工艺参数对激光熔覆高铬不锈钢涂层组织与性能的影响

Effect of Microstructure Properties of High Chromium Stainless Steel Powder Through Process Parameters by laser cladding

采用激光熔覆技术在42CrMo钢基体上制备了高铬不锈钢涂层,测试不同工艺参数对熔覆层的组织形貌、金属成分、相组成及硬度的影响。研究结果表明,熔覆层组织较为致密,与基体结合较好,内部呈现出向上生长的枝晶形式。由于只能依靠母材本身的热传导散热,因此靠近母材一侧的冷却速度较小,树枝晶生长较慢且粗大,靠近表面,熔覆组织从树枝晶渐渐向上转变为细小的等轴晶。通过XRD测试结果发现,其相结构为Fe-Cr相,主要为马氏体组织,含有少量的残余奥氏体。熔覆层显微硬度维持在630-680HV左右。

A high-chromium stainless steel coating was prepared on the 42CrMo steel matrix by laser cladding technology,and the influence of different process parameters on the micromorphology,metal composition,phase composition and hardness of the cladding layer was tested.The results show that the cladding layer is more densely organized,better combined with the matrix,and the interior shows an upward growth dendrite form.Since it can only rely on the heat conduction of the base metal itself to dissipate heat,the cooling rate near the side of the base material is small,the branch crystals grow slower and coarser,close to the surface,and the cladding tissue gradually changes from the branch crystal upwards to a small isoaxial crystal.Through the XRD test results,it was found that the phase structure was Fe-Cr phase,mainly martensitic tissue,containing a small amount of residual austenite.The microhardness of the cladding layer is maintained at about 630-680HV.