SCM435冷镦钢的球化退火工艺  

Spheroidizing annealing of SCM435 cold heading steel

作　　者：南鹏飞[1,2] 王福明[1,2] 刘振民 李永亮[1,2] 张婧[1,2] 

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]北京科技大学钢铁冶金新技术国家重点实验室,北京100083 [3]邢台钢铁有限责任公司,河北邢台054027

出　　处：《金属热处理》2016年第11期92-97,共6页Heat Treatment of Metals

摘　　要：在两相区＋亚温区球化退火工艺的基础上,对SCM435冷镦钢进行球化退火试验。根据SCM435钢的化学成分,利用Thermo-Calc软件进行热力学计算得到对应的A1、A3温度分别为728℃、780℃。在综合分析影响球化效果因素的基础上,重点考虑亚温区保温温度、保温时间对球化效果的影响,依次进行试验方案的设定。由试验结果可知：当在两相区温度为758℃,保温30 min时,亚温区保温温度688-698℃,保温4-5 h时,会得到良好的球化效果和较低的硬度;缩短两相区保温时间为25 min时,亚温段在698℃下保温4 h,就可以得到很好的球化组织和较低的硬度。Based on intercritical subcritical spheroidizing annealing,some experiments were carried out on SCM435 cold heading steel.The temperatures of critical points A1 and A3 were calculated to be 728 ℃ and 780 ℃,respectively,by using Thermo-Calc software based on chemical composition of the SCM435 steel. On basis of comprehensive analysis on the factors which influence spheroidizing process,with consideration of the holding temperature and time in the subcritical period,the values and scheme of the experiment were designed. The experimental results show that under the condition of the holding temperature at 758 ℃ for 30 min in the intercritical period,a good spheroidizing effect can be obtained when the samples are held between 688 ℃ or 698 ℃ for 4 - 5 h; while decreasing the time to 25 min in the intercritical period,preferable spheroidized microstructure and lower hardness can be obtained when annealed at 698 ℃ for 4 h in the subcritical area.

关 键 词：SCM435钢 球化退火 两相区 碳化物 冷镦钢 

分 类 号：TG156.21[金属学及工艺—热处理]