阅读说明：本技术 一种电渣熔炼用大端面电极坯高效起弧的方法 (Efficient arc striking method for large-end-face electrode blank for electroslag smelting ) 是由 刘佳伟 许立伟 郑壮 于 2021-06-18 设计创作，主要内容包括：本发明涉及一种电渣熔炼用大端面电极坯高效起弧的方法,属于电渣熔炼技术领域,解决大端面电极坯在引弧材料消耗过程中不能及时起弧化渣的技术问题,解决方案为：起弧材料由原来的“引锭板+引弧板+引弧钢屑”改为“引锭板+引弧板+引弧钢屑+渣料围堰”,保证燃弧温度影响范围与渣料布置范围重合范围扩大；并匹配起弧阶段配电参数：第一阶段电压电流采用小电流起弧,第二阶段按照曲线斜率逐步提升功率,第三阶段伴随加渣过程逐步缓慢提升至功率峰值,第四阶段缓将功率,匹配设定熔速,实施平稳过渡进入熔炼阶段。通过采用起弧材料布置和配电参数设定相结合的方法,达到高效起弧化渣,既安全有效、节约材料,又提高生产效率。(The invention relates to a method for efficiently striking an arc on a large end face electrode blank for electroslag smelting, belongs to the technical field of electroslag smelting, solves the technical problem that the large end face electrode blank cannot strike the arc and melt slag in time in the process of arc striking material consumption, and adopts the following technical scheme: the arc striking material is changed from the original 'a dummy bar plate, an arc striking plate and arc striking steel scraps' into 'the dummy bar plate, the arc striking steel scraps and a slag material cofferdam', so that the overlapping range of the impact range of the arc striking temperature and the arrangement range of the slag material is expanded; and matching the power distribution parameters in the arcing stage: the voltage and current of the first stage are started by adopting small current, the power of the second stage is gradually increased according to the slope of the curve, the power of the third stage is gradually and slowly increased to the peak value of the power along with the slag adding process, the power of the fourth stage is slowly increased to match the set melting speed, and the stable transition is implemented to enter the melting stage. By adopting the method of combining the arrangement of the arcing materials and the setting of the power distribution parameters, the high-efficiency arcing slagging is realized, the safety and the effectiveness are realized, the materials are saved, and the production efficiency is improved.)

1. A method for efficiently starting arc of a large-end-face electrode blank for electroslag smelting is characterized by comprising the following steps:

s1, arranging an arc striking material:

placing a dummy bar plate (1) on a bottom crystallizer, welding an arc striking plate (2) above the center of the dummy bar plate (1), then enclosing the edge of the arc striking plate (2) to form an annular slag material cofferdam (3) with the slag content of 5%, uniformly mixing slag materials and the contact edge of arc striking steel scraps, wherein the height of the slag material cofferdam (3) is lower than the height of the center of the arc striking plate (2), and the width of the slag material cofferdam (3) is smaller than the diameter of the crystallizer and larger than the diameter of an electrode blank;

s2, setting electroslag smelting power distribution parameters:

the first stage is as follows: within 0-5 minutes after power transmission, voltage is configured according to 60% of a given smelting electrical system, and current is configured according to 40% of the given smelting electrical system;

and a second stage: within 5-8 minutes after power transmission, the voltage is increased to 70% of the configuration of the established smelting electrical system, and the current is increased to 55% of the configuration of the established smelting electrical system;

and a third stage: adding 10% of the set total slag charge within 10 minutes after power supply is carried out for 8-95 minutes, gradually increasing the set voltage from the second-stage voltage configuration to 90% configuration of the set smelting electrical system along with the slag adding process, and gradually increasing the current from the second-stage current configuration to 80% configuration of the set smelting electrical system;

a fourth stage: after the power is transmitted for 95 minutes to 2 hours, firstly, the residual slag is completely and slowly added into a smelting furnace, and the power is slowly increased to the peak power (the voltage and the current are increased to the set maximum value) until the slag is completely melted; then slowly reducing the power, matching with the set melting speed, and enabling the melting furnace to smoothly transit into a melting stage.

2. The method for efficiently starting the arc of the electrode blank with the large end face for electroslag smelting according to claim 1, wherein the method comprises the following steps: the thickness of the arc striking plate (2) is 20-35 mm.

3. The method for efficiently starting the arc of the electrode blank with the large end face for electroslag smelting according to claim 1, wherein the method comprises the following steps: in the established smelting electrical system, the voltage is set in a gradient configuration of 60% -90%, and the current is set in a gradient configuration of 40% -80%.

4. The method for efficiently starting the arc of the electrode blank with the large end face for electroslag smelting according to claim 1, wherein the method comprises the following steps: the melting speed is set as follows: the initial peak value is 10-20% higher than the set value, and the peak value returns to the set value within 30 min.

Technical Field

The invention belongs to the technical field of electroslag smelting, and particularly relates to a method for efficiently striking an arc on a large-end-face electrode blank for electroslag smelting.

Background

The large-end-face electrode blank is an electrode blank with the diameter larger than 700mm, the diameter of the end face of the electrode blank is large, a large-area barrier is formed below the end face of the electrode blank, slag materials descend to the arc striking plate and then form a slope at the edge, the slag materials cannot reach the arc striking temperature influence range of the arc striking materials, arc striking and slag melting cannot be carried out in time in the consumption process of the arc striking materials, partial insulation is caused to cause power transmission failure, safety and quality problems are easily caused, original auxiliary materials are wasted, and the production efficiency is reduced.

Disclosure of Invention

The invention provides a method for efficiently striking an arc on a large end face electrode blank for electroslag smelting, aiming at overcoming the defects of the prior art and solving the technical problem that the large end face electrode blank cannot strike the arc and melt slag in time in the process of arc striking material consumption. By adopting the method of combining the arrangement of the arcing materials and the setting of the power distribution parameters, the high-efficiency arcing slagging is realized, the safety and the effectiveness are realized, the materials are saved, and the production efficiency is improved.

The design concept of the invention is as follows: the arc striking material is changed from the original 'a dummy bar plate, an arc striking plate and arc striking steel scraps' into 'the dummy bar plate, the arc striking steel scraps and slag enclosure', so that the overlapping range of the impact range of the arcing temperature and the arrangement range of slag charge is ensured to be expanded.

The invention is realized by the following technical scheme.

A method for efficiently starting arc of a large-end-face electrode blank for electroslag smelting comprises the following steps:

s1, arranging an arc striking material:

placing a dummy bar plate on a bottom crystallizer, welding a run-on plate above the core of the dummy bar plate, then enclosing the edge of the run-on plate to form an annular slag cofferdam with the slag content of 5%, uniformly mixing slag and the contact edge of run-on steel scraps, wherein the height of the slag cofferdam is lower than that of the center of the run-on plate, and the width of the slag cofferdam is smaller than the diameter of the crystallizer and larger than that of an electrode blank;

s2, setting electroslag smelting power distribution parameters:

the first stage is as follows: within 0-5 minutes after power transmission, voltage is configured according to 60% of a given smelting electrical system, and current is configured according to 40% of the given smelting electrical system, so that low-current arcing is ensured;

and a second stage: within 5-8 minutes after power transmission, the voltage is increased to 70% of the configuration of the established smelting electrical system, the current is increased to 55% of the configuration of the established smelting electrical system, and the influence range of the arcing temperature is further expanded to form a preliminary slag pool;

and a third stage: adding 10% of the total slag charge every 10 minutes after power transmission for 8-95 minutes; the set voltage is gradually increased to 90% of the set smelting electrical system from the second-stage voltage configuration along with the slag adding process, and the current is gradually increased to 80% of the set smelting electrical system from the second-stage current configuration;

a fourth stage: after the power is supplied for 95 minutes to 2 hours, firstly, slowly adding all the residual slag into a smelting furnace, and slowly increasing the power to the peak power until the slag is completely melted down; then slowly reducing the power, matching with the set melting speed, and enabling the melting furnace to smoothly transit into a melting stage.

Further, the thickness of the arc striking plate is 20-35 mm.

Furthermore, in the established smelting electrical system, the voltage is set in a gradient configuration of 60% -90%, and the current is set in a gradient configuration of 40% -80%.

Further, the melting rate was set as: the initial peak value is 10-20% higher than the set value, and the peak value returns to the set value within 30 min.

Compared with the prior art, the invention has the beneficial effects that:

by adopting the arc striking method provided by the invention, the one-time success rate of electroslag arc striking of the large-end-face electrode blank reaches 100%, the quality hidden trouble caused by the damage of protective atmosphere due to the midway addition of arc striking materials is solved, the arc striking materials and slag materials are saved, and the production efficiency is improved.

Drawings

FIG. 1 is a schematic diagram of an arrangement of arcing materials in the prior art;

FIG. 2 is a schematic top view of the arrangement of the arcing materials of the present invention;

fig. 3 is a front half-sectional structural schematic view of the arrangement of the arcing materials in the present invention.

In the figure, 1 is a dummy bar plate, 2 is an arc striking plate, and 3 is a slag cofferdam.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention. Unless otherwise specified, the examples follow conventional experimental conditions.

In the specific embodiment, the steel grade is R1Cr18Ni9Ti, and the steel ingot weight is 8.5T. Refining the steel ingot by adopting an electroslag remelting method, wherein the diameter of a crystallizer is 1000mm, and the diameter of an electrode blank is 800 mm; in the existing established smelting electrical system: the set voltage of the melting period is 80V, the peak voltage is 85V, the set current of the melting period is 16KA and the peak current is 17KA, and the melting speed of the melting period is 900 Kg/h.

A method for efficiently starting arc of a large-end-face electrode blank for electroslag smelting comprises the following steps:

s1, arranging an arc striking material:

placing an ignition plate 1 on a bottom crystallizer, welding an arc striking plate 2 above the center of the ignition plate 1, wherein the thickness of the arc striking plate 2 is 35mm, then arranging an annular slag material cofferdam 3 with the slag content of 5% at the edge of the arc striking plate 2, and uniformly mixing slag materials and the contact edge of arc striking steel scraps, wherein the height of the slag material cofferdam 3 is lower than the height of the center of the arc striking plate 2, and the width of the slag material cofferdam 3 is smaller than the diameter of the crystallizer and larger than the diameter of an electrode blank;

s2, setting electroslag smelting power distribution parameters:

the first stage is as follows: within 0-5 minutes after power transmission, voltage is configured according to 60% of a given smelting electrical system, and current is configured according to 40% of the given smelting electrical system;

and a second stage: within 5-8 minutes after power transmission, the voltage is increased to 70% of the configuration of the established smelting electrical system, and the current is increased to 55% of the configuration of the established smelting electrical system;

and a third stage: adding 10% of the total slag charge every 10 minutes after power transmission for 8-95 minutes; the set voltage is gradually increased to 90% of the set smelting electrical system from the second-stage voltage configuration along with the slag adding process, and the current is gradually increased to 80% of the set smelting electrical system from the second-stage current configuration;

a fourth stage: after the power is supplied for 95 minutes to 2 hours, firstly, slowly adding all the residual slag into a smelting furnace, and slowly increasing the power to the peak power until the slag is completely melted down; then the power is slowly reduced, the melting speed is set to be 900Kg/h in the matching melting period, and the melting furnace smoothly transits to enter the melting stage.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.