Cr12MoV冷作模具钢渗硼层表面与界面分析

采用热浸渗法对Cr12MoV冷作模具钢进行渗硼处理，通过扫描电镜、能量色谱和X射线衍射分析渗硼层表面-界面形貌、化学元素分布和物相组成，对结合界面进行线扫描和面扫描分析，讨论了热浸法渗硼机理，并对残余应力和残余奥氏体进行测试。测试结果表明：渗硼层表面存在着细小气孔，与不溶于硼化物的原子扩散相关；渗硼层表面形成的高硬FeB按照(002)方向择优生长；渗硼层结合界面化学元素发生相互扩散，元素分布均匀；渗硼处理后表面残余应力由拉应力变为压应力，同时残余奥氏体转变为马氏体，改善了冷作模具的摩擦与磨损性能。

Analysis of Surface-interface of Boronized Layer on Cr12MoV Cold-worked Die Steel

The surface of Cr12MoV cold-worked die steel is boronized by the method of hot-dipping, and the surface and interface morphologies and the chemical and phase compositions are analyzed by SEM, EDS and XRD, respectively. The residual stress and retained austenite on the surface are analyzed, and the hot-dipped boronizing mechanism is discussed. The results show that the tiny pores exist on the surface of boronized layer, and are related to the elements which are not solubled in boride. FeB is formed in the diffusion layer that has a preferred orientation in crystal plane (002), and the chemical reactions and mutual diffusion of elements occur in the layer. The surface residual stress is changed from tensile stress to compressive stress, and the retained austenite is transformed into martensite after boronizing, which improves the friction and wear properties of cold-worked die steel.