含硼低碳贝氏体钢冲击值不稳定原因分析  

Reasons of Unstable Impact Energy for a Boron-containing Low Carbon Bainitic Steel

作　　者：王吉满[1,2] 段琳娜[1,2] 孙新军[2] 刘清友[2] 朱心昆[1] 

机构地区：[1]昆明理工大学材料与冶金工程学院,云南昆明650093 [2]钢铁研究总院结构材料研究所,北京100081

出　　处：《物理测试》2009年第1期37-41,共5页Physics Examination and Testing

摘　　要：对一种未回火的低碳贝氏体钢的冲击韧性进行了研究,分析了微观组织、断口形貌、夹杂物与冲击韧性的关系。结果表明,在纤维区和剪切唇所占的比例大,韧窝大而均匀的情况下冲击韧性较高。扫描电镜发现,具有较低冲击功试样的缺口根部启裂区普遍存在较大尺寸的夹杂物,绝大部分为Al、Ca的氧化物及硫化物。同时,随着夹杂物数量的增加,冲击功明显降低。The impact toughness of an untempered low-carbon bainitic steel was studied, and the relationship between the impact toughness and fracture morphology, inclusions, and microstructure was analyzed. The results show that higher impact energy can be obtained when the fracture surface has larger fraction of shear lips and fiber region with bigger and more homogeneous dimples. It is observed by SEM that there exist large size inclusions, which are mainly composed of oxides and sulfides containing Al and Ca in the crack initiation region for the samples with lower impact energy. At the same time, with the increasing of the number of inclusions, the impact energy decreases significantly.

关 键 词：冲击韧性 断口形貌 夹杂物 微观组织 

分 类 号：TG142.15[一般工业技术—材料科学与工程]