高Al+冷轧TRIP钢显微组织的观察和控制.pdfVIP

高 Al 冷轧 TRIP 钢显微组织的观察与控制 1，2 1 2 1 徐 锟 沈新群 刘国权 （1. 宝钢集团常州轧辊制造公司，常州 213019 ； 2. 北京科技大学材料科学与工程学院，北京 100083 ） 摘 要 本文研究了Al 合金化获得 TRIP 效应的冷轧低碳汽车钢板的显微组织及其控制方法。对实验钢两相区等 温淬火和贝氏体区退火热处理后得到的试样，利用 Lepera 试剂进行着色腐蚀，通过对彩色金相组织的观察研究奥 氏体在两相区和贝氏体区两个温度区间等温时的相转变特征。对两相区等温淬火和贝氏体区退火后试样进行X 衍 射分析，通过比较(211) 与(220) (331) 衍射峰的积分强度确定残余奥氏体的相对量，用(220) 峰的晶格常数来计算 α γ γ γ 碳含量，研究了连续退火工艺对两相区等温条件下的奥氏体体积分数、贝氏体区退火条件下的残余奥氏体体积分数 及其碳浓度的影响规律。结果表明，通过热处理工艺的控制可以保证实验钢在高Al 低Si 含量时仍可获得TRIP 效 应所需要的较高残余奥氏体数量和残余奥氏体中较高的碳浓度。 关键词 高Al 冷轧TRIP 钢 显微组织 残余奥氏体 Study and Control of Microstructure of High Al-alloyed Cold Rolling TRIP Steel Xu Kun1,2 Shen Xinqun1 Liu Guoquan2 (1. Baosteel Group Changzhou Roll Manufacture Company, Changzhou, 213019; 2.School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing ,100083) Abstract The microstructure of 0.22C-1.63Mn-1.5Al cold rolling TRIP steel has been studied in this work. The samples after intercritical quenching and isothermal bainitic transformation were color etched using the Lepera method. The evolution of austeninite during the two step process was studied. The volume fraction of retained austenite(Ar) was determined by XRD using the Direct Comparison Method. This method was the integrated intensity of (211)α and (220) γ and (331) γ peaks. In addition, the lattice parameter of the austenite phase was used to calculate the carbon content of Ar. Effect of intercritical annealing on volume fraction of aust