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CN-121976047-A - Shallow flattening control method for electroslag metal liquid pool

CN121976047ACN 121976047 ACN121976047 ACN 121976047ACN-121976047-A

Abstract

The invention belongs to the technical field of electroslag remelting metallurgy, and relates to a control method for shallow leveling of an electroslag metal liquid pool. The invention optimizes the electrode, controls the current density, optimizes the slag system components and sets the blowing pipe in the slag bath for stirring the slag, thereby realizing the shallow flattening control of the electroslag metal bath. The method promotes the crystallization to grow in a finer mode, improves the density and mechanical property of the steel ingot, has the advantages of small shallow flattening molten pool depth, short floating path of inclusions, more stable and orderly convection of the molten pool, reduces the retention of the inclusions caused by vortex in a deep molten pool, is beneficial to fully removing the inclusions, reduces the inclusion content in the steel, improves the purity of the steel, ensures that the solidification process of the shallow flattening molten pool is uniformly advanced from the edge to the center, ensures more complete feeding, and can effectively reduce the volumetric defects such as shrinkage cavity, looseness and the like in the steel ingot.

Inventors

  • LI DEJUN
  • ZHAO LIANG
  • JIA JIXIANG
  • HUANG YUPING
  • YANG JI
  • LI BOYANG
  • FAN SIPENG
  • SUN SHEN

Assignees

  • 鞍钢股份有限公司

Dates

Publication Date
20260505
Application Date
20260209

Claims (8)

  1. 1. The method for controlling the shallow flattening of the electroslag metal liquid pool is characterized by comprising the following process steps of: (1) The electrode for electroslag remelting comprises a first electrode section, a transition section and a second electrode section which are sequentially connected from top to bottom, wherein the first electrode section and the second electrode section are of cylindrical structures, the diameter of the second electrode section is 1.1-1.25 times of that of the first electrode section, and the length of the second electrode section is 5% -10% of the total length of the electrode for electroslag remelting; (2) The electroslag remelting process is divided into 5 stages according to the melting time, wherein the initial stage accounts for 12% -18% of the total melting time, the first transition stage accounts for 3% -8% of the total melting time, the middle stage accounts for 36% -42% of the total melting time, the second transition stage accounts for 3% -7% of the total melting time, and the final stage accounts for 35% -45% of the total melting time; The current density at each stage is controlled as follows: the current density in the initial stage is controlled to be 0.30-0.40A/mm 2 ; the current density in the first transition stage is controlled to be 0.25-0.35A/mm 2 ; the current density in the middle stage is controlled to be 0.20-0.30A/mm 2 ; the current density in the second transition stage is controlled to be 0.15-0.25A/mm 2 ; the current density in the final stage is controlled to be 0.12-0.20A/mm 2 ; (3) The electroslag material comprises, by mass, 40% -45% of CaF 2 50%-55%、Al 2 O 3 %, 3% -5% of BaO and 1% -3% of BN; (4) A blowing pipe is arranged in the slag bath.
  2. 2. The method for controlling shallow flattening of electroslag metal pool according to claim 1, wherein the transition section has a truncated cone structure with a taper of 40 ° -45 °.
  3. 3. The method for controlling the shallow flattening of an electroslag metal bath according to claim 1, wherein the lance is horizontally placed at a vertical distance of 30-50mm from the metal level.
  4. 4. The method of controlling shallow pool of electroslag metal according to claim 1, wherein the size of the lance is smaller than the diameter of the first electrode segment.
  5. 5. The method for controlling the shallow flattening of an electroslag metal bath according to claim 1, wherein the blowing pipe has a U-shaped structure and is made of tungsten carbide ceramic.
  6. 6. The method for controlling shallow flattening of electroslag metal pool according to claim 1, wherein the blowing pipe is uniformly distributed with gas spraying holes, and the included angle between the direction of sprayed gas and the axial direction of the electrode is 30 ° -90 °.
  7. 7. The method for controlling the shallow flattening of an electroslag metal pool according to claim 1, wherein the gas spouting port has a pore diameter of 0.5-2.0mm.
  8. 8. The method for controlling shallow flattening of an electroslag metal pool according to claim 1, wherein the gas blown by the blowing pipe is argon gas, and the blowing flow is 2-5L/min.

Description

Shallow flattening control method for electroslag metal liquid pool Technical Field The invention relates to the technical field of electroslag remelting metallurgy, in particular to a control method for shallow leveling of an electroslag metal liquid pool. Background In the field of electroslag metallurgy, the geometry of the metal bath is a central factor in determining the metallurgical quality and production efficiency. Due to technical characteristics, the traditional electroslag metallurgy process often forms a deep metal liquid pool structure, and the depth ratio of the deep metal liquid pool structure is more than 3. The deeper liquid pool form can obviously weaken the dynamic stability of the metallurgical process, and simultaneously cause the problem of component segregation in the metal melt, so that the quality defects of uneven structure, performance fluctuation and the like of the final product are caused, and the application value of the product in the field of high-end manufacturing is directly influenced. Along with the continuous rising of the requirements of modern industry on high-quality metal materials, an innovative technology capable of accurately regulating and controlling the form of a metal liquid pool and realizing shallow leveling of the liquid pool is developed, and the novel technology becomes a key break for improving the competitiveness of the electroslag metallurgy process and has important engineering practical value and wide market application prospect. For example, patent application number CN202110520913.6 discloses a constant bath shape electroslag remelting method based on electrode rotation speed control, wherein the temperature of the slag bath is precisely regulated and controlled by the electrode rotation speed control, so that a stable and shallow shape of a metal bath is obtained. By increasing the rotation speed of the consumable electrode from 0 to the first rotation speed and adopting a step-by-step speed regulation strategy subsequently, molten metal is dispersed and dripped, the convection heat exchange between the slag bath and the solid electrode is enhanced, the electrode melting efficiency is improved, the slag bath and the metal molten pool are more uniform in temperature, a shallow flat metal molten pool is easy to form, macroscopic defects are suppressed, and the solidification quality is improved. Although molten metal liquid drops can be thrown out through centrifugal force to achieve shallow flattening of a metal molten pool, liquid drops with relatively low temperature can be directly thrown to the vicinity of an edge copper plate of a crystallizer without a heating process of high Wen Zhachi due to the centrifugal force, scabs are easily formed, and the surface quality of a steel ingot is reduced. In addition, the method has a great limitation that the method is only suitable for the electrode with the circular cross section, but in actual production, a plurality of electrodes with square or rectangular cross sections cannot realize the rotation operation. Disclosure of Invention The invention aims to improve the quality of products in the metallurgical process by changing the original hydrodynamic behavior of a metal liquid pool by a control method capable of realizing shallow flattening of the electroslag metal liquid pool so as to achieve the effect of accurately regulating and controlling the liquid pool morphology. In order to achieve the above object, the technical scheme of the present invention is as follows: the control method for shallow flattening of the electroslag metal liquid pool comprises the following process steps: (1) The electrode for electroslag remelting comprises a first electrode section, a transition section and a second electrode section which are sequentially connected from top to bottom, wherein the first electrode section and the second electrode section are of cylindrical structures, the diameter of the second electrode section is 1.1-1.25 times of that of the first electrode section, and the length of the second electrode section is 5% -10% of the total length of the electrode for electroslag remelting; (2) The electroslag remelting process is divided into 5 stages according to the melting time, wherein the initial stage accounts for 12% -18% of the total melting time, the first transition stage accounts for 3% -8% of the total melting time, the middle stage accounts for 36% -42% of the total melting time, the second transition stage accounts for 3% -7% of the total melting time, and the final stage accounts for 35% -45% of the total melting time; The current density at each stage is controlled as follows: the current density in the initial stage is controlled to be 0.30-0.40A/mm 2; the current density in the first transition stage is controlled to be 0.25-0.35A/mm 2; the current density in the middle stage is controlled to be 0.20-0.30A/mm 2; the current density in the second transition stage is controlled to be 0