Laser Cladding Fe-Cr-Si-P Amorphous Coatings on 304L Stainless

摘要:

：采用激光熔覆技术在304L不锈钢基体表面制备了Fe-Cr-Si-P非晶复合涂层。利用光学显微镜（OM）、X射线衍射仪（XRD）、扫描电子显微镜（SEM）、电化学测试系统和摩擦磨损试验机等分析了涂层的组织结构、相组成、耐蚀及耐磨等性能。研究结果表明，激光熔覆层组织主要由表层“梅花”形树枝晶区，中心非晶区和树枝晶结合区组成，熔覆层与基体呈现良好的冶金结合。熔覆层中除了非晶相外，还有少量Fe3P和Fe2Si等金属间化合物相。涂层的硬度HV0.2约为8000 MPa，是基体硬度的4倍；腐蚀电位Ecorr和自腐蚀电流密度icorr分别为–449.3 mV和–4.34 μA/cm2；在100 N载荷下摩擦系数仅为0.076，具有较好的综合性能。

Abstract:

The Fe-Cr-Si-P amorphous composite coatings were fabricated on 304L stainless steel by laser cladding. The microstructure, the phase composition, the microhardness, the corrosion and wear resistance of the coatings were analyzed by optical microscope (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), a microhardness tester, an electrochemical measurement system and a friction and wear tester. The results show that the cladding coating mainly contains plum-like dendrite crystals in the surface, an amorphous in center region and a dendrite crystals in binding zone. A good metallurgical bond is obtained between the coating and substrate. Except amorphous phase, the cladding coating contains a small amount of Fe3P and Fe2Si phases. The coating has a good performance. The microhardness HV0.2 is about 8000 MPa; the Ecorr and icorr are –449.3 mV and 4.34 μA/cm2, respectively; the frictions coefficient at the load of 100 N is 0.076.