Sub-critical anneal

Homogenization (soaking of cast metals) Stress Relieving (sub-critical anneal / PWHT)... 

Stress Relief A heat treatment process to reduce internal residual stress by heating to a desired temperature and holding for a suitable period of time, also known as a sub-critical anneal. Residual stresses can be induced by forging, casting, forming, welding or cold working of metal. 

Sub-Critical Anneal A high temperature tempering process for steel that produces many of the benefits of annealing but does not require coohng at a controlled rate. 

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