Microstructure and fatigue crack growth behavior in tungsten inert gas welded DP780 dual-phase steel |
| |
| Affiliation: | 1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China;2. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China;3. Technical Research Institute, Shougang Corporation, Ltd., Beijing 100043, China;1. Department of Mechanical and System Engineering, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671–2280, Japan;2. Department of Mechanical Engineering, National University Corporation-Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090–8507, Japan;3. Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090–8507, Japan;1. Queensland Centre for Advanced Materials Processing and Manufacturing (AMPAM), School of Mechanical and Mining Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia;2. School of Science and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland 4575, Australia;1. School of Materials, The University of Manchester, Manchester M13 9PL, United Kingdom;2. School of Mechanical, Aerospace & Civil Engineering, The University of Manchester, Manchester M13 9PL, United Kingdom;1. School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, PR China;2. Southwest Technique and Engineering Institute, Chongqing 400039, PR China;1. Key Laboratory of Superlight Materials & Surface Technology, Ministry of Education, Harbin Engineering University, Harbin 150001, PR China;2. Shenyang Jinbo Gas Compression Manufacturing Co. Ltd., Shenyang 110027, PR China;1. Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Department of Materials, Trojanova 13, 120 00 Praha 2, Czech Republic;2. Department of Physics of Materials, Charles University, Ke Karlovu 5, 121 16 Prague 2, Czech Republic |
| |
| Abstract: | The purpose of this study was to evaluate microstructural and mechanical change of DP780 steel after tungsten inert gas (TIG) welding and the influence of notch locations on the fatigue crack growth (FCG) behavior. The tempering of martensite in the sub-critical heat affected zone (HAZ) resulted in a lower hardness (~ 220 HV) compared to the base material (~ 270 HV), failure was found to originate in the soft HAZ during tensile test. The fusion zone (FZ) consisted of martensite and some acicular ferrite. The joint showed a superior tensile strength with a joint efficiency of 94.6%. The crack growth path of HAZ gradually deviated towards BM due to the asymmetrical plastic zone at the crack tip. The FCG rate of the crack transverse to the weld was fluctuant. The Paris model can describe the FCG rate of homogeneous material rather well, but it cannot precisely represent the FCG rate of heterogeneous material. The fatigue fracture surface showed that the stable expanding region was mainly characterized by typical fatigue striations in conjunction with secondary cracks; the rapid expanding region contained quasi-cleavage morphology and dimples. However, ductile fracture mechanism predominated with an increasing stress intensity factor range (ΔK). The final unstable failure fractograph was subtotal dimples. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
