Secondary hardening in steels arises out of the

1.	Secondary hardening in steels arises out of the
A.	precipitation of fine alloy carbides at high temperatures.
B.	refinement of ferrite grain size by working.
C.	decomposition of retained austenite upon heat treatment.
D.	precipitation of complex inter-metal-lics upon heat treatment.
Answer» D. precipitation of complex inter-metal-lics upon heat treatment.

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Secondary hardening in steels arises out of the

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