阅读说明：本技术 通过预设电流值控制电渣钢锭质量的方法 (Method for controlling quality of electroslag steel ingot through preset current value ) 是由 秦雷 于 2020-10-31 设计创作，主要内容包括：本发明提供一种通过预设电流值控制电渣钢锭质量的方法,涉及电渣重熔技术领域,通过PLC驱动电机正反转从而控制电极插入渣池的深度,从而控制渣池的发热量,以实现对熔炼速度的控制。本发明可以实现对熔炼速度的控制。(The invention provides a method for controlling quality of an electroslag steel ingot through a preset current value, and relates to the technical field of electroslag remelting. The invention can realize the control of the smelting speed.)

1. A method for controlling quality of an electroslag steel ingot through a preset current value is characterized in that a PLC (programmable logic controller) is used for driving a motor to rotate forward and backward so as to control the depth of an electrode inserted into a slag pool, so that the heat productivity of the slag pool is controlled, and the smelting speed is controlled.

2. The method for controlling the quality of an electroslag steel ingot through the preset current value according to claim 1, is characterized by comprising the following steps of:

(1) setting a smelting current value;

(2) keeping the smelting voltage unchanged, and driving the electrode to lift by the PLC through the driving electrode;

(3) measuring the actual current value during smelting by using an ammeter;

(4) if the actual current value is higher than the smelting current value, the PLC drives the electrode to drive the electrode to rise;

(5) if the actual current value is lower than the smelting current value, the PLC drives the electrode to drive the electrode to descend;

(6) from R ═ KL/S, it is known that the electrode insertion depth is inversely proportional to the slag resistance of the slag.

3. A method for controlling the quality of an electroslag steel ingot by a preset current value according to claim 1, wherein the diameter of the electroslag furnace crystallizer is inversely proportional to the insertion depth of the electrode.

4. A method for controlling the quality of an electroslag steel ingot through a preset current value according to claim 1, wherein the diameter of the crystallizer is 400mm-900mm, and the depth of the electrode inserted into the slag bath is 30mm-40 mm.

5. A method for controlling the quality of an electroslag steel ingot through a preset current value according to claim 1, wherein the insertion depth of an electroslag furnace electrode with a crystallizer diameter of more than 800mm is 30 mm.

6. A method for controlling quality of an electroslag steel ingot by preset current value according to claim 1, wherein the insertion depth of the electroslag furnace electrode with the crystallizer diameter below 400mm is 40 mm.

Technical Field

The invention relates to the technical field of electroslag remelting, in particular to a method for controlling the quality of an electroslag steel ingot through a preset current value.

Background

The electroslag steel is widely applied due to good quality and longer service life, particularly widely applied to aerospace and various military products, and also widely applied to civil industry in recent years. How to further improve the quality of the electroslag steel is in front of people, and in the electroslag remelting process, the depth of the electrode inserted into the slag bath has great influence on the whole electroslag remelting process and also has great influence on the quality of the electroslag steel.

Disclosure of Invention

In order to meet the actual requirements in the prior art, the invention aims to provide a method for controlling the quality of an electroslag steel ingot through a preset current value.

In order to achieve the purpose, the method for controlling the quality of the electroslag steel ingot through the preset current value controls the depth of the electrode inserted into the slag bath through the positive and negative rotation of the PLC driving motor, so that the heat productivity of the slag bath is controlled, and the smelting speed is controlled.

The method comprises the following steps:

(1) setting a smelting current value;

(2) keeping the smelting voltage unchanged, and driving the electrode to lift by the PLC through the driving electrode;

(3) measuring the actual current value during smelting by using an ammeter;

(4) if the actual current value is higher than the smelting current value, the PLC drives the electrode to drive the electrode to rise;

(5) if the actual current value is lower than the smelting current value, the PLC drives the electrode to drive the electrode to descend.

(6) From R ═ KL/S, it is known that the electrode insertion depth is inversely proportional to the slag resistance of the slag.

In the electroslag remelting process, the liquid slag acts as a pure resistance element, and the resistance value of the liquid slag plays an important role in the remelting process. The depth of the electrode inserted into the slag pool can adjust the slag resistance within a certain range, the slag resistance of the slag actually used is reduced if the electrode is inserted deeply, and the slag resistance of the slag actually used is larger if the electrode is inserted shallowly. The conclusion is drawn according to ohm' S law R-KL/S, the depth of the electrode inserted into the slag pool is actually equivalent to the height range of the slag pool, the height of the slag pool is larger, and the slag resistance is larger.

The whole electroslag remelting process is realized by means of heating when current passes through slag, a molten slag pool is a pure resistance element, and the heat productivity when the current passes through the slag pool is determined by the slag resistance of the slag pool which is effectively utilized, so that the heat productivity of the slag pool can be controlled within a certain range by controlling the insertion depth of an electrode, and great influence is generated on the smelting speed and the whole smelting process.

Preferably, the diameter of the crystallizer of the electroslag furnace is inversely proportional to the insertion depth of the electrode.

Preferably, the diameter of the crystallizer is 400mm-900mm of the electroslag furnace, and the depth of the electrode inserted into the slag bath is 30mm-40 mm.

Preferably, the insertion depth of the electroslag furnace electrode with the diameter of the crystallizer being more than 800mm is 30 mm.

Preferably, the insertion depth of the electroslag furnace electrode with the diameter of the crystallizer below 400mm is 40 mm.

The invention has the beneficial effects that:

according to the invention, the insertion depth of the electrode is controlled by presetting the current value, so that the heating value of the slag bath is controlled within a certain range, and the smelting speed and the whole smelting process are greatly influenced.

Drawings

FIG. 1 is a diagram of the steps of the method of the present invention.

Detailed Description

Referring to the attached drawings in the specification, in the method for controlling the quality of an electroslag steel ingot through a preset current value, the PLC drives the motor to rotate forward and backward so as to control the depth of the electrode inserted into the slag bath, so that the heat productivity of the slag bath is controlled, and the smelting speed is controlled.

The method comprises the following steps:

(1) setting a smelting current value;

(2) keeping the smelting voltage unchanged, and driving the electrode to lift by the PLC through the driving electrode;

(3) measuring the actual current value during smelting by using an ammeter;

(4) if the actual current value is higher than the smelting current value, the PLC drives the electrode to drive the electrode to rise;

(5) if the actual current value is lower than the smelting current value, the PLC drives the electrode to drive the electrode to descend.

(6) From R ═ KL/S, it is known that the electrode insertion depth is inversely proportional to the slag resistance of the slag.

In the electroslag remelting process, the liquid slag acts as a pure resistance element, and the resistance value of the liquid slag plays an important role in the remelting process. The depth of the electrode inserted into the slag pool can adjust the slag resistance within a certain range, the slag resistance of the slag actually used is reduced if the electrode is inserted deeply, and the slag resistance of the slag actually used is larger if the electrode is inserted shallowly. The conclusion is drawn according to ohm' S law R-KL/S, the depth of the electrode inserted into the slag pool is actually equivalent to the height range of the slag pool, the height of the slag pool is larger, and the slag resistance is larger.

The whole electroslag remelting process is realized by means of heating when current passes through slag, a molten slag pool is a pure resistance element, and the heat productivity when the current passes through the slag pool is determined by the slag resistance of the slag pool which is effectively utilized, so that the heat productivity of the slag pool can be controlled within a certain range by controlling the insertion depth of an electrode, and great influence is generated on the smelting speed and the whole smelting process.

The diameter of the crystallizer of the electroslag furnace is inversely proportional to the insertion depth of the electrode.

The diameter of the crystallizer is 400mm-900mm, and the depth of the electrode inserted into the slag bath is 30mm-40 mm.

The insertion depth of the electroslag furnace electrode with the crystallizer diameter of more than 800mm is 30 mm.

The insertion depth of the electroslag furnace electrode with the diameter of the crystallizer below 400mm is 40 mm.

The key of the control method for controlling the electrode insertion depth is that the set value of the current is reasonably selected, if the set current is selected to be larger, the electrode insertion is deeper, and if the set current is selected to be smaller, the electrode insertion is shallower. The electrode insertion depth should be matched to the diameter and filling ratio of the mould, which is generally small, suitably deep, and shallow for large diameter moulds. The proper insertion depth is controlled by selecting a proper current set value, whether the current set value is proper or not is mainly observed by observing the fluctuation value of the actual current in smelting, and if the fluctuation value of the current is very small or even in a straight line in the smelting process and the electrode is always descending, the current set value needs to be properly reduced if the insertion depth of the electrode is larger. If the fluctuation range of the current is very large in the smelting process, even the obvious bright arc phenomenon appears in the crystallizer, which indicates that the insertion depth of the electrode is small, the set value of the current needs to be properly increased. Experiments show that for an electroslag furnace with a crystallizer diameter of less than 600mm, the actual smelting current is controlled to fluctuate within the range of 300A-500A around the set current value, the depth of the electrode inserted into the slag bath is about 40mm, and the head of the electrode is in a slightly downward convex shape.

The diameter of the crystallizer is above 800mm, the actual smelting current is controlled to fluctuate within the range of 500A-800A around the set current value, the insertion depth of the electrode is about 30mm, and the head of the electrode is plane or slightly concave upwards.