WC含量及热处理对WC-Fe60熔覆层组织与性能的影响

Effects of WC content and heat treatment on microstructure and properties of WC-Fe60 clad layer

利用激光熔覆技术在20钢表面制备了WC质量分数分别为0、10%、20%的WC-Fe60复合熔覆层,并对20%WC-Fe60熔覆层分别在600、800℃进行热处理,研究WC含量及热处理对WC-Fe60熔覆层组织与性能的影响。结果表明,激光熔覆WC-Fe60复合熔覆层组织以树枝晶和等轴晶为主。随着WC含量的增加,熔覆层内枝晶明显减少,等轴晶数量增加,熔覆层的显微硬度、耐磨性能逐渐提升,但耐蚀性能有所降低。20%WC-Fe60熔覆层经热处理后,组织较未热处理时细小,显微硬度、耐磨性能及耐蚀性能都获得极大提升,其中经600℃热处理的熔覆层获得最佳的耐磨、耐蚀性能。

WC-Fe60 composite clad layers with WC(mass fraction of 0,10%and 20%)were prepared on the surface of 20 steel by laser cladding technology.The 20% WC-Fe60 clad layer was heat treated at 600℃ and 800℃,respectively.And the effects of WC content and heat treatment on microstructure and properties of the WC-Fe60 clad layer were studied.The results show that the microstructure of the laser cladding WC-Fe60 composite clad layer is mainly composed of dendrites and equiaxed grains.With the increase of WC content,the number of dendrites in the clad layer decreases significantly,while the number of equiaxed crystals increases.The microhardness and wear resistance of the clad layer gradually improve,but the corrosion resistance decreases.After heat treatment,the microstructure of the 20% WC-Fe60 clad layer is smaller than that without heat treatment,and the microhardness,wear resistance and corrosion resistance are greatly improved.Among them,the clad layer after heat treatment at 600℃ obtains the best wear and corrosion resistance.