稀土对H13钢固体渗硼层高温摩擦磨损性能的影响

Effect of Rare Earth Ce on High Temperature Friction and Wear Property of Pack Boronized H13 Steel

研究了稀土氯化物CeCl3添加量对H13钢固体渗硼层截面形貌、显微硬度、表面粗糙度以及相组成的影响,以及稀土催渗辅助渗硼H13钢的高温摩擦磨损性能。结果表明:添加2.5%和5%的稀土显著提高渗硼层厚度、显微硬度与致密性,但是表面粗糙度略有提高;10%稀土渗硼试样的渗层最厚,但是其显微硬度、致密性明显下降,表面粗糙度提高;稀土辅助渗硼层中除Fe2B相外还出现了(Fe,Cr)2B相;与不加稀土渗硼试样相比,5%稀土渗硼试样的渗层磨穿时间约增加一倍,磨损率降低21%;5%稀土渗硼试样磨损率比未渗硼H13钢降低了61%,并且也低于10%稀土渗硼试样。因此,加入5%稀土催渗辅助渗硼H13钢的高温耐磨损性能较优。

H13 steel was boronized by pack cementation process with CeCl3 containing powder mixture and the effect of the CeCl3 amount in the powder mixture on the microstructure, microhardness, surface roughness and phase composition of the formed boronizing layer on H13 steel was characterized,while the high temperature friction and wear properties of the boronized steel were also studied. The results show that the thickness, microhardness and densification of the boronizing layers were enhanced significantly by adding 2.5% and 5% CeCl3 in the powder mixture, while the surface roughness was increased slightly. With 10% CeCl3 in the powder mixture, the thickness of boronizing layer reached a maximum, but its microhardness and densification decreased obviously, while the surface roughness increased to Ra3.32. In addition to Fe2 B phase,（Fe, Cr）2B phase appears in the boronizing layer. Compared to the boronized steel prepared with the powder mixture free of CeCl3, the worn out time for the boronized steel prepared with the powder mixture containing 5% CeCl3 prolonged two times with a wear rate 21% lower. The boronized steel with the powder mixture containg 5% CeCl3 exhibited better wear resistance rather than the bare steel as well as the steel boronized with the powder mixture containg 10%CeCl3.. Thus, the boronized steel with the powder mixture containg 5% CeCl3 possesses relatively superior high temperature wear performance.