William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Converting Raw Materials to Steel Product Forms

Raw Material

C3-4.5% C

Excess Cremoved

(oxidation)

Heat treatment

Mechanical treatment

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Blast Furnace(Iron Making)

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Steel Making (Oxygen Furnace)Pig iron: up to 30% scrap Pure oxygen reacts with liquid 45 minutes => 200 tons of steel

to create iron-oxideC reacts with iron oxide to produce CO

Superior to open-hearth:•sulfur contamination avoided (no external fuels)•trace nitrogen in oxygen used for refining, so low N in steel (<0.004%)•residual oxygen in steel less, so few deoxidizing agents required•lower impurities (less scrap)

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Open Hearth Steelmaking Process

Shallow bath of steel heated with flame

Slag to remove phosphorous and sulfur

~6-10 hours ==> 200 tons of steel

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Electric Arc FurnaceElectrodes positioned above cold steel scrap and arc is struckIncreased temperature control60-90 tons per day

Serope Kalpakjian. Manufacturing Engineering and Technology, 3rd Edition. Addison-Wesley Publishing Co. 1995

Continuous Casting

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Hot Strip Rolling Mill(Not necessary for continuous casting)

H2O spray tocontrol temp.

Temperature just slightly above recrystallization temp. (avoid excessive grain growth)- breaks down coarse grains of ingots - refined grains- heals porosity - strength increases in roll direction

Intermediate Material Product Forms

Slabs: (processes into plate, sheet)

Blooms: (processes into shapes and rails)

Billets: (processed into bars, rods, pipe, tubes)

24”-60”2”-9”

6x6”-12x12”

2x2”-5x5”

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

AISI-SAE carbon-steel compositions

Plain carbon steels constitute ~85% of steel used in U.S. (although very little in aerospace)

1st two digits denote type(10 = plain carbon steel)

Last two digits indicate amount of C in hundredth percent

Effect of Trace Elements on Carbon Steel

0-1% manganese: reacts with sulfur, to produce MnS soft inclusionsincreased yield strength

0-0.05% sulfur: if insufficient manganese, sulfur will react with iron at grain boundaries, cracking during working

0-0.04% phosphorous: forms brittle Fe3P compound

0-0.03% silicon: forms silicate inclusions (SiO2) but has little effect on properties

Limitations of Plain Carbon Steels:

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

General Effects of Alloying Elements in Steel

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

- allows advantage of tempered martensite throughout- allows slower quench

Effects of alloy elements in steelGenerally ~1-4%

Effects of alloy elements in steelGenerally ~1-4%

Effects of alloy elements in steel

Residual Elements in Steel

Alloys Favorably Affecting Properties

--- Element with most influence

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Principal Types of Standard Alloy Steels

AISI-SAE System

1st two digits indicate principal alloy or group of alloys

Last two digits indicate amount of C in hundredth percent

Serope Kalpakjian. Manufacturing Engineering and Technology, 3rd Edition. Addison-Wesley Publishing Co. 1995

AISI-SAE Designations for Steels and Their Major

Alloying Elements

William D. Callister, Jr. Materials Science and Engineering, An Introduction. John Wiley & Sons, Inc. 1985

AISI/SAE and UNS Designation Systems and Composition Ranges for Plain Carbon Steel and

Various Low Alloy Steels

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Nominal Compositions and Typical Applications of Select Standard Alloy Steels

William D. Callister, Jr. Materials Science and Engineering, An Introduction. John Wiley & Sons, Inc. 1985

Typical Applications and Mechanical properties for Oil-Quenched and Tempered Steels

Serope Kalpakjian. Manufacturing Engineering and Technology, 3rd Edition. Addison-Wesley Publishing Co. 1995

Common Applications for Common Steels

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Chemical Compositions and Typical Applications of Low-Alloy Chromium-Molybdenum Steels

Chromium: improves hardenability, strength and wear resistance

Combination allows slower oil quench to produce martensite, which reduces thermal gradients and internal stresses

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Continuous Cooling Diagram, AISI 4140 Alloy Steel

Ferrite to pearlite transformation is delayed

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Material Properties for Chromium-

Molybdenum Steels

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Chemical Compositions and Typical Applications of Low-Alloy Nickel-Chromium-Molybdenum Steels

Nickel with Chromium: improved elastic limit, hardenability, impact resistance and fatigue resistance

Molybdenum: further improvements to hardenability and reduced embrittlement

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Continuous Cooling Diagram, AISI 4340 Alloy Steel

Ferrite to pearlitetransformation is significantly delayed

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Material Properties for Normalized and Annealed Nickel-Chromium-Molybdenum Alloy Steels

William F. Smith. Structure and Properties of Engineering Alloys. McGraw-Hill Publishing Co. 1981`

Material Properties for Quenched and Tempered Nickel-

Chromium-Molybdenum Alloy

Steels

Stainless SteelHigh Chromium content (>10%)Corrosion resistant, hight strength and ductility“Stainless” ==> chromium oxide resists corrosion

Stainless Steel

* Corrosion resistance decreases with carbon content, due to chromium carbide formation

Thus, stainless steel utensils generally low in carbon content (what does this imply?)

*

*

Serope Kalpakjian. Manufacturing Engineering and Technology, 3rd Edition. Addison-Wesley Publishing Co. 1995

Mechanical Properties and Applications of Select Annealed Stainless Steels

Serope Kalpakjian. Manufacturing Engineering and Technology, 3rd Edition. Addison-Wesley Publishing Co. 1995

Tool and Die SteelsHigh strength, impact toughness, wear resistance

Elevated operating temperatureM more common

Impact toughness(dies, punches, chisels)

Serope Kalpakjian. Manufacturing Engineering and Technology, 3rd Edition. Addison-Wesley Publishing Co. 1995

Tool and Die Materials for Metalworking

Serope Kalpakjian. Manufacturing Engineering and Technology, 3rd Edition. Addison-Wesley Publishing Co. 1995

Approximate Cost of Raw Materials for Various Product Forms

Materials Properties For Steels

MIL-HDBK-5E, Chapter 2

Richard A. Flinn and Paul K. Trojan. Engineering Materials and Their Applications, 4th Edition. Houghton Mifflin Co. 1990.

Hardness and Hardenability

Richard A. Flinn and Paul K. Trojan. Engineering Materials and Their Applications, 4th Edition. Houghton Mifflin Co. 1990.

Representative Hardenability Curves

Richard A. Flinn and Paul K. Trojan. Engineering Materials and Their Applications, 4th Edition. Houghton Mifflin Co. 1990.

Hardenability Example

Richard A. Flinn and Paul K. Trojan. Engineering Materials and Their Applications, 4th Edition. Houghton Mifflin Co. 1990.

Hardenability Example