Three-dimensional shape detection and reconstruction method of molten pool in laser full penetration welding of thick steel plate

Abstract

The invention discloses a three-dimensional shape detection and reconstruction method for a thick-steel-plate laser full-penetration weld pool. The method includes the following steps that firstly, the oxide skin of a first part and the oxide skin of a second part are removed, the first part and the second part are aligned with each other, laser welding is conducted with the side face of the first part serving as the starting point, and when the laser beam arrives at the side face of the second part, heterogeneous metal is led into the weld pool, the laser beam is cut off at the same time, and the heterogeneous metal is evenly distributed in the weld pool through stirring, wherein the laser beam moves towards the side face of the second part in the welding process, and it is ensured that the shape of the weld pool has been in a quasi-stable state when the laser beam arrives at the side face of the second part; secondly, two-dimensional information of the shapes of different sections of the weld pool is obtained through macro metallic phase analysis; thirdly, the three-dimensional shape of the weld pool is reconstructed according to the two-dimensional information of the shapes of different sections of the weld pool. By means of the method, the three-dimensional information of the weld pool can be safely and effectively obtained at the low cost.

Description

technical field [0001] The invention relates to a three-dimensional shape detection and reconstruction method, in particular to a three-dimensional shape detection and reconstruction method of a thick steel plate laser full penetration welding molten pool. Background technique [0002] The three-dimensional shape of the laser welding molten pool contains rich welding quality information, which is an important basis for judging whether the laser welding process parameters are reasonable and predicting the quality of welded joints. Studying the three-dimensional morphology of the laser welding pool can better understand the mass transfer and heat transfer phenomena in the laser welding process, especially the three-dimensional shape of the solid / liquid interface at the back of the molten pool will affect the grain growth direction and ultimately affect the weld seam Microstructure and mechanical properties of welded joints. [0003] At present, only two-dimensional informatio...

AI Technical Summary

Problems solved by technology

There are the following main problems in the study of the three-dimensional shape of the laser deep penetration welding pool through numerical simulation: 1. It is difficult to obtain the high-temperature physical characteristic parameters of the material required for numerical simulation; 2. The correctness of the numerical simulation calculation results itself needs to be verified by test results. Therefore, its correctness verification is limited to the two-dimensional information such as the shape of the upper and lower surfaces of the molten pool and the cross-sectional shape of the weld seam, and the three-dimensional shape of the solid / liquid interface inside the workpiece cannot be verified by experiments.

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