硼铸铁缸套激光表面熔凝组织和性能的研究

Investigation on Microstructure and Performance of Boron Cast Iron Cylinder Liner with Laser Remelting

为了提高硼铸铁缸套的耐磨性能 ,对硼铸铁气缸套进行激光熔凝处理。利用扫描电子显微镜观察了激光熔凝处理后的显微组织。利用显微硬度计检测了激光熔凝组织的显微硬度 ,同时进行了以GCr15钢标准环为配副的环块磨损试验。研究结果表明 ,硼铸铁经激光熔凝处理后得到了共晶莱氏体 +马氏体组织 ,而且激光熔覆层厚度可控 ,组织和性能稳定 ,熔凝强化表层显微硬度达到 80 0～ 12 0 0HV0 2。磨损试验结果显示 ,激光熔凝处理后 ,磨损截面积比未处理的试样减小了 44 4% 。

In order to improve the wear performance of boron cast iron cylinder liner,the laser remelting process has been used.The microstructure of boron cast iron samples was observed with SEM,and the rule of the microhardness's change was analyzed.The wearability of the boron cast iron sample has been measured in tribological test with the piston ring sample of GCr15 steel.The results indicated that the microstructure of laser remelting zone consisted of ledeburite and martensite,its depth can be controled and its microhardness reaches 800～1200HV0.2.Microstructure and performance are stable.The result of tribological test indicated that its wear section area has reduced 44.4% than that of samples without laser remelting which is an effective method to improve the wear performance of boron cast iron cylinder liner.