Hot working

In metallurgy, hot working refers to processes where metals are plastically deformed above their recrystallization temperature.

This is important because recrystallization keeps the materials from strain hardening, which ultimately keeps the yield strength and hardness low and ductility high.

The upper limit for hot working is determined by various factors, such as: excessive oxidation, grain growth, or an undesirable phase transformation.

In practice materials are usually heated to the upper limit first to keep forming forces as low as possible and to maximize the amount of time available to hot work the workpiece.

Hot working improves the engineering properties of the workpiece because it replaces the microstructure with one that has fine spherical shaped grains.