高钒半高速钢合金熔覆层回火态显微组织和性能

Microstructure and Properties of Tempered High Vanadium Semi High Speed Steel Alloy Cladding Layer

为了满足对轧辊表面快速修复的需求,采用激光熔覆技术,将自主设计并制备的高钒半高速钢合金粉末熔覆到轧辊合金钢表面,考虑到锻钢轧辊和激光熔覆层组织之间的差异性,为了稳定组织,对熔覆层进行回火处理,回火温度为500℃并保温2 h.结果表明,熔覆层的相组成主要是马氏体;其表面主要是细小等轴晶,晶内马氏体呈针状平行分布,回火后分解为铁素体和碳化物;其横截面的平均硬度为663.4 HV,是基体硬度的1.8倍;熔覆层平均摩擦系数为0.708,磨损率为6.142×10^(-6)mm^(3)·N^(-1)·m^(-1),磨损性能较基体提高25倍,磨损形貌较好,与磨损量结果保持一致.

In order to meet the demand for rapid repair of roll surface,laser cladding technology was used to clad the self‑designed and prepared high vanadium semi high speed steel alloy powder on the surface of roll alloy steel.Considering the difference between the structures of forged steel roll and laser cladding layer,in order to stabilize the structure,the cladding layer was tempered with 500℃and 2 h.The results show that the phase composition of the cladding layer is mainly martensite.The surface of the cladding layer is mainly fine equiaxed crystal,and the intragranular martensite is distributed in parallel in needle shape,which is decomposed into ferrite and carbide after tempering.The average hardness of the cross‑section of the cladding layer is 663.4 HV,1.8 times that of the substrate.The average friction coefficient of the cladding layer is 0.708,the wear rate is 6.142×10^(-6)mm^(3)·N^(-1)·m^(-1),the wear performance is 25 times higher than that of the substrate,and the wear morphology is good,in accordance with the wear amount results.