PSI - Issue 33

Wei Song et al. / Procedia Structural Integrity 33 (2021) 795–801 Author name / Structural Integrity Procedia 00 (2019) 000–000

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1. Introduction Many industries use high or ultra-high strength steel to enhance the load-carrying capabilities of critical components in some heavy engineering structures, such as shipbuilding, offshore construction, railways (Guo et al. (2016), Amraei et al. (2016) and Khurshid et al. (2015)). Its superior properties demonstrate a tremendous potential application of these materials. In terms of materials manufacturing processing, welding is an indispensable fabricating step that can mitigate the complexity of large engineering structures by Ghosh (2010). To guarantee the superior mechanical properties of the welded joints with base metal, corresponding welding consumables containing similar chemical compositions with base metal are recommended to fabricate welded joints. However, with the increase of steel grades, the strategy for fabricating evenmatched welded joints can have some adverse effects on weld integrity properties and manufacturing processing, such as cold cracking susceptibility, decreasing of ductile and fatigue life, or additional utilization of post-welding heat treatment. Cold cracking was often occurred due to the interaction of diffusible hydrogen, susceptible microstructures, and tensile residual stress in welds (Lee, et al. (2016)). In order to enhance the weld resistance of hydrogen-induced cold cracking, ductile, fatigue properties, reduce tension residual stress and pre heating temperature, an appropriate chemical composition weld consumable for high strength steel is a practical approach for the above problems (Gibmeier, et al. (2014)). Thus, it is unavoidable to induce yield strength mismatch between base metal and weldment. This paper presents the FE numerical simulations of the arc welding processing of 10CrNi3MoV high strength steel. The thermal and physical properties of the weld deposits of steel are firstly investigated. Then, the isotropic, kinematic, and isotropic-kinematic (mixed) plastic constitutive models are employed to comprehensively examine the sensitivities of WRS taking SSPT into account for mis-matched welded joints. Finally, model predictions are compared with experimental test results for these welded joints. Nomenclature SSPT Solid-State Phase Transformation (SSPT) GMAW Gas Metal Arc Welding SP-GMAW Single Pulsed Gas Metal Arc Welding BM Base Metal

EM Even-matched Materials UM Under-matched Materials 2D Two-Dimensional

2. Experiment 2.1. Materials

The material in our investigation was 10CrNi3MoV steel, which was received in quenched and tempered condition. Fig. 1 shows the actual weld plate scheme and multipass welded beads with a V-groove by different welding processing for the mismatched welded joints. The butt-welded joints were fabricated by Single Pulsed Gas Metal Arc Welding (SP-GMAW) processing for evenmatched configuration using corresponding wire (wire diameter Φ 1.2mm). Gas Metal Arc Welding (GMAW) processing was applied for undermatched welded joints by lower strength filler metal (wire diameter Φ 1.2mm). 2.2. Weldment fabrications Two rectangular blocks (500 × 150 × 16 mm) of 10CrNi3MoV steel were used as the BM, six layers deposits by eleven passes for EM and UM weldments were realized after back-chipping processing. Single V-Groove shape with 60° angle and 1mm root face was filled by the matching welding material. The welded joints were first deposited by eight passes with the fixed constraint in the plate's center. To correct the distortion of the plate and remove some defeats at the weld root, the back-chipping process was conducted for the thick plate due to the angle distortion in the