Matse 259 Exam 4 Review UPDATED
ACTUAL QUESTIONS AND CORRECT
ANSWERS
Coarse Pearlite - CORRECT ANSWER high diffusion allows Carbon atoms to diffuse over
long distances and form thick lamellae
Fine Pearlite - CORRECT ANSWER low diffusion allows Carbon atoms to diffuse over short
distances and form thin lamellae
Martensite - CORRECT ANSWER NOT diffusion driven
independent of time
Stress Relief - CORRECT ANSWER component is heated to low temperature, held there then
cooled to room temperature by air
Normalizing - CORRECT ANSWER redefines grains to produce uniform size distribution
cools to 900-950C
Severity of Quench - CORRECT ANSWER indicates rate of cooling
water=most severe
Free machining - CORRECT ANSWER unweldable
Low Carbon steel - CORRECT ANSWER <.25 wt% C
*nonresponsive to heat treatments, but still machinable and weldable
*soft and weak
Applications: automobile bodies, structural shapes, tin cans, buildings, bridges
Medium Carbon steel - CORRECT ANSWER .25-.6 wt% C
, *are heat treatable
*have a large combination of mechanical characteristics
Applications: railway tracks/wheels, machine parts, gears, crankshafts
High Carbon steel - CORRECT ANSWER .6-1.4 wt% C
*hard, strong, relatively brittle
Applications: chisels, hammers, knives, hacksaw blades
High alloy steels (stainless and tool) - CORRECT ANSWER *hard and wear resistant
*are widely resistant to corrosion
Applications: cutting tools, surgical tools, food processing equipment, drills, cutlery
White cast steel - CORRECT ANSWER hard and brittle
intermediary in production of malleable cast iron
virtually unmachinable
Sigma - CORRECT ANSWER in stainless steels decreases corrosion resistance
Classes of Stainless Steel (based on Microstructure Constituents) - CORRECT
ANSWER *ferritic
*austenitic
*martensitic
*duplex (combination of ferrite and austenite)
*precipitation hardening(heat treatable to form precipitates)
Ferritic Stainless Steel - CORRECT ANSWER *magnetic up to 750 degrees C
*NOT HEAT TREATABLE.. hardened and strengthened by cold work
Austenitic Stainless Steel - CORRECT ANSWER *more corrosion resistant than ferritic
*also NOT HEAT TREATABLE, but is hardened and strengthened by cold work
ACTUAL QUESTIONS AND CORRECT
ANSWERS
Coarse Pearlite - CORRECT ANSWER high diffusion allows Carbon atoms to diffuse over
long distances and form thick lamellae
Fine Pearlite - CORRECT ANSWER low diffusion allows Carbon atoms to diffuse over short
distances and form thin lamellae
Martensite - CORRECT ANSWER NOT diffusion driven
independent of time
Stress Relief - CORRECT ANSWER component is heated to low temperature, held there then
cooled to room temperature by air
Normalizing - CORRECT ANSWER redefines grains to produce uniform size distribution
cools to 900-950C
Severity of Quench - CORRECT ANSWER indicates rate of cooling
water=most severe
Free machining - CORRECT ANSWER unweldable
Low Carbon steel - CORRECT ANSWER <.25 wt% C
*nonresponsive to heat treatments, but still machinable and weldable
*soft and weak
Applications: automobile bodies, structural shapes, tin cans, buildings, bridges
Medium Carbon steel - CORRECT ANSWER .25-.6 wt% C
, *are heat treatable
*have a large combination of mechanical characteristics
Applications: railway tracks/wheels, machine parts, gears, crankshafts
High Carbon steel - CORRECT ANSWER .6-1.4 wt% C
*hard, strong, relatively brittle
Applications: chisels, hammers, knives, hacksaw blades
High alloy steels (stainless and tool) - CORRECT ANSWER *hard and wear resistant
*are widely resistant to corrosion
Applications: cutting tools, surgical tools, food processing equipment, drills, cutlery
White cast steel - CORRECT ANSWER hard and brittle
intermediary in production of malleable cast iron
virtually unmachinable
Sigma - CORRECT ANSWER in stainless steels decreases corrosion resistance
Classes of Stainless Steel (based on Microstructure Constituents) - CORRECT
ANSWER *ferritic
*austenitic
*martensitic
*duplex (combination of ferrite and austenite)
*precipitation hardening(heat treatable to form precipitates)
Ferritic Stainless Steel - CORRECT ANSWER *magnetic up to 750 degrees C
*NOT HEAT TREATABLE.. hardened and strengthened by cold work
Austenitic Stainless Steel - CORRECT ANSWER *more corrosion resistant than ferritic
*also NOT HEAT TREATABLE, but is hardened and strengthened by cold work
