CrMoV 合金堆焊层组织结构及抗冲蚀磨损性能研究

摘要

采用手工电弧焊工艺在20钢基体表面制备 CrMoV 合金堆焊层进行相组成、显微组织、耐冲蚀磨损性能及冲蚀磨损机理研究。结果表明，堆焊层数增加母材稀释率减小，堆焊层显微组织主要为马氏体、残余奥氏体及合金碳化物。第二、三堆焊层显微硬度最高，堆焊层平均显微硬度达780 HV，为基体硬度的4倍多。在所有冲蚀角度范围内， CrMoV 合金堆焊层耐泥沙冲蚀磨损性能优于20钢；冲蚀角度小于30°时冲蚀磨损机制以微切削为主，大于30°时以疲劳损伤及局部塑性变形为主；砂粒粒径增加，堆焊层及20钢的冲蚀磨损率均有所增加，但不与粒径的增加值成正比。%CrMoV surfacing coatings were deposited on 20 steel substrates using shielded metal arc welding.The microstructure,erosion wear resistance performance and erosion wear mechanism of CrMoV coatings were studied.It was shown that with increase in surfacing layers,the dilution rate of parent material decreases;the microstructure of surfacing layers consists of martensite,residual austensite and alloy carbides;the highest hardness of surfacing alloy exists at the second and third layers;the average micro-hardness of surfacing layers is 780HV,it is more than 4 times of the matrix one.The erosion wear tests showed that CrMoV coating has a better erosion resistance capacity than 20 steel substrate does;the erosion wear mechanism of CrMoV coating is mainly micro-cutting at small impact angles,and mainly fatigue damage and local plastic deformation at large impact angles;the erosion wear rate of surface coating increases with increase in particle size,but it is not directly proportional to the particle size.