| 铁素体和珠光体含量影响变形过程的原位研究 |
| |
| 作者姓名： | 段桂花 张平 李金许 宿彦京 乔利杰 |
| |
| 作者单位： | 北京科技大学腐蚀与防护中心环境断裂教育部重点实验室, 北京 100083 |
| |
| 基金项目： | 油气藏地质及开发工程”国家重点实验室(西南石油大学)资助项目;国家自然科学基金 |
| |
| 摘 要： | 在扫描电镜下原位观察了两种钢的拉伸变形过程，两种钢分别为以铁素体为主、含少量珠光体的纯净高强钢和以珠光体为主、含少量先共析铁素体的车轮钢.纯净钢拉伸时，不论试样厚度满足平面应变与否，均以铁素体的滑移变形为主，并最终导致韧性开裂，裂纹连续扩展，少量的珠光体对整个变形断裂过程几乎没有影响；断口呈现韧窝状.对于车轮钢，当试样厚度很薄不满足平面应变条件时，尽管先共析铁素体很少，拉伸时，仍以先共析铁素体的变形为先导过程，并在先共析铁素体与珠光体的界面处优先开裂，成为不连续微裂纹，断口呈现韧窝和准解理两种混合特征；当试样厚度满足平面应变条件时，则以珠光体中渗碳体片层的脆性开裂为主，断口呈现准解理特征.
|
| 关 键 词： | 高强钢 车轮钢 铁素体 珠光体 原位拉伸 塑性变形 |
| 收稿时间： | 2013-06-05 |
In situ studies on the effect of ferrite and pearlite contents on the deformation process |
| |
| Affiliation: | Key Laboratory of the Ministry of Education (MOE) for Environmental Fracture, Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083, China |
| |
| Abstract: | In situ tensile tests in a scanning electron microscope(SEM) were carried out using single-edge notched specimens for two types of steels:a pure high-strength steel(HSS) composed mainly of ferrite and a small amount of pearlite,and a wheel steel composed mainly of pearlite and a small amount of proeutectoid ferrite. Regardless of the specimen thickness meeting the plane strain condition or not,the process of deformation and cracking for the pure HSS starts at ferrite slip,then continuously propagates and finally results in ductile fracture; the small amount of pearlite has nearly no impact on the overall deformation process; and the fracture surface is composed of dimples. However,for the wheel steel,when the specimen thickness is thin,which means that it does not meet the plane strain condition,plastic deformation occurs firstly in proeutectoid ferrite,even though its amount is very small,and then microcracks initiate and grow along the interface of proeutectoid ferrite and the pearlite colony,and finally evolves into discontinuous microcracks. The fracture surface fractograph presents both dimple and quasi-cleavage characteristics. For a wheel steel specimen with the thickness meeting plane strain condition,plastic deformation and cracking mainly occurs in the pearlite colony,which results in cleavage fracture. |
| |
| Keywords: | |
| 本文献已被 万方数据 等数据库收录！ |
| 点击此处可从《》浏览原始摘要信息 |
|
点击此处可从《》下载全文 |
|
