Method for improving quality of casting blank

Abstract

The invention discloses a method for improving the quality of a casting blank. The method comprises the following steps that the cooling water flow of a crystallizer is adjusted to 130 m<3> / h-140 m<3> / h; (2), according to the atomization effect, the nozzle model of each section is selected, wherein the nozzle model of a foot roller section is 3 / 8PZ10067QZ5, the nozzle model of a section I of a spraying section is 3 / 8PZ4565QZ2, the nozzle model of a section II of the spraying section is HPZ2.5-65QZ2, and the nozzle section of a section III of the spraying section is HPZ2.5-65QZ2; (3), the casting speed of 70# and 82B high-carbon steel is set to be 1.75+ / -0.02 m / min; (4), electromagnetic stirring parameters of the crystallizer of the 70# and 82B high-carbon steel are set as follows that the current is 320 A, the frequency is 3.5 Hz, and the specific water flow is 0.78 L / kg; and (5), secondary cooling water distribution is conducted, specifically, section III water supply is closed, section II water is reduced to 5 m<3> / h-6 m<3> / h, and section I water is reduced to 10 m<3> / h-11 m<3> / h. According to the method, after processes such as casting machine secondary cooling nozzles, electric stirring parameters and water distribution are optimized, internal cracks and center segregation defects are effectively controlled, and the internal quality of the casting blank is further improved.

Description

technical field [0001] The invention relates to the technical field of continuous casting machines, in particular to a method for improving the quality of cast slabs. Background technique [0002] When the 1#, 2#, and 3# continuous casting machines in the steelmaking plant were reconstructing the 160 billet, the main quality problem of the casting billet at the initial stage of the new process was the high probability of internal cracks, occasionally accompanied by serious single Cracks, in addition, there is a certain amount of carbon segregation inside the variety steel. [0003] 1. Low-magnification inspection and analysis of 160 square billets: [0004] [0005] It can be seen from the low-magnification inspection results of the cast slab that the pass rate of the sum of various cracks ≤ 2.0 for ordinary steel is 79.5%, while the pass rate of the sum of various cracks ≤ 1.0 for variety steel is only 85.7%. From the analysis of the occurrence of individual cracks, wh...

AI Technical Summary

Problems solved by technology

[0011] The segregation of carbon components inside the slab is unstable, the maximum segregation index is greater than 1.15, and the segregation index is less than or equal to 1.1, and the qualified rate is lower than 95%.

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