Technique control method for preventing CSP continuous casting machine from cast-on breakout

Abstract

The invention discloses a technique control method for preventing a CSP continuous casting machine from cast-on breakout. The technique control method for preventing the CSP continuous casting machinefrom the cast-on breakout comprises steps of controlling the chemical composition and superheat degree of the continuous casting tundish liquid steel, sealing the seepage-proof steel of a continuouscasting cast-on dummy bar head sealing kit, adding special protective slags for the cast-on, and controlling the cast-on time of the continuous casting machine. The chemical composition of the continuous casting tundish steel liquid is set to comprises less than or equal to 0.06wt% of the low-carbon steel series C, and more than or equal to 0.17wt% of the medium carbon steel series C, the gas N isless than or equal to 50 ppm, and superheat degree of the liquid steel is controlled to be 15-40 DEG C. The technique control method for preventing the CSP continuous casting machine from the cast-onbreakout can effectively prevent cast-on breakout accidents of a thin slab-billet continuous casting machine, thereby improving the product quality and realizing the production of high-quality defect-free continuous casting billets.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a process control method for preventing breakout of a CSP continuous casting machine. Background technique [0002] CSP (contract strip production) is a compact strip production process, which was researched and developed by German Schlomann SMS (SMS). The main features of the continuous casting machine with CSP technology are the vertical curved casting machine and the funnel-shaped mold. The molten steel level in the mold rises quickly when the casting is started. The melting conditions of slag and mold slag are poor, the liquid level fluctuates greatly, and the initial billet shell is thinner. Compared with normal production continuous casting, breakout is more likely to occur, that is, the so-called open pouring breakout. [0003] As one of the most frequent occurrences of various types of continuous casting breakouts, breakouts are generally defined as breako...

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Problems solved by technology

[0003] As one of the most frequent occurrences of various types of continuous casting breakouts, breakouts are generally defined as breakouts that occur before the slab passes through the top bending roll of the continuous casting machine; crack sensitivity due to incompatibility of molten steel composition Strong, poor performance of pouring mold slag, poor sealing of the casting head and improper control of the starting time of pouring, etc., cause the primary solidified billet shell to be unable to resist the hydrostatic pressure after it exits the crystallizer, and the shell is weak at the Cracks occur after leaving the crystallizer or entering the fan-shaped section, so that molten steel flows into the secondary cooling room and sprinkles on the fan-shaped section and other equipment, causing accidents such as equipment burning. The normal production order is disrupted, and the molten steel is forced to return to the furnace, resulting in increased production costs, deterioration of product quality, and difficulty in the turnover of equipment spare parts.

[0004] On the other hand, the existing continuous casting ingot head sealing kit such as figure 1 As shown, it mainly includes ferroalloy consumables 2 and bolts 3. Bolts 3 connect ferroalloy consumables 2 and dummy head 1. The sealing kit of this structure leaves gaps between ferroalloy consumables 2 and the four copper plates of mold 7. Gap, during steel casting production, the molten steel that first enters the crystallizer 7 is easy to leak from the gap, resulting in steel breakout, which further aggravates the probability of steel breakout at start-up

[0005] At present, there are few technologies for controlling breakout of thin slab continuous casting machines, and most of them are aimed at conventional slab continuous casting machines, and mainly are patented methods for preventing breakouts in the continuous casting process of continuous casting machines; such as Shen Minggang of Liaoning University of Science and Technology Patent application "A Production Method and Device for Efficiently Controlling Continuous Casting Breakout" (CN 106493329A), which is a system and device for predicting breakout during conventional slab continuous casting. Setting a magnetic field under the crystallizer requires an electromagnetic induction device system, which is complex and has low accuracy; another example is the patent application "A Slab Continuous Casting Breakout Prediction Control Method" (CN 101332499A) by Tian Jianliang of Shanghai Meishan Iron and Steel Co., Ltd. According to the temperature change prediction of the conventional slab continuous casting machine crystallizer thermocouple, the breakout is mainly aimed at the bonded breakout, which has limitations, and there are many external interference factors, so it is not very applicable to the thin slab casting breakout prevention

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