Laser, tungsten inert gas, and metal active gas welding of DP780 steel: Comparison of hardness, tensile properties and fatigue resistance

被引：100
作者：
Lee, Jeong Hun [1 ]
Park, Sung Hyuk [2 ]
Kwon, Hyuk Sun [3 ]
Kim, Gyo Sung [3 ]
Lee, Chong Soo [1 ,4 ]
机构：
[1] Pohang Univ Sci & Technol, Dept Mat Sci & Engn, Pohang 790784, South Korea
[2] Korea Inst Mat Sci, Light Met Div, Chang Won 642831, South Korea
[3] POSCO Global R&D Ctr, Inchon 406840, South Korea
[4] Pohang Univ Sci & Technol, Grad Inst Ferrous Technol, Pohang 790784, South Korea
来源：
MATERIALS & DESIGN | 2014年 / 64卷
关键词：
Dual-phase steel; Laser welding; Tungsten inert gas welding; Metal active gas welding; Tensile properties; Fatigue; STRENGTH LOW-ALLOY; WELDED-JOINTS; MICROSTRUCTURE; BEHAVIOR;
D O I：
10.1016/j.matdes.2014.07.065
中图分类号：
T [工业技术];
学科分类号：
08 ;
摘要：
The microstructural characteristics, tensile properties and low-cycle fatigue properties of a dual-phase steel (DP780) were investigated following its joining by three methods: laser welding, tungsten inert gas (TIG) welding, and metal active gas (MAG) welding. Through this, it was found that the size of the welded zone increases with greater heat input (MAG > TIG > laser), whereas the hardness of the weld metal (WM) and heat-affected zone (HAZ) increases with cooling rate (laser > TIG > MAG). Consequently, laser-and TIG-welded steels exhibit higher yield strength than the base metal due to a substantially harder WM. In contrast, the strength of MAG-welded steel is reduced by a broad and soft WM and HAZ. The fatigue life of laser-and TIG-welded steel was similar, with both being greater than that of MAG-welded steel; however, the fatigue resistance of all welds was inferior to that of the non-welded base metal. Finally, crack initiation sites were found to differ depending on the microstructural characteristics of the welded zone, as well as the tensile and cyclic loading. (C) 2014 Elsevier Ltd. All rights reserved.
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收藏
页码：559 / 565
页数：7
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