阅读说明：本技术 一种高锰钢的炼钢方法 (Steelmaking method of high manganese steel ) 是由 李建朝 赵国昌 李�杰 龙杰 高雅 付冬阳 付振坡 刘丹 袁平 师帅 赵晓辉 于 2021-08-16 设计创作，主要内容包括：一种高锰钢的炼钢方法,采用LF炉进行精炼,在LF炉渣变白之前分批次向钢液中加入电解锰,按重量计,当钢液中锰含量达到a％±2％时,再加入铝脱氧剂进行脱氧变渣,所述a％为高锰钢成品目标锰含量范围的中限。本发明减少了钢液中的氮含量,使钢液中的氮含量在60ppm以下,减少了AlN夹杂在晶界析出,消除了高锰高铝钢因AlN夹杂导致开裂。(A steel-making method of high manganese steel adopts an LF furnace for refining, electrolytic manganese is added into molten steel in batches before LF furnace slag is whitened, and when the manganese content in the molten steel reaches a% +/-2% by weight, an aluminum deoxidizer is added for deoxidation and slag change, wherein the a% is the middle limit of the target manganese content range of a high manganese steel finished product. The method reduces the nitrogen content in the molten steel, ensures that the nitrogen content in the molten steel is below 60ppm, reduces the precipitation of AlN inclusions in crystal boundaries, and eliminates the cracking of the high-manganese high-aluminum steel caused by the AlN inclusions.)

1. A steel-making method of high manganese steel adopts an LF furnace for refining, electrolytic manganese is added into molten steel in batches before LF furnace slag is whitened, and when the manganese content in the molten steel reaches a% +/-2% by weight, an aluminum deoxidizer is added for deoxidation and slag change, wherein the a% is the middle limit of the target manganese content range of a high manganese steel finished product.

2. The method as claimed in claim 1, wherein the LF refining process is performed, and the temperature of the molten steel is raised to 1580-.

3. The steel-making method of high manganese steel according to claim 1, wherein electrolytic manganese is added to the molten steel in batches, 2.5-3.5 tons of electrolytic manganese are added each time, the adding time interval is 10-15 minutes, and the adding times are determined according to the target requirement of manganese content of the high manganese steel finished product.

4. The method of producing steel of high manganese steel according to claim 1, wherein said deoxidizer is aluminum particles.

5. The steel-making method of high manganese steel according to claim 4, wherein said deoxidizer further contains one or more of aluminum wire, calcium carbide, and carbon powder.

6. The steel-making method of high manganese steel according to claim 5, wherein 20-27 kg of aluminum wire, 1.5-2.0 kg of calcium carbide, 1.2-1.6 kg of aluminum particles and 0.005-0.02 kg of carbon powder are added per ton of steel in the deoxidation and slag change process.

7. The method of producing high manganese steel according to any one of claims 1 to 6, wherein the white slag is kept at 25 to 30 mm after the refining slag is whitened.

8. The method for making steel of high manganese steel according to any one of claims 1 to 6, wherein the weight percentage of Mn and Al in the high manganese steel is 18-30% and 1.5-5% respectively.

Technical Field

The invention belongs to the technical field of ferrous metallurgy, and particularly relates to a high manganese steel making method.

Background

The Fe-Mn-Al series austenite high-manganese non-magnetic steel has high strength, high toughness and high work hardening performance, and is an indispensable structural material for superconducting energy storage equipment, magnetofluid power generation equipment, superconducting generators, superconducting power transmission, electromagnetic propulsion ships and the like.

More than 18% of manganese element is required to maintain stable austenite and low magnetic permeability, and more than 1.5% of Al element is required to prevent phase transformation in the sample processing process. Because the steel has higher manganese and aluminum contents, the manganese content reaches more than 18 percent, and the aluminum content reaches more than 1.5 percent, when producing steel grades with high manganese and aluminum contents, the LF refining period is longer because a large amount of manganese alloy needs to be added, and the N content in molten steel is easily increased and the aluminum nitride inclusion is increased by feeding manganese after the slag is white in the traditional LF refining process; a large amount of aluminum nitride inclusions can be precipitated at a grain boundary in the solidification process, so that large-area cracks are generated on the surface of a steel plate, and the flaw detection of the steel plate is improper, so that a novel manganese feeding method aiming at high-manganese high-aluminum steel is required to be invented.

Disclosure of Invention

The invention aims to provide a steel-making method of high manganese steel, which can reduce aluminum nitride inclusions in the steel.

The technical scheme of the invention is as follows: a steel-making method of high manganese steel adopts an LF furnace for refining, electrolytic manganese is added into molten steel in batches before LF furnace slag is whitened, and when the manganese content in the molten steel reaches a% +/-2% by weight, an aluminum deoxidizer is added for deoxidation and slag change, wherein the a% is the middle limit of the target manganese content range of a high manganese steel finished product.

Further, in the LF refining process, the temperature of the molten steel is raised to 1580-.

Further, adding electrolytic manganese into the molten steel in batches, wherein 2.5-3.5 tons of electrolytic manganese are added each time, the adding time interval is 10-15 minutes, and the adding times are determined according to the target requirement of the manganese content of the high manganese steel finished product.

Further, the deoxidizer is aluminum particles.

Further, the deoxidizer also contains one or more of aluminum wires, calcium carbide and carbon powder.

Further, a deoxidizing agent is added for carrying out a deoxidation and slag change process, and 20-27 kg of aluminum wire, 1.5-2.0 kg of calcium carbide, 1.2-1.6 kg of aluminum particles and 0.005-0.02 kg of carbon powder are added per ton of steel.

Furthermore, white slag is kept at 25-30mim after refining slag is whitened.

Further, the high manganese steel contains 18-30 wt% of Mn and 1.5-5 wt% of Al.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in:

according to the invention, electrolytic manganese is added firstly and then the smelting process of slag changing is carried out, oxygen is utilized as a surface active substance, oxygen is enriched on the surface, and can occupy a part of surface positions capable of adsorbing nitrogen, so that the adsorption of nitrogen on the positions is hindered, the nitrogen content in the molten steel is reduced, the nitrogen content in the molten steel is enabled to be below 60ppm, the precipitation of AlN inclusion on a crystal boundary is reduced, and the cracking of high-manganese high-aluminum steel caused by the AlN inclusion is eliminated. The manganese content of the high-manganese high-aluminum steel plate produced by the method is accurately controlled, the inclusions are below 1.0 grade, and the flaw detection can be qualified for GB I grade.

Detailed Description

Embodiments of the present invention will be described below. The present invention is not limited to the following embodiments.

The initial smelting of the molten steel is carried out by adopting an electric furnace/converter, the C in the molten steel is more than or equal to 0.07 percent, the P in the molten steel is less than or equal to 0.005 percent, and the temperature is 1540-5 ℃ and 1560 ℃. And (3) refining the molten steel by adopting an LF (ladle furnace), after an LF refining ladle, raising the temperature of the molten steel to 1580-1620 ℃, adding electrolytic manganese in batches before the LF slag turns white, starting to add 2.5-3.5 tons of electrolytic manganese, then adding 2.5-3.5 tons of electrolytic manganese every 10-15 minutes, and determining the adding times according to the target requirement of the manganese content of the high manganese steel finished product. And when the manganese content reaches a% +/-2%, adding aluminum particles, aluminum wires, calcium carbide, carbon powder and the like for deoxidation and slag change, wherein the adding amount is 20-27 kg of aluminum wires per ton of steel, 1.5-2.0 kg of calcium carbide per ton of steel, 1.2-1.6 kg of aluminum particles per ton of steel and 0.005-0.02 kg of carbon powder per ton of steel. The bottom argon blowing pressure in the LF refining temperature rising process step is 0.3-0.5Mpa, and the bottom argon blowing pressure in the atmospheric argon stirring step is kept at 1.0-1.5Mpa during the manganese electrolysis, so that the electrolytic manganese is ensured to be fully melted. White slag keeps 25-30mim after refining slag becomes white.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Examples 1 to 6

Examples 1-5 were produced using the above-described embodiment, and the chemical compositions and weight percent ranges of the produced steel sheets are shown in table 1. The temperature of the molten steel, the weight of electrolytic manganese added each time, the time interval of the electrolytic manganese added and the times of the electrolytic manganese added when the electrolytic manganese is added in the LF refining process are shown in Table 2, the middle limit a% value of the target manganese content range of the high manganese steel finished product is shown in Table 3, the Mn content in the molten steel when the deoxidizer is added for deoxidation and slag change is shown in Table 3, the adding amount of aluminum wires, aluminum particles, calcium carbide and carbon powder is shown in Table 3, and the white slag holding time after the refined slag is whitened is shown in Table 3.

TABLE 1

TABLE 2

TABLE 3

The inclusions in the high-manganese high-aluminum steel plates obtained in examples 1 to 6 are graded according to inclusion grading standard of GB10561-2005 steel nonmetal inclusion content determination standard rating chart microscopic inspection method, the inclusions are below 1.0 level, flaw detection can be combined with I level according to GB/T2970 one-step 2016 thick steel plate ultrasonic detection method, and the surface is good and has no cracks.

Although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made thereto without departing from the spirit and scope of the invention and it is intended to cover in the claims the invention as defined in the appended claims.