500 MPa级高延性汽车方管用钢的开发及加工硬化机理  

Development of 500 MPa Grade High Ductility Automotive Square Tube Steel and Research of Work Hardening Mechanism

作　　者：惠亚军 吴科敏 肖宝亮 许克好 壬志伟 刘锟 HUI Yajun;WU Kemin;XIAO Baoliang;XU Kehao;WANG Zhiwei;LIU Kun(Research Institute of Technology of Shougang Group Co., Ltd.;Beijing Key Laboratory of Green Recyclable Process for Iron and Steel Production;Beijing Shougang Co., Ltd.)

机构地区：[1]首钢集团有限公司技术研究院 [2]绿色可循环钢铁流程北京市重点实验室 [3]北京首钢股份有限公司

出　　处：《首钢科技》2019年第2期26-34,共9页Shougang Science and Technology

摘　　要：釆用OM、SEM和TEM等分析方法对500 MPa级高延性汽车方管用钢不同成分体系下钢材的显微组织与力学性能进行分析,并研究了加工硬化机理。结果表明,2种试验钢制管前力学性能相似,低碳-低猛-铌-钛微合金化试验钢屈强比较高;制管后低碳-低猛-铌-钛微合金化试验钢加工硬化程度显著,屈服强度和抗拉强度分别增加了45,26 MPa,断后伸长率降低6.0%;高碳-高锰-铌微合金化试验钢屈服强度和抗拉强度分别增加了22,10 MPa,断后伸长率降低4.0%。制管后低碳-低猛-铌-钛微合金化试验钢位错强化引起的强度增量增加显著,达到了82 MPa,明显高于高碳-高锰-铌微合金化试验钢位错强化的贡献(65MPa),对于制管用途而言,高碳-高锰-铌微合金化试验钢制管后综合力学性能更加优异。The microstructure and mechanical properties of 500 MPa grade high ductility automotive square tube steel under different chemical components were analyzed by OM, SEM and TEM, and the work hardening mechanism was studied. The results showed that the mechanical properties of the two kind of test steel were similar before tube?fonning process, and the yield ratio of the low carbo low manganese- niobium-titanium microalloyed test steel was relatively high. After tube-forming process, the low carbon-low manganese- niobium- titanium microalloyed test steel had a significantly work hardening, the yield strength and tensile strength increased by 45 and 26 MPa, respectively, while the elongation decreased by 6. 0%. The yield strength and tensile strength of the high carbonhigh manganese- niobium microalloyed test steel increased by 22 and 10 MPa, respectively, while the elongation decreased by 4. 0%. After tube-forming process, the strength increment caused by the dislocation strengthening of the low carbon-low manganeseiobiuin-titanium microalloyed test steel increased significantly, reaching 82 MPa, which was significantly higher than that of the high carbon-high manganeseiobium microalloyed test steel (65 MPa). For the application of square tube, the high carbon-high manganese- niobium microalloyed test steel had better comprehensive mechanical properties after tube-forming process.

关 键 词：500 MPA级 方管用钢 强化机制 加工硬化 位错 

分 类 号：TU472.6[建筑科学—结构工程]