Phase-field method-based microstructure evolution simulation method in welding process in transient state

Abstract

The invention provides a phase-field method-based microstructure evolution simulation method in a welding process in a transient state. The phase-field method-based microstructure evolution simulation method in the welding process in the transient state comprises the following steps of simplifying conditions and initializing a model, building the model according to parameters of a solidification process of a welding pool; building a macro transient heat transfer and growth rate model, wherein the welding pool is regarded to be formed by combining two semi-elliptical spheres, one semi-elliptical sphere is in a molten state and the other semi-elliptical sphere is in a solidified state in the welding process; building the macro transient heat transfer and growth rate model on the basis of hypotheses; building a microstructure evolution model and building a phase-field model of simulating microstructure evolution of the welding pool on the basis of the Ginzburg-Landau theory; and carrying out macro-micro coupling calculation, introducing a transient temperature gradient and a dendrite growth rate into the model, calculating a macro-micro coupled phase-field model and obtaining a microstructure evolution simulation result of the welding pool.

Description

technical field [0001] The invention relates to a method for simulating microstructure evolution in a transient welding process based on a phase field method. Background technique [0002] The performance of welded joints depends not only on its macro-defects, but also on factors such as grain size and internal structure. The formation process of weld microstructure is complex and affected by many factors. Therefore, the study of microstructural evolution during solidification of welds is a complex and important field. In this field of research, numerical simulation is playing an increasingly important role. [0003] Traditional research is mostly based on test data and experience. Not only does the research process take a long time and cost a lot of money, but it is also limited due to the complexity of the weld solidification process, and it is often difficult to meet the ever-increasing process precision and accuracy. sexual demands. With the rapid development of comp...

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Problems solved by technology

[0004] At present, most of the simulation results of the microstructural evolution of the solidification of the weld pool are based on the "probabilistic" theoretical method for simulation and prediction, which lacks a solidification theoretical basis, and at the same time cannot fully reflect the microstructure of the dynamic solidification process of the weld pool. Features of Organizational Evolution

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