30CrMnSiA和30CrMnSiNi2A高强钢激光熔覆修复后的组织特征与力学性能  

Microstructures and Mechanical Properties of 30CrMnSiA and 30CrMnSiNi2A High-Strength Steels After Laser-Cladding Repair

作　　者：庞小通 龚群甫[2] 王志杰 李铸国[1] 姚成武[1] Xiaotong Pang;Qunfu Gong;Zhijie Wang;Zhuguo Li;Chengwu Yao(Shanghai Key Laboratory of Materials Laser Processing and Modification,School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;PLA 4724 Plant,Shanghai 200436,China)

机构地区：[1]上海交通大学材料科学与工程学院,上海市激光制造与材料改性重点实验室,上海200240 [2]中国人民解放军第四七二四工厂,上海200436

出　　处：《中国激光》2020年第11期44-54,共11页Chinese Journal of Lasers

基　　金：上海市军民融合专项(JMRH-2018-1033)

摘　　要：针对30CrMnSiA和30CrMnSiNi2A高强钢的修复问题,采用30CrMnSiA合金粉末在两种基体上进行多层多道激光熔覆,研究了熔覆层、基体、热影响区的微观组织和力学性能。对于30CrMnSiA基体,其熔覆层组织主要为索氏体;随着层数增加,熔覆层中的索氏体减少,马氏体增多,盖面层主要为马氏体组织;热影响区组织主要为马氏体和少量块状铁素体,其中块状铁素体为原基体中铁素体的未熔相。对于30CrMnSiNi2A基体,其熔覆层组织主要为索氏体,随着层数增加,马氏体含量逐渐增加,但仍以索氏体为主;热影响区组织主要为索氏体和粗晶马氏体。在力学性能上,30CrMnSiA基体上熔覆层的硬度大于30CrMnSiNi2A基体上熔覆层的硬度,热影响区软化现象不明显,而30CrMnSiNi2A热影响区软化现象明显;30CrMnSiA基体上熔覆层试样的抗拉强度为基体的90%以上,且其冲击韧性、延伸率均优于基体;30CrMnSiNi2A基体上熔覆层试样的冲击韧性优于基体,但其抗拉强度、延伸率则大大低于基体。实验结果表明:30CrMnSiA合金粉末适合用于30CrMnSiA钢的激光熔覆修复,而对于30CrMnSiNi2A钢,则需要进一步减少热输入,以减小热影响区的宽度,减少粗晶马氏体的生成以及多层熔覆过程中马氏体的分解。Substrates of 30CrMnSiA and 30CrMnSiNi2A high-strength steels were repaired by a multilayer laser-cladding process using 30CrMnSiA alloy powders.The microstructures and mechanical properties of the cladding layers,substrates,and heat-affected zones were analyzed.The cladding layers on both the 30CrMnSiA and 30CrMnSiNi2A substrates exhibited a mainly sorbite microstructure.As the number of cladding layers increased,the sorbite and martensite contents on the 30CrMnSiA substrate decreased and increased,respectively,and a mainly martensite microstructure was observed in the cap layer.In the heat-affected zone(HAZ)of the 30CrMnSiA substrate,the microstructure was mainly martensite and small amount of blocky ferrite,and the ferrite was identified as the unmelted phase of the original ferrite matrix.In contrast,as the number of cladding layers on the 30CrMnSiNi2A substrate increased,the martensite content gradually increased,but sorbite remained the dominant microstructure.In the heat-affected zone of the 30CrMnSiNi2A substrate,the microstructure was mainly sorbite and coarse-grained martensite.The mechanical properties of the high-strength steels were also analyzed.The microhardness values were larger in the cladding layer on the 30CrMnSiA substrate than those on the 30CrMnSiNi2A substrate,and the softening phenomenon of the heat-affected zone was more obvious on the 30CrMnSiNi2A substrate than that on the 30CrMnSiA substrate.The tensile strength of the cladded sample on 30CrMnSiA substrate was over 90%of the substrate,and the impact toughness and elongation of the cladded samples were better than those of the 30CrMnSiA substrate.On the 30CrMnSiNi2A substrate,the cladding improved the impact toughness but significantly reduced the tensile strength and elongation.The results confirmed the suitability of 30CrMnSiA powders for laser-cladding repair of 30CrMnSiA steel.However,when the powders were used to repair 30CrMnSiNi2A steel,the heat input of the multilayer laser-cladding must be lowered to reduce the width of heat-a

关 键 词：激光技术 激光熔覆 多层涂层 高强钢修复 马氏体 索氏体 

分 类 号：V261.8[航空宇航科学与技术—航空宇航制造工程]