Abstract: The microstructure and hardness distribution of 35CrMo steel after a composite treatment of ion nitriding and laser transformation hardening is presented, and the sliding abrasive wear tests are carried out under the conditions of different technologies and materials. The results show that the hardening depth of steel by composite treatment is much larger than that of single treatment of ion nitriding. In the condition of sliding wears the composite treatment can offer much better wear-resistance, compared with single treatment of ion nitriding or laser transformation hardening for 35CrMo steel, it is basically equal to that of GCrl5 steel treated by quenching and low temperature tempering.

Key words: Composite treament, Ion nitriding, Laser transformation hardening, Sliding abrasive wear