20CrMnTi钢凸轮轴表面磨损失效分析  

Failure analysis on surface wear of 20CrMnTi steel camshaft

作　　者：焦丽[1] 葛保红 张燕明[1] 徐向阳[1] 孙思东[1] 

机构地区：[1]河北华北柴油机有限责任公司,河北石家庄050081

出　　处：《金属热处理》2015年第9期221-224,共4页Heat Treatment of Metals

摘　　要：采用宏观检验、润滑油油品性能测试、化学成分分析、力学性能测试、金相检验和显微硬度测试等手段对20CrMnTi钢单体泵凸轮轴表面磨损失效的原因进行了分析。结果表明,造成该凸轮轴表面磨损的主要原因是,凸轮轴表层组织中硬而脆的块状及网状碳化物降低了轴颈表面的接触疲劳强度,加大了其沿晶剥落的可能性。其次,磨削二次淬火马氏体的出现,在迭加了上述组织缺陷的基础上,产生了裂纹和脆性剥落。剥落的颗粒成为磨粒参与磨削,导致凸轮轴早期磨损失效。Wear cause of the 20CrMnTi steel monoblock pump camshaft was analyzed by means of macroscopic examination, lubricating oil property test, chemical compositions analysis, mechanical property test, metallographic examination and microhardness test. The results show that the main reason for the surface wear of the camshaft is attributed to the hard and brittle blocky and network carbide in the surface layer which reduces the contact fatigue strength of the camshaft journals and increases the probability of the spalling along grain boundary. Secondly, the secondary quenched martensite after grinding leads to the crack and brittle spalling on the basis of the structure defects. The spalled particles are play intensive abrasion role and lead to the early wear failure of the monoblock pump camshaft.

关 键 词：凸轮轴 磨损失效 块状及网状碳化物 磨削淬火 

分 类 号：TG115[金属学及工艺—物理冶金]