A Method for Solving Cracks in the Corner of Casting Slab and Nozzle Arrangement Method

Abstract

The invention provides a method for solving the cracks at the corners of the slab. The method comprises the following steps: Step 1, draw the temperature change curve of the reference temperature point at the corner during the continuous casting process and the cooling transition curve of the steel type in the same graph, and Add the characteristic position of the equipment; step 2, according to the intersection point position of the temperature change curve and the steel cooling transformation curve, determine the position where the grain boundary band structure is formed and cause embrittlement to start; step 3, according to the grain boundary zone determined in step 2 The location where the embrittlement starts due to the formation of the slab structure determines the location where the quenching process is performed at the corners of the slab, thereby eliminating the cracks at the corners of the slab. The invention also provides a method for arranging the nozzles to solve the cracks at the corners of the slab. According to this method, the position where the band structure is formed can be accurately found, so that the quenching process is given in a targeted manner, and the grain boundary embrittlement of the austenite at the edge and corner of the microalloyed steel slab is changed from the mechanism, thereby Avoid corner cracks during stress.

Description

technical field [0001] The invention relates to the technical field of continuous casting, in particular to a method for solving corner cracks of a slab and a nozzle arrangement method. Background technique [0002] During the continuous casting production process, surface crack defects of the slab will seriously affect the quality of the finished product, such as corner cracks of the slab, including transverse cracks on the edge surface, transverse cracks at the corners, and transverse cracks deviating from the corners. In the middle, there will be defects such as cracks on the edge of the plate, which will affect the quality of the plate, especially for wide and thick plates. Therefore, at present, the cast slab needs to be inspected and cleaned before rolling, which brings great difficulty, increased workload and cost. [0003] Especially for micro-alloy steels containing Nb, V, B, etc., as well as aluminum-killed, high-nitrogen steels, etc., ferrite, carbonitrides, and ...

AI Technical Summary

Problems solved by technology

Converting the two-dimensional heat transfer at the corner of the slab to the one-dimensional heat transfer at the chamfered surface, this technical measure has greatly improved the crack defects at the corner of the microalloy casting slab, but it still does not solve the problem of austenite grain boundary brittleness. Therefore, cracks cannot be eliminated, especially for cracks deviated from the corners, and the transverse crack defects in the corners of the slab cannot be completely eliminated.

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