Rolling contact fatigue performance of 316 stainless steel treated by laser shock processing
NIU Jianxin1, DAI Fengze2*, PEI Zhipeng2, ZHENG Yueyang2, GAO Huiming3
1. Torrance Precision Machinery(Shanghai)Co. Ltd., Shanghai 200210, China; 2. School of Mechanical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 3. National Die Quality Supervision and Inspection Center, Kunshan, Jiangsu 215300, China
Abstract：The 316 stainless steel was subjected to laser shock processing(LSP), and the mechanical properties including the microhardness, surface roughness and residual stress were investigated. The rolling contact fatigue test was also conducted to compare the S-N curve with and without LSP. The results show that LSP can significantly improve the surface microhardness. When the single laser pulse energy is 6 J, the microhardness increases by 20%. The depth of the affected layer increases with the increase of laser energy. When the laser energy is 6 J, the depth of the affected layer is about 0.9 mm. With the increases of laser energy, the surface roughness also shows an upward trend, rising from 0.41 μm to 1.91 μm. In addition, LSP generates a residual compressive stress amplitude of up to 280 MPa on the surface of 316 stainless steel. The rolling contact fatigue experiment shows that LSP can effectively improve the contact fatigue performance of 316 stainless steel. The fatigue life of the untrea-ted specimen is about 4.72×104 and 1.08×105 times when the contact stress is 848 MPa and 708 MPa, respectively. While after LSP, the fatigue life of the specimen is increased by 2.1% and 15%, respectively, under the same stress conditions.
