表面织构-离子氮化复合处理改善316不锈钢的摩擦学性能

Improvement in Tribological Property of 316 Stainless Steel via Surface Texturing-Plasma Nitriding Duplex Treatment

针对奥氏体不锈钢表面硬度低、摩擦因数大、耐磨性差等问题,对316不锈钢进行电化学处理获得表面织构,再对获得表面织构的试样进行离子氮化处理。在干摩擦和脂润滑条件下研究了316不锈钢基材和复合处理试样与GCr15钢球和Si3N4陶瓷球配副的摩擦学行为。结果表明:复合处理后试样表层主要由ε相、γ′相和CrN相组成,表面硬度为1 048HV0.1;在干摩擦条件下,表面织构未被完全破坏,在摩擦过程中起到了捕捉磨屑、降低磨损的作用;在脂润滑条件下,表面织构起到了储存油脂提供二次润滑源的作用。与两种摩擦配副在两种测试条件下,复合处理试样的磨损失重量均远低于316不锈钢基体。

The austenitic stainless steels are seldom operated in tribological-related engineering conditions by the drawbacks of low surface hardness values,high coefficient of friction and poor wear resistance.In this paper,electrochemical tests were first conducted to obtain surface texture on 316 stainless steel.Then,the surface textured 316 stainless steel was treated by plasma nitriding.The tribological performance of 316 stainless steel substrates and duplex treated samples were investigated under dry and grease lubrication conditions against GCr15 steel and Si_3N_4 ceramic balls,respectively.The results show that the duplex treated layer consists ofε,γ′,CrN and with a surface micro-hardness of 1 048HV0.1.Under dry sliding,the surface texture that can capture wear debris and reduce friction is not completely worn out.Compared with the untreated samples,the duplex treated samples decrease mass losses.Under grease lubrication condition,the surface texture plays a role of storing grease and provided secondary lubrication effect.As compared with the untreated samples,the duplex treated samples presented far lower mass losses when they slid against two counterparts under dry and lubrication conditions.