Matse 259 Final Exam Review With 100%
Correct Answers
Coarse Pearlite
high diffusion allows Carbon atoms to diffuse over long distances and form thick lamellae
Fine Pearlite
low diffusion allows Carbon atoms to diffuse over short distances and form thin lamellae
Martensite
NOT diffusion driven
independent of time
Process Annealing
used to negate effects of coldwork and to soften and increase ductility
recovery and recrystalization can occur
Stress Relief
component is heated to low temperature, held there then cooled to room temperature by air
Normalizing
redefines grains to produce uniform size distribution
cools to 900-950C
Full Annealing
used to produce coarse pearlite
Spheroidizing
takes 24-48 hrs
Severity of Quench
indicates rate of cooling
water=most severe
10XX Steel
Mn added
41XX, 43XX steel
Most common steel
92XX steel
used in forging to promote pearlite
Free machining
unweldable
, Low Carbon steel
<.25 wt% C
strengthened by coldwork
ferrite and pearlite
Medium Carbon steel
.25-.6 wt% C
High Carbon steel
.6-1.4 wt% C
Gray Cast Steel
damps vibrational energy
high resistance to wear
White cast steel
hard and brittle
intermediary in production of malleable cast iron
virtually unmachinable
Sigma
in stainless steels decreases corrosion resistance
Stainless Steel Microstructure Constituents
ferrite
austenite
martinsite
duplex
precipitation hardening
Ferritic Stainless Steel
11-29 wt% Cr
no nickel
little carbon
Austenitic Stainless Steel
more corrosion resistant than ferritic
18 wt% Cr
8 wt% Ni
Wrought Aluminium Alloy
4 numbers
lead number tells main alloy element
temper designations
aircraft uses
Correct Answers
Coarse Pearlite
high diffusion allows Carbon atoms to diffuse over long distances and form thick lamellae
Fine Pearlite
low diffusion allows Carbon atoms to diffuse over short distances and form thin lamellae
Martensite
NOT diffusion driven
independent of time
Process Annealing
used to negate effects of coldwork and to soften and increase ductility
recovery and recrystalization can occur
Stress Relief
component is heated to low temperature, held there then cooled to room temperature by air
Normalizing
redefines grains to produce uniform size distribution
cools to 900-950C
Full Annealing
used to produce coarse pearlite
Spheroidizing
takes 24-48 hrs
Severity of Quench
indicates rate of cooling
water=most severe
10XX Steel
Mn added
41XX, 43XX steel
Most common steel
92XX steel
used in forging to promote pearlite
Free machining
unweldable
, Low Carbon steel
<.25 wt% C
strengthened by coldwork
ferrite and pearlite
Medium Carbon steel
.25-.6 wt% C
High Carbon steel
.6-1.4 wt% C
Gray Cast Steel
damps vibrational energy
high resistance to wear
White cast steel
hard and brittle
intermediary in production of malleable cast iron
virtually unmachinable
Sigma
in stainless steels decreases corrosion resistance
Stainless Steel Microstructure Constituents
ferrite
austenite
martinsite
duplex
precipitation hardening
Ferritic Stainless Steel
11-29 wt% Cr
no nickel
little carbon
Austenitic Stainless Steel
more corrosion resistant than ferritic
18 wt% Cr
8 wt% Ni
Wrought Aluminium Alloy
4 numbers
lead number tells main alloy element
temper designations
aircraft uses
