【作者】 许云华； 朱金华； 王发展； 武红； 熊建龙；

【Author】 Xu Yuhua Zhu Jinhua (Xi’an Jiaotong University,Xi’an,Shaanxi 710049) Wang Fazhan Wu Hong Xiong Jianlong (Xi’an University of Arch.& Technology,Xi’an,Shaanxi 710055)

【机构】 西安交通大学材料强度国家重点实验室； 西安建筑科技大学耐磨材料研究所；

【摘要】 对不同冲击角度下45钢亚表层组织结构进行了考察与研究．冲击载荷下亚表层结构可分为强烈塑性变形区和一般塑性变形区,随着冲击角度的变小,亚表层总厚度增加,强烈塑变区的绝对厚度也大幅增加．当冲击角度为90°时,亚表层中仅存在强烈塑性变形区,没有明显的一般塑性变形区．非90°冲击角度下,亚表层组织的塑性变形具有明显的方向性,并且随着冲击角度的减小,晶粒变形取向趋向于冲击方向,其程度也越来越严重．冲击次数达到一定数值后,强烈塑变区中出现超细化层．珠光体中碳化物的细化主要是由于剪切滑移带的扩展受阻而导致的剪切分离．更多还原

【Abstract】 Subsurface structure characteristics of medium-carbon annealed steel at different impact angles have been estimated and studied.In general,two subsurface zones such as intensive plastic deformed zone and mild plastic deformed zone are observed in medium-carbon annealed steel subjected to repetitive impact wear.Disintegration of crystallites appear obviously in the intensive plastic deformed zone.Both the overall thickness of subsurface and the absolute thickness of fragmented zone would increase as the impact angle de- creases;Only the intensive plastic deformed zone is markedly observable,but the mild plastic deformed zone is barely detectable under 90° impact.The plastic deformed directions of crystallites tend toward the direction of impact and the degree of deformation becomes more serious with impact angle decreasing.Super-fragment- ed layer appears in intensive plastic deformed zones as impact times reach a certain value.The carbides are fractured and fragmented in form of shear fracture mainly because the carbides act as a barrier to the propaga- tion of the shear band.更多还原