摘要
FV520B马氏体不锈钢具有高强度、高韧性以及良好的耐腐蚀性等优点,被广泛应用于压缩机叶片、燃气轮机的压气机叶片、核反应堆的结构组件制造,该材料在含有腐蚀性介质的环境中长期服役,材料表面易因磨损和腐蚀复合作用导致性能退化,同时该类大型装备部件制造时间长、产品附加值高等特点,催生出该类合金部件巨大的再制造需求,通过激光熔覆工艺可以提升表面硬度、耐磨性、腐蚀性修复损伤并延长结构件寿命,对建设循环性经济和资源绿色可持续利用具有重要意义。为此,基于激光熔覆优化工艺,在FV520B马氏体不锈钢表面激光熔覆制备了FeCrNiSi合金覆层,并开展了覆层组织与力学性能试验研究与验证。研究结果表明,熔覆层的顶部以细小、致密的等轴晶为主,中部以具有二次枝晶伴生的柱状树枝晶为主,底部以胞状晶为主;熔覆层主要由铁素体(a-Fe)、Fe-Cr、Cr_(7)C_(3)等物相组成;熔覆层的平均显微硬度为625.4 HV 0.2,与基体材料相比提高了约11.1%;熔覆层的平均摩擦系数为0.3808,磨损量约为4.5 mg,较基体分别降低11.9%和38.4%。对接试样的平均抗拉强度886.7 MPa,较基体降低了19.3%,对接试样抗拉强度小于基体,但仍然具有较高的抗拉强度,符合再制造部件的力学性能标准。相关理论和工艺方法研究为FV520B马氏体不锈钢的再制造提供了参考和借鉴。
FV520B martensitic stainless steel has the advantages of high strength,high toughness and good corrosion resistance.It is widely used in compressor blades,compressor blades of gas turbines,and structural components of nuclear reactors.The material has been in service for a long time in an environment containing corrosive media.The surface of the material is prone to deterioration due to wear and corrosion complexation.At the same time,the long manufacturing time of this type of large equipment components and high product added value have created huge remanufacturing demand for this type of alloy components.Through laser cladding technology,surface hardness,wear resistance,corrosion repair damage and extend the life of structural parts,which is of great significance to the construction of a circular economy and green and sustainable use of resources.Based on the laser cladding optimization process,FeCrNiSi alloy cladding was prepared on the surface of FV520B martensite stainless steel,and experimental research and verification of the cladding structure and mechanical properties were carried out.The research results show that the top of the cladding layer was mainly composed of small and dense equiax crystals,the middle was mainly columnar dendrites with secondary dendrites,and the bottom was mainly cell-like crystals.The cladding layer was mainly composed of ferrite(a-Fe),Fe-Cr,Cr_(7)C_(3) and other phases;the average microhardness of the cladding layer was 625.4 HV 0.2,which was about 11.1%higher than that of the matrix material;the average friction coefficient of the cladding layer was 0.3808,and the wear amount was about 4.5 mg,which was 11.9%and 38.4%lower than the matrix,respectively.The average tensile strength of the docking sample was 886.7 MPa,which was 19.3%lower than the matrix.The tensile strength of the docking sample was smaller than that of the matrix,but it still had a higher tensile strength,which meets the mechanical properties standards of remanufactured parts.Relevant theories and process methods research provide reference and reference for the remanufacturing of FV520B martensitic stainless steel.
作者
范天昊
周立涛
郝云波
FAN Tianhao;ZHOU Litao;HAO Yunbo(Shanghai GZclad Laser Technologies Co.,Ltd.,Shanghai 201620,China;Shanghai Aerospace Equipment Manufacture Co.,Ltd.,Shanghai 201601,China)
出处
《表面工程与再制造》
2025年第2期46-53,共8页
Surface Engineering & Remanufacturing
