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Fe64Ni36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480HV0.2, 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 bulk metallic glasses are very attractive because of their excellent mechanical properties and corrosion resistance. Fe-Cr-Ni-Co-B amorphous alloy powders were cladded on a 304L stainless substrate by laser cladding technique. The microstructure and corrosion resistance properties were analyzed by XRD, OM, SEM and electrochemical measurement. The results show that the microstructure of the cladding coating is uniform and compact and there are no obvious cracks and stomata. In regions near the interface with the substrate, the microstructure exhibits planar crystalline and columnar crystalline solidification morphology. It is mainly strips-like dendritic crystalline in the coating, which exhibits various size and growth directions because of different composition and cooling rate in different region. The coatings mainly consist of Fe64Ni36 and (FeCrNi) solid solution phases. The coating microhardness shows a uniform distribution. The average hardness of the coating was 480HV0.2, which was about 2.5 times of the 304L stainless substrate. The coatings show excellent corrosion resistance with a higher Ecorr and lower icorr than the 304L stainless substrate.