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Fe基非晶合金具有优异的机械性能与耐蚀性。采用激光熔覆技术在304L不锈钢基体表面熔覆Fe-Cr-Ni-Co-B非晶粉末涂层,利用X射线衍射仪、光学显微镜、扫描电镜和电化学测试系统研究了涂层组织及耐蚀性能。研究结果表明,涂层组织涂层均匀、致密,无裂纹、气孔等缺陷。结合区为平面晶和柱状晶、熔覆层为“丝条状”树枝晶。熔覆层各区域由于成分和冷却速度的差异,致使树枝晶的大小和生长方向明显不同。涂层主要由Fe_(64)Ni_(36)和(FeCrNi)固溶体组成。熔覆层硬度分布较为均匀,涂层平均硬度约为480HV_(0.2),约是304L不锈钢基材的2.5倍。熔覆层的腐蚀电位高于304L基材,自腐蚀电流密度小于304L基材,具有较强的耐蚀性。
Fe-based amorphous alloy has excellent mechanical properties and corrosion resistance. The Fe-Cr-Ni-Co-B amorphous powder coating was deposited on the surface of 304L stainless steel by laser cladding. The microstructure and properties of the coating were studied by X-ray diffraction, optical microscope, scanning electron microscopy and electrochemical measurement. Erosion performance. The results show that the coating coating uniform, dense, no cracks, porosity and other defects. The binding zone is a plane crystal and a columnar crystal, the cladding layer is a “filamentous” dendrite. Due to the difference of composition and cooling rate, the size and growth direction of dendrites are obviously different in all regions of cladding layer. The coating mainly consists of Fe_ (64) Ni_ (36) and (FeCrNi) solid solution. The hardness distribution of the coating is more uniform, the average hardness of the coating is about 480HV_ (0.2), about 2.5 times higher than that of 304L stainless steel. The corrosion potential of the cladding layer is higher than 304L substrate, self-corrosion current density is less than 304L substrate, has a strong corrosion resistance.