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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