Effect of residual stresses on distortion of nitrided parts

Conclusions

• 1. Improper machining — sag of the workpiece, inaccurate centering, improper grinding — leads to considerable distortion of parts before nitriding.

• 2. Straightening and subsequent removal of residual stresses by stabilization tempering reduces distortion during nitriding to the minimum. The higher the temperature and the longer the tempering time, the greater the reduction of distortion after nitriding.

• 3. Denitriding in vacuum (1·10⁻⁴ mm Hg), followed by straightening, stabilization tempering, and nitriding eliminates rejects due to distortion.