Stress relieving is used to reduce residual stress created by machining, welding, casting, straightening, or severe cold work. The goal is not to significantly change hardness or produce a new phase transformation, but to relax locked-in internal stresses that could cause distortion or cracking later.
This is particularly important before finishing machining, after heavy weld fabrication, or prior to service environments where residual stress could drive distortion or stress-corrosion problems.
In most steels, the cycle is kept below the lower critical temperature, so the base microstructure is largely retained.
At Braddock, stress relieving would be used when dimensional stability and stress reduction are more important than altering the material’s fundamental heat-treated condition.
Stress relieving is applied to components with residual stress from fabrication or prior thermal processing.
The part is heated to a subcritical temperature appropriate to the alloy and held long enough for internal stresses to relax. The exact temperature depends on the material and prior condition; the objective is to reduce stress without substantial transformation of the matrix.
Cooling is usually controlled enough to avoid reintroducing large thermal gradients.
For weldments, the cycle may also reduce hardness gradients and residual stresses near the heat-affected zone, though it is not a substitute for full post-weld heat treatment in every code case.
Braddock would control stress-relief temperature, hold time, support of the part during the cycle, and cooling practice because these variables determine how effectively residual stress is reduced without unwanted property change.
