Method for detecting solidification tail end position of casting blank on line

Abstract

The invention discloses a method for detecting the solidification tail end position of a casting blank on line, which comprises the following steps of: driving a steel nail taking sulfur as a tracer into a continuous casting blank through a special nail gun, sampling at the position corresponding to the nail of the continuous casting blank, and analyzing; the morphology of a solid phase region and a liquid phase region of a casting blank is different, the thickness of a solidification layer can be measured by means of macroscopic inspection, sulfur print analysis and the like, the comprehensive solidification coefficient and the solidification end point of the casting blank under various working conditions are calculated according to the thickness of a blank shell, and the method has important significance for improving the internal quality of the continuous casting blank.

Description

Technical Field

[0001] The invention relates to a method for a steel-making enterprise to detect the position of the end of solidification of a casting blank on-line. Background Art

[0002] After years of production and technical optimization, the process system and production technology level of slab continuous casting machines have undergone great changes. In order to further improve the quality of the slab, improve the solidification cooling process, and better develop the secondary cooling dynamic soft reduction technology in the future, it is necessary to accurately understand the solidification shell thickness of the slab under various working conditions.

[0003] A search found an invention patent with application (patent) number CN202111080607.1 entitled "A method for quickly detecting the end position of solidification of a continuous casting billet". By comparison, the present invention is very different from this invention. The above-mentioned invention mainly utilizes a continuous casting machine straightening machine to apply a certain pressure to the continuous casting billet, and compares different pressed samples formed by pressing down different rollers with the non-pressed samples, so as to quickly and accurately determine the end position of solidification of the continuous casting billet. Summary of the invention

[0004] The object of the present invention is to provide a method for online detection of the end position of solidification of a casting, which can measure the end position of solidification by means of low-magnification inspection, sulfur print analysis and the like.

[0005] The technical scheme adopted by the present invention is a method for online detecting the end position of the solidification of the ingot, comprising a set of nail shooting system, wherein the nail shooting inspection system is composed of a nail shooting gun, a support and a firing controller; when the firing command is started, the firing controller fires the firing pin, the firing pin hits the primer of the bullet, triggering the explosion of the gunpowder in the bullet, and the bullet hits the nail with strong force, and the nail flies out along the barrel of the gun at high speed under the action of the strong impact kinetic energy of the bullet, and is shot into the high-temperature ingot, the nail is made of high-carbon steel, the length is 110mm-160mm, two sulfur grooves are arranged on both sides of the nail, the sulfur in the sulfur groove is used as a tracer, enters the ingot with the nail, and diffuses in the liquid phase cavity, and marks the melting position of the nail in the sulfur print, so as to find the thickness of the ingot shell at the nail position; the position of the nail is determined by the sulfur in the sulfur groove, so as to prevent the nail from being planed off and the melting position of the nail from being found.

[0006] The present invention detects the solidification end position of the ingot by a nail shooting method. The method is that a steel nail with sulfur as a tracer is driven into the continuous casting ingot by a special nail shooting gun, and samples are taken at the corresponding position of the nail shooting in the continuous casting ingot for analysis. Since the steel nail driven into the ingot is melted after encountering liquid steel, the morphology of the solid phase area and the liquid phase area of ​​the ingot is different, and the solidification end position can be measured by low-magnification inspection, sulfur print analysis and other means.

[0007] By using the continuous casting billet nail shooting test system, the solidification shell thickness of each typical steel grade continuous casting billet of the slab continuous casting machine can be tested in actual production. The data of solidification shell thickness, solidification coefficient and solidification point position of each typical steel grade at different parts in the late stage of secondary cooling under various drawing speeds are tested and calculated. These data can provide important references for the production of slab continuous casting machines, improvement of billet quality and implementation of dynamic light pressure in secondary cooling. This method is applicable to the same type of steelmaking enterprises. By analyzing the test data and taking measures to optimize the process and improve the equipment, the internal defect rate of the continuous casting billet can be reduced to a lower level and the quality of the continuous casting billet can be improved. Implementation

[0008] A method for online detection of the end position of solidification of a casting blank comprises a set of nail shooting system, wherein the nail shooting inspection system is composed of a nail shooting gun, a support and a firing controller; the firing controller is also called an electric control box, and its main function is to convert an electrical signal into a magnetic control operation, so as to control and fire a firing pin, and the electric control box has 6 control buttons, which can simultaneously operate and control 6 nail shooting guns for nail shooting; and the electric control box has a delay function, which can start the firing pins of the nail shooting guns at the same time or at different times for a period of several seconds after a command is given to perform a nail shooting test, or can start only some nail shooting guns at a time and start the remaining nail shooting guns after a longer period of time. When the firing command is initiated, the magnetic control element controller fires the firing pin, which hits the primer of the bullet, causing the gunpowder in the bullet to explode. The bullet hits the nail with great force, and the nail flies out at high speed along the barrel of the gun under the powerful impact kinetic energy of the bullet and shoots into the high-temperature ingot. The explosive force of the bullet is divided into three types: high, medium and low, which can be selected according to the thickness of the ingot, the thickness of the solidified shell and the type of steel. The nail body is made of high carbon steel with a length of 110mm-160mm, which can be designed and manufactured individually as required. There are two sulfur grooves on both sides of the nail. The functions of the sulfur grooves are: 1) The sulfur in the sulfur groove acts as a tracer, enters the ingot with the nail, and diffuses in the liquid phase hole. The melting position of the nail can be marked in the sulfur print, so as to find the shell thickness at the nail position; 2) Determine the position of the nail to prevent the nail from being planed away and the melting position of the nail cannot be found.

Claims

1. A method for online detection of the end position of solidification of a casting, characterized in that It includes a nail shooting system. The nail shooting inspection system consists of a nail gun, a support and a firing controller. When the firing command is started, the firing controller fires the firing pin, and the firing pin hits the primer of the bullet, causing the gunpowder in the bullet to explode. The bullet hits the nail with great force. Under the action of the powerful impact kinetic energy of the bullet, the nail flies out at high speed along the barrel and chamber and is shot into the high-temperature ingot. The nail is made of high-carbon steel with a length of 110mm-160mm. There are two sulfur grooves on both sides of the nail. The sulfur in the sulfur groove serves as a tracer, enters the ingot with the nail, and diffuses in the liquid phase hole to mark the melting position of the nail in the sulfur print, so as to find the ingot shell thickness at the nail position. The position of the nail is determined by the sulfur in the sulfur groove to prevent the nail from being planed off and the melting position of the nail from being found.