The most common heat treatment for carbon steel weldments is stress relief.  The localized heat inherent in welding processes creates non-uniform stresses in the steel parts.  Stress relief heat treatment provides an improvement in dimensional stability by tempering the parts in the 1000 ^oF to 1250 ^oF range.  These temperatures do not change the microstructure of the steel part, and may reduce the hardness only slightly.  These temperatures do temper the weld and reduce the hardness and tendency to crack in the weld bead itself.

Stress relief heat treatments may be performed in special fixtures to straighten welded parts or to hold dimensional tolerances.  The most common post heat treatment finishing is sand blast or shot blast cleaning.