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CN-116949311-B - Grain refiner for brass and preparation method and use method thereof

CN116949311BCN 116949311 BCN116949311 BCN 116949311BCN-116949311-B

Abstract

A grain refiner for brass is prepared from (by weight) potassium fluoborate 40-60%, potassium fluotitanate 2-10%, potassium fluoride 5-10%, aluminum 5-15%, ferroboron 20-30%, nano carbon powder 2-5%, potassium chloride 1-5%, manganese powder 2-5% and unavoidable impurities in balance. The preparation method comprises the steps of drying raw materials in a baking oven at 105-150 ℃, grinding/mechanically crushing corresponding powder/blocks to the required particle size, punching aluminum into an aluminum shell with one end sealed through a plate, mixing the raw materials according to the raw material proportion, quantitatively weighing, filling the powder into the aluminum shell, and sealing the tail of the aluminum shell. The preparation process is simple and easy to operate, the grain refiner has good refining effect, the average grain size is reduced from the common level of 0.02-0.03mm to the level of 0.005-0.01mm, and after the structure is refined, the fine and uniform crystal structure of the brass cast ingot can be ensured, thereby being beneficial to reducing the defects of cracks, shrinkage cavity, cold insulation and the like on the surface of the cast.

Inventors

  • ZHOU BINGQING
  • CHAO GUOHUI
  • XIANG YANLONG
  • WANG DONG
  • ZHU PENGFEI
  • SHEN BO

Assignees

  • 宁波金田铜业(集团)股份有限公司

Dates

Publication Date
20260508
Application Date
20230712

Claims (8)

  1. 1. A grain refiner for brass is characterized by being prepared from the following raw materials, by mass, 40-60% of potassium fluoborate, 2-10% of potassium fluotitanate, 5-10% of potassium fluoride, 5-15% of aluminum, 20-30% of ferroboron, 1-5% of nano carbon powder, 1-4% of potassium chloride, 1-5% of manganese powder and the balance of unavoidable impurities; all the raw materials except aluminum are ground or mechanically crushed to the required particle size, uniformly mixed and filled into a tubular aluminum shell with one end sealed by a plate material.
  2. 2. The grain refiner for brass according to claim 1, wherein said potassium fluoroborate, potassium fluorotitanate, potassium fluoride and potassium chloride are in the form of powder and have an average particle diameter of 40 to 80. Mu.m.
  3. 3. The grain refiner for brass according to claim 1, wherein said ferroboron is Fe-20B alloy, and said ferroboron is in the form of powder having an average grain size of 80 to 150. Mu.m.
  4. 4. The grain refiner for brass according to claim 1, wherein said manganese powder is pure manganese powder having an average particle diameter of 80 to 150 μm.
  5. 5. The grain refiner for brass according to claim 1, wherein the average particle size of the nano carbon powder is 40-80. Mu.m.
  6. 6. The grain refiner for brass according to claim 1, wherein said aluminum is pure aluminum and the aluminum shell has a size of phi (20-30) mm× (200-400) mm.
  7. 7. A method for preparing the grain refiner for brass according to any one of claims 1 to 6, characterized by comprising the steps of: 1) Drying raw materials of potassium fluoborate, potassium fluotitanate, potassium fluoride, nano carbon powder, potassium chloride, manganese powder, aluminum and ferroboron in a baking oven at 105-150 ℃, grinding or mechanically crushing corresponding powder to a required particle size, and punching the aluminum into an aluminum shell with one end sealed by a plate; 2) Mixing the raw materials according to the proportion, and uniformly mixing the raw materials for more than 2 hours by using a powder uniformly mixer, wherein the uniform mixing degree of the powder is more than 95 percent; 3) Quantitatively weighing by using an electronic balance or a powder filling machine, and filling the powder into an aluminum shell; 4) And (5) packaging the aluminum shell with the grain refiner by using a tail sealing machine.
  8. 8. A method for using the grain refiner for brass prepared and obtained according to claim 7, which is characterized in that after the components are qualified and are converted at 1030-1050 ℃, a proper amount of grain refiner coated by an aluminum shell is pressed into copper water for less than 30cm by using a related appliance to be fully dissolved for 10-30s, and fully stirred, and is subjected to drawing casting after standing for 15-30min at 1000-1030 ℃, wherein the added amount of the grain refiner for brass has the following relation with the mass of a brass melt, namely the mass ratio of the grain refiner for brass to the brass melt is 8 multiplied by 10 -5 -1.1×10 -4 , namely 80-110g of grain refiner is added into each ton of brass melt.

Description

Grain refiner for brass and preparation method and use method thereof Technical Field The invention belongs to the technical field of copper and copper alloy, and relates to a grain refiner for brass, a preparation method and a use method thereof. Background The continuous casting brass section bar can be applied to the pipe joint fields of water pipes, gas pipes and the like due to lower price and proper processability, and compared with the tiny and uniform recrystallization structure of the extrusion brass section bar, the continuous casting brass section bar can generate the problems of red impact and Wen Dun cracking due to the thick and continuous casting structure. Therefore, in order to solve the problem of coarse continuous casting structure, the prior mature solution is to refine the as-cast structure by using a special brass grain refiner so as to achieve the hot processing performance similar to that of the extruded recrystallization structure. The grain refiner applicable to brass products at present can be generally divided into alloys such as Al-Ti-B, fe-Si, rare earth and the like, salts such as KBF 4、Na2CO3, mixtures and the like according to different active ingredients. The action mechanism is that non-spontaneous nucleation core is directly added or reacted in the melt, so that the melt realizes grain refinement through heterogeneous nucleation in the solidification process. The existing refiner technology has the following defects that 1, polishing particles exist after ingot slicing and polishing, 2, the refiner has short action time or the refining effect has a fading phenomenon, 3, the adding amount and the operation or the process are complex, and 4, certain components are easy to absorb water or pollute melt. Through investigation, the prior Chinese patent No. CN 201910802640.7-20 parts by mass of ferrosilicon alloy, KBF 4 -92 parts by mass, carbonate 1-5 parts by mass and manganese 3.5-6 parts by mass of a brass alloy grain refiner, and a preparation process and a use method thereof. The brass grain refiner takes iron element as a nucleation core, improves the fluidity of brass alloy melt, reduces macroscopic casting defects and improves the grain refining long-acting property on the premise of ensuring the refining effect. However, the preparation process is complex, the ferrosilicon alloy is required to be refined by a melt atomization condensation method at 1530-1580 ℃, KBF 4 and carbonate are dried and ground at 150-250 ℃, and the drying temperature is high. Disclosure of Invention The first technical problem to be solved by the invention is to provide a grain refiner for brass, which has high refining effect and contains a plurality of heterogeneous nucleation sites, and can avoid 'poisoning' of the refiner caused by large fusion of single heterogeneous sites. The second technical problem to be solved by the invention is to provide a preparation method of the grain refiner for brass, which has simple process and operation method, and the prepared refiner has good refining effect, effectively improves the casting fluidity of the cast ingot, improves the surface and internal quality of the cast ingot, and avoids macroscopic casting defects. The third technical problem to be solved by the invention is to provide a use method of a grain refiner for brass. The invention solves the first technical problem and adopts a technical scheme that the grain refiner for brass is characterized by being processed by the following raw materials, by mass, 40-60% of potassium fluoborate, 2-10% of potassium fluotitanate, 5-10% of potassium fluoride, 5-15% of aluminum, 20-30% of ferroboron, 1-5% of nano carbon powder, 1-4% of potassium chloride, 1-5% of manganese powder and the balance of unavoidable impurities. Preferably, the potassium fluoroborate, potassium fluorotitanate, potassium fluoride and potassium chloride are in the form of powder, and the average particle size is 40-80 μm. Preferably, the average particle size of the nano carbon powder is 40-80 μm. If the particle size of the powder is less than 40 mu m, the powder can be dispersed more quickly in a melt, but is easier to agglomerate and not easy to flow, and certain production is blocked, while if the particle size is more than 80 mu m, the powder is not easy to agglomerate and is better in fluidity, but cannot be dispersed quickly after entering the melt, and floating slag is easy to cause, so that the effective components are reduced. Therefore, the powder with the particle size of 40-80 mu m not only has certain fluidity and is easy to operate and produce, but also can ensure that the powder can be dispersed and play a role more quickly after entering a melt. Preferably, the ferroboron is Fe-20B alloy, the ferroboron is powdery, and the average grain size is 80-150 mu m. Preferably, the manganese powder is pure manganese powder, and the average particle size of the manganese powder is 80-150 mu m. The particle size of the metal/a