Which of the following heat treatment processes is used for softening the hardened material ?

A. Diamond
B. Graphite
C. Carborundum
D. Pumice stone

A. High co-efficient of thermal expansion
B. Low thermal conductivity
C. High corrosion resistance
D. All A., B. and C.

A. Compression
B. Extrusion
C. Injection
D. None of these

A. Molybdenum
B. Phosphorus
C. Chromium
D. Vanadium

A. Hot rolled
B. Chrome carbon
C. Cold rolled
D. Stainless