激光淬火后Cr12MoV渗铬层的摩擦与磨损性能

摘要

The chromized and laser quenching treatment were conducted on the surface of Cr12 MoV cold worked die steel with salt bath method,the morphologies and phase components of the chromized layer were analyzed with SEM and XRD,respectively.The friction coefficient,wear properties and wear mechanism of the chromized layer were discussed.The results show that the thickness of the chromized layer is about 20μm,where Cr element exhibits gradient distribution to form the enrich-ment layer.The phases of chromized layer are composed of CrC3 ,CrC2 ,(Fe,Cr)2 C3 and Cr with dense Cr2O3 film on the surface of chromized layer after chromizing and laser quenching treatment;the combination mode of chromized layer-substrate is metallurgical combination and mechanical combina-tion,and metallurgical bonding ability is enhanced with chromizing and laser quenching.The friction and wear test is conducted using SiC ceramic ball as fiction pair,average friction coefficient of the chromized layer after laser quenching is 0.5795,decreases by 40.9% and 19.2% comparing with that of the original state and chromizing treatment respectively,reducing adhesion wear,the wear mode is abrasive wear,and the hardened layer and hard phase are main mechanisms of increasing wear per-formance.%利用激光对Cr12MoV冷作模具钢盐浴渗铬后进行表面激光淬火处理,通过SEM扫描电镜和X射线衍射仪分析渗铬层组织结构和物相组成,考察渗铬层摩擦因数与磨损性能,对磨损机理进行讨论.结果表明:渗铬层厚度约为20μm,Cr含量呈梯度分布,在渗铬层中形成富集层;渗铬层物相由CrC3,CrC2,(Fe,Cr)2 C3和Cr组成,经渗铬十激光淬火后渗铬层表面形成致密Cr2O3膜;渗铬层-基体为冶金十机械结合方式,经渗铬十激光淬火后冶金结合能力增强;用SiC陶瓷球为对磨件进行干摩擦磨损实验,经渗铬十激光淬火后渗铬层平均摩擦因数为0.5795,比原始状态和渗铬处理分别降低了40.9%和19.2%,减少了黏着磨损,磨损形式为磨料磨损,淬硬层和硬质相是提高磨损性能的主要机制.