Preparation method of copper-magnesium-phosphorus alloy

Abstract

The invention provides a preparation method of a copper-magnesium-phosphorus alloy, and belongs to the technical field of copper-magnesium alloys. According to the preparation method of the copper-magnesium-phosphorus alloy, yellow phosphorus melt is guided into molten copper through a nitrogen carrier and a graphite pipe, the stirring effect on the copper melt can be achieved, gathering and floating of inclusions are facilitated, and the copper-magnesium-phosphorus alloy is obtained; and along with upward floating of nitrogen bubbles, the reduction effect is achieved. The raw materials are electrolytic copper, magnesium ingots and yellow phosphorus which are compounded to serve as a covering agent, the covering agent can react with oxygen, water and the like in the atmosphere, a protective atmosphere is formed on the surface of molten copper, oxidation of the molten copper is retarded, the covering agent has good wetting capacity, the crucible wall can be well wetted, good covering performance is achieved, and diffusion and deoxidation effects are achieved; and the staying time in high-temperature-state air reduces air suction of alloy liquid and oxidation strengthening for preventing oxidation and air suction, the covering effect is achieved, molten metal is protected, and the smelting operation quality is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of copper-magnesium-phosphorus alloys, and in particular relates to a preparation method of the copper-magnesium-phosphorus alloy. Background Art

[0002] Copper-magnesium master alloys are mostly used to produce pearlite ductile iron. The oxidation and burning of phosphorus, magnesium and calcium elements cause the actual composition of the alloy to be far from the nominal composition, and the distribution and morphology of the second phase in the organization cannot be controlled, resulting in the failure of the alloy's mechanical properties and cutting performance to achieve the expected effect. The solution is: phosphorus is added in the form of copper-phosphorus master alloy. Copper-phosphorus master alloy is the earliest phosphorus-containing master alloy developed and applied. People added it in the form of P-containing alloys. The first developed is a copper-phosphorus master alloy with a P content of 8% to 10%. The Cu-P alloy is added to the hypereutectic aluminum-silicon alloy melt. The release of P element is slow, and the density of the copper-phosphorus alloy sinks to the bottom, resulting in unstable modification effect. Some hypereutectic aluminum-silicon alloys that do not contain Cu cannot be used. However, there is no relevant report on copper-magnesium-phosphorus alloys. Therefore, those skilled in the art are in urgent need of developing a preparation method for copper-magnesium-phosphorus alloys to make up for the defects of the prior art and meet the existing market demand and performance requirements. Summary of the invention

[0003] In view of the above shortcomings of the prior art, the main purpose of the present invention is to provide a method for preparing a copper-magnesium-phosphorus alloy.

[0004] A method for preparing a copper-magnesium-phosphorus alloy comprises the following steps: (1) Ingredients: The alloying elements are proportioned according to the weight percentage of phosphorus (5%-6%), magnesium (6%-8%) and copper (balance), and yellow phosphorus, magnesium plate and electrolytic copper raw materials are selected and weighed; (2) Copper is placed in a cleaned crucible, covered with a layer of anthracite, and melted. After the copper is melted, yellow phosphorus is melted at 60-70°C, and the melted yellow phosphorus is transferred to a storage tank. When nitrogen is passed through, it is introduced into the crucible containing copper liquid through a graphite tube, and the nitrogen flow rate is controlled; (3) The copper liquid is superheated to 1120-1150°C, the anthracite is removed, and a layer of covering agent with a thickness of 15-20 mm is filled, and then the magnesium ingot is pressed into the copper liquid with a graphite bell jar. After the magnesium is completely melted, the graphite bell jar is taken out, the alloy liquid is stirred evenly, and poured into an iron mold coated with a coating and preheated to 100-120°C, thereby obtaining the product.

[0005] Furthermore, the covering agent is a mixture of 30-40 parts of sylvite, 40-50 parts of bischofite, 3-5 parts of cryolite, and 0.3-0.5 parts of calcium fluoride, which is stirred evenly.

[0006] Furthermore, the anthracite is a granular No. 1 anthracite with a size of 10-20 mm, a sulfur content of less than 0.3%, and a true density of ≥1.82 g / cm 3 , ash content ≤3.5%.

[0007] Furthermore, the electrolytic copper is Cu-CATH-1 or Cu-CATH-2.

[0008] Furthermore, the yellow phosphorus is a high-quality yellow phosphorus with a content of greater than 99.9% in benzene.

[0009] Furthermore, the magnesium ingot is Mg99.98 or Mg99.99. Beneficial effects of the present invention:

[0010] The preparation method of copper-magnesium-phosphorus alloy disclosed in the present invention introduces yellow phosphorus melt into the copper liquid through a nitrogen carrier through a graphite tube, can achieve stirring effect on the copper melt, help the aggregation and floating of inclusions, and achieve the effect of reducing with the floating of nitrogen bubbles. The raw materials of the present invention are electrolytic copper, magnesium ingots and yellow phosphorus, and potassium salt, bischofite, cryolite and calcium fluoride are compounded as covering agents, which can react with oxygen and water in the atmosphere, and form HCl, H2, C12 and other protective atmospheres on the surface of the copper liquid. The oxidation of the copper liquid is slowed down, it has good wetting ability, and forms a composite compound, so it has a certain refining ability, and can also wet the crucible wall well, has good coverage, has diffusion and deoxidation effects, and the residence time in the air at high temperature reduces the air intake and oxidation of the alloy liquid, strengthens the prevention of oxidation and air intake, plays a covering role to form protection for the metal melt, completely isolates the metal solution from the air, so that it cannot react with the air, and the alloy solution can no longer inhale air, thereby preventing the oxidation of metal elements and other phenomena, and ensuring the quality of smelting operations. DETAILED DESCRIPTION

[0011] The present invention is further described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto. Example 1

[0012] 1.5T medium frequency induction furnace, medium carbon NZT-DDM-400A grade anthracite, granular No. 1 anthracite with a size of 10~20mm, sulfur content of 0.2%, true density of 1.88g / cm 3 , ash content ≤3.5%; the covering agent is a mixture of 30 parts of sylvite, 40 parts of hydrochlorobenzene from Western Magnesium, 3 parts of Ruihu CH-1 cryolite, and 0.3 parts of calcium fluoride from Deao Refining; Ruihu electrolytic copper Cu-CATH-1; Xingfa Chemical's high-quality industrial yellow phosphorus with a content of more than 99.9% in benzene; Tianyu magnesium ingot is Mg99.98.

[0013] Step 1: Batching: According to the weight percentage of mass, phosphorus is 5%, magnesium is 6%, and copper is the balance. The alloy elements are proportioned, and yellow phosphorus, magnesium plate, and electrolytic copper raw materials are selected and weighed; Step 2: Put the copper into the cleaned crucible, add the dry distilled anthracite at the bottom of the high-purity graphite crucible, and select 20mm anthracite to ensure that it evenly covers the bottom 30mm thick. Then, add the electrolytic copper plate, and the order of addition is: first add small pieces of electrolytic copper plates, and then add large pieces of copper plates. Be careful not to stack too much or too heavy to avoid damaging the crucible and causing pressure. Then, cover it with a layer of anthracite, and then start the 1.5T medium-frequency induction furnace and turn on the power for heating. At the same time, turn on the power switch of the circulating water pump to ensure the normal operation of the circulating cooling system and melt the copper. After the copper is melted, melt the yellow phosphorus at 70°C, transfer the melted yellow phosphorus to the storage tank, pass 0.2MPa99.99% nitrogen, and introduce it into the crucible containing the copper liquid through a graphite tube. Control the nitrogen flow rate to 2.5m 3 / h; Step 3: Superheat the molten copper to 1120℃, remove the anthracite, and fill a layer of covering agent 15-20 mm thick, then use a graphite bell to press the magnesium ingot into the molten copper. After the magnesium is completely melted, take out the graphite bell, stir the alloy liquid evenly, and pour it into an iron mold that has been coated with paint and preheated to 100-120℃.

[0014] Product chemical composition: Cu: balance, P: 5%, Mg: 6%, O: <0.001%, the sum of other impurities such as Bi and Pb is less than 0.10%. Example 2

[0015] 1.5T medium frequency induction furnace, Xinwang Carbon 10~20mm granular No. 1 anthracite, sulfur content less than 0.3%, true density ≥1.82g / cm 3 , ash content ≤3.5%; the covering agent is a mixture of 40 parts of potassium salt, 50 parts of hydrochlorobenzene from Western Magnesium, 5 parts of Ruihu CH-0 cryolite, and 0.5 parts of Arkema calcium fluoride. Nandu Huabai electrolytic copper Cu-CATH-2. Jixing Chemical Industry's superior industrial yellow phosphorus with a content of more than 99.9% in benzene. Tianyu magnesium ingot is Mg99.98.

[0016] Step 1: Batching: According to the weight percentage of mass percentage, phosphorus is 6%, magnesium is 8%, and copper is the balance. The alloy elements are proportioned, and yellow phosphorus, magnesium plate, and electrolytic copper raw materials are selected and weighed; Step 2: Put the copper into the cleaned crucible, add the dry distilled anthracite at the bottom of the high-purity graphite crucible, and select 20mm anthracite to ensure that it evenly covers the bottom 30mm thick. Then, add the electrolytic copper plate, and the order of addition is: first add small pieces of electrolytic copper plates, and then add large pieces of copper plates. Be careful not to stack too much or too heavy to avoid damaging the crucible and causing pressure. Then, cover it with a layer of anthracite, and then start the 1.5T medium-frequency induction furnace and turn on the power for heating. At the same time, turn on the power switch of the circulating water pump to ensure the normal operation of the circulating cooling system and melt the copper. After the copper is melted, melt the yellow phosphorus at 70°C, transfer the melted yellow phosphorus to the storage tank, pass 0.25MPa of 99.99% nitrogen, and introduce it into the crucible containing the copper liquid through a graphite tube, and control the nitrogen flow rate to 2m 3 / h; Step 3: Superheat the molten copper to 1150℃, remove the anthracite, and fill a layer of covering agent 15~20 mm thick, then use a graphite bell to press the magnesium ingot into the molten copper. After the magnesium is completely melted, take out the graphite bell, stir the alloy liquid evenly, and pour it into an iron mold that has been coated with paint and preheated to 100~120℃.

[0017] Product chemical composition: Cu: balance, P: 6%, Mg: 8%, O: <0.001%, the sum of other impurities such as Bi and Pb is less than 0.10%.

[0018] Note: Refer to the following standard chemical composition analysis according to the chemical analysis method of copper and copper alloys Part 1: Determination of copper content; YS / T 283-2009 Copper master alloy ingot.

Claims

1. A method for preparing a copper-magnesium-phosphorus alloy, characterized in that: The following steps are involved: (1) Ingredients: The alloying elements are proportioned according to the weight percentage of phosphorus (5%-6%), magnesium (6%-8%) and copper (balance), and yellow phosphorus, magnesium plate and electrolytic copper raw materials are selected and weighed; (2) Copper is placed in a cleaned crucible, covered with a layer of anthracite, and melted. After the copper is melted, yellow phosphorus is melted at 60-70°C, and the melted yellow phosphorus is transferred to a storage tank. When nitrogen is passed through, it is introduced into the crucible containing copper liquid through a graphite tube, and the nitrogen flow rate is controlled; (3) The copper liquid is superheated to 1120-1150°C, the anthracite is removed, and a layer of covering agent with a thickness of 15-20 mm is filled, and then the magnesium ingot is pressed into the copper liquid with a graphite bell jar. After the magnesium is completely melted, the graphite bell jar is taken out, the alloy liquid is stirred evenly, and poured into an iron mold coated with a coating and preheated to 100-120°C, thereby obtaining the product.

2. The method for preparing a copper-magnesium-phosphorus alloy according to claim 1, characterized in that: The covering agent is a mixture of 30-40 parts of sylvite, 40-50 parts of bischofite, 3-5 parts of cryolite and 0.3-0.5 parts of calcium fluoride, which is stirred evenly.

3. The method for preparing a copper-magnesium-phosphorus alloy according to claim 1, characterized in that: The anthracite is a granular No. 1 anthracite with a size of 10-20 mm, a sulfur content of less than 0.3%, and a true density of ≥1.82 g / cm 3 , ash content ≤3.5%.

4. The method for preparing a copper-magnesium-phosphorus alloy according to claim 1, characterized in that: The electrolytic copper is Cu-CATH-1 or Cu-CATH-2.

5. The method for preparing a copper-magnesium-phosphorus alloy according to claim 1, characterized in that: The yellow phosphorus is a high-quality yellow phosphorus with a content of more than 99.9% in benzene.

6. The method for preparing a copper-magnesium-phosphorus alloy according to claim 1, characterized in that: The magnesium ingot is Mg99.98 or Mg99.99.