Stress Relief Annealing

Stress relief annealing is a heat treatment applied to reduce residual stresses that accumulate in the part during processes such as welding, forging, casting, cold forming, or heavy machining. Unlike other types of annealing, the aim is not to change the microstructure, but only to reduce the internal stress level.

The stress relief temperature is determined depending on the type of steel and its alloy content. In practice, the steel is heated to a temperature below the A1 critical transformation temperature, usually in the range of 550–650 °C. After reaching this temperature at every point of the part, it is held for a sufficient time and then cooled slowly and controllably in the furnace.

PURPOSE OF STRESS RELIEF TREATMENT:
• Reducing internal stresses resulting from manufacturing processes,
• Preventing dimensional and axial displacements that may occur during precision machining,
• Eliminating the risk of cracking in welded joints and the Heat Affected Zone (HAZ),
• Maintaining the dimensional stability of the steel under harsh operating conditions,
• Increasing resistance to stress corrosion cracking.