MMET 207 EXAM 2 STUDY GUIDE
Hardenability - Answers :Ability to form martensite
Aluminum - Answers :Killing agent in steel (Removes Oxygen)
Aids Nitriding
Sulfur & Phosphorous (Good) - Answers :Improve machinability
Sulfur & Phosphorous (Bad) - Answers :Reduce weldability, ductility and toughness
Chromium Oxide - Answers :Type of corrosion that stays on surface and protects the
metal
Chromium - Answers :-Stainless Steels (11.5%)
-Increases hardenability - causes slower cool, but more martensite
-Increases high-temperature strength
-Increases tensile and creep strength
Chromium Carbides - Answers :Hard and wear resistant particles (microconstituents)
Nickel - Answers :-Increases hardenability (not as much as Cr)
-Increases toughness even in low temperature
-Promotes Austenitic Structure
Through Hardening - Answers :-Cool something over 1 inch in diameter
Ex. Nickel helps
Copper - Answers :-Bonds to oxygen to form a corrosion layer
-Rust layer stays on the metal easier
-Steel that weathers has a high copper content
-Increases toughness
*Copper Build-up in recycling process* - Answers :*Lowers Impact Strength*
-The use of pig iron combats this
Manganese - Answers :Add to "tie up the sulfur" (Combats bad sulfur impacts)
-Increases hardenablilty
Free-machining steels - Answers :Sulfur and manganese pre-added
-Do not weld
*Silicon* - Answers :Killing agent of oxygen
Improves toughness and hardenability
*Improves fluidity of molten metal*
, Molybdenum - Answers :Promotes grain refinement
Smaller, finer grains above the AC3
Improves ductility, hardenability, and high-temp strength
Vanadium - Answers :Promotes grain refinement
Improves hardenability
Creates carbides making harder spots for stronger but not too brittle material
*Boron* - Answers :A tiny amount improves hardenability
*.005-.003%*
Lead - Answers :Improves machinability
-an easy smooth cut, can't be welded
Nitrogen - Answers :Improves strength for interstitial material
Nitriding - Answers :Bonds to form nitrides with hard wear resistance
-Added to surface of the material
AISI/SAE System - Answers :First 2 digits indicate alloying element if present
10 - Answers :Plain Carbonized Steel
11 - Answers :Resulfirized steel
Ex. 1040 - Answers :Plain Carbonized Steel with 0.4% Carbon
E (Prefix) - Answers :Electric Arc Furnace
X (Prefix) - Answers :Composition varies from normal
H (Suffix) - Answers :Indicates hardenability requirements met
*Low Carbon Steel Range* - Answers :*0-.3%*
*Medium Carbon Steel Range* - Answers :*.3-.6%*
*High Carbon Steel Range* - Answers :*0.6-2.0%*
Ex. 4140 and 4340 - Answers :Toughness is approximately the same as low carbon
steel
Yield strength is 4 to 5 times that of low Carbon steel
H Steels - Answers :Hot worked
-Try to harden steels
-More expensive
Hardenability - Answers :Ability to form martensite
Aluminum - Answers :Killing agent in steel (Removes Oxygen)
Aids Nitriding
Sulfur & Phosphorous (Good) - Answers :Improve machinability
Sulfur & Phosphorous (Bad) - Answers :Reduce weldability, ductility and toughness
Chromium Oxide - Answers :Type of corrosion that stays on surface and protects the
metal
Chromium - Answers :-Stainless Steels (11.5%)
-Increases hardenability - causes slower cool, but more martensite
-Increases high-temperature strength
-Increases tensile and creep strength
Chromium Carbides - Answers :Hard and wear resistant particles (microconstituents)
Nickel - Answers :-Increases hardenability (not as much as Cr)
-Increases toughness even in low temperature
-Promotes Austenitic Structure
Through Hardening - Answers :-Cool something over 1 inch in diameter
Ex. Nickel helps
Copper - Answers :-Bonds to oxygen to form a corrosion layer
-Rust layer stays on the metal easier
-Steel that weathers has a high copper content
-Increases toughness
*Copper Build-up in recycling process* - Answers :*Lowers Impact Strength*
-The use of pig iron combats this
Manganese - Answers :Add to "tie up the sulfur" (Combats bad sulfur impacts)
-Increases hardenablilty
Free-machining steels - Answers :Sulfur and manganese pre-added
-Do not weld
*Silicon* - Answers :Killing agent of oxygen
Improves toughness and hardenability
*Improves fluidity of molten metal*
, Molybdenum - Answers :Promotes grain refinement
Smaller, finer grains above the AC3
Improves ductility, hardenability, and high-temp strength
Vanadium - Answers :Promotes grain refinement
Improves hardenability
Creates carbides making harder spots for stronger but not too brittle material
*Boron* - Answers :A tiny amount improves hardenability
*.005-.003%*
Lead - Answers :Improves machinability
-an easy smooth cut, can't be welded
Nitrogen - Answers :Improves strength for interstitial material
Nitriding - Answers :Bonds to form nitrides with hard wear resistance
-Added to surface of the material
AISI/SAE System - Answers :First 2 digits indicate alloying element if present
10 - Answers :Plain Carbonized Steel
11 - Answers :Resulfirized steel
Ex. 1040 - Answers :Plain Carbonized Steel with 0.4% Carbon
E (Prefix) - Answers :Electric Arc Furnace
X (Prefix) - Answers :Composition varies from normal
H (Suffix) - Answers :Indicates hardenability requirements met
*Low Carbon Steel Range* - Answers :*0-.3%*
*Medium Carbon Steel Range* - Answers :*.3-.6%*
*High Carbon Steel Range* - Answers :*0.6-2.0%*
Ex. 4140 and 4340 - Answers :Toughness is approximately the same as low carbon
steel
Yield strength is 4 to 5 times that of low Carbon steel
H Steels - Answers :Hot worked
-Try to harden steels
-More expensive
