铁基粉末冶金材料表面滚压致密化效果及组织演变  

Microstructure evolution and densification behavior of iron-based powder metallurgy materials by surface rolling densification technology

作　　者：刘潇 李星毅 肖志瑜[2] LIU Xiao;LI Xingyi;XIAO Zhiyu(Faculty of Science,Henan Institute of Technology,Xinxiang 453003,China;National Engineering Research Centre of Near-net-shape Forming for Metallic Materials,South China University of Technology,Guangzhou 510641,China)

机构地区：[1]河南工学院理学部,新乡453003 [2]华南理工大学国家金属材料近净成型工程技术研究中心,广州510641

出　　处：《粉末冶金技术》2024年第5期456-463,共8页Powder Metallurgy Technology

基　　金：国家自然科学基金项目资助(52274343);河南省教育厅高等学校重点科研项目(22B430013)。

摘　　要：采用不同滚压压力对不同密度的Fe–2Cu–0.6C粉末冶金材料进行表面滚压加工,研究材料密度和滚压压力对致密化效果的影响。结果表明:滚压压力和材料密度是影响表面致密化效果的主要因素。随着滚压压力的增加,致密层厚度和表面硬度显著增加。材料密度对表面致密化效果的影响随着滚压压力的增加而减弱。当滚压压力较小时,致密层厚度和表面硬度随着材料密度的增加而增加;当滚压压力较大时,不同密度材料表面硬度和致密层厚度接近。滚压后表面层珠光体沿滚压方向弯曲,靠近表面的层片间距变小,部分区域层片发生扭折,出现波浪形,甚至部分渗碳体破碎断裂;铁素体细化,沿着滚压方向弯曲,在铁素体晶粒边界存在大量位错纠缠和位错墙。铁素体细化和珠光体变形为表面强化提供了有利的条件。Fe–2Cu–0.6C powder metallurgy materials with the different density were treated by surface rolling process under the different pressure.The effects of material density and rolling pressure on the densification behavior were investigated.The results show that,the rolling pressure and material density are the main parameters on the surface densification.With the increase of rolling pressure,the densification depth and surface hardness increase significantly.The effect of material density on the surface densification decreases with the increase of rolling pressure.The surface densification depth and surface hardness increase with the increase of material density under a low rolling pressure.However,the values of densification depth and surface hardness for the materials with the different density are approximately equal under a high rolling pressure.After rolling process,the pearlite in the surface layer bends along the rolling direction,the lamellar spacing near the surface becomes smaller,some of the laminates are twisted and wavy,and even some cementite breaks.Ferrite is stretched along the rolling direction,and the grains are refined.Massive dislocation tangle and dislocation walls exist at the grain boundary of ferrite.The refinement of ferrite and deformation of pearlite provide the favorable conditions for improving surface strengthen.

关 键 词：铁基粉末冶金材料 滚压加工 表面致密化 硬度 微观组织 

分 类 号：TF125[冶金工程—粉末冶金]