Ferrochromium alloy and preparation method thereof

Abstract

The present invention discloses an iron-chromium alloy and a preparation method thereof. The alloy components and their mass percentages are: 30% recycled iron-chromium alloy, 16% chromium, 3% coke, 1.2% iron-chromium lignin sulfonate, 4.8% other metals, and the balance is iron and unavoidable impurities. The present invention relates to the technical field of recycling secondary resources containing iron and chromium. By mixing the recycled iron-chromium alloy with the iron-chromium lignin sulfonate and then smelting at high temperature, it is helpful to reduce the iron and chromium elements in the iron-chromium alloy to metallic iron and chromium. This process is beneficial to improving the purity of the iron-chromium alloy, thereby improving its mechanical properties and corrosion resistance. During the high-temperature smelting process, the addition of the iron-chromium lignin sulfonate helps to promote organic reactions and oxidation reactions, and improve the fluidity and stability of the metal liquid during the smelting process. This helps to evenly distribute the alloy components and further improve the performance of the iron-chromium alloy.

Description

Technical Field

[0001] The invention relates to the technical field of recycling secondary resources containing iron and chromium, in particular to an iron-chromium alloy and a preparation method thereof. Background Art

[0002] As an important alloy material, ferrochromium alloy is widely used in various fields, such as metallurgy, chemical industry, machinery manufacturing, etc. The traditional method for preparing ferrochromium alloy mainly uses metallic iron and metallic chromium as the main raw materials, adds other metal elements for smelting, and finally cools and solidifies into an alloy. In addition, there is another method that melts the recycled ferrochromium alloy and then cools and solidifies it. However, the existing method for preparing ferrochromium alloy has certain limitations.

[0003] First, the existing iron-chromium alloy preparation method is limited in the degree of fusion of metallic iron and metallic chromium during the smelting process. Since metallic iron and metallic chromium have high melting points and different physical and chemical properties, it is difficult to fully fuse the iron and chromium elements during the smelting process, which affects the mechanical properties and corrosion resistance of the alloy.

[0004] Secondly, when the recycled ferrochromium alloy is fused with the newly refined and melted ferrochromium alloy during the reuse process, the two are difficult to fuse well due to their different initial forms, which in turn affects the performance of the alloy steel. This problem has largely limited the recycling rate of ferrochromium alloy, which is not conducive to resource conservation and environmental protection.

[0005] In view of the problems existing in the existing ferrochromium alloy preparation method, it is necessary to study a new preparation method to improve the performance of ferrochromium alloy and realize the efficient utilization of recycled ferrochromium alloy. Summary of the invention

[0006] In view of the deficiencies of the prior art, the present invention provides an iron-chromium alloy and a preparation method thereof, which solves the problem that the existing recycled iron-chromium alloy is not easy to fuse with the newly refined and melted iron-chromium alloy.

[0007] To achieve the above object, the present invention is implemented through the following technical scheme: an iron-chromium alloy, characterized in that the alloy components and their mass percentages are: 30% recycled iron-chromium alloy, 16% chromium, 3% coke, 1.2% iron-chromium lignin sulfonate, 4.8% other metals, and the balance is iron and unavoidable impurities.

[0008] Preferably, the other metals include: 2.1% molybdenum, 1.3% cobalt, 0.55% sulfur, 0.45% silicon, 0.2% manganese, 0.1% phosphorus and the balance nickel.

[0009] Preferably, the mass percentage of iron is 43.5%-44.5%.

[0010] A method for preparing an iron-chromium alloy, using the iron-chromium alloy as described in any one of the above items for preparation, comprising the following steps:

[0011] S1. Mix the recycled iron-chromium alloy with 1 part of iron-chromium lignin sulfonate, and send it into an induction furnace for high-temperature smelting, and the temperature is controlled between 1500° C. and 1600° C. to obtain a uniform base liquid;

[0012] S2, crushing and grinding the iron and chromium raw materials to form fine grains, with the particle size controlled to be above 100 mesh;

[0013] S3, putting the coke, the remaining iron-chromium lignin sulfonate, molybdenum, cobalt, sulfur, silicon, manganese, phosphorus and nickel and the crushed and ground iron-chromium grains into a mixer, and mixing them thoroughly to obtain a mixture;

[0014] S4, gradually adding the mixture into the prepared base liquid, continuing to smelt at high temperature, the temperature being controlled between 1600° C. and 1700° C., to obtain a mixed liquid;

[0015] S5. Pour the mixed solution into a casting mold, and allow the mixed solution to naturally cool and solidify in the casting mold to obtain an iron-chromium alloy ingot.

[0016] Preferably, in step 2, the particle size distribution of the grains satisfies D90 less than 200 μm.

[0017] Preferably, in step S4, inert gas protection is used during the smelting process to prevent the alloy from oxidation.

[0018] Preferably, in step S4, the obtained mixed solution is subjected to electromagnetic stirring.

[0019] Preferably, in step S5, the material of the casting mold is graphite or alumina, and the casting mold preheating temperature is 200°C to 400°C.

[0020] Preferably, in step S5, the obtained iron-chromium alloy ingot is subjected to solution treatment and water quenching treatment, the solution treatment temperature is 1050°C to 1100°C, and the holding time is 2 to 4 hours; the water quenching aging treatment temperature is 550°C to 650°C, and the holding time is 6 to 8 hours.

[0021] Preferably, in step S1, the recycled iron-chromium alloy is subjected to a treatment to remove the oxidation layer and then subjected to high-temperature smelting.

[0022] Beneficial effects of the present invention: By using an iron-chromium alloy and a preparation method thereof provided by the present invention, the following technical effects are achieved compared with the prior art:

[0023] 1. By mixing the recycled ferrochromium alloy with ferrochromium lignin sulfonate and then smelting it at high temperature, it helps to reduce the iron and chromium elements in the ferrochromium alloy to metallic iron and chromium. This process is conducive to improving the purity of the ferrochromium alloy, thereby improving its mechanical properties and corrosion resistance.

[0024] 2. During high-temperature smelting, the addition of ferrochrome lignin sulfonate helps promote organic reactions and oxidation reactions, and improves the fluidity and stability of the metal liquid during the smelting process. This helps to evenly distribute the alloy components and further improve the performance of the ferrochrome alloy.

[0025] 3. After the new iron ore is crushed, lignin sulfonate is added and then put into the base liquid. After electromagnetic stirring and the silk-reducing characteristics of iron-chromium lignin sulfonate, the two metal liquids accelerate the flow characteristics and promote the reaction effect. This process helps to improve the preparation efficiency of iron-chromium alloy and reduce production costs.

[0026] 4. The efficient utilization of recycled iron-chromium alloy is achieved, which is beneficial to resource conservation and environmental protection. At the same time, the prepared iron-chromium alloy has excellent mechanical properties and corrosion resistance, meeting the needs of different fields for high-performance alloy materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a photograph of the cemented carbide of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. As long as the effects of the present invention can be exerted, various changes can be made to the implementation scheme.

[0029] According to one aspect of the present invention, the present invention provides the following technical solution:

[0030] An iron-chromium alloy, the alloy components and their mass percentages are: 30% of recycled iron-chromium alloy, 16% of chromium, 3% of coke, 1.2% of iron-chromium lignin sulfonate, 4.8% of other metals, and the balance is iron and unavoidable impurities.

[0031] The recycled iron-chromium alloy is used for fusion and reuse, and 0.6% of iron-chromium lignin sulfonate is added for catalytic reaction to help reduce the iron and chromium elements in the iron-chromium alloy to metallic iron and chromium, thereby promoting the reaction effect.

[0032] The ferrochrome lignin sulfonate added during the smelting and recycling of ferrochrome alloy has a strong silk-reducing property, which improves the fluidity and stability of the metal liquid during the smelting process and helps to evenly distribute the alloy components.

[0033] The above-mentioned other metals include: 2.1% molybdenum, 1.3% cobalt, 0.55% sulfur, 0.45% silicon, 0.2% manganese, 0.1% phosphorus and the balance nickel.

[0034] The mass percentage of iron is 43.5%-44.5%, and the purity of iron is not less than 99.5%.

[0035] This embodiment also discloses a method for preparing an iron-chromium alloy, which is prepared by using any of the above-mentioned iron-chromium alloys, and comprises the following steps:

[0036] S1. Recycling of ferrochromium alloy treatment:

[0037] The recycled iron-chromium alloy is mixed with 1 part of iron-chromium lignin sulfonate and sent into an induction furnace for high-temperature smelting, and the temperature is controlled between 1500°C and 1600°C to obtain a uniform base liquid;

[0038] It should be noted that before high-temperature smelting of the recycled ferrochromium alloy, the oxide layer needs to be removed.

[0039] S2. Treatment of iron and chromium raw materials:

[0040] The iron and chromium raw materials are crushed and ground to form fine grains with a particle size of more than 100 mesh; the particle size distribution of the grains satisfies D90 less than 200μm;

[0041] The iron and chromium are mechanically crushed and ground to ensure the uniformity and fineness of the raw materials, which is beneficial to improving the performance of the alloy.

[0042] S3, preparing a mixture:

[0043] Putting the coke, the remaining iron-chromium lignin sulfonate, molybdenum, cobalt, sulfur, silicon, manganese, phosphorus and nickel and the crushed and ground iron-chromium grains into a mixer, and mixing them thoroughly to obtain a mixture;

[0044] The combination of coke and ferrochrome lignin sulfonate forms a reducing agent and a dispersant, which improves the fluidity and stability of the molten metal during the smelting process and helps to evenly distribute the alloy components.

[0045] S4, high temperature smelting:

[0046] The mixture is gradually added to the prepared base liquid, and the smelting is continued at high temperature. The temperature is controlled between 1600°C and 1700°C to obtain a mixed liquid, and the mixed liquid is electromagnetically stirred. It should be noted that inert gas protection is used during the smelting process to prevent oxidation of the alloy, wherein the inert gas is argon.

[0047] S5. Post-smelting treatment:

[0048] The mixed solution is poured into a casting mold, and the mixed solution is naturally cooled and solidified in the casting mold to obtain an iron-chromium alloy ingot; the casting mold material is graphite or alumina, and the casting mold preheating temperature is 200°C to 400°C. Then, the obtained iron-chromium alloy ingot is subjected to solid solution treatment and water quenching treatment, the solid solution treatment temperature is 1050°C to 1100°C, and the holding time is 2 to 4 hours; the water quenching treatment aging treatment temperature is 550°C to 650°C, and the holding time is 6 to 8 hours.

[0049] The iron-chromium alloy of the present invention was produced according to the above process, and the material properties were tested. The results are shown in the following table.

[0050]

[0051] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An iron-chromium alloy, characterized in that: The alloy components and their mass percentages are: 30% recycled iron-chromium alloy, 16% chromium, 3% coke, 1.2% iron-chromium lignin sulfonate, 4.8% other metals, and the balance is iron and unavoidable impurities.

2. The iron-chromium alloy according to claim 1, characterized in that: The other metals include: 2.1% molybdenum, 1.3% cobalt, 0.55% sulfur, 0.45% silicon, 0.2% manganese, 0.1% phosphorus and the balance nickel.

3. The iron-chromium alloy according to claim 1, characterized in that: The mass percentage of the iron is 43.5%-44.5%.

4. A method for preparing an iron-chromium alloy, using the iron-chromium alloy according to any one of claims 1 to 3 for preparation, characterized in that: The steps include: S1. Mix the recycled iron-chromium alloy with 1 part of iron-chromium lignin sulfonate, and send it into an induction furnace for high-temperature smelting, and the temperature is controlled between 1500° C. and 1600° C. to obtain a uniform base liquid; S2, crushing and grinding the iron and chromium raw materials to form fine grains, with the particle size controlled to be above 100 mesh; S3, putting the coke, the remaining iron-chromium lignin sulfonate, molybdenum, cobalt, sulfur, silicon, manganese, phosphorus and nickel and the crushed and ground iron-chromium grains into a mixer, and mixing them thoroughly to obtain a mixture; S4, gradually adding the mixture into the prepared base liquid, continuing to smelt at high temperature, the temperature being controlled between 1600° C. and 1700° C., to obtain a mixed liquid; S5. Pour the mixed solution into a casting mold, and allow the mixed solution to naturally cool and solidify in the casting mold to obtain an iron-chromium alloy ingot.

5. The method for preparing an iron-chromium alloy according to claim 4, characterized in that: The particle size distribution of the grains in step 2 satisfies D90 less than 200 μm.

6. The method for preparing an iron-chromium alloy according to claim 4, characterized in that: In step S4, inert gas protection is used during the smelting process to prevent the alloy from oxidation.

7. The method for preparing an iron-chromium alloy according to claim 4, characterized in that: In step S4, the obtained mixed solution is subjected to electromagnetic stirring.

8. The method for preparing an iron-chromium alloy according to claim 4, characterized in that: In step S5, the material of the casting mold is graphite or alumina, and the casting mold preheating temperature is 200°C to 400°C.

9. The method for preparing an iron-chromium alloy according to claim 4, characterized in that: In step S5, the obtained iron-chromium alloy ingot is subjected to solution treatment and water quenching treatment, the solution treatment temperature is 1050°C to 1100°C, and the holding time is 2 to 4 hours; the water quenching aging treatment temperature is 550°C to 650°C, and the holding time is 6 to 8 hours.

10. The method for preparing an iron-chromium alloy according to claim 4, characterized in that: In step S1, the recycled iron-chromium alloy is subjected to a treatment for removing the oxidation layer and then subjected to high-temperature smelting.

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