摘要
采用固体渗碳法对95W-3.4Ni-1.6Fe高比重合金进行了渗碳处理,并在球棒试验机上研究了渗碳处理对钨合金接触疲劳性能的影响。利用SEM、EDS、XRD、表面形貌仪等手段对渗碳钨合金的显微组织和疲劳损伤形貌等进行了表征。结果表明,渗碳处理后钨合金表面由较薄的多孔碳化钨层和被碳化钨包裹的改性钨颗粒层组成。渗碳处理不仅降低了钨合金的接触疲劳性能而且加剧了对偶件钢球的磨损。钨合金的损坏机制为剥落和层状分离,次表层主裂纹易在最大剪切应力处萌生并沿着钨–钨界面扩展。渗碳钨合金的损坏是由碳化钨颗粒的剥落造成,同时剥落后的碳化钨颗粒在接触界面间充当第三体,加剧了渗碳钨合金的表面磨损。
95W?3.4Ni?1.6Fe heavy alloy was carburized by pack carburization. Microstructure and hardness of the carburized alloywere investigated by SEM, EDS XRD. Effect of carburization on the rolling contact fatigue (RCF) property of the alloy was studied.The results showed that the carburized layer was composed of the outer, porous WC layer and the modified subsurface layer witheach W grain surrounded by a WC shell. Carburization not only decreased the RCF performance of the alloy but also aggravated thewear of the counter balls. The untreated alloy was damaged by two modes of spalling and delamination under RCF condition. Thesubsurface main crack of the untreated alloy initiated where the maximum shear stress existed and preferentially propagated alongthe W?W interfaces. Spalling was the main failure mode of the carburized alloys, and the crumbling WC particles intensified theabrasion of the carburized surface.
作者
王光宏
屈盛官
和锐亮
胡可
李小强
Guang-hong WANG;Sheng-guan QU;Rui-liang HE;Ke HU;Xiao-qiang LI(National Engineering Research Center of Near-net-shape Forming Technology for Metallic Materials,South China University of Technology, Guangzhou 510640, China)
基金
Project(9140A18070114JW16001)supported by the Advanced Research Fund of Department of Defense,China
Project(2014M562171)supported by the China Postdoctoral Science Foundation
关键词
钨合金
接触疲劳
渗碳
剥落
tungsten alloy
rolling contact fatigue
carburization
spalling
