690合金管在不同法向载荷下的切向微动磨损性能研究

Tangential Fretting Wear Characteristics of 690 Alloy Tubes under Different Normal Force

目的通过690合金管/405不锈钢块(线接触)的切向微动试验,探究690合金管在不同法向载荷作用下的切向微动磨损机制和损伤演变规律。方法采用自制的多功能复合微动磨损试验机,研究法向载荷(10、20、40 N)对690合金传热管/405不锈钢抗振条的切向微动磨损性能的影响。通过分析摩擦系数和耗散能,获得试验过程中的动力学信息,再通过光学显微镜、扫描电镜对磨痕进行微观分析,获得其磨损机制以及损伤演变规律。结果当位移幅值为100、200μm,法向载荷为10、20、40 N时,690合金管/405不锈钢块的微动运行状态处于完全滑移区。随着法向载荷的增加,摩擦耗散能和摩擦力增大,690合金管的损伤加剧,产生的磨屑增加,磨痕表面的剥落坑被磨屑覆盖而减少,摩擦系数呈下降趋势。沿微动方向,690合金表面的磨损区域内O、Fe、Ni和Cr的含量呈锯齿变化;沿接触方向,690合金管的磨损深度也呈现锯齿状,这都是690合金管和405不锈钢块均为非理想平面所致。结论总体而言,随着法向载荷的增加,690合金管和405不锈钢块的磨损体积增加,690合金管主要的磨损机制为剥层和磨粒磨损。

The work aims to explore the tangential fretting wear mechanism and damage laws of 690 alloy tube through the tangential fretting wear tests of 690 alloy tube/405 stainless steel(tube-on-plate configuration).The effect of normal force(10 N,20 N and 40 N)on tangential fretting wear of 690 alloy tube/405 stainless steel seismic strip was studied by self-made multifunctional composite fretting wear tester.The friction coefficient and dissipated energy were analyzed to obtain the dynamics information during the test.Then,the wear scars were examined through optical microscope and scanning electron microscopy to obtain wear mechanism and damage laws.When the displacement amplitude was 100μm and 200μm and the normal force was 10 N,20 N and 40 N,the fretting state of 690 alloy tube/405 stainless steel block was in the complete slip zone.With the increase of normal force,the friction dissipation energy and friction force increased,the damage of 690 alloy tube was intensified,the wear debris increased,the delamination pits on wear scar surface decreased due to be covered with wear debris and the friction coefficient showed the decrease trend.Along the fretting direction,the contents of O,Cr,Fe and Ni were serrated and the wear depth was also serrated along the motion direction due to the line contact,which was caused by non-ideal plane of 690 alloy tube and 405 stainless steel block.Overall,the wear volume of 690 alloy tube and 405 stainless steel block increases with the increase of normal force.The main wear mechanism of 690 alloy tube is delamination and abrasive wear.