45钢激光渗硼后的显微组织及相结构分析

用扫描电子显微镜和Ｘ射线衍射仪对４５钢激光渗硼层的显微组织和相结构进行了分析，结果表明４５钢激光渗硼后，渗硼区的显微组织：表层为胞晶组织，次表层为树枝晶组织，再往里为共晶组织。渗硼区组织的相组成为α－Ｆｅ、ＦｅＢ、Ｆｅ２Ｂ、Ｆｅ３（Ｃ·Ｂ）及Ｂ４Ｃ相等。不同显微组织中各相所占比例不同，因而导致各区显微硬度不同。

Microstructure and Phase Structure of Laser Boronized Steel 45

The microstructure and structural states of the steel 45 laserboriding layer and the boriding effect under different parameters were investigated and analyzed respectively by means of scanning electron microscope(SEM) and X-Ray diffrattion (XRD). The analytical results show that the laser boronized layer, from the surface to the inside, is composed of three parts: peritectic structure, dendritic structure, and eutectic structure, and four kinds of phases, FeB, Fe 2B, Fe 3(C.B) and B 4C, is found in the laser boronized layer. The microhardness in different regions of the laser boronized layer varies with the volume fraction of the above phases in these regions.