We can make steel harder by ( )
A. quench
B. annealing
C. tempering
D. normalizing
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The purpose of tempering is to ( )
A. make steel softer
B. make steel harder
C. relieve the internal stresses
Which speed of cool is the fastest?
A. quench
B. annealing
C. tempering
The heat treatment includes :
A. annealing
B. quench
C. tempering
D. shaping
Shaping operations of metal include :
A. casting in moulds
B. forging
C. squeezing
D. bending