CAJ | 학술논문

为了探寻20Mn2车桥管在加工过程中产生推方裂缺陷的原因,借助光学显微镜、扫描电子显微镜、氧氮分析仪等测试手段,研究了推方裂的影响因素和形成机理.结果表明裂纹均出现在冷推方后的方管角部,缺陷试样氮的质量分数达70×10?6以上,在裂纹试样低倍组织中发现上贝氏体组织,裂纹处有钢中夹杂物存在.通过降低钢液增氮、提高淬火冷速以及减少钢中夹杂物,可以有效减少推方裂的产生.
위료탐심20Mn2차교관재가공과정중산생추방렬결함적원인,차조광학현미경、소묘전자현미경、양담분석의등측시수단,연구료추방렬적영향인소화형성궤리.결과표명렬문균출현재랭추방후적방관각부,결함시양담적질량분수체70×10?6이상,재렬문시양저배조직중발현상패씨체조직,렬문처유강중협잡물존재.통과강저강액증담、제고쉬화랭속이급감소강중협잡물,가이유효감소추방렬적산생.
@@@@To find out the origin of 20Mn2 axle crack defects during rolling round pipes to square pipes, the formation mechanism and influencing factors of the crack defects were studied by optical microscopy, scanning electron microscopy, and O/N automatic analyzer. It is shown that cracks all appear at the corners of square pipes, where the mass fraction of nitrogen is more than 70×10?6. Upper bainite is found in the microstructure of cracked specimens and there are non-metal inclusions at the cracks. The crack defects can be effectively decreased through reducing the nitrogen content of liquid steel, enhancing the cooling speed of quenching, reducing inclusions in the steel.