CWB Level-3 Module 21 Questions with 100% Correct Answers

CWB Level-3 Module 21 Questions with 100%
Correct Answers
Carbon Solubility Correct Answer: BCC-0.02% Weight @
723C


FCC-2.0% Weight


Allotropic Forms of Iron Correct Answer: Below 910C
=BCC


910C-1390C=FCC


1390C-1534C=BCC


What is a true stable form of iron Correct Answer:
Graphite (other forms of cast iron)


When a steel is heated into the_____________ region all
carbon will dissolve to form a single phase Correct
Answer: Austenite


Spacing between plates is dependent on how fast the
pearlite is Correct Answer: Growing

, When steel has less that 0.8% Carbon (Hypo-eutectoid)
when cooling from the austenite region ____________ will
be formed first from the austenite Correct Answer: Ferrite


Faster Cooling produces finer ___________________
Correct Answer: Pearlite


BCT (Tetragonal shape) Correct Answer: A rapid quench
cannot prevent the change from the FCC Structure. The
Presence of trapped carbon in the BCC phase distorts it
to the BCT (Dislocation is very high)


Martensite Correct Answer: Constituent formed by rapid
cooling


-Appearance of a mass of needles


-Hard and brittle


-Hardness determined by amount of carbon


Martensite formation depends only on____________ not
____________ held at temp Correct Answer: Temperature
not length