SU1503989A1 - Method of automatic detecting of surface land-like defect on a continuously cast ingot when casting - Google Patents

Abstract

The invention relates to metallurgy, and more specifically to the automation of continuous casting machines. The goal is to increase the yield of a suitable metal by accurately determining the defective part of the workpiece in the form of a ca. The essence of the invention is that during the continuous casting of metal, the rate at which the ingot is drained from the mold and the rate at which the metal level in the mold changes is compared at the time when the drawing speed exceeds the rate of metal drop by 0-0.1 m / min fix the beginning of the defective area, when this value is greater than 0.1 m / min fix the end of the defective area. 1 il.

Description

The invention relates to metallurgy, in particular to the automation of continuous casting machines.

The aim of the invention is to increase reliability.

The drawing shows a functional diagram of a device intended for implementing the method.

The scheme contains a liquid metal level gauge in the crystallizer consisting of a source of radioactive radiation 1 and a block of 2 meters mounted on the mold 3, block 4 of the secondary instrument of the measuring system, adder 5, block 6 of the comparison, setpoint 7 for the values of the boundary values. The SRI of the parameter, tachogenerator 8 (exhaust speed sensor) and inverter 9.

During the casting process on a continuous casting machine, the signal from the block 2 of the counters enters the block 4 of the second apparatus, where signals about the position of the level of metal 10 in the mold 3 and about the rate of change of this level are detected. These signals on existing caster are transmitted respectively to the tundish stopper control system (to automatically maintain the level of the metal in the mold) and to the metal breaking system. The signal of the rate of change of the level of the metal is supplied, in addition, to the input of the sum S0L.

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torus 5 through inverter 9 (to change the sign of the signal to the opposite).

The second input of the adder 5 receives a signal about the speed of pulling of the ingot. With a tachogenerator 8. Thus, in the adder 5, the magnitude of the excess of the speed of drawing is selected over the rate of level drop, i.e. Vg + (- Vyp) .. This signal is fed to the b block of the comparison. The values of the boundary values of the parameter are set by the setting device 7. From the comparison block 6, the signal that the value of the parameter -15 parameter exceeds 0.1 m / min at the given time (i.e., does not form c) or is in the interval from O to 0.1 m / min (i.e., a surface defect is being formed — by sa) 20 are transferred to the automated process control system of the continuous casting machine to organize a rational-dissection of the continuous ingot per slab.

The method is implemented as follows. 25

At the CCM, carbon steel is poured into ingots with a cross section of 0.25 x X 1.65 m at a speed of 1.0 m / min, the level of the metal in the mold has practically stabilized at O, 1+ 30 ± O, 004 m below the upper edge of the copper wall of the crystallizer, The rate of change in the level of the metal in the mold during casting varies in the range of +0.003 m / min. The process is stable, the difference between the speed of the ingot extrusion and the drop in the level of the metal in the mold Vg-Vyp 1.0 - (+ 0.003) 0.1. When the time of planned replacement of the Q-night glass is approached, the ingot extrusion speed is gradually reduced to a value of 0.2 m / min, the accuracy of maintaining the metal level in the crystallizer is at the same level as 0, H +0.004 m, and 003 m / min. The surface quality of the ingot being cast is within acceptable limits.

V g- V ,, p 0,2 - (+0,003)

 Oh, 1 m / min.

A change of pouring cup begins. The jet of molten metal from the granite overlaps, the ingot extrusion rate remains the same V. - gy 0.2 m / min, the rate of fall of the level of the metal in the mold in this case becomes equal to V jp .Vg

 0.2 m / min, the difference Vvp Oh,

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v.6; less than 0.1 m / min, the automation system records the beginning of the formation of a defect on the surface of the cast ingot. After 40 s, the glass was replaced and the metal supply to the crystallizer resumed, the metal level during this time dropped by 0.13 m from the original, this is not lower than the minimum acceptable value, equal to 0.26 m from the top of the copper wall. The metal level in the mold at a given flow rate of the metal supplied to the crystal; the metal metal continues to fall at a speed of VVP 0.15 m / min. The difference VB- V ,, p is 0.2-0.15 0.05 m / min, g0.1 m / min, the system of fic-continuation of the formation of the defective area.

Increase the flow rate of the metal supplied to the mold. The level starts to increase with a speed of V, p 0.05 m / min. The difference Vg - - V ,, 0,2 - (-0,05) 0,25 m / min 0.1 m / min, the system records the end of the defective area on the cast ingot. ;

The method of automatically determining the process of casting a surface defect of a continuous-cast ingot caused by a break in the supply of metal to the mold makes it possible to increase the yield of suitable metal due to the exact determination of the defective part of the workpiece in the form of cS arising from interruptions in the supply of metal to the mold.

Claims (1)

Invention Formula A method for automatically determining in the process of casting a surface defect in the form of sa on a continuously cast ingot includes measuring the rate of ingot extrusion, characterized in that, in order to increase reliability, the ingot extrusion rate and the rate of change of the metal level in the crystallizer and in the interval are compared The speeds at the ingot drawing rate equal to the rate of change of the level, up to the speed of pulling of the ingot, greater than the rate of change of the level by the amount of 0.1 m / min, determine the beginning of the formation At the rate of a change in the level by an amount greater than 0.1 m / min, the end of the belt formation is determined when the rate of the pull-out & Signal o5t / ffo $ He on the control system stop bezel penetration - Signal is this the way of the breakthrough 6АУУТП signal cv about obrazobamiai n poys on merged