阅读说明：本技术 一种扁平电极坯料的制备方法 (Preparation method of flat electrode blank ) 是由 李海强 裴兰科 葛春钰 赵明哲 刘海燕 罗世轩 于 2021-08-20 设计创作，主要内容包括：本发明涉及一种扁平电极坯料的制备方法,包括如下步骤：1)钢锭模设计及制造；2)钢锭模组装；3)钢水冶炼及钢锭浇注；4)电极坯料缓冷及精整；本发明采用铸造方式成功制备出超长(长度6m以上)、超薄(厚度250mm以下)的扁平电极坯料,最终生产出的电极能够满足大型板坯电渣重熔的要求。(The invention relates to a preparation method of a flat electrode blank, which comprises the following steps: 1) designing and manufacturing an ingot mold; 2) assembling an ingot mold; 3) smelting molten steel and pouring steel ingots; 4) slowly cooling and finishing the electrode blank; the invention successfully prepares the ultra-long (more than 6m in length) and ultra-thin (less than 250mm in thickness) flat electrode blank by adopting a casting mode, and the finally produced electrode can meet the requirement of large slab electroslag remelting.)

1. The preparation method of the flat electrode blank is characterized in that the length of the flat electrode blank is more than or equal to 6m, and the thickness of the flat electrode blank is less than or equal to 250 mm; the preparation process comprises the following steps:

1) designing and manufacturing an ingot mold;

determining the sizes of all parts of the ingot mould according to the overall dimension of the flat electrode blank, and designing a pouring system; horizontal ingot mold is adopted, pouring is carried out, and molten steel rising holes are 4 holes; the ingot mould consists of an upper box and a lower box, and the upper box and the lower box are respectively cast and molded; the upper box and the lower box after casting respectively polish the surfaces and process a primary opening and a secondary opening, and then are preassembled;

2) assembling an ingot mold;

spraying demoulding paint on the inner wall of the ingot mould, then assembling, and baking after assembling to keep the temperature of the ingot mould above 50 ℃; covering a riser after the ingot mould is assembled;

3) smelting molten steel and pouring steel ingots;

after molten steel is subjected to electric furnace smelting, ladle refining and vacuum degassing, pouring the molten steel into a steel ingot mold; the tapping temperature is 1540-1550 ℃, the pouring temperature is 1490-1510 ℃, and the pouring time is 10-16 minutes;

4) slowly cooling and finishing the electrode blank;

and demolding after the casting is finished for 24 hours, carrying out hot cutting on a riser on the demolded electrode blank, carrying out chemical component analysis and surface finishing, and obtaining a flat electrode blank finished product which meets the technical requirements.

Technical Field

The invention relates to the technical field of electrode manufacturing, in particular to a preparation method of a flat electrode blank of an electrode used in large slab electroslag remelting.

Background

With the development of science and technology, a large amount of high-quality special steel is urgently needed by modern mechanical systems. Electroslag remelting is one of the main means of special metallurgy. The electroslag steel ingot has the advantages of compact structure, uniform components, smooth surface, high yield, etc. and the slab produced by electroslag remelting technology can omit the cogging process, be directly fed into a plate rolling mill, reduce the forging ratio and save the working hours, so the electroslag remelting technology for large slabs is a necessary means for producing high-end steel products such as high-end die steel, submarine pressure-resistant shell steel, boiler container steel, nuclear power steel, etc.

An electrode for electroslag remelting of a large slab is prepared from an electrode blank which is usually produced by continuous casting; however, the electrode blank with high alloy, small trial production and special requirements cannot be produced by continuous casting, and the electrode blank produced by forging has low yield and higher cost. The invention successfully prepares the electrode blank, in particular to an ultra-long and ultra-thin flat electrode blank by a casting mode, has no precedent of casting processing so far, and has large processing difficulty.

Disclosure of Invention

The invention provides a preparation method of a flat electrode blank, which is characterized in that an ultra-long (more than 6m in length) and ultra-thin (less than 250mm in thickness) flat electrode blank is successfully prepared by adopting a casting mode, and finally, the produced electrode can meet the requirement of large slab electroslag remelting.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of a flat electrode blank comprises the steps of enabling the length of the flat electrode blank to be larger than or equal to 6m and enabling the thickness of the flat electrode blank to be smaller than or equal to 250 mm; the preparation process comprises the following steps:

1) designing and manufacturing an ingot mold;

determining the sizes of all parts of the ingot mould according to the overall dimension of the flat electrode blank, and designing a pouring system; horizontal ingot mold is adopted, pouring is carried out, and molten steel rising holes are 4 holes; the ingot mould consists of an upper box and a lower box, and the upper box and the lower box are respectively cast and molded; the upper box and the lower box after casting respectively polish the surfaces and process a primary opening and a secondary opening, and then are preassembled;

2) assembling an ingot mold;

spraying demoulding paint on the inner wall of the ingot mould, then assembling, and baking after assembling to keep the temperature of the ingot mould above 50 ℃; covering a riser after the ingot mould is assembled;

3) smelting molten steel and pouring steel ingots;

after molten steel is subjected to electric furnace smelting, ladle refining and vacuum degassing, pouring the molten steel into a steel ingot mold; the tapping temperature is 1540-1550 ℃, the pouring temperature is 1490-1510 ℃, and the pouring time is 10-16 minutes;

4) slowly cooling and finishing the electrode blank;

and demolding after the casting is finished for 24 hours, carrying out hot cutting on a riser on the demolded electrode blank, carrying out chemical component analysis and surface finishing, and obtaining a flat electrode blank finished product which meets the technical requirements.

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

the casting method is adopted to successfully prepare the ultra-long (the length is more than 6 m) and ultra-thin (the thickness is less than 250 mm) flat electrode blank, and the finally produced electrode can meet the requirement of large slab electroslag remelting.

Drawings

Fig. 1a is a front view of a flat electrode blank according to the invention.

Fig. 1b is a top view of fig. 1 a.

FIG. 2a is a front view of the upper box of the ingot mold according to the present invention.

Fig. 2b is a top view of fig. 2 a.

Fig. 2c is a right side view of fig. 2 b.

FIG. 3a is a front view of the lower box of the ingot mold according to the present invention.

Fig. 3b is a bottom view of fig. 3 a.

Fig. 3c is a left side view of fig. 3 b.

FIG. 4a is a front view of the ingot mold according to the invention.

Fig. 4b is a front view of fig. 4 a.

Fig. 4c is a side view of fig. 4 b.

Detailed Description

The invention relates to a preparation method of a flat electrode blank, as shown in figures 1a and 1b, the length of the flat electrode blank is more than or equal to 6m, and the thickness of the flat electrode blank is less than or equal to 250 mm; the preparation process comprises the following steps:

1) designing and manufacturing an ingot mold;

determining the sizes of all parts of the ingot mould according to the overall dimension of the flat electrode blank, and designing a pouring system; horizontal ingot mold is adopted, pouring is carried out, and molten steel rising holes are 4 holes; the ingot mould (shown in figures 4a-4 c) consists of an upper box (shown in figures 2a-2 c) and a lower box (shown in figures 3a-3 c), which are cast separately; the upper box and the lower box after casting respectively polish the surfaces and process a primary opening and a secondary opening, and then are preassembled;

2) assembling an ingot mold;

spraying demoulding paint on the inner wall of the ingot mould, then assembling, and baking after assembling to keep the temperature of the ingot mould above 50 ℃; covering a riser after the ingot mould is assembled;

3) smelting molten steel and pouring steel ingots;

after molten steel is subjected to electric furnace smelting, ladle refining and vacuum degassing, pouring the molten steel into a steel ingot mold; the tapping temperature is 1540-1550 ℃, the pouring temperature is 1490-1510 ℃, and the pouring time is 10-16 minutes;

4) slowly cooling and finishing the electrode blank;

and demolding after the casting is finished for 24 hours, carrying out hot cutting on a riser on the demolded electrode blank, carrying out chemical component analysis and surface finishing, and obtaining a flat electrode blank finished product which meets the technical requirements.

The following examples are carried out on the premise of the technical scheme of the invention, and detailed embodiments and specific operation processes are given, but the scope of the invention is not limited to the following examples. Any person skilled in the art should be able to substitute or change the technical solution of the present invention and its inventive concept within the technical scope of the present invention.

[ examples ] A method for producing a compound

In the present embodiment, as shown in fig. 1a and 1b, the prepared flat electrode blank has a length of 6m and a thickness of 250 mm; the preparation process comprises the following steps:

1) designing and manufacturing an ingot mold:

the design of the ingot mould structure and related parameters and the design of a pouring system (including the design of a bottom plate and the design of a runner system) are carried out according to the size of the electrode, so that the inner cavity ruler, the surface and the internal quality of the ingot mould can meet the requirements.

The conventional ingot mold is generally divided into two types, i.e., a large upper part and a small lower part, and the large upper part and the small lower part are used for realizing vertical pouring. The invention breaks the conventional ingot mould design, and the ingot mould adopts a horizontal ingot mould, so that the length of the blank can be effectively ensured to reach more than 6000 mm.

The invention calculates the formula epsilon (l) through the linear shrinkage rate according to the steel grade characteristics of the flat electrode blank₁-l₂)/l₂(l₁Is the linear dimension of the model,. l₂The linear dimension of the casting) to calculate the length dimension of the ingot mould. The linear shrinkage of the steel for electrode material was about 1.6%, and the result was substituted into the formula to obtain (l) 1.6%₁-6000)/6000, obtaining l₁6096mm, namely the dimension of the ingot mould in the length direction is 6100mm, which can meet the dimension requirement of the cast product. The thickness of the ingot mould is calculated according to the draft angle, when the width of the casting is 1000mm, the draft angle is 5mm on one side and 10mm on both sides, and the size of the ingot mould when the thickness of the blank is 250mm is 260 mm. I.e. the final ingot mould has a cavity size of 260mm (thickness) x 1180mm (width) x 6100mm (length).

The conventional steel ingot casting is carried out in a downward pouring mode, and a molten steel ascending hole is single-hole casting. The pouring system of the embodiment still adopts a pouring mode of pouring, but the molten steel lifting hole is designed into 4 holes. The thickness of the ingot mould is only 260mm, so that the phenomenon of mould sticking caused by strong impact generated by rising molten steel due to single-hole pouring is caused, and the phenomenon of mould sticking can be effectively avoided by designing 4-hole pouring.

Casting an upper box (as shown in fig. 2a-2 c) and a lower box (as shown in fig. 3a-3 c) which form the ingot mold, polishing the surface of each box body, simultaneously machining the primary and secondary openings, and pre-assembling the ingot mold after machining (as shown in fig. 4a-4 c).

2) Assembling an ingot mold:

and (3) spraying demoulding paint on the inner wall of the ingot mould, then assembling, baking the ingot mould after assembling to ensure that the temperature of the ingot mould is more than 50 ℃, and covering a dead head of the assembled ingot mould by using a cover plate to avoid secondary pollution.

3) Smelting molten steel and pouring steel ingots;

molten steel is processed by the processes of electric furnace smelting, ladle refining and VD vacuum degassing, the smelting process requirements are strictly executed in the molten steel processing process, the components and the purity of the molten steel are ensured, the tapping temperature is 1540 ℃, the pouring temperature is 1500 ℃, the body pouring time is 11 minutes, and the impact of the molten steel is avoided; the pouring time of the dead head is 6 minutes, and the dead head is fully poured, so that the feeding of the molten steel is ensured.

4) Slowly cooling and finishing an electrode blank:

and (3) a steel ingot is subjected to cold box making, demoulding is carried out after the pouring is finished for 24 hours according to the demoulding process requirement, the obtained electrode blank is subjected to hot-cutting feeder head after demoulding, and chemical component analysis and surface finishing are carried out.

In the embodiment, the size of the prepared electrode blank is 250mm in thickness and 6000mm in length, the electrode manufacturing requirements are met, the surface quality meets the requirements through appearance inspection, and the chemical components and various performance indexes meet the requirements.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.