Hu Wenfeng, Zhu Hongmei, Hu Jipeng, Li Baichun, Qiu Changjun
Provincial Key Laboratory of Advanced Laser Manufacturing Technology, University of South China, Hengyang 421001, China.
Materials (Basel). 2020 Feb 12;13(4):826. doi: 10.3390/ma13040826.
Martensitic stainless steel (MSS) coatings with different vanadium (V) contents (0-1.0 wt%) by microalloying have been successfully fabricated utilizing a unique laser cladding technique. The microstructure and properties of the resulting MSS coatings, with and without element V addition, have been carefully investigated by various advanced techniques, including XRD, SEM, TEM, microhardness tester, universal material testing machine, and electrochemical workstation. It was found that the V-free coating was mainly composed of martensite (M) and ferrite (F), trace C and N, while the V-bearing coatings consisted of M, F, C, and VN nano-precipitates, and their number density increased with the increase of V content. The V microalloying can produce a significant impact on the mechanical properties of the resulting MSS laser-cladded specimens. As the V content increased, the elongation of the specimen increased, while the tensile strength and microhardness increased firstly and then decreased. Specifically, the striking comprehensive performance can be optimized by microalloying 0.5 wt% V in the MSS coating, with microhardness, tensile strength, yield strength, and elongation of 500.1 HV, 1756 MPa, 1375 MPa, and 11.9%, respectively. However, the corrosion resistance of the specimens decreased successively with increasing V content. The microstructure mechanisms accounting for the property changes have been discussed in detail.
采用独特的激光熔覆技术成功制备了微合金化钒（V）含量不同（0-1.0 wt%）的马氏体不锈钢（MSS）涂层。利用包括XRD、SEM、TEM、显微硬度计、万能材料试验机和电化学工作站在内的各种先进技术，对添加和未添加元素V的所得MSS涂层的微观结构和性能进行了仔细研究。结果发现，无V涂层主要由马氏体（M）和铁素体（F）、微量C和N组成，而含V涂层由M、F、C和VN纳米析出相组成，且其数量密度随V含量的增加而增加。V微合金化对所得MSS激光熔覆试样的力学性能有显著影响。随着V含量的增加，试样的伸长率增加，而抗拉强度和显微硬度先增加后降低。具体而言，通过在MSS涂层中微合金化0.5 wt%的V可优化显著的综合性能，其显微硬度、抗拉强度、屈服强度和伸长率分别为500.1 HV、1756 MPa、1375 MPa和11.9%。然而，试样的耐腐蚀性随V含量的增加而依次降低。详细讨论了导致性能变化的微观结构机制。
