东北大学学报:自然科学版 ›› 2017, Vol. 38 ›› Issue (9): 1251-1256.DOI: 10.12068/j.issn.1005-3026.2017.09.009

• 材料与冶金 • 上一篇    下一篇

焊接速度对双相钢激光焊接接头组织和性能的影响

董丹阳, 蒋迪, 杨润尘   

  1. (东北大学 理学院, 辽宁 沈阳110819)
  • 收稿日期:2016-04-18 修回日期:2016-04-18 出版日期:2017-09-15 发布日期:2017-09-08
  • 通讯作者: 董丹阳
  • 作者简介:董丹阳(1979-),女,辽宁锦州人,东北大学副教授.
  • 基金资助:
    国家自然科学基金资助项目(51101029,51571052); 国家大学生创新创业训练计划(201510145017).

Effects of Welding Speed on Microstructure and Properties of Laser Welded Joints of Dual-Phase Steel

DONG Dan-yang, JIANG Di, YANG Run-chen   

  1. School of Sciences, Northeastern University, Shenyang 110819, China.
  • Received:2016-04-18 Revised:2016-04-18 Online:2017-09-15 Published:2017-09-08
  • Contact: DONG Dan-yang
  • About author:-
  • Supported by:
    -

摘要: 为提高汽车车身用双相钢(DP钢)激光焊接构件在动态载荷下应用的可靠性,研究焊接速度对1.4mm厚DP780钢脉冲激光焊接接头组织和不同应变速率下拉伸性能的影响规律.结果表明,不同激光焊接速度下DP780钢接头均存在熔合区硬化和外侧热影响区软化现象,随焊接速度增加,接头的软化程度降低.接头的强度随应变速率增加而增加,抗拉强度和断裂延伸率随焊接速度增加呈先增加后减少的趋势.当焊接速度为400mm/min时,接头表面成形性好、熔深和熔宽适中、无焊接缺陷、外侧热影响区软化程度最低(软化率为9%),熔合区硬度适中,接头整体强度和塑性指标达到最佳值.

关键词: 双相钢, 激光焊接, 焊接速度, 力学性能, 应变速率

Abstract: In order to improve the service reliability of the welded component for auto-body under the dynamic load, the effects of laser welding speed on the microstructure and tensile properties at various strain rates of the pulsed laser welded joints of 1.4mm thick DP780 steel were studied. The results showed that the DP780 welded joints exhibit the hardening in the fusion zone and the softening in the outer heat-affected zone under various welding speeds. The softening degree of the welded joints decreases with increasing welding speed. The strength of the welded joints increases with increasing strain rate, and the ultimate tensile strength and fracture elongation increase first and then decrease with increasing welding speed. The welded joints with good surface morphology, moderate weld width and penetration, no weld defect are fabricated when the welding speed is 400mm/min. And the softening degree of the outer heat-affected zone is the lowest with the softening fraction of 9% and the hardness in the fusion zone is moderate. The overall strength and ductility of the DP780 welded joint reach an optimum value under the welding speed of 400mm/min.

Key words: dual-phase steel, laser welding, welding speed, mechanical properties, strain rate

中图分类号: