhose primary chemical components are carbon and

manganese in addition to iron, are referred to as manganese in addition to iron, are referred to as carbon carbon

steelssteels or or mild structuralmild structural steels steels. The materials of this type are . The materials of this type are

generally least expensive; they have quite adequate strength generally least expensive; they have quite adequate strength

and ductility characteristics, and are therefore by far the most and ductility characteristics, and are therefore by far the most

widely used grades. One of the most prominent of these steels widely used grades. One of the most prominent of these steels

are ASTM grade A36, with a specified minimum yield stress are ASTM grade A36, with a specified minimum yield stress

of36 of36 ksiksi..

STEELSTEELHigh-strength, low-alloy (HSLA) steelsHigh-strength, low-alloy (HSLA) steels

represent a relatively recent development in steelmaking. The higher represent a relatively recent development in steelmaking. The higher

strength (42 to 65 strength (42 to 65 ksiksi) is achieved by adding small amounts of additional ) is achieved by adding small amounts of additional

chemical elements. Two of the most common HSLA steels are ASTM chemical elements. Two of the most common HSLA steels are ASTM

grade A572 and A588.grade A572 and A588.

High-strength quenched and tempered alloy steels:- High-strength quenched and tempered alloy steels:-

used for structural purposes are essentially available only as grade A514 used for structural purposes are essentially available only as grade A514

today. With a yield stress level of 90 to 100 today. With a yield stress level of 90 to 100 ksiksi, the increase in strength is , the increase in strength is

achieved through heat treatment. A514 is available only in plate form, up achieved through heat treatment. A514 is available only in plate form, up

to 6 inches thick.to 6 inches thick.

STEELSTEEL some elements used in structural some elements used in structural

steels:steels: Carbon Carbon (C)(C) Manganese Manganese (Mn)(Mn) Aluminum Aluminum (Al)(Al) Chromium Chromium (Cr)(Cr) Columbium Columbium (Cb)(Cb) Copper Copper (Cu)(Cu) Molybdenum Molybdenum (Mo)(Mo) Nickel Nickel (Ni)(Ni) Phosphorus Phosphorus (P)(P) and Sulfur and Sulfur (S)(S) Silicon Silicon (Si)(Si) Vanadium Vanadium (V)(V) Other chemical elementsOther chemical elements

STEELSTEELSteel AlloysSteel Alloys

Steel Alloys can be divided into five groupsSteel Alloys can be divided into five groups Carbon SteelsCarbon Steels High Strength Low Alloy SteelsHigh Strength Low Alloy Steels Quenched and Tempered SteelsQuenched and Tempered Steels Heat Treatable Low Alloy SteelsHeat Treatable Low Alloy Steels Chromium-Molybdenum SteelsChromium-Molybdenum Steels

Carbon steels are normally classified as shown Carbon steels are normally classified as shown below.below.

Low-carbon steelsLow-carbon steels:-:-

contain up to 0.30 weight percent C. The largest category contain up to 0.30 weight percent C. The largest category of this class of steel is flat-rolled products (sheet or strip) of this class of steel is flat-rolled products (sheet or strip) usually in the cold-rolled and annealed condition. The usually in the cold-rolled and annealed condition. The carbon content for these high-formability steels is very carbon content for these high-formability steels is very low, less than 0.10 weight percent C, with up to 0.4 low, less than 0.10 weight percent C, with up to 0.4 weight percent Mn. For rolled steel structural plates weight percent Mn. For rolled steel structural plates and sections, the carbon content may be increased to and sections, the carbon content may be increased to approximately 0.30 weight percent, with higher approximately 0.30 weight percent, with higher manganese up to 1.5 weight percent.manganese up to 1.5 weight percent.

STEEL STEEL classification of Carbon steel classification of Carbon steel

Medium-carbon steels:- Medium-carbon steels:-

are similar to low-carbon steels except that the carbon are similar to low-carbon steels except that the carbon

ranges from 0.30 to 0.60 weight percent and the manganese ranges from 0.30 to 0.60 weight percent and the manganese

from 0.60 to 1.65 weight percent. Increasing the carbon from 0.60 to 1.65 weight percent. Increasing the carbon

content to approximately 0.5 weight percent with an content to approximately 0.5 weight percent with an

accompanying increase in manganese allows medium-accompanying increase in manganese allows medium-

carbon steels to be used in the quenched and tempered carbon steels to be used in the quenched and tempered

condition.condition.

STEEL STEEL classifications of Carbon steelclassifications of Carbon steel

High-carbon steels:- High-carbon steels:-

contain from 0.60 to 1.00 weight percent C with manganese contain from 0.60 to 1.00 weight percent C with manganese

contents ranging from 0.30 to 0.90weight percent.contents ranging from 0.30 to 0.90weight percent.


High-strength low-alloy (HSLA) steels, High-strength low-alloy (HSLA) steels,

or micro alloyed steels, are designed to provide better or micro alloyed steels, are designed to provide better

mechanical properties than conventional carbon steels. They mechanical properties than conventional carbon steels. They

are designed to meet specific mechanical properties rather are designed to meet specific mechanical properties rather

than a chemical composition. The chemical composition of than a chemical composition. The chemical composition of

a specific HSLA steel may vary for different product a specific HSLA steel may vary for different product

thickness to meet mechanical property thickness to meet mechanical property


Requirements. The HSLA steels have low carbon contents Requirements. The HSLA steels have low carbon contents

(0.50 to ~0.25 weight percent C) in order to produce (0.50 to ~0.25 weight percent C) in order to produce

adequate formability and weld ability, and they have adequate formability and weld ability, and they have

manganese contents up to 2.0 weight percent. Small manganese contents up to 2.0 weight percent. Small

quantities of chromium, nickel, molybdenum, copper, quantities of chromium, nickel, molybdenum, copper,

nitrogen, vanadium, niobium, titanium, and zirconium are nitrogen, vanadium, niobium, titanium, and zirconium are

used in various combinations.used in various combinations.


Steel Material with Large Cross-sectionSteel Material with Large Cross-section

STEEL STEEL Structural Steel Sections Structural Steel Sections

Steel material with large cross-section

Thin Steel Plate:-Thin Steel Plate:-



Tee Bares


Flat baresSquare bares

Round baresHexagon bares Square tubing


Round ShaftingHoned Shafting

I Beam Section

Bar Size Shapes

Structural-Size Shapes

"W" Shapes

"HP" Shapes

• "L" Shapes

STEEL STEEL Market forms of SteelMarket forms of Steel

•"S" Shapes

•"C" Shapes

•"M" Shapes

•"MC" Shapes

The nominal loads and load combinations shall be as

stipulated by the applicable code under which the structure

is designed or dictated by the conditions involved. In the

absence of a code, the loads, including impact and crane

loads, and load combinations, shall be those stipulated in

ASCE 7. For design purposes, the loads stipulated by the

applicable code or ASCE 7 shall be taken as nominal loads.

STEEL STEEL Basic DefinitionsBasic Definitions

STEEL STEEL Loads Loads

Trusses are structures composed entirely of two force members .

They consists generally of triangular sub-element and are

constructed and supported so as to prevent any motion.

STEEL STEEL TrussesTrusses

STEEL STEEL Trusses Trusses

STEELSTEEL

ENDEND

building material building material palestine university chapter no.#4 steel

Documents

steel carbon manganese

steels properties

steel slide

steel general steel

steel highstrength

tempered alloy steels

types of steel

mild structural steels