【摘要】 在实验室利用Gleeble-3500热模拟试验机对3种C、Cr成分体系的高耐候热轧H型钢进行连续冷却转变规律测试,研究冷却速度对试验钢组织与显微硬度的影响。结果表明:Cr含量较低的试验钢铁素体转变区域较大,而Cr含量较高的试验钢铁素体转变区域较小;C与Cr含量均较高时,贝氏体转变区域较小,C与Cr元素以一定比例协同作用可改变贝氏体转变动力学过程,增长转变孕育期,减慢长大速度;C含量较低时(质量分数低于0.02%时),在试验冷速范围内,未出现马氏体转变;低碳高铬成分体系试验钢对冷却敏感性较低,冷却速度在5℃/s以内时其性能均满足要求。更多还原

【Abstract】 Continuous cooling transformation of three kinds of C and Cr components of high weathering hot rolled H-beam steels were tested with Gleeble-3500 thermal simulation machine to study the influence of cooling rate on microstructure and micro-hardness. The results show that the area of ferrite transformation region of the tested steel with lower Cr content is larger, and that with higher Cr content is smaller. When the content of C and Cr is high, the area of bainite transformation region is smaller, the kinetic process of bainite transformation is changed by a certain proportion of C and Cr elements, which increases the transition period and slows down the growth rate. When the mass fraction of C is lower than 0.02%, within the region of test cooling rate, no martensitic transformation occurrs. The tested steel with low carbon and high chromium composition system has lower sensitivity to cooling, when the cooling rate is within 5 ℃/s, its performance meets the requirements.更多还原