• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2017, Vol. 53 ›› Issue (8): 35-42.doi: 10.3901/JME.2017.08.035

• • 上一篇    下一篇

第三代汽车钢温热成形工艺研究及性能评价

李晓东1, 韩硕1, 王存宇2,3, 常颖1, 胡平1, 董瀚2   

  1. 1. 大连理工大学汽车工程学院 大连 116024;
    2. 钢铁研究总院华东分院 北京 100081;
    3. 太原钢铁(集团)有限公司 太原 030003);
  • 出版日期:2017-04-15 发布日期:2017-04-15
  • 作者简介:

    李晓东,男,1979年出生,博士研究生,高级工程师。主要研究方向为先进制造技术。

    E-mail:lixiaodong@dlut.edu.cn

    常颖(通信作者),女,1978年出生,博士,副教授。主要研究方向为高强钢成形技术。

    E-mail:yingc@dlut.edu.cn

  • 基金资助:
    * 国家自然科学基金(51571048)、辽宁省自然科学基金(2014028001)、中国博士后科学基金(2016M591425)和中央高校基本科研业务费(DUT15QY09,DUT16ZD201)资助项目; 20160725收到初稿,20161114收到修改稿;

Research on the Warm-hot Forming Process and Its Performance Evaluation for the Third-generation Automobile Steel

LI Xiaodong1, HAN Shuo1, WANG Cunyu2,3, CHANG Ying1, HU Ping1, DONG Han2   

  1. 1. School of Automotive Engineering, Dalian University of Technology, Dalian 116024;
    2. East China Branch, Central Iron & Steel Research Institute (CISRI), Beijing 100081;
    3. Taiyuan Iron and Steel(Group) Co., Ltd., Taiyuan 030003);
  • Online:2017-04-15 Published:2017-04-15

摘要:

中锰钢为最新的第三代汽车钢,其成形性和力学性能的改善是当前汽车轻量化领域的前沿课题。提出超细晶中锰钢的温热成形技术,通过科学优选奥氏体化温度、保温时间和成形温度作为工艺参数因子,采用正交试验和极差分析的方法,引入断裂韧度性能参数,综合评估抗拉强度、伸长率、撕裂强度及单位面积裂纹扩展能性能指标,得出温热成形中锰钢的最优工艺参数组合,即奥氏体化温度为810 ℃、保温时间为7 min、成形温度为550 ℃。并通过断口形貌和真实的汽车B柱冲压件,从微观结构和宏观性能角度验证了所得工艺参数的有效性。测试结果显示,当采用最优工艺参数组合时,具有均匀的断口形貌特征;微观结构具有细化的马氏体板条形貌,板条平均长度尺寸在2~3 μm;宏观性能良好,抗拉强度均在1 400 MPa以上,具有较好的塑性和断裂韧度。研究结果表明,温热成形技术是有效的中锰钢冲压成形方法,为第三代汽车钢的温热成形实际应用起到积极的促进作用。

关键词: 撕裂强度, 塑性, 温热成形, 正交试验, 中锰钢

Abstract:

As a third-generation automobile steel, the enhancement of mechanical properties and formability for the medium-Mn steel is becoming a cutting-edge topic. In this research, a warm-hot stamping process for the medium-Mn steel is proposed. The methods of orthogonal experiments, range analysis and comprehensive evaluation are used to investigate the optimal process parameters. The warm-hot stamping process with austenization temperature of 810 ℃, soaking time of 7 minutes and deformation temperature of 550 ℃ are optimal. Tear tests show that the fracture morphologies are uniformly distributed and fine-grained martensite laths with the average size of 2-3 μm are observed when the optimal process parameters are applied. Moreover, an automotive B-pillar is warm-stamped to examine the new process. The excellent comprehensive performance including strength, plasticity and fracture toughness is achieved. As a result, the warm-hot forming process for the medium-Mn steel is proved to be effective and will promote the industrial application of the third-generation automobile steels.

Key words: ductility, orthogonal experiment, tear strength, warm-hot stamping, medium-Mn steel