中国激光, 2017, 44 (3): 0302011, 网络出版: 2017-03-08
激光熔覆高硬度铁基涂层枝晶间残余奥氏体相特征
Characteristics of Interdendritic Residual Austenite in Laser Cladding of High Hardness Iron-Based Coating
激光技术 激光熔覆 裂纹 晶界韧化 残余奥氏体 laser technique laser cladding crack grain boundary toughening retained austenite
摘要
激光熔覆制备了一种高硬度铁基涂层,涂层平均硬度约为775 HV,未发现裂纹缺陷。对涂层显微组织进行表征,结果显示,涂层为均匀、细小的树枝晶组织形态,初生枝晶内为马氏体相,枝晶间为残余奥氏体相,残余奥氏体基体上弥散分布着颗粒状碳化物。枝晶间有Mo、Cr、W、Nb等元素偏聚,但涂层中的C元素分布均匀。枝晶间残余奥氏体存在大量层错,并在层错密集区有马氏体相析出。
Abstract
The high hardness iron-based coating is prepared by using laser cladding, in which the average hardness is about 775 HV and no cracks are found. The results characterizing the coating microstructure show that the coating consists of uniform and tiny cellular dendrites, martensite distributes in primary dendrites, residual austenite is precipitated in the interdendritic region, and carbides distribute dispersively in the residual austenite substrate. The segregation of molybdenum, chromium, wolfram and niobium exists in the interdendritic region, but carbon distributes uniformly in the cladding layer. Many stacking faults are observed in the residual interdendritic austenite, and matensite separats out in the stacking faults intensive area.
李林起, 姚成武, 黄坚, 冯凯, 李铸国. 激光熔覆高硬度铁基涂层枝晶间残余奥氏体相特征[J]. 中国激光, 2017, 44(3): 0302011. Li Linqi, Yao Chengwu, Huang Jian, Feng Kai, Li Zhuguo. Characteristics of Interdendritic Residual Austenite in Laser Cladding of High Hardness Iron-Based Coating[J]. Chinese Journal of Lasers, 2017, 44(3): 0302011.