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CN-122012983-A - Lead brass alloy and preparation method and application thereof

CN122012983ACN 122012983 ACN122012983 ACN 122012983ACN-122012983-A

Abstract

The invention discloses a lead brass alloy, which comprises, by mass, 57-60% of Cu, 0.8-1.9% of Pb0.2%, less than or equal to 0.2% of Fe, less than or equal to 0.2% of Sn, 0.1-0.2% of Ni, less than or equal to 0.1% of Al, less than or equal to 0.01% of Si, and the balance Zn and unavoidable impurities, wherein the lead brass alloy comprises an alpha phase, a beta phase and a Pb elementary substance phase, the area percentage of the alpha phase is 40-60%, and the area percentage of the beta phase is 35-55%. The lead brass alloy has proper mechanical property and wear resistance, lower ductile-brittle transition temperature and better low-temperature toughness. The invention also discloses a preparation method of the lead brass alloy, which comprises the process flows of smelting, traction continuous casting, extrusion, aisle straightening, peeling and extending, and finished product annealing, wherein the temperature of the finished product annealing is 280-450 ℃, and the invention also discloses the application of the lead brass alloy in a valve in a low-temperature medium environment.

Inventors

  • XU XUEHONG
  • WANG DONG
  • XU TIANLU
  • SHEN BO
  • SUN JIAN

Assignees

  • 宁波金田铜业(集团)股份有限公司

Dates

Publication Date
20260512
Application Date
20260331

Claims (10)

  1. 1. A lead brass alloy is characterized by comprising, by mass, 57-60% of Cu, 0.8-1.9% of Pb0.2% or less of Fe, 0.2% or less of Sn, 0.1-0.2% of Ni, 0.1% or less of Al and 0.01% or less of Si, and the balance of Zn and unavoidable impurities; The lead brass alloy comprises an alpha phase, a beta phase and a Pb elementary substance phase, wherein the area percentage of the alpha phase is 40-60%, and the area percentage of the beta phase is 35-55%.
  2. 2. The lead brass alloy of claim 1, wherein the average grain size of the alpha phase and beta phase is 20 μιη or less.
  3. 3. The lead brass alloy of claim 1, wherein the average size of the elemental Pb phases is 3 μιη or less, and the distribution of the elemental Pb phases is greater than 10000/mm 2 .
  4. 4. The lead brass alloy of claim 1, wherein the lead brass alloy has an average grain size of 5-20 μm.
  5. 5. The lead brass alloy of claim 1, wherein the lead brass alloy has an impact absorption work of 14-30J at-196 ℃ to 0 ℃.
  6. 6. A method for preparing a lead brass alloy according to any of claims 1-5, wherein the preparation method comprises the steps of smelting, traction continuous casting, extrusion, aisle alignment, peeling extension and finished product annealing; Proportioning and smelting according to the mass percentages of the components of the lead brass alloy; The annealing temperature of the finished product is 280-450 ℃.
  7. 7. The method for producing a lead brass alloy according to claim 6, wherein the extrusion temperature of the extrusion is 570-650 ℃, the extrusion speed is 15-25mm/s, and the extrusion ratio is 10-30.
  8. 8. The method for producing a lead brass alloy according to claim 6, wherein the extrusion pressure is 5-18MPa.
  9. 9. The method for preparing the lead brass alloy according to claim 6, wherein the smelting feeding sequence comprises red copper, lead brass production return material, copper foam, zinc ingot, stirring, adding a slag remover, stirring and skimming, standing and converter.
  10. 10. Use of a lead brass alloy according to any of claims 1-5, or a copper alloy made according to the method of making a lead brass alloy according to any of claims 5-9, in a valve in a medium environment at temperatures from-196 ℃ to 0 ℃.

Description

Lead brass alloy and preparation method and application thereof Technical Field The invention belongs to the technical field of copper alloy, and particularly relates to a lead brass alloy and a preparation method and application thereof. Background Most metals have increased material strength with decreasing temperature, while toughness decreases, and the materials exhibit low-temperature brittleness, which is not excellent in transportation environments of low-temperature media such as liquefied natural gas, liquid nitrogen, and the like. Copper and copper alloy have excellent toughness and lower ductile-brittle transition temperature, can be applied to liquid helium (-269 ℃) and become good materials for low-temperature valves. The invention patent application with publication number CN119710358A discloses an ultralow-temperature high-toughness copper alloy material and a preparation method thereof, and an ultralow-temperature high-toughness copper alloy material and a preparation method thereof, belonging to the technical field of ultralow-temperature high-toughness nonferrous metal materials. The material comprises, by mass, 15-25% of nickel (Ni), 2-6% of manganese (Mn), 2.5-6.5% of aluminum (Al), 0.2-1.0% of phosphorus (P), and the balance of copper and unavoidable impurities. The preparation method comprises the steps of proportioning (pure Cu, pure nickel and pure manganese), melting, heat preservation, cooling, melting of Cu-P intermediate alloy and pure aluminum, heat preservation, casting molding, forging and solid solution aging heat treatment. The invention patent application with publication number CN106916996B discloses a low-temperature ultra-high-toughness wear-resistant copper alloy and a preparation method thereof, belonging to the technical field of metal materials and preparation thereof. The copper alloy comprises, by mass, 25.0-45.0% of nickel, 2-15% of manganese, 1-8% of zinc, 0.1-5.0% of titanium, 0.5-5% of iron, 0.1-3% of chromium and the balance of copper. The preparation method comprises the steps of proportioning, casting, hot extrusion, hot forging and finished product. The invention improves the low-temperature comprehensive mechanical property and wear resistance of the alloy and ensures the alloy to have good processing property by adding elements such as manganese, zinc, titanium, iron, chromium and the like. However, both patent applications realize low-temperature toughness by controlling the content of alloy elements under the condition of white copper alloy, but still do not obtain copper alloy with better low-temperature toughness, lower ductile-brittle transition temperature, proper mechanical property and wear resistance and excellent comprehensive performance. Disclosure of Invention The invention provides a lead brass alloy which has proper mechanical property and wear resistance, lower ductile-brittle transition temperature and better low-temperature toughness. The invention provides a lead brass alloy, which comprises, by mass, 57-60% of Cu, 0.8-1.9% of Pb0.8, less than or equal to 0.2% of Fe, less than or equal to 0.2% of Sn, 0.1-0.2% of Ni, less than or equal to 0.1% of Al, less than or equal to 0.01% of Si, and the balance of Zn and unavoidable impurities; The lead brass alloy comprises an alpha phase, a beta phase and a Pb elementary substance phase, wherein the area percentage of the alpha phase is 40-60%, and the area percentage of the beta phase is 35-55%. Preferably, the area percentage of the Pb elemental phase is 1-2%. The invention is characterized in that the content of Sn, al and Si in the alloy is limited, the zinc equivalent is that the alloy elements except Cu and Zn are multiplied by the content of the alloy elements according to the zinc equivalent coefficient, the zinc equivalent coefficient of Sn (+2), al (+8) and Si (+10) is positive, the sum of Zn is equivalent to increase, the alpha phase is reduced, the beta phase is increased, and the Si equivalent is equivalent to 10 zinc equivalents, so that the content of Si is particularly limited, and the Zn equivalent is controlled in a smaller range, thereby reducing the beta phase. According to the invention, by increasing the content of Ni, ni can be better dissolved on the matrix, so that the increase of the content of Ni reduces the amount of Zn dissolved in the matrix, and further reduces the beta phase, so that the volume ratio of the alpha phase is higher, and therefore, the brass alloy provided by the invention has better low-temperature toughness. The face-centered cubic structure determines that the alpha phase has no low-temperature brittle transition, the brittle fracture risk is radically avoided, the elongation rate is increased along with the reduction of temperature, the beta phase is relatively low-temperature sensitive due to the face-centered cubic structure, the ductile-brittle transition risk exists, and the embrittlement risk of the beta phase is in an acceptable range under t