Nickel-chromium intermediate alloy and preparation method thereof

Abstract

The invention relates to a nickel-chromium intermediate alloy and a preparation method thereof, and belongs to the technical field of alloy smelting. The nickel-chromium intermediate alloy comprises the following components of, in percentage by weight, 68-72% of Cr, Si smaller than or equal to 0.2%, Al smaller than or equal to 0.1%, Fe smaller than or equal to 0.2%, C smaller than or equal to 0.05%, Cu smaller than or equal to 0.002%, S smaller than or equal to 0.0015%, P smaller than or equal to 0.0025%, O smaller than or equal to 0.005%, N smaller than or equal to 0.005%, Sb smaller than or equal to 10 ppm, Sn smaller than or equal to 5 ppm, Bi smaller than or equal to 5 ppm, Pb smaller than or equal to 5 ppm, As smaller than or equal to 10 ppm and the balance Ni. The method has the beneficial effects that the obtained nickel-chromium intermediate alloy is good in consistency, and the stability requirement of nickel-chromium-based alloy smelting raw materials is fully met.

Description

technical field

[0001] The invention relates to a nickel-chromium master alloy and a preparation method thereof, belonging to the technical field of alloy smelting. Background technique

[0002] Superalloys (superalloys) are used in the hot end parts of aero-engines or gas engines, and are key core materials. The quality stability of domestic superalloys is not as good as that of foreign advanced enterprise products, especially in terms of long-term service life. Most superalloys contain a higher content of elemental chromium to improve oxidation resistance. Generally, electrolytic chromium or thermite chromium is used to add chromium, but because of their high oxygen and nitrogen content or the presence of more oxygen and nitrogen compound inclusions, it is difficult to remove during the smelting process of superalloys, which will endanger the purity and stability of superalloys. The production of some high-end single crystal nickel-chromium-based superalloy materials in C...

Examples

Embodiment 1

[0020] The present embodiment prepares nickel-chromium master alloy according to the following method:

[0021] 1. Raw material pretreatment, according to the conventional method, clean the surface of the raw material and process it into the size required for entering the furnace; after the raw material pretreatment, weigh: thermite chromium 14.2Kg, carbon (high purity graphite) 0.007Kg, nickel-magnesium master alloy 0.067 Kg, nickel-calcium master alloy 0.167Kg, Jinchuan nickel 5.546Kg.

[0022] 2. Add Jinchuan nickel, carbon and 7Kg thermite chromium into the crucible. Vacuumize the combined furnace to 0.02Pa, power 20KW for electric heating, increase the power to 50KW after the material turns red, and adjust the temperature to 1560°C after the material is completely melted, reduce the power to 15KW and refine for 5Min. Turn off the power and cool down to the conjunctival temperature, fill it with argon to 0.5MPa, add the remaining metal chromium and send it to 50KW to cont...

Embodiment 2

[0025] The present embodiment prepares nickel-chromium master alloy according to the following method:

[0026] 1. Pre-treatment of raw materials: clean the surface of raw materials according to conventional methods and process them into the size required for entering the furnace; after pre-treatment of raw materials, weigh: 14Kg of thermite chromium, 0.005Kg of carbon (high-purity graphite), 0.033Kg of nickel-magnesium master alloy , nickel-calcium master alloy 0.083Kg, Jinchuan nickel 5.865Kg.

[0027]2. Add Jinchuan nickel, carbon and 7Kg thermite chromium into the crucible. Vacuumize the combined furnace to 0.02Pa, power 20KW for heating, increase the power to 50KW after the material turns red, and adjust the temperature to 1550°C after the material is completely melted, reduce the power to 15KW and refine for 5Min. Turn off the power and cool down to the conjunctival temperature, fill it with argon to 0.8Mpa, add the remaining metal chromium and send it to 50KW to contin...

technical field

[0001] The invention relates to a nickel-chromium master alloy and a preparation method thereof, belonging to the technical field of alloy smelting. Background technique

[0002] Superalloys (superalloys) are used in the hot end parts of aero-engines or gas engines, and are key core materials. The quality stability of domestic superalloys is not as good as that of foreign advanced enterprise products, especially in terms of long-term service life. Most superalloys contain a higher content of elemental chromium to improve oxidation resistance. Generally, electrolytic chromium or thermite chromium is used to add chromium, but because of their high oxygen and nitrogen content or the presence of more oxygen and nitrogen compound inclusions, it is difficult to remove during the smelting process of superalloys, which will endanger the purity and stability of superalloys. The production of some high-end single crystal nickel-chromium-based superalloy materials in C...

Examples

Embodiment 1

[0020] The present embodiment prepares nickel-chromium master alloy according to the following method:

[0021] 1. Raw material pretreatment, according to the conventional method, clean the surface of the raw material and process it into the size required for entering the furnace; after the raw material pretreatment, weigh: thermite chromium 14.2Kg, carbon (high purity graphite) 0.007Kg, nickel-magnesium master alloy 0.067 Kg, nickel-calcium master alloy 0.167Kg, Jinchuan nickel 5.546Kg.

[0022] 2. Add Jinchuan nickel, carbon and 7Kg thermite chromium into the crucible. Vacuumize the combined furnace to 0.02Pa, power 20KW for electric heating, increase the power to 50KW after the material turns red, and adjust the temperature to 1560°C after the material is completely melted, reduce the power to 15KW and refine for 5Min. Turn off the power and cool down to the conjunctival temperature, fill it with argon to 0.5MPa, add the remaining metal chromium and send it to 50KW to cont...

Embodiment 2

[0025] The present embodiment prepares nickel-chromium master alloy according to the following method:

[0026] 1. Pre-treatment of raw materials: clean the surface of raw materials according to conventional methods and process them into the size required for entering the furnace; after pre-treatment of raw materials, weigh: 14Kg of thermite chromium, 0.005Kg of carbon (high-purity graphite), 0.033Kg of nickel-magnesium master alloy , nickel-calcium master alloy 0.083Kg, Jinchuan nickel 5.865Kg.

[0027]2. Add Jinchuan nickel, carbon and 7Kg thermite chromium into the crucible. Vacuumize the combined furnace to 0.02Pa, power 20KW for heating, increase the power to 50KW after the material turns red, and adjust the temperature to 1550°C after the material is completely melted, reduce the power to 15KW and refine for 5Min. Turn off the power and cool down to the conjunctival temperature, fill it with argon to 0.8Mpa, add the remaining metal chromium and send it to 50KW to contin...

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