CN107164648A - The grain refiner and its preparation and application of a kind of environmentally friendly brass - Google Patents

Abstract

The grain refiner of environment-friendly brass and its preparation and use method, its composition weight percent is: Al-Sr alloy is 36-38, Al-B alloy is 33-35, Zr is 12-15, Al-Fe alloy 5-8.5, NaAlF6 6-7.5, CaCO3 3-4, and the balance is unavoidable impurities. The preparation process of the grain refiner is simple, environmentally friendly and pollution-free, and the use effect is remarkable. After use, the fluidity of the molten metal can be improved, and the grain size of the environmentally friendly brass can be reduced from the original 70-100 μm to 30-50 μm. The finished product The surface is smoother and more detailed, improving the flatness and smoothness after polishing and the surface oxidation resistance.

Description

A kind of grain refiner of environment-friendly brass and its preparation and use method

technical field

The invention relates to an environment-friendly brass refiner and a preparation and use method thereof, and is particularly suitable for an environment-friendly silicon brass grain refiner and a preparation and use method thereof.

Background technique

Lead brass has extremely high machinability, excellent cold and hot casting performance, is easy to cut, and the surface of the processed workpiece is smooth and clean. It is widely used in electronic telecommunications, home appliances, aviation, hardware ornaments and sanitary plumbing products. Lead exists in solid solution as a free element. When it comes into contact with people, soil, and water sources, lead will enter the water and nature, causing harm to the environment and having a great impact on human health. In order to meet the requirements of environmental protection, some environmentally friendly brass products that replace lead brass have emerged as the times require, such as silicon lead-free brass, bismuth brass, selenium brass, etc. Due to the high price of bismuth and selenium metals, the price of silicon metal is reasonable, and silicon brass has good machinability, wear resistance and cold and hot casting performance, so it is a better alternative green brass material.

Environmentally friendly silicon brass is mainly used for plumbing parts such as bathrooms and valves. The production process is remelting-casting-trimming-finishing-polishing-machining-electroplating-assembly-inspection-packaging-warehousing. Among them, casting, polishing and electroplating have high requirements for environmental protection silicon brass ingots, not only strict composition control requirements, but also no impurities, pores, and inclusions, and the ingot grains should be fine and uniform, and the metal fluidity is good to ensure The material has good machinability, which ensures that there will be no fracture during the stamping process. In view of this, it is particularly important to develop a refiner for environment-friendly brass and its application method, especially the refiner for grain refinement of environment-friendly silicon brass.

CN201510714013 discloses a silicon brass alloy and its preparation method and application, which regulates the phase composition and distribution state of the alloy by adding B and Ti composite grain refiners, but does not mention the degree and effect on grain refinement Effect.

Contents of the invention

The technical problem to be solved by the present invention is to develop an environmentally friendly brass grain refiner, and its preparation and use method. After adding the refiner, the fluidity of molten brass is improved, and the cast brass ingot Small and uniform crystal grains, less dendrites, good polishing quality, effectively improving the quality of environmentally friendly brass products.

Grain refiner for environment-friendly brass, its composition weight percentage is: Al-Sr alloy is 36-38, Al-B alloy is 33-35, Zr is 12-15, Al-Fe alloy is 5-8.5, NaAlF6 6 to 7.5, CaCO3 is 3 to 4, and the balance is unavoidable impurities.

The Sr content in the Al-Sr alloy is 9-10% by weight, and the balance is Al; the B content in the Al-B alloy is 10-12% by weight, and the balance is Al; the Al-Fe alloy The content of Fe is 7-8% by weight, and the balance is Al.

A grain refiner for silicon brass, which is composed of 36-38% by weight of Al-Sr alloy, 35% by weight of Al-B alloy, 5% by weight of Al-Fe alloy, and 12-14% by weight of Zr Weight, NaAlF6 is 6-7% by weight, CaCO3 is 3% by weight, and the balance is unavoidable impurities.

A kind of grain refiner of polished tin brass, its composition is that Al-Sr alloy is 35% by weight, Al-B alloy is 33% by weight, Al-Fe alloy is 5.5% by weight, Zr is 15% by weight, NaAlF6 is 7.5% by weight, CaCO3 is 3% by weight, and the balance is unavoidable impurities.

A kind of grain refiner of bismuth brass, its composition is that Al-Sr alloy is 38% by weight, and Al-B alloy is 30% by weight, and Al-Fe alloy is 8.5% by weight, and Zr is 13% by weight, and NaAlF is 7% by weight, CaCO3 is 3.5% by weight, and the balance is unavoidable impurities.

The preparation method of the environment-friendly brass grain refiner is to turn the massive Al-Sr alloy, Al-B alloy and Al-Fe alloy into curly strips and crush them into crumbs, and crush the massive zirconium into fine particles , CaCO3 and NaAlF6 are commercially available white powders, the above raw materials are mixed in proportion, stirred evenly, poured into copper foil and packaged for later use.

The method of using the environmentally friendly brass grain refiner is to control the temperature of the copper water at 1050°C to 1070°C after the copper is melted and slag removed, and add a refiner accounting for 0.03% to 0.06% of the amount of copper water. Stir for 1-5 minutes, and finally stand still for 5-10 minutes, and start casting when the temperature is 1050-1060 °C.

As an optimization, add the grain refiner after high-pressure spraying, press it into 2/1 of the copper water, stir for 1-5 minutes, and stand still for 5-10 minutes after stirring.

The invention has the advantages of simple preparation process of refiner, environmental protection and pollution-free, convenient use, remarkable effect, after use, the grain size of environmentally friendly brass can be reduced from 60-100 μm to 30-50 μm, and the metal melt can be improved. The fluidity, the internal impurities are more evenly distributed, there are no pitting, meteor tail, concave and convex defects, the surface of the finished product is smoother and more detailed, and the surface flatness and smoothness after polishing are better, which improves the oxidation resistance of the metal surface .

Description of drawings

Figure 1 shows that the grain size without adding refiner is 70 μm.

Figure 2 shows that the grain size is 35 μm after adding 0.03% refinement dose.

Figure 3 is without adding refiner.

Figure 4 shows the addition of finer agents.

Figure 5 shows that the grain size without adding refiner is 70 μm.

Figure 6 shows the addition of 0.03% refiner with a grain size of 30 μm.

Figure 7 shows the grain size of 60 μm without adding refiner.

Figure 8 shows the addition of 0.04% refiner with a grain size of 40 μm.

Figure 9 shows the grain size of 60 μm without adding refiner.

Figure 10 shows the addition of 0.04% refiner with a grain size of 35 μm.

Fig. 11 is the metallographic diagram of Comparative Example 1. The grain size of 0.03% KBF4 is 50 μm.

detailed description

Embodiments of the present invention will be described in further detail below in conjunction with the accompanying drawings.

Example 1

Select Al-Sr alloy 38wt%, Zr12wt%, Al-B alloy 35wt%, Al-Fe alloy 5wt%, NaAlF67wt%, CaCO3 3wt%, prepare grain refiner according to the above ratio, powder raw material Fully uniform, and then packaged with copper foil.

Carry out environmentally friendly silicon brass smelting in a 2-ton industrial frequency induction furnace. First, the aluminum-iron alloy is melted together with the copper. After the copper water composition is tested and passed, the temperature of the copper water is controlled at 1050 ° C ~ 1070 ° C, and the refiner is added. The amount of the copper added is 0.03% of the total amount of copper water. After the addition, it is artificially stirred for 3 to 5 minutes, and finally stands still for 5 to 10 minutes. The temperature starts to cast when the temperature is 1050 to 1060 ° C.

After using the refiner, the silicon brass grains are greatly refined, and the grain size is reduced from 70 μm to 35 μm, which effectively improves the fluidity of the molten metal, makes the inclusions evenly distributed, and the product surface quality is smooth. See Figures 1 to 4, Figures 2 and 4 are the metallographic diagrams and ingot surface photos of silicon brass after adding the grain refiner composed of Example 1, illustrating the grain structure refinement and surface High quality finish.

Example 2

Select Al-Sr alloy 36 wt %, Zr14 wt %, Al-B alloy 35 wt %, Al-Fe alloy 5 wt %, NaAlF6 6 wt %, CaCO3 4 wt %, and prepare grain refiner in proportion. The powdered raw materials are fully uniform, and then packaged with copper foil.

Silicon brass is smelted in a 2-ton industrial frequency induction furnace. First, the aluminum-iron alloy is melted together with red copper. After the copper water composition is qualified, the temperature of the copper water is controlled at 1050 ° C ~ 1070 ° C, and 0.03% of the total amount of copper water is added. After adding the chemical agent, manually stir for 3-5 minutes, and finally stand still for 5-10 minutes, and start casting when the temperature is 1050-1060 °C.

After using the refiner, the silicon brass grains are greatly refined, and the grain size is reduced from 70 μm to 30 μm, which effectively improves the fluidity of the molten metal, makes the inclusions evenly distributed, and the product surface quality is smooth. See Fig. 5 and Fig. 6 below. Fig. 6 shows that the grain structure of the grain refining agent composed according to this embodiment is significantly refined after adding silicon brass compared with that without adding it.

Example 3

Select Al-Sr alloy 36 wt %, Zr15 wt %, Al-B alloy 33 wt %, Al-Fe alloy 5.5 wt %, NaAlF67.5 wt %, CaCO3 3 wt %, and prepare grain refiner in proportion The chemical powder raw materials are fully uniform, and then packaged with copper foil.

Environmentally-friendly polished tin-copper ingots are smelted in a 2-ton industrial frequency induction furnace. After the copper water composition is tested and passed, the temperature of the copper water is controlled at 1050°C to 1070°C, and the amount of refining agent added is 0.04% of the total amount of copper water. . After adding, manually stir for 3-5 minutes, and finally stand still for 5-10 minutes, and start casting when the temperature is 1050-1060 °C.

After using the refiner, the silicon brass grains are greatly refined, and the grain size is reduced from 60 μm to 30 μm, which effectively improves the fluidity of the molten metal, makes the inclusions evenly distributed, and the product surface quality is smooth. As shown in Figure 7 and Figure 8, it can be clearly shown from Figure 8 that the grain structure of the polished tin-copper ingot after adding the grain refiner is significantly finer than that without adding the grain refiner.

Example 4

Select Al-Sr alloy 38 wt %, Zr13 wt %, Al-B alloy 30 wt %, Al-Fe alloy 8.5 wt %, NaAlF6 7 wt %, CaCO3 3.5 wt %, and prepare grain refiner in proportion. The powdered raw materials are fully uniform, and then packaged with copper foil.

Smelting bismuth brass copper ingots in a 2-ton power frequency induction furnace. When the copper water composition is qualified, control the temperature of the copper water at 1010°C to 1050°C, and add a refiner with an amount of 0.04% of the total amount of copper water. . After adding, manually stir for 3-5 minutes, and finally stand still for 5-10 minutes, and start casting when the temperature is 1020-1050 °C.

After using the refiner, the bismuth brass grains are greatly refined, and the grain size is reduced from 60 μm to 35 μm, which effectively improves the fluidity of the molten metal, makes the inclusions evenly distributed, and the product surface quality is smooth. As shown in Figure 9 and Figure 10, the proportion of grain refiner added in Figure 10 is significantly more refined than that without adding it.

Comparative example 1

Silicon brass is smelted in a 2-ton industrial frequency induction furnace. First, the aluminum-iron alloy is melted together with red copper. After the copper water composition is qualified, the temperature of the copper water is controlled at 1050 ° C ~ 1070 ° C, and the purchased refiner KBF4 is selected. Add 0.03% refiner to the total amount of copper water, stir for 2.5 minutes, stand still for 5 minutes after stirring, and then cast when the temperature measurement reaches 1030°C after standing still.

After using the purchased refiner, the grain size was reduced from 70 μm to 50 μm, and the refinement in Comparative Example 1 was not significant, as shown in FIG. 11 .

Table 1, the comparison table of the use effect of environmental protection brass grain refiner

Table 1 shows that the grain refining agent of the present invention is better than existing KBF4 to the grain refinement degree of silicon brass, tin brass and bismuth brass, and its polished surface finish, red punch does not crack, and turning performance all better.

Claims (7)

1. Grain refiner for environmentally friendly brass, its composition weight percentage is: 36-38 for Al-Sr alloy, 33-35 for Al-B alloy, 12-15 for Zr, 5-8.5 for Al-Fe alloy , NaAlF6 is 6-7.5, CaCO3 is 3-4, and the balance is unavoidable impurities. 2. the grain refining agent of environment-friendly brass according to claim 1 is characterized in that in the described Al-Sr alloy, Sr content is 9～10% by weight, and surplus is Al; Described Al-B alloy The B content in the alloy is 10-12% by weight, and the balance is Al; the Fe content in the Al-Fe alloy is 7-8% by weight, and the balance is Al. 3. the grain refiner of environment-friendly brass according to claim 1 is characterized in that a kind of grain refiner of silicon brass, its composition is that Al-Sr alloy is 36～38% weight, Al- B alloy is 35% by weight, Al-Fe alloy is 5% by weight, Zr is 12-14% by weight, NaAlF6 is 6-7% by weight, CaCO3 is 3% by weight, and the balance is unavoidable impurities. 4. the grain refiner of environment-friendly brass according to claim 1 is characterized in that a kind of grain refiner of polished tin brass, and its composition is that Al-Sr alloy is 35% weight, and Al-B Alloy is 33% by weight, Al-Fe alloy is 5.5% by weight, Zr is 15% by weight, NaAlF6 is 7.5% by weight, CaCO3 is 3% by weight, and the balance is unavoidable impurities. 5. the grain refiner of environment-friendly brass according to claim 1 is characterized in that a kind of grain refiner of bismuth brass, its composition is that Al-Sr alloy is 38% weight, Al-B alloy is 30% by weight, Al-Fe alloy is 8.5% by weight, Zr is 13% by weight, NaAlF6 is 7% by weight, CaCO3 is 3.5% by weight, and the balance is unavoidable impurities. 6. The method of using the environment-friendly brass grain refiner according to claim 1, characterized in that after the copper is melted and the slag is removed, the temperature of the copper water is controlled at 1050°C to 1070°C, and 0.03% of the amount of copper water is added. %~0.06% refiner, after adding, manually stir for 1~5min, and finally stand still for 5~10min, and start casting at the temperature of 1050~1060℃. 7. The method for using the environment-friendly brass grain refiner according to claim 1, characterized in that as an optimization, the grain refiner is added after the high-pressure flame spraying, and it is pressed into 2/1 of the copper water place, stir for 1 to 5 minutes, and stand still for 5 to 10 minutes after stirring.