Continuous casting billet surface crack propagation critical strain measurement and crack propagation prediction method

Abstract

The invention discloses a continuous casting billet surface crack propagation critical strain measurement and crack propagation prediction method and belongs to the technical field of continuous casting. The method is characterized in that a three-dimensional thermal / mechanical coupling model is established, in a continuous casting process, the continuous casting billet transfers heat and deforms,a continuous evolution cloud chart of the surface strain of the casting full-flow continuous casting billet is obtained, a test temperature range is obtained, in the test temperature range, a high-temperature tensile experiment of a prefabricated crack sample is carried out to obtain a stress-strain curve, through crack microstructure observation under different dependent variables, the continuous casting billet surface crack propagation critical strain can be accurately measured, continuous casting billet surface crack propagation is predicted based on the critical strain, an implementationcountermeasure for reducing surface crack propagation is provided for production, then crack defects are controlled, and the casting billet quality is improved.

Description

technical field [0001] The invention relates to the technical field of continuous casting, in particular to a method for measuring the critical strain of crack propagation on the surface of a continuous casting slab and predicting the crack propagation. Background technique [0002] Crack defects are very easy to occur during the solidification process of continuous casting slabs, which is one of the three major quality problems of continuous casting slabs. Cracks in continuous casting slabs have different types and complex causes, but most of them are caused by internal and external forces such as thermal stress and mechanical stress at a certain position of the continuous casting slab during the casting process exceeding the thermoplastic limit of the slab itself at this position. Therefore, to study the law of crack initiation and propagation in continuous casting slabs, it is necessary to first determine the critical criteria for crack initiation and crack propagation ba...

AI Technical Summary

Problems solved by technology

It can be seen that most of the above research methods measure the critical strain at fracture by stretching the cast slab at high temperature, but none of them can accurately measure the critical strain of the further expansion of existing microcracks.

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