|
|
|
| Characteristics of Welding Crack Defects and Failure Mode in Resistance Spot Welding of DP780 Steel |
| Xiao-pei WANG1,Yong-qiang ZHANG1,Jian-bin JU1,Jian-qiang ZHANG2,Jian-wei YANG1 |
1. Shougang Research Institute of Technology, Beijing 100043, China
2. College of Science,China University of Petroleum Beijing, Beijing 102249, China |
|
|
|
|
Abstract The mechanical properties of welded joints in resistance spot welding of DP780 steel were tested, and three different types of welding cracks in welded joints were investigated by optical microscopy, scanning electron microscopy and electron back-scattered diffraction. Finally, the failure mode of the welded joints in shear tensile test was discussed. It is found the shear tensile strength of welded joints can be greatly improved by adding preheating current or tempering current. The surface crack in welded joint is intergranular fracture, while the inner crack in welded joint is transgranular fracture, and the surface crack on the edge of the electrode imprint can be improved by adding preheating current or tempering current. The traditional failure mode criterion advised by American Welding Society is no longer suitable for DP780 spot welds and the critical nugget size suggested by Pouranvari is overestimated.
|
|
Received: 24 February 2016
Published: 18 October 2016
|
|
Corresponding Authors:
Xiao-pei WANG
E-mail: wangxp198710@163.com
|
|
|
|
| [1] |
Ming MA,Hua DING,Zheng-you TANG,Jing-wei ZHAO,Zhou-hua JIANG,Guang-wei FAN. Effects of Temperature and Strain Rate on Flow Behavior and Microstructural Evolution of Super Duplex Stainless Steel under Hot Deformation[J]. Chinese Journal of Iron and Steel, 2016, 23(3): 244-252. |
| [2] |
ZHAO Jin-long,XI Yan,SHI Wen,LI Lin. Microstructure and Mechanical Properties of High Manganese TRIP Steel[J]. Chinese Journal of Iron and Steel, 2012, 19(4): 57-62. |
| [3] |
DING Hao;DING Hua;QIU Chun��lin;TANG Zheng��you;ZENG Jian��min;YANG Ping. Formability of TRIP/TWIP Steel Containing Manganese of 18.8%[J]. Chinese Journal of Iron and Steel, 2011, 18(1): 36-40. |
| [4] |
Zou De-ning;HAN Ying;ZHANG Wei;et al. [J]. Chinese Journal of Iron and Steel, 2010, 17(8): 50-54. |
| [5] |
ZTANG heng-you; DING Hua; et al. Effect of Baking Process on Microstructures and Mechanical Properties of Low Silicon TRIP Steel Sheet with Niobium[J]. Chinese Journal of Iron and Steel, 2010, 17(7): 68-74. |
| [6] |
ZHANG Zi-Cheng;ZHU Fu-xian LI Yan-mei. Effect of Thermomechanical Control Processing on Microstructure and Mechanical Properties of Fe-0.2C-1.44Si-1.32Mn Hot-rolled TRIP Steel[J]. Chinese Journal of Iron and Steel, 2010, 17(7): 44-44. |
|
|
|
|
2016, Vol. 23 
