工程科学学报，第38卷，第6期：820826,2016年6月 Chinese Journal of Engineering,Vol.38,No.6:820-826,June 2016 DOI:10.13374/j.issn2095-9389.2016.06.011:http://journals.ustb.edu.cn 热成形温度对高强钢方管组织及性能的影响 彭雪锋)，韩静涛)区，晏培杰》，王宇” 1)北京科技大学材料科学与工程学院，北京1000832)上海宝钢型钢有限公司，上海201900 ☒通信作者，E-mail:hanjt@usth.cdu.cn 摘要为了克服传统辊弯工艺和设备对室温下高强钢的影响，提出弯角局部感应加热辊压成形工艺制备高强钢方管，并通 过单向拉伸试验、断口形貌观察、微观组织扫描电镜观察和X射线衍射分析研究热辊压成形温度对高强钢方管弯角处组织及 力学性能的影响.结果表明，随着温度的升高，弯角力学性能得到明显的改善，断口形貌由室温下解理断裂逐渐过渡为韧性 断裂，弯角处微观组织由板条状贝氏体向粒状贝氏体发展且多边形铁素体晶粒开始长大，方管外表面周向和纵向残余应力都 明显降低且分布更加合理.综合实验分析，高强钢方管热辊压成形工艺的最佳温度为650℃. 关键词辊压成形：高强钢：感应加热；断裂行为：残余应力 分类号TG142.1 Effect of hot forming temperature on the microstructure and mechanical properties of high strength square tubes PENG Xue-feng",HAN Jing-tao,YAN Peijie,WANG Yu 1)School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China 2)Shanghai Baosteel Section Steel Co.Ltd.,Shanghai 201900,China Corresponding author,E-mail:hanjt@ustb.edu.cn ABSTRACT To overcome the challenge of traditional roll forming process and equipment on high strength square tubes at room temperature,hot roll forming process using local induction heating was proposed to produce high strength square tubes.A series of tests including tensile testing,fracture morphology,scanning electron microscopy (SEM)and X-ray diffraction were performed to investigate the effect of hot forming temperature on the microstructure and mechanical properties of high strength square tubes.Experi- mental results show that as the temperature rises,the mechanical properties of the corners improve significantly.The fracture morphol- ogy gradually changes from cleavage fracture at room temperature to ductile fracture.The microstructures at the corners are developed from lath bainite to granular bainite and the polygonal ferrite begins to grow.Moreover,the circumferential and longitudinal residual stresses on the outside surface of the square tubes are reduced and reasonably redistributed.Based on the analyses of experimental results,the optimum forming temperature for high strength square tubes is 650C. KEY WORDS roll forming:high strength steel;induction heating:fracture behavior;residual stress 随着我国汽车工业的快速发展，汽车轻量化是改 尽管高强钢的应用越来越受到人们的青睐，但是 善汽车油耗的关键问题0，为了降低汽车重量而不损 高强钢的成形技术尚需深入研究.高强钢在室温下屈 害其碰撞性能，除了采用轻量化材料铝合金、镁合金以 服强度高，使其在成形过程中对设备和工艺要求较 及聚合物外，以高强钢或超强高钢代替传统普碳钢，是 高；高强钢产生的回弹量较大，降低产品的尺寸精 未来汽车工业的发展趋势P-. 度：同时其屈强比高，即安全成形区域相对较小，变 收稿日期：2015-0604工程科学学报，第 38 卷，第 6 期: 820--826，2016 年 6 月 Chinese Journal of Engineering，Vol． 38，No． 6: 820--826，June 2016 DOI: 10． 13374 /j． issn2095--9389． 2016． 06． 011; http: / /journals． ustb． edu． cn 热成形温度对高强钢方管组织及性能的影响 彭雪锋1) ，韩静涛1) ，晏培杰2) ，王 宇1) 1) 北京科技大学材料科学与工程学院，北京 100083 2) 上海宝钢型钢有限公司，上海 201900  通信作者，E-mail: hanjt@ ustb． edu． cn 摘 要 为了克服传统辊弯工艺和设备对室温下高强钢的影响，提出弯角局部感应加热辊压成形工艺制备高强钢方管，并通 过单向拉伸试验、断口形貌观察、微观组织扫描电镜观察和 X 射线衍射分析研究热辊压成形温度对高强钢方管弯角处组织及 力学性能的影响． 结果表明，随着温度的升高，弯角力学性能得到明显的改善，断口形貌由室温下解理断裂逐渐过渡为韧性 断裂，弯角处微观组织由板条状贝氏体向粒状贝氏体发展且多边形铁素体晶粒开始长大，方管外表面周向和纵向残余应力都 明显降低且分布更加合理． 综合实验分析，高强钢方管热辊压成形工艺的最佳温度为 650 ℃ ． 关键词 辊压成形; 高强钢; 感应加热; 断裂行为; 残余应力 分类号 TG142. 1 Effect of hot forming temperature on the microstructure and mechanical properties of high strength square tubes PENG Xue-feng1) ，HAN Jing-tao1)  ，YAN Pei-jie2) ，WANG Yu1) 1) School of Materials Science and Engineering，University of Science and Technology Beijing，Beijing 100083，China 2) Shanghai Baosteel Section Steel Co． Ltd．，Shanghai 201900，China  Corresponding author，E-mail: hanjt@ ustb． edu． cn ABSTＲACT To overcome the challenge of traditional roll forming process and equipment on high strength square tubes at room temperature，hot roll forming process using local induction heating was proposed to produce high strength square tubes． A series of tests including tensile testing，fracture morphology，scanning electron microscopy ( SEM) and X-ray diffraction were performed to investigate the effect of hot forming temperature on the microstructure and mechanical properties of high strength square tubes． Experi￾mental results show that as the temperature rises，the mechanical properties of the corners improve significantly． The fracture morphol￾ogy gradually changes from cleavage fracture at room temperature to ductile fracture． The microstructures at the corners are developed from lath bainite to granular bainite and the polygonal ferrite begins to grow． Moreover，the circumferential and longitudinal residual stresses on the outside surface of the square tubes are reduced and reasonably redistributed． Based on the analyses of experimental results，the optimum forming temperature for high strength square tubes is 650 ℃ ． KEY WOＲDS roll forming; high strength steel; induction heating; fracture behavior; residual stress 收稿日期: 2015--06--04 随着我国汽车工业的快速发展，汽车轻量化是改 善汽车油耗的关键问题［1］． 为了降低汽车重量而不损 害其碰撞性能，除了采用轻量化材料铝合金、镁合金以 及聚合物外，以高强钢或超强高钢代替传统普碳钢，是 未来汽车工业的发展趋势［2--3］． 尽管高强钢的应用越来越受到人们的青睐，但是 高强钢的成形技术尚需深入研究． 高强钢在室温下屈 服强度高，使其在成形过程中对设备和工艺要求较 高［4］; 高强钢产生的回弹量较大，降低产品的尺寸精 度［5］; 同时其屈强比高，即安全成形区域相对较小，变