稀土渗碳对GCr15钢激光熔凝层摩擦行为的作用

为了提高在航空航天和民用等领域中广泛使用的GCr15钢的表面强度及耐磨性能,采用激光熔凝方法对GCr15钢表面稀土渗碳层进行改性处理,研究了稀土渗碳对激光熔凝改性层摩擦系数及磨损量的影响.结果表明:稀土渗碳使GCr15钢表面激光熔凝改性层的摩擦系数有所下降且在整个摩擦过程中波动较小,磨损失重为未经改性处理的基体材料失重的14%(质量分数);随着摩擦时滑动距离的增加及载荷的加大,稀土渗碳激光熔凝改性处理降低磨损失重的作用也显著增大;稀土渗碳层的磨损形式为犁沟磨损,而稀土渗碳激光熔凝处理的改性层则属于局部擦伤型;稀土渗碳在钢表面激光熔凝处理中的作用主要表现为细化晶粒、微合金化、净化和改善组织致密性.

Effect of rare-earths carburizing on friction behavior of GCr15 steel laser melting layer

In order to improve the surface strength and wear-resistance property of GCr15 steel applied widely in the fields of aerospace and civil use, the laser melting treatments (LRT) on RE(rare-earths) carburizing layer of GCr15 steel were carried out and the effects of the complex treatments of RE carburizing and LRT on friction coefficient and wear extent were investigated. The experimental results showed that the friction coefficient of RE carburizing laser melting layer were steadily decreased, and the wear weight-loss was 14%(mass fraction)compared to unmodified GCr15 steel. The wear weight loss of GCr15 steel is apparently deduced by RE carburizing laser melting modification with the increase of friction slide distance and loading weight. The type of abrasion in the RE carburizing layer was plow-groove, while scratch abrasion was the dominant one in the RE carburizing-LRT layers. The functions of RE carburizing on the LRT include the refining of the grain sizes, micro-alloying, purifying and complex treatments improve the densification of the microstructure.