Microstructure analysis and hardness prediction based on microstructure evolution theory in multi-pass welded joint

Zhang, Qingya; Zhuo, Zichao; Zhou, Hong; Wang, Jiangchao

doi:10.1177/09544062211073101

Cited by 5 publications

(6 citation statements)

References 30 publications

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“…Based on the heat conduction theory and temperature dependent material thermal physical properties, the welding thermal cycle at each node of the finite element model can be obtained by solving the transient nonlinear heat transfer equation according to the welding conditions. 15,16,[21][22][23] The body heat source model with uniform power density is used to simulate the heat source of the moving welding arc. The power density is determined by the welding current, welding voltage, welding speed, and heat efficiency of welding arc, as described in equation (1).…”

Section: Thermal Analysis With Femmentioning

confidence: 99%

“…[17][18][19] In this study, the evolution of residual stress is the contribution of temperature variation and is related to the phase transformation on cooling. In this paper, the modified microstructure evolution model developed by Zhang et al 23 is employed to predict the microstructure evolution process during multi-pass butt welding. In this study, X M , X B , X F , X P , and X RA are volume fraction of Martensite, Bainite, Ferrite, Pearlite and retained Austenite under each thermal cycle.…”

Section: Microstructure Evolution Theorymentioning

confidence: 99%

“…All of them are controlled by the following equations equations (3)-(5). 23,24 Among them, the volume fractions of Martensite and Bainite can be obtained according to the superposition principle. Moreover, Austenite grain size affected the Austenite decomposition products especially Martensite, which was closely associated with the prior austenite grain size.…”

Section: Microstructure Evolution Theorymentioning

confidence: 99%

“…In this study, the in-house code was programmed by FORTRAN and then compiled with Intel Parallel Studio XE 2011 based on the platform of Ubuntu 14.04 OS and Dell PowerEdge T420 Server. [21][22][23] The parallel computation technology with eight threads was used to improve the prediction efficiency. To clarify the influence of SSPT and initial stress on residual stress, four simulation cases were performed in the current study.…”

Section: Residual Stress Calculationmentioning

confidence: 99%

“…17–19 In this study, the evolution of residual stress is the contribution of temperature variation and is related to the phase transformation on cooling. In this paper, the modified microstructure evolution model developed by Zhang et al 23 is employed to predict the microstructure evolution process during multi-pass butt welding.…”

Section: Introductionmentioning

confidence: 99%

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Accurate evaluation on residual stress considering solid-state phase transformation and initial stress in thick weld

Zhang

Wang

2022

Proceedings of the Institution of Mechanical Engineers, Part C:

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During the welding process of thick plates, it is difficult to evaluate the residual stress distribution in thick welds accurately because complicated residual stress is generated by multi-thermal cycles. In this study, a multi-pass butt joint was fabricated using Q690 high strength steel with the thickness of 75 mm, meanwhile experiments were carried out to characterize the microstructure and measure the through-thickness distribution of longitudinal residual stress in a butt-welded joint by the contour method. Then numerical methods were developed to predict the through-thickness distribution of residual stress in butt-welded joints. To evaluate residual stress accurately and efficiently, the effects of solid-state phase transformation (SSPT) and initial stress were taken into consideration, and the parallel computation technology and iterative substructure method were employed. The root-mean-square error (RMSE) was employed to evaluated the prediction accuracy of numerical methods between measurement and numerical results of residual stress. Through comparing the simulated results with experimental data, the validity of the developed numerical methods was verified. Numerical results indicate that the through-thickness distribution of residual stress in butt-welded joints is very complex and peak value of tensile stress can be found in the area adjacent to the heat-affected zone (HAZ). Moreover, the RMSE is significantly decreased from 307 to 8 when considering the effect of SSPT on residual stress in weld vicinity, and the RMSE is apparently decreased from 137 to 11 when considering the effect of initial stress on residual stress in base metal.

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