Laser peening processing effect on mechanical and tribological properties of rolling steel 100Cr6

This study is divided into two parts. In the first part, the influence of laser peening on the surface properties of a steel was studied. Investigative observations and comparative tests were effected on 100Cr6 rolling steel, untreated and treated by one and two passes of laser peening. Three principal parameters were analysed: surface morphology, mechanical state (residual stresses and hardness). These analyses showed that laser peening processing (LP) created a hardened layer. In the second part, the influence of the LP on the tribological behaviour of 100Cr6 rolling steel was studied. A linear rolling-sliding contact between 100Cr6 steel and a roller of 40CrMoV13 steel was used for different types of friction tests: firstly, a comparative study of the tribological behaviour of the steel untreated and treated by one and two passes of laser peening. Secondly, investigative tests were conducted under various contact pressures on steel which had been either untreated or treated by one laser peening pass. The experiments showed that there is a critical pressure which limits the protective properties of the treatment.