07steelap

55 %
45 %
Information about 07steelap

Published on November 8, 2008

Author: charliechong

Source: slideshare.net

Steels for special applications EF420 lecture 7

This lecture covers Deep drawing steel Structural steel Pressure equipment steel Pipeline steel

Deep drawing steel

Structural steel

Pressure equipment steel

Pipeline steel

Sheet steel for deep drawing Up to 3mm thick

Formable sheet steel Motor body panels, whitegoods, etc Ductility for deep drawing, work hardened Pure ferrite, Interstitials controlled Carbon less than 0.10% Age hardening Strain aging

Motor body panels, whitegoods, etc

Ductility for deep drawing, work hardened

Pure ferrite, Interstitials controlled

Carbon less than 0.10%

Age hardening

Strain aging

Age hardening Quenched low carbon steel C, N and O retained in super saturated solid solution Hardness raised from 130 to 180 HV on aging for 500 h at 20°C Intermediate carbides and nitrides (epsilon) are precipitated during aging Aging is more rapid when paint is baked

Quenched low carbon steel

C, N and O retained in super saturated solid solution

Hardness raised from 130 to 180 HV on aging for 500 h at 20°C

Intermediate carbides and nitrides (epsilon) are precipitated during aging

Aging is more rapid when paint is baked

Strain aging On aging, interstitial elements migrate to dislocations, where they form solute atmospheres N, O and C in solution are responsible This locks mobile dislocations, leading to an increase in yield strength (upper yield) When the dislocations break away from the solute atmospheres, the flow strain is reduced (lower yield point) The brake-away from solute atmospheres is localised giving ugly stretcher-strains or Lüders lines

On aging, interstitial elements migrate to dislocations, where they form solute atmospheres

N, O and C in solution are responsible

This locks mobile dislocations, leading to an increase in yield strength (upper yield)

When the dislocations break away from the solute atmospheres, the flow strain is reduced (lower yield point)

The brake-away from solute atmospheres is localised giving ugly stretcher-strains or Lüders lines

Yielding behaviour Stress MPa Strain % Elastic behaviour Upper yield point Lower yield point

Lüders lines

Prevention of strain aging Control interstitials Low carbon, aluminium killed Decarburised steels Anneal in wet hydrogen Expensive Deep draw immediately after rolling 2% temper rolling just before drawing Keep steel in cold storage after rolling

Control interstitials

Low carbon, aluminium killed

Decarburised steels

Anneal in wet hydrogen

Expensive

Deep draw immediately after rolling

2% temper rolling just before drawing

Keep steel in cold storage after rolling

Structural and pressure equipment steels Strength and toughness

Composition and properties For Weldability Carbon 0.25% maximum Manganese 0.3 to 1.5% Carbon equivalent (IIW) often 0.45 maximum Strength specified minimum not exceeding 450MPa (normal grades) or 800MPa for quenched and tempered grades Some grades suitable for low temperature (impact tested)

For Weldability

Carbon 0.25% maximum

Manganese 0.3 to 1.5%

Carbon equivalent (IIW) often 0.45 maximum

Strength specified minimum not exceeding 450MPa (normal grades) or 800MPa for quenched and tempered grades

Some grades suitable for low temperature (impact tested)

Carbon equivalent formulae A measure of hardenability and weldability High CE, High risk of hydrogen induced cracking in HAZ. CE IIW widely used. P cm preferred for microalloyed steel

A measure of hardenability and weldability

High CE, High risk of hydrogen induced cracking in HAZ.

CE IIW widely used. P cm preferred for microalloyed steel

Delivery conditions Plates, bars, rolled sections (bulb flats, angles, tees, columns and beams), tubes, forgings Hot rolled (as-rolled) Normalised Controlled rolled or TMCP

Plates, bars, rolled sections (bulb flats, angles, tees, columns and beams), tubes, forgings

Hot rolled (as-rolled)

Normalised

Controlled rolled or TMCP

TMCP and TMCR steels Rolling carried out below recrystallisation temp Grain refined A + F rolling with accelerated cooling Microalloyed Rely on processing

Rolling carried out below recrystallisation temp

Grain refined

A + F rolling with accelerated cooling

Microalloyed

Rely on processing

As-rolled structural steel Coarse ferrite & pearlite Grow inside austenite grains Prior austenite grains Between Ar 1 and Ar 3 fine ferrite grains grow round austenite grain boundaries

As-rolled steel Mixed grain size Reasonable properties, not sufficient low temperature toughness for critical uses

Mixed grain size

Reasonable properties, not sufficient low temperature toughness for critical uses

Controlled rolled steel Between Ar 1 and Ar 3 fine ferrite grains grow round and within austenite grain boundaries Deformed austenite grains Fine ferrite & pearlite grow inside austenite grains Below Ar 3

Controlled rolled steel Finer and more even grain than as-rolled Higher strength, better toughness AS 1548-7-460T AS 3678 Grades 350, 400, 450 Offshore structural steels

Finer and more even grain than as-rolled

Higher strength, better toughness

AS 1548-7-460T

AS 3678 Grades 350, 400, 450

Offshore structural steels

Next step Work while between Ar 1 and Ar 3 Austenite + ferrite Even finer grains Accelerated cool necessary Or toughness poor

Work while between Ar 1 and Ar 3

Austenite + ferrite

Even finer grains

Accelerated cool necessary

Or toughness poor

Examples High strength line pipe steels X80, X90 High strength steels to replace QT structural steels

High strength line pipe steels

X80, X90

High strength steels to replace QT structural steels

Problems with TMCP steel Effect of subsequent austenitisation Normalising, hot forming Destroys fine grain structure Loss of strength and toughness High arc energy welding Low strength HAZ CTOD inferior to normalised steel

Effect of subsequent austenitisation

Normalising, hot forming

Destroys fine grain structure

Loss of strength and toughness

High arc energy welding

Low strength HAZ

CTOD inferior to normalised steel

Structural steels Buildings, bridges, etc designed to AS1538, AS3990 or AS4100 Carbon steel plates to AS3678 Grades 250, 300, 350, 400 Carbon steel hot rolled sections to AS 3679.1 same grades Formability and weldability important Can select impact tested grades

Buildings, bridges, etc designed to AS1538, AS3990 or AS4100

Carbon steel plates to AS3678 Grades 250, 300, 350, 400

Carbon steel hot rolled sections to AS 3679.1 same grades

Formability and weldability important

Can select impact tested grades

Pressure vessel steels Closed vessels under pressure. Designed to AS1210. Covered by regulation. Carbon steel plate to AS 1548. Better quality than structural. Killed steels Designation shows steelmaking practice Can select impact tested and normalised grades Weldability and formability important

Closed vessels under pressure. Designed to AS1210. Covered by regulation.

Carbon steel plate to AS 1548.

Better quality than structural. Killed steels

Designation shows steelmaking practice

Can select impact tested and normalised grades

Weldability and formability important

Shipbuilding and offshore Classification authority specifications (Lloyds, DnV etc) Different quality than pressure vessel or structural Through-thickness properties can be important Weldability and formability Grades A through E, AH through EH

Classification authority specifications (Lloyds, DnV etc)

Different quality than pressure vessel or structural

Through-thickness properties can be important

Weldability and formability

Grades A through E, AH through EH

Pipe and tube products Pipe intended to carry fluid at pressure Tube - structural shape May be cold formed Boiler tubes are carrying pressure and are fired Pipe fittings - valves, flanges, tees, elbows, reducers

Pipe intended to carry fluid at pressure

Tube - structural shape

May be cold formed

Boiler tubes are carrying pressure and are fired

Pipe fittings - valves, flanges, tees, elbows, reducers

Pipe manufacture Welded pipe and tube ERW, SAW long lengths Seamless pipe and tube. Piercing a billet. Restricted to 12m lengths

Welded pipe and tube ERW, SAW long lengths

Seamless pipe and tube. Piercing a billet. Restricted to 12m lengths

Pipe sizes Standard throughout world Nominal bore and scheduled wall thickness Standard and extra strong ASTM A106 Grade B ASTM A333 Grade 6 “fine grain” impact tested at -46°C

Standard throughout world

Nominal bore and scheduled wall thickness

Standard and extra strong

ASTM A106 Grade B

ASTM A333 Grade 6 “fine grain” impact tested at -46°C

Transmission line pipe Cross country pressure pipe lines Strength is important as is weldability Sophisticated HSLA steels API (American Petroleum Institute) grades API 5L Grade B, API 5L X42, X46, X52, X56, X60, X65 and X70

Cross country pressure pipe lines

Strength is important as is weldability

Sophisticated HSLA steels

API (American Petroleum Institute) grades

API 5L Grade B, API 5L X42, X46, X52, X56, X60, X65 and X70

Quenched and tempered plate Structural (Bisalloy 60, 70, 80) AS1554 Part 4 (AS 3597, ASTM A514, A517) Pressure Vessel (Bisalloy 80PV) AS1210 (AS3597, ASTM A517) Military (BIS812EMA, HY80) Wear plates (Bisalloy 320, 360, 400, 500) HSLA micro alloyed with boron etc

Structural (Bisalloy 60, 70, 80)

AS1554 Part 4 (AS 3597, ASTM A514, A517)

Pressure Vessel (Bisalloy 80PV)

AS1210 (AS3597, ASTM A517)

Military (BIS812EMA, HY80)

Wear plates (Bisalloy 320, 360, 400, 500)

HSLA micro alloyed with boron etc

Add a comment

Related presentations

Related pages

www.mech.uwa.edu.au

Hier sollte eine Beschreibung angezeigt werden, diese Seite lässt dies jedoch nicht zu.
Read more

Kristian Medri - Pipl - Pipl - People Search

Information about Kristian Medri from Ontario. Profile Photos, Address History, Phone Numbers, Relatives, Education, Publications and more
Read more

Api 1169 part-2 - slidesearch.org

Api 1169 part-2. Tweet. Information about Api 1169 part-2. Engineering. Published on September 19, 2014. Author: charliechong. ... 07steelap. Tweet. 08. 11 ...
Read more

API572-PPT - SlideSearch.org - #1 Slide Search Engine

API572-PPT. Tweet. Information about API572-PPT. Education. Published on September 19, ... 07steelap. Tweet. 08. 11. 2008 0 views 09 Castiron. Tweet. 08 ...
Read more