Classification of Steels-1 (1)

85
Classification of Steels & Cast Iron and Associated Properties Dr G Balachandran Chief Technical Officer Kalyani Carpenter Special steels Ltd., Mundhwa, Pune - 411036

description

Steel

Transcript of Classification of Steels-1 (1)

Page 1: Classification of Steels-1 (1)

Classification of Steels & Cast Iron

and Associated Properties

Dr G Balachandran

Chief Technical Officer

Kalyani Carpenter Special steels Ltd.,

Mundhwa, Pune - 411036

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Fe-C Phase Diagram

A1

A2

A3

Acm

A4

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Effect of Alloying Elements

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Single Phase • Ferrite (α-Fe)

• Austenite (γ-Fe)

• Delta Iron (δ-Fe)

• Graphite (C)

• Martensite

What are Phases?

Multi-Phase • Pearlite (α-Fe + Fe3C )

• Bainite

α-Fe + Fe3C

γ-Fe + Fe3C

• Dual Phase

Austenite (γ-Fe)

• Duplex Phase

Austenite (γ-Fe) + α-Fe

• Carbides

Composition & Heat treatment modify the phase formation

- This influences the mechanical properties

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Ferrite Iron Phase

• Body-center cubic crystal structure

• Stable up to 912°C in Fe-C system

• Density: 7.86 grams/cm 3 at 20°C

• Soft and very ductile phase

Austenite Iron Phase

• Face-center cubic crystal structure

• Stable from 740°C to 1493°C

• Density: 7.84 grams/cm 3 at 20°C

• Strong, hard and tough phase

Delta Iron Phase

• Body-center cubic crystal structure

• Stable from 1394 °C to 1538°C

• Forms at very high temperatures

Understanding Phases & Crystal structure

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0.08%C 0.20%C 0.60%C

Plate like cementite morphology Cementite as spherodite

Understanding Phases

Dual Phase Structures Pearlite – Ferrite + Fe3C

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Diffusion of Carbon in Pearlite

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Pearlite Formation

• Austenite precipitates Fe3C at

Eutectoid Transformation

Temperature (727°C).

• When slow cooled, this is Pearlite

(looks like Mother of Pearl)

(a) coarse pearlite (b) fine pearlite 3000X

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Bainite Microstructure • transforms similar to martensite by shear but has carbides interspersed • C > 0.1%. • Transforms to ferrite + cementite with sufficient time & temp - semi-stable at <150°C • • Upper bainite (550-350°C) - Rods of Fe3C • Lower bainite (350-250°C) – Plates of Fe • High Si material bainite has austenite + carbide

Bainite & Ausferrite

Lower bainite Upper bainite Ausferrite

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Martensite Phase

• Body centered tetragonal crystal structure

• C>0.1%

•At adequate time and temperature

- forms ferrite + cementite

• Density: 7.8 g./cc at 20°C

• Very hard & strong phase

with minimal ductility

• Needle-like microstructure

Non Equilbrium Phase- Martensite

Tempered Martensite

• Precipitates C saturated in the matrix

- forms equilibrium ferrite + carbide

Plate martensite+

Retained austenite Lath martensite

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Non Equilbrium Phase- Martensite

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Retained Austenite

If we end up heat treatment in between Ms and Mf then

- Residual austenite transforms to bainite/pearlite as a f(cooling rate)

Even below Mf some Retained austenite is present

Amount of retained austenite = f( Ms-Mf)

- If (Ms-Mf) is narrow retained austenite increases

- increases with alloying element Mn, Cr, Ni & C

Below Ms & close to Ms

slower cooling enhances martensite formation

Below Ms & close to Mf

accelerated cooling enhances martensite formation

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Graphite Carbon Phase

• Layered hexagonal structure

• Covalent bonded atoms in each layer

• Density: 2.25 grams/cm 3 at 20°C

• Layers easily slide against each other and make

graphite a solid lubricant

• Soft and low strength

Graphite Phase in Iron

Graphite distribution in gray cast iron, spheroidal & compacted

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Carbide Phases in Iron

Carbides in Steels

First Group : M3C M7C3 M23C6 + M6C ( M4C)

- Cr, Mo, W

- W3C, Mo2C

Second Group: MC

- V, Ti, Nb, Ta (bcc)

- High Alloy Steels

Wt.%i Cr Mo W

<2% (Fe,Cr)3C (Fe,Mo)3C (Fe,W)3C

6-10% (Fe,Cr)3C+ (FeCr)7C3 Fe3Mo3C Fe3W3C

10-20% (FeCr)23C6 Fe3Mo3 Fe3W3C+Fe3W2

Non Carbide forming Elements : Si, Ni, Cu, Al

Neutral Element : Co

Carbide formers: Fe, Mn, Cr, Mo, W, Nb, V, Zr, Ti

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Spheroidite

• If tempered for a long time,

Fe3C forms “spheres” and

grows inside Ferrite.

• Very soft, easy to machine

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Transformation diagrams

- predicts microstructures that forms from austenite

- as a function of time, temperature and cooling rate

• Time-temperature transformation (TTT) diagrams

- Extent of transformation with time at a constant temperature.

• Continuous cooling transformation (CCT) diagrams

- Extent of transformation as a function of time for a continuously

decreasing temperature.

Austenite Transformation Diagrams

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Time-Temperature Transformation

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Continuous Cooling Transformation 34CrNiMo6 Steel

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Slow Cooling

Time in region

indicates amount of

microconstituent!

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Medium Cooling

Cooling Rate, R, is

Change in Temp /

Time °C/s

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Fast Cooling

This steel is very

hardenable… 100%

Martensite in ~ 1

minute of cooling!

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Tempering in 34CrNiMo6 Influence of tempering

temperature on

Mechanical Properties

Carbon

Clustering

Spinodal

decompose

Meta

stable

carbide

Retained

austenite

decompose

Cementite

Alloy

carbides

Coarsening

of carbides

in ferrite

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Tempered Martensite Embrittlement

300oC Embrittlement

Stage 2:

Retained austenite

carbides + ferrite

HC steel more Ret Aust

Stage 1:

Forms very small

Metastable carbides

(10 nm)

Hypoeutectoid steels forms

ε-carbide (Fe2.4C)

Hypereutectoid steels forms

Hagg (Fe2.2C)+η-(Fe2C)

Stage 3:

Metastable carbides

fine globular cementite

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Relevant Material Properties

• Discontinuous Yielding and Lüder’s Lines

• YS, TS, el., K, n, and r

– r value is used to express the anisotropy of materials

• Planar anisotropy

• Normal anisotropy

t

wr

4

2 45900 rrrrm

4

2 45900 rrrr

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Cast Irons

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Cast Iron

• 2 to 4%C

• 1-3% Si improve castability

• C is in the form of

– graphite & cementite

• Features:

– Low melting temperature

(1153ºC to 1400ºC)

– Low shrinkage

– Easily machinable

– Low impact resistance

– Low ductility

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Materials Selection

• Mechanical properties

– Stiffness, strength, ductility, fatigue, creep

• Manufacturability

– Machining, Mechanical working, Casting, Welding

• Physical properties

– Density, Melting point, Thermal conductivity

• Cost

– Availability, ease of processing

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Cast Irons

• Microstructure of cast iron modified

by heat treatment

– Pearlite

– Ferrite

• Gray cast iron

– Fracture surface appears gray

because of graphite flakes

• White cast iron

– Fracture surface appears white

(shiny)

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Cast Iron Family

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Cast Iron Family

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Cast Irons

• Types

Gray cast iron

- Carbon as graphite flakes

2.5 - 4% C and 1 - 3% Si (Promotes formation of graphite)

Nodular cast iron

• Carbon as spherical graphite nodules

• 3-4% C & 1.8 -2.8 % Si + Mg or Ce, and low impurities

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Cast Irons

Types

– White cast iron

• Carbon as cementite

– Malleable cast iron

• Carbon as irregular graphite nodules

• Heat treating white cast iron

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Gray Iron Microstructure

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Spherodised Graphite Microstructure

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Spheoridal Graphite Iron Austempered Ductile Iron

Spherodised Graphite Iron Microstructure

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Gray Iron Mechanical Properties

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Grade

Tensile

Strength

(In MPa)

Hardness

(BHN)

IS : 210-

1978

(Indian

Std)

ISO / R 185-

1961

(Int. Std)

BS 1452 :

1961

(UK Std)

DIN 1691-

1964

(German

Std)

ASTM A-48-

1976

(American

Std.)

FG 150 15 10 GG-15 20A/25A 150 130-180

FG 200 20 12 GG-20 30A 200 160-220

FG 220 14 220 180-220

FG 260 25 17 GG-25 35A 260 180-230

FG 300 30 20 GG-30 45A 300 180-230

FG 350 35 23 GG-35 50A 350 207-241

FG 400 40 26 GG-40 60A 400 207-270

Gray Iron Mechanical Properties

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Grade

Tensile

Strength

(In MPa)

Yield

Strengt

h

(In

MPa)

%E

Hardne

ss

(BHN)

(ISO Standerd

1083,

UK Standard

B52789,

Indian Standard IS

1862)

ASTM A 536

(American

Standard)

SAE J434C

(American

Standard)

Ferritic grade

350/22 350 215 22 107-130

370/17 370 230 17 <179

400/18 60-40-18 D4018 400 259 18 120-140

400/15 400 250 15 130-180

400/12 400 250 12 <201

420/12 60-42-10 420 278 12 140-155

Ductile Iron Mechanical Properties

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Grade

Tensile

Strength

(In MPa)

Yield

Strengt

h

(In

MPa)

Elongat

ion

%

Hardne

ss

(BHN)

(ISO Standerd

1083,

UK Standard

B52789,

Indian Standard IS

1862)

ASTM A 536

(American

Standard)

SAE J434C

(American

Standard)

Intermediate grade (Ferrite + Pearlite)

450/10 65-45-12 D4512 450 305 10 150-172

500/7 70-50-05 500 339 7 172-216

80-55-06 D5506 552 379 6 187-255

Intermediate grade (Pearlite + Ferrite)

600/3 80-60-03 600 372 3 216-247

Pearlitic grade

700/2 100-70-03 D7003 700 416 2 247-265

800/2 800 471 2 245-335

900/2 120-90-02 900 526 2 280-360

Ductile Iron Mechanical Properties

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White Cast Iron Mottled Cast Iron Malleabled Cast Iron

White Cast Irons

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Classification of Steels

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Nomenclature of Steels

• Common nomenclature AISI/SAE and ASTM

– The American Iron and Steel Institute (AISI)

– Society of Automotive Engineers (SAE)

– American Society for Testing and Materials (ASTM)

• Others GOST, Japan, Russia, DIN, AFNOR etc.

• Universal/Unified Numbering System (UNS)

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ASTM Specification

• ASTM A 582/A 582M-95b (2000), Grade 303 Se – Free maching bar

A- Means Ferrous Metal includes steels, cast iron, alloy & stainless steels

No.582 – Arbitrary – no relevance to properties

M- Metric or SI units, Absence of N => fps units

95 => year of adoption or last revision

B => third revision in the std

2000 => year of last approval

Grade 303 Se => indicates grade

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ASTM Specification

Grade: describes chemical composition

Type : indicates the type of deoxidation followed

Class: Indicates strength level or surface finish

Sometimes this may not be followed

ASTM A 106-02a Grade A, Grade B, Grade C – Seamless Carbon pipe for high temp

service

Grade A :0.25%C (max) ; >45 ksi Tensile strength

Grade B :0.30%C (min) ; >60 ksi Tensile strength

Grade A :0.35%C (max) ; >70 ksi Tensile strength

ASTM A 276-03, Type 304, 316, 410 – Stainless and Heat resisting Bars and shapes

Type 304, 316, 410 are based on SAE designation for stainless steel

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ASTM Specification

In Pipes-P, Tubes-T and Forging-F products

• ASTM A 335/A 335M-03, Grade P22 Seamless Ferritic Alloy Steel Pipe for

High temperature service

• ASTM A 213/A 213M-03a, Grade T22, Seamless Ferritic and Austenitic Alloy

Steel Boiler, superheater and Heat Exchanger Tubes

• ASTM A 312/A 312M-03, Grade TP304, Seamless and Welded Austenitic

stainless steel Pipes

• ASTM A 336/A 336M-03a, Grade F22 – Steel Forgings, Alloy for pressure and

High Temperature Parts

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UNS Designation

Alpha numeric with a letter followed by five numbers

Represents only chemical composition

Not a specification

SAE 1040 is represented as UNS G 10400

G – is prefix for Carbon and alloy steel

Next four numeric degits are SAE designation of the steel

The intermediate letters “B” & “L” is replaced by the fifth digit

Prefix E – EAF makes 5th digit

SAE Grades with hardenability requirement are given by “H” HXXXXX

Carbon and Alloy Steels not referred to in SAE system categorized prefix “K”

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ASTM Specification

• ASTM A 582/A 582M-95b (2000), Grade 303 Se – Free maching bar

A- Means Ferrous Metal includes steels, cast iron, alloy & stainless steels

No.582 – Arbitrary – no relevance to properties

M- Metric or SI units, Absence of N => fps units

95 year of adoption or last revision

B=> third revision in the std

2000 => year of last approval

Grade 303 Se => indicates grade

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AISI/SAE Classification of Steels

• Four digit

– First two digits identify the alloy type

– Last two digits indicate the carbon content

Example

• AISI/SAE 1020 - Plain carbon steel (10xx) which has 0.20 wt.% carbon (xx20)

• Plain carbon steel (10xx) are inexpensive, limitations include

– Poor hardenability because the critical cooling rate is very high

– Rapid cooling leads to distortion and cracking

– Poor corrosion resistance

– Poor impact resistance at low temperature

• Alloy steels were developed to address these issues

– Alloying changes the eutectoid composition, the eutectoid carbon content and the critical

cooling rate

– These alloys are more expensive, but a better combination of properties is obtained

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1015 1040 1095

Plain Carbon Steels

AISI/ SAE Classification

1213 Plain Carbon AISI Grades

10XX Mn =1% Max

15XX Mn=1.0 to 1.6%

13XX Mn=1.6-1.9%

11XX Resulfurised

12XX Resulphurised & rephosphorised

Generally when alloying elements >1.5%

it is low alloy steel (13XX )

Above alloying elements >8%

high alloy steel

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Comite’ Europeen de Normalisation [CEN] for steels is EN 10027

Part 1 Steel Names

Part 2 Steel Numbers

EN 10027-1 Based on application and mechanical or physical properties

A letter indicates application a number follows qualifying properties

S – structural steel L- Line pipe steel

R – Rail steel P- Pressure related

EN 10028-3 steel name P275N

EN 10027-2 Steel designated based on chemical composition

Divided into 4 sub-groups

EN 10222-2 steel name 13CrMo4-5

EN 10250-4 steel names X2 CrNi18-9

European Standard

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European Standard

EN 10027-2 - system for assigning number

Steel Numbers 1.XXXX

1 refers to steel

First two digits represent steel group number

EN 10222-2 Steel Name 18CrMo4-5, steel number 1.7335

EN 10250-4 Steel Name X2CrNi18-9, steel number 1.4307

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Carbon & Alloy Steels

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Cr & Cr-Mo Steels

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Ni-Cr-Mo Steels

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Cr-Mo-Al, Cr-V & B Steels

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Structural Steel Plates

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Structural Carbon Steel Plates

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Structural Carbon Steel Plates

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Alloy Steel & HSLA Plates

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Pressure Vessel Steels

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Pressure Vessel Plate Steels

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Similar specification exists for different steel grades

High alloy steel [stainless steels]

Specification exists for steel

Tubes, Pipes, Forgings, Bars, Strips

Application based steels

- Springs, bearings, valves, etc.

Further Specification in Steels

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Further Classification of Steels

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Classification of Steels

Classification by structure Classification by Commercial name or application

Alloys without Eutectic (<2%C)

Ferritic

Ferrite - pearlitic

Pearlitic

Martensitic

Bainitic

Austenitic

Precipitation Hardened

AusteniticFerritic

Duplex structure

Steel

Plain Carbon

Low Carbon Steel (<0.2)

Medium Carbon Steel (0.2-0.5)

High Carbon Steel (0.2-0.5)

Low alloy steel (<8%)

High alloy steel (>8%)

Corrosion resistant steels

Heat Resistant steels

Wear resistant steels

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Carbon and Alloy steels

• Composition & Processing are controlled

- to meet property requirements of different applications

• Alloying elements are added to steels for

Hardenability

Strength

Hardness

Toughness

Wear resistance

Workability

Weldability

Machinability

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Steel Classification

Nb, Ti, V, Al, Cr, Ni, Mo

Co, Cu, Mo, W, Mn, Si, Steel

Plain Carbon Steel Alloy Steel

Low

Carbon

Steel

Medium

Carbon

Steel

High

Carbon

Steel

Low

Alloy

Steel

High

Alloy

Steel

C>0.9 C=0.2-0.5 C<0.2 Alloying

Element <5%

Alloying

Element >5% Flat products

Structural

Rolled steels

Machine parts

Heat treatable

Tool steel

Wear, abrasion

Heat resistance

Corrosion

resistance

Automotive Panels

Steel wt.%C

Low Carbon < 0.25

Very Low Carbon <0.10

Extra Low Carbon <0.06

Ultra Low Carbon <0.005

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Advanced High Strength Steels

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Advanced High Strength Steels

Hot Rolled Plates

Cold Rolled Plates Dual Phase

Steel

Martensitic

steel

Advanced High Strength Steels

TRIP

Steel

TWIP

Steel

5 Grades

YS=280/500

UTS=600/800

%E=30/20

n=0.21 to 0.14

r=1.0

YS=450

UTS=800

%E=26/32

n=0.24

r=0.9

YS=700

UTS=800

%E=10/15

n=0.13

r=1.0

YS=950/1250

UTS=1200/1520

%E=5/4

n=0.07/0.065

r=1.0

Grades

YS=352 / 586

UTS=469 / 676

%E=52 / 17

n=0.15 / 0.12

r=1.1 / 1.0 / NA

Complex

Phase

Steel HSLA

steel YS=200/324

UTS=800/1750

%E=90

n=0.5

r=1.0

HSLA

(Microalloyed

Bainitic)

steel

Grades

YS=350 / 586

UTS=407 / 676

%E=52 / 17

n=0.17 / 0.12

r=1.1 / 1.0 / NA

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Development of Austenitic Stainless Steels

302 302B

Si added for

scale resistance

304

Lower C

Reduce carbide

304L

Welding

347

Nb, Ta

stabilisers

348

Nb, low Ta, Co

Nuclear application

321

Ti

stabilisers

316

Mo

Corrosion Resist.

High temp. strength

317

More Mo

Better

corrosion

Resist

317L

Welding

301

Lower Cr,Ni

Work Hardening

improved

303

S added

Improved

Machinability

201

Ni, replaced partly

By Mn & N

Cost savings

303Se

Se added

Improved

machine surface

305

Increased Ni

Lower

work hardening

308 to 310

Cr, Ni increase

Corrosion Resist

Scael Resist

308

Cr, Ni increase

Corrosion Resist

Scael Resist

0.15C/18Cr/5Ni

18Cr/12Ni

17Cr/7Ni 18Cr/9Ni-0.07(S+Se) 0.05C/18Cr/8Ni 0.1C/17Cr/12Ni/2Mo 0.15C/20Cr/11Ni

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Precipitation Hardened Stainless Steels

Precipitation Hardened

Austenitic Martensitic Semi Austenitic

A286

0.08C-1.4Mn-15Cr

-26Ni-1.3Mo- 2 Ti-

0.35Al-0.3V-0.003B

17-7 PH

0.07C-0.6Mn

-17Cr-7Ni-1.15 Al

17-4 PH

0.07C-0.2Mn-16Cr

-4Ni-0.2Nb-3.4Cu

17-4 PH

15-5 PH

13-8 17-7 PH

11-10 PH

Custom 450

Custom 455®

Custom 465®

Custom 475™

C Cr Ni Mo Co Ti Cb Cu Al

0.04 16.5 4.2 -- -- --

0.3 3.3

0.01

15.0 4.0 -- -- --

0.3 3.5 --

0.05 12.7 8.0 2.3 -- -- -- --

1.2

0.07 17 7 -- -- -- -- --

1.15

0.03 11 10 2.0 --

0.9 -- --

0.2

0.05 14.8 6.5 0.8 -- --

0.6 1.5 --

0.05 11.5 8.6 -- --

1.3 0.3 2.2 --

0.05 12.0 11.0 1.0 --

1.7 -- -- --

0.05 11.0 8.0 5.0 8.5 -- -- --

1.25

Precipitates :

Cu, NiTi, Ni3Al, Ni3Mo

Low C

Lath martensite aged

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Martensitic Stainless Steels

420

403

Same alloy

Higher quality

416

S added

Machinability

410 Nb

Nb easens

Heat treatment

Improve prop

410

Lower C

Corrosion Resist.

414

Ni added

Corrosion

reist

431

Cr increase

Corrosion

resist

440C

C increased

For quench hadness

Cr increased for

Corrosion resist

420F

S added

Improved

Machinability

440B

C decreased

Toughness

improved

440F

Se added

improved

machinability

405

Al added

Minimise

air hardening

Non-hardenable

440A

C decreased

Toughness

improved

0.15C-13Cr

0.15C-12Cr

0.12C-16Cr-0.07Se

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Ferritic Stainless Steels

430

430F

S added

Improved

machinability

409

Cr reduced

Cost saving

Ti added for

improved

fabrication

430 Ti

Ti added

Improved

Fabricability

442

Cr added

improved

Scale resist

446

Cr increased

Scale resist

improved

25%Cr 18%Cr 13%Cr

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Classification of Tool & Die Steels

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Alloy classification of tool steels

W – water hardening

O – oil hardening

A – air hardening

D – high %C (1.5-2.25%C); high %Cr

(~12%Cr) (cold work dies – really a stainless steel;

excellent wear resistance)

Cold Work Tool steels

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Classification of Tool steels

Grade Prefix Specific grades

Cold Work W- water hardened

O- Oil hardened

A- Air hardened Med alloy

D- High C, High Cr

W1, W2, W5

O1,O2, O6, O7

A2, A4, A6, A7, A8, A9, A10, A11

D2, D3, D4, D5, D7

Shock

Resistance

S S1, S2, S4, S5, S6, S7

Hot Work H H10-H19 Cr type

H20-H39 W type

H40-H-59 Mo type

High Speed M (Mo)

T (W)

M1, M2, M3-1, M3-2,M4, M6, M7 M10,

M33, M34, M36, M41, M42, M56, M50

T1, T4, T5, T6, T8, T15

Special

purpose

P

L

Mold steel P6, P20, P21

Die Steel: L2, L6

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Elements in Tool steels Element Dissolved

in ferrite

Combined

in carbide

Combined

as carbide

Compound Elemental

Nickel Ni Ni3Al

Silicon Si SiO2.MxOy

Manganese Mn ------- Mn (Fe,Mn)3C MnS; MnO-

SiO2

Chromium Cr-------- Cr (FeCr)3C

Cr7C3

Cr23C6

Molybdenum Mo------- Mo Mo2C

Tungsten W------- W W2C

Vanadium V------- V V4C3

Titanium Ti------- Ti TiC

Columbium Cb --------- Cb CbC

Aluminium Al Al2O3:AlN

Copper Cu (small)

Lead Pb Pb

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• Shock resistance (cold applications)

Medium %C

Toughness is the main concern

<5% total alloys

• High speed tool steels

Tx – tungsten

Mx – Molybdenum

Up to 25% total alloy content

High %C – sharpness held e.g. HSS – drills for metal

Shock Resistant Tool Steels

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Requirements: Used at low temperature –toughness

Cold-work tool steels include all class S alloys.

Among the toughest of the tool steels,

Typically used for screw driver blades, shear blades, chisels, knockout

pins, punches, and riveting tools.

Tool steels – Shock Resistant

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Cold work tool steels:

use limited cold conditions

will soften if over tempered 17-95°C

Up to ~5% total alloy content; high %C

High %C steels:

High hardness therefore

good sharpness and wear resistance

All high-chromium class D,

Medium-alloy air-hardening class A alloys,

Water hardening W alloys

Oil hardening O alloys

Typical applications include cold working operations such as stamping

dies, draw dies, burnishing tools, coining tools, and shear blades

Cold Work Tool Steels

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Requirements: Used at high temperature – toughness

Hot-work tool steels include

All chromium, tungsten, and molybdenum class H alloys

They are typically used for forging, die casting, heading, piercing, trim,

extrusion, and hot-shear and punching blades.

Hot Work Tool Steels

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• Hot work tool steels:

Hot application H1x, H2x, H3x

Cr, Mo, W – main alloy elements

H1x – Cr

H2x, H3x – W

H4x, H5x – Mo’

• Medium carbon

• Up to 25% alloy content

• Toughness at high temperature is main requirement

Hot Work Tool steels

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Special Purpose Tool Steels

• Plastic Mold Steel

• P6, P20, P21 series, NAK 52

• Die Steels :L2, L6

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Requirements: Used at high temperature –sharpness

High-speed alloys include

molybdenum class (M1 to M52)

tungsten class (T1 to T15)

Up to 25% Total alloy content

High C gives sharpness

High-speed tools steels are hardened to 62-67 HRC

Maintains hardness in service temperatures as high as 540 °C

very useful in high speed machinery.

Typical applications are end mills, drills, lathe tools,

planar tools, punches, reamers, routers,

taps, saws, broaches, chasers, and hobs.

High Speed Steels

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Conclusion

Basic Classification of steel grade has been introduced

You can send your questions to [email protected]