超声表面滚压加工对20CrMoH钢摩擦磨损性能的影响

目的 提高20CrMoH钢的耐磨性能.方法 设置不同的超声滚压力(700、1000、1300 N)与次数(3、6次),对20CrMoH钢进行超声表面滚压加工.采用扫描电子显微镜、粗糙度测量仪、光学显微镜、显微硬度测量仪、X射线应力分析仪、端面型滑动磨损试验机和3D形貌仪等设备,分别对加工前后试样的表面形貌、粗糙度、金相...

Effect of Ultrasonic Surface Rolling on Friction and Wear Properties of 20CrMoH Steel

In order to improve the wear resistance of 20CrMoH steel,different ultrasonic rolling forces(700 N,1000 N and 1300 N)and passes(3 passes and 6 passes)were applied to perform ultrasonic surface rolling on 20CrMoH steel.The surface morphology,roughness,microstructure,microhardness,surface residual compressive stress and friction and wear properties of the samples before and after ultrasonic surface rolling were analyzed by scanning electron microscope,roughness tester,optical microscope,microhardness tester,X-ray stress analyzer,sliding wear tester of end-face type and 3D profilometer.Compared with the untreated sample,the properties of the samples processed by ultrasonic surface rolling were greatly improved,the surface appearance of material was significantly smoother,the roughness Ra decreased from 0.82μm to 0.331μm,the surface microhardness increased from 760HV_0.2 to 856HV_0.2,with an increase by 12.63%,and the surface residual compressive stress increased from–286 MPa to–565 MPa.The wear mechanism changed from predominantly abrasive and fatigue wear of untreated samples to predominantly abrasive and oxidative wear.The wear resistance of the sample was the best after 6 passes of ultrasonic surface rolling under the force of 1000 N.Compared with the untreated sample,the wear volume was reduced from 2.29 mm³to 0.74 mm³,with a decrease by 67.69%.Ultrasonic surface rolling can effectively improve the surface quality of 20CrMoH steel samples,refine the surface grain structure,increase the surface microhardness and surface residual compressive stress,and significantly improve the wear resistance of the material.