High-purity nickel-chromium-iron resistance alloy and preparation method thereof

Abstract

The invention discloses a high-purity nickel-chromium-iron resistance alloy and a preparation method thereof, and relates to the technical field of metallurgy, and the high-purity nickel-chromium-iron resistance alloy comprises the following chemical elements in percentage: less than 0.05% of C, 0.80-1.80% of Si, 0.50-1.50% of Mn, less than or equal to 0.015% of P, less than or equal to 0.008% of S, 35-45% of Ni, 18.00-23.00% of Cr, 0.5-2.50% of Co, 0.10-0.60% of Ti, 0.05-2.50% of La + Zr, 0.10-0.60% of Al, and the balance of iron and impurity elements. The high-purity iron-chromium-aluminum alloy blank is prepared by adopting a double-vacuum process, and the sum of [O] and [N] is less than or equal to 100ppm; a high-temperature pouring mode is adopted, a developed columnar crystal structure is obtained, and favorable conditions are provided for vacuum self-consumption stable melting speed; rapid demolding is adopted after vacuum induction and vacuum self-consumption, and serious internal cracks are prevented from being formed in the steel ingot; uniform and sufficient deformation of the structure is obtained through the roughing mill large deformation + continuous rolling + rapid cooling process, carbide precipitation is avoided, and the production efficiency is high.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, in particular to a high-purity nickel-chromium-iron resistance alloy and a preparation method thereof. Background Art

[0002] With the rapid development of my country's industrial technology, the metallurgical, electronic, mechanical industries and metal heat treatment departments have higher and higher requirements for electric heating alloys. Electric heating alloys refer to resistance alloys that use the resistance characteristics of metals to make heating elements, including nickel-chromium and iron-chromium-aluminum alloys. They are suitable for electric heating elements working in the temperature range of 950-1400°C and are usually used in industrial electric furnaces, laboratory electric furnaces and household appliances. For electric heating alloys with operating temperatures below 1100°C, nickel-chromium and nickel-chromium-iron alloys are currently mainly used. At present, for the smelting of nickel-chromium-iron resistance alloy billets, most companies use a non-vacuum induction furnace + electroslag remelting process. The oxygen, nitrogen, phosphorus and sulfur content in the product is relatively high, and the problem of stable product quality and ensuring that the service life meets user requirements has not been solved.

[0003] In order to solve the above technical problems, a high-purity nickel-chromium-iron resistance alloy and a preparation method thereof are proposed. Summary of the invention

[0004] The object of the present invention is to provide a high-purity nickel-chromium-iron resistance alloy and a preparation method thereof to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: A high-purity nickel-chromium-iron resistance alloy. The chemical element percentages of the pure nickel-chromium-iron resistance alloy are: C: <0.05%, Si: 0.80-1.80%, Mn: 0.50-1.50%, P≤0.015%, S≤0.008%, Ni: 35-45%, Cr: 18.00%-23.00%, Co: 0.5-2.50%, Ti: 0.10-0.60%, La+Zr: 0.05-2.50%, Al: 0.10-0.60%, and the rest are iron and impurity elements.

[0006] As a further solution of the present invention: the percentages of chemical elements in the pure nickel-chromium-iron resistance alloy are: C: <0.03%, Si: 1.10-1.50%, Mn: 0.65-1.30%, P≤0.010%, S≤0.006%, Ni: 37-43%, Cr: 19.00%-22.00%, Co: 0.9-2.10%, Ti: 0.20-0.40%, La+Zr: 0.15-2.00%, Al: 0.20-0.50%, and the rest are iron and impurity elements.

[0007] As a further solution of the present invention: the percentages of chemical elements in the pure nickel-chromium-iron resistance alloy are: C: <0.02%, Si: 1.30%, Mn: 0.10%, P≤0.008%, S≤0.006%, Ni: 40%, Cr: 21.00%, Co: 1.50%, Ti: 0.35%, La+Zr: 1.30%, Al: 0.35%, and the rest are iron and impurity elements.

[0008] Another object of the present invention is to provide a method for preparing the subject, comprising the following steps: Pure iron, nickel, chromium and cobalt are sandblasted and then batched according to chemical composition; Preheat the chute and put the prepared pure iron, metal nickel, metal chromium and metal cobalt into the crucible; Perform vacuum induction melting of various raw materials in the crucible to obtain annealed castings; The casting is subjected to a vacuum consumable treatment to obtain an intermediate piece.

[0009] As a further solution of the present invention: the preparation method also includes: rolling the intermediate piece to obtain a bar.

[0010] As a further solution of the present invention: the preheating of the chute and the loading of the prepared pure iron, metal nickel, metal chromium and metal cobalt into the crucible comprises: Heat the chute in a heating furnace at 1000℃-1400℃, and keep warm for ≥2h; When loading the crucible, a small piece of pure iron is placed on the bottom, pure iron rods are placed around the crucible, and carbon, metallic nickel, metallic chromium, metallic cobalt are loosely placed in the middle.

[0011] As a further solution of the present invention: the vacuum induction melting of various raw materials in the crucible to obtain the annealed casting includes: Evacuate the vacuum, and start to supply power after the vacuum degree is ≤10pa; Melt the metal at low power for 5-7h. After melting, adjust the temperature to 1600℃-1620℃, stir and refine for 60-80 minutes; test [O]+[N]≤85ppm; then add metal aluminum, silicon and manganese with argon filling, add ferrotitanium after refining for 8-12min, stir for 4-6 minutes, finally add rare earth lanthanum and zirconium, stir for 4-6 minutes, adjust the temperature to 1520℃-1530℃ for steel casting; After 40-50 minutes, the mold is broken and quickly put back into the furnace for the first annealing process.

[0012] As a further solution of the present invention: the first furnace annealing process includes heating to 800-900°C at a heating rate of ≤80°C / hour, keeping the temperature for 4-5h, and cooling to room temperature along with the furnace.

[0013] As a further solution of the present invention: the step of subjecting the casting to vacuum consumable treatment to obtain the intermediate piece comprises: The induction ingot after the casting surface is polished is loaded into the vacuum consumable furnace and evacuated; the consumable process starts when the vacuum degree is less than 15pa; the consumable process is that the melting rate of the ingot body is controlled at 8-10kg / min; the feeding stage rate is controlled at 2.5-3kg / min; After the self-consumable process is completed, the mold is broken after cooling for 70-90 minutes, and then quickly put back into the furnace for the second annealing process to obtain the intermediate part.

[0014] As a further solution of the present invention: in the second furnace annealing process, the demoulding consumable ingot is quickly transferred to the adding furnace, heated to 800-900°C at a heating rate of ≤100°C / hour, kept warm for 4-6h, and cooled to room temperature with the furnace to obtain the intermediate part.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: a high-purity iron-chromium-aluminum alloy billet with [O]+[N]≤100ppm is prepared by a double vacuum process; a developed columnar crystal structure is obtained by a high-temperature casting method, which provides favorable conditions for the stable melting rate of vacuum self-consumption; rapid demolding is adopted after vacuum induction and vacuum self-consumption to avoid the formation of serious internal cracks in the steel ingot; a rough rolling mill large deformation + continuous rolling + rapid cooling process is used to obtain uniform and sufficient deformation of the structure and avoid carbide precipitation, and the production efficiency is high. DETAILED DESCRIPTION

[0016] The technical solution of the present invention is further described in detail below in conjunction with specific implementation methods.

[0017] The invention provides a high-purity nickel-chromium-iron resistance alloy: the percentage of chemical elements of the pure nickel-chromium-iron resistance alloy is: C: <0.05%, Si: 0.80-1.80%, Mn: 0.50-1.50%, P≤0.015%, S≤0.008%, Ni: 35-45%, Cr: 18.00%-23.00%, Co: 0.5-2.50%, Ti: 0.10-0.60%, La+Zr: 0.05-2.50%, Al: 0.10-0.60%, and the rest are iron and impurity elements.

[0018] In some embodiments, the percentages of chemical elements in the pure nickel-chromium-iron resistance alloy are: C: <0.03%, Si: 1.10-1.50%, Mn: 0.65-1.30%, P≤0.010%, S≤0.006%, Ni: 37-43%, Cr: 19.00%-22.00%, Co: 0.9-2.10%, Ti: 0.20-0.40%, La+Zr: 0.15-2.00%, Al: 0.20-0.50%, and the rest are iron and impurity elements.

[0019] In some embodiments, the percentages of chemical elements in the pure nickel-chromium-iron resistance alloy are: C: <0.02%, Si: 1.30%, Mn: 0.10%, P≤0.008%, S≤0.006%, Ni: 40%, Cr: 21.00%, Co: 1.50%, Ti: 0.35%, La+Zr: 1.30%, Al: 0.35%, and the rest are iron and impurity elements.

[0020] In some embodiments, the percentages of chemical elements in the pure nickel-chromium-iron resistance alloy are: C: 0.015%, Ni: 38%, Si: 1.10%, Mn: 0.65%, Cr: 18.00%, Co: 1.20%, Ti: 0.25%, La+Zr: 0.20%, Al: 0.5%, and the remainder is Fe and impurity elements.

[0021] In some embodiments, the percentages of chemical elements in the pure nickel-chromium-iron resistance alloy are: C: 0.012%, Ni: 40%, Si: 1.50%, Mn: 1.5%, Cr: 20.00%, Co: 2.00%, Ti: 0.40%, La+Zr: 0.15%, Al: 0.45%, and the remainder is Fe and impurity elements.

[0022] A method for preparing a high-purity nickel-chromium-iron resistance alloy comprises the following steps: S1. Sandblasting pure iron, metallic nickel, metallic chromium and metallic cobalt, and then batching them according to their chemical components; S2, preheating the chute, and placing the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible; In some embodiments, the step S2, preheating the chute and loading the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible, comprises: Heat the chute in a heating furnace at 1000℃-1400℃, and keep warm for ≥2h; When loading the crucible, a small piece of pure iron is placed on the bottom, pure iron rods are placed around the crucible, and carbon, metallic nickel, metallic chromium, metallic cobalt are loosely placed in the middle.

[0023] S3, performing vacuum induction melting of various raw materials in the crucible to obtain annealed castings; In some embodiments, the step S3, performing vacuum induction melting of various raw materials in the crucible to obtain a casting that has been annealed, comprises: Evacuate the vacuum, and start to supply power after the vacuum degree is ≤10pa; Melt the metal at low power for 5-7h. After melting, adjust the temperature to 1600℃-1620℃, stir and refine for 60-80 minutes; test [O]+[N]≤85ppm; then add metal aluminum, silicon and manganese with argon filling, add ferrotitanium after refining for 8-12min, stir for 4-6 minutes, finally add rare earth lanthanum and zirconium, stir for 4-6 minutes, adjust the temperature to 1520℃-1530℃ for steel casting; After 40-50 minutes, the mold is broken and quickly put back into the furnace for the first annealing process.

[0024] The first furnace annealing process includes heating to 800-900°C at a heating rate of ≤80°C / hour, keeping the temperature for 4-5h, and cooling to room temperature along with the furnace.

[0025] S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece; In some embodiments, the step S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece, comprises: The induction ingot after the casting surface is polished is loaded into the vacuum consumable furnace and evacuated; the consumable process starts when the vacuum degree is less than 15pa; the consumable process is that the melting rate of the ingot body is controlled at 8-10kg / min; the feeding stage rate is controlled at 2.5-3kg / min; After the self-consumable process is completed, the mold is broken after cooling for 70-90 minutes, and then quickly put back into the furnace for the second annealing process to obtain the intermediate part.

[0026] Among them, the second furnace annealing process quickly transfers the demoulding consumable ingot to the adding furnace, heats it to 800-900℃ at a heating rate of ≤100℃ / hour, keeps it warm for 4-6h, and cools it to room temperature with the furnace to obtain the intermediate part.

[0027] S5. Roll the intermediate piece to obtain a bar.

[0028] In some embodiments, the step S5, rolling the intermediate piece to obtain a bar, comprises: Heat to 800±10℃ at a heating rate of 60℃ / h, keep warm for 180min, then heat to 1200±10℃ at a heating rate of 100℃ / h, keep warm for 300min, then take out of the furnace; The total number of deformation passes is 19, and the billet specification is 215mm×215mm square billet. The deformation from the billet to the first 4 passes is ≤5%, and the deformation from the 8th to the 11th pass is 22%. The final rolling temperature is 980℃-1050℃; The 4-stand continuous rolling mill is used, and the last two stands are Φ180mm finishing stands. The rolling speed is 1.8-2.3m / S, and the final rolling temperature is between 730-750℃. Φ180mm bars are rolled out, and then air-cooled while moving on the chain cooling bed; The temperature is raised to 650-700°C at a heating rate of 60°C / h, and the heat preservation time is 210 minutes. Then it is taken out of the furnace, and straightened when the temperature drops to 350-500°C. The flaw detection is qualified to obtain high-purity nickel-chromium-iron resistance alloy rods.

[0029] Example 1 A high-purity nickel-chromium-iron resistance alloy: the percentage of chemical elements of the pure nickel-chromium-iron resistance alloy is: C: <0.05%, Si: 1.80%, Mn: 1.50%, P≤0.015%, S≤0.008%, Ni: 45%, Cr: 23.00%, Co: 2.50%, Ti: 0.60%, La+Zr: 2.50%, Al: 0.60%, and the rest are iron and impurity elements.

[0030] A method for preparing a high-purity nickel-chromium-iron resistance alloy comprises the following steps: S1. Sandblasting pure iron, metallic nickel, metallic chromium and metallic cobalt, and then batching them according to their chemical components; S2, preheating the chute, and loading the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible; In some embodiments, the step S2, preheating the chute and loading the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible, comprises: Heat the chute in a heating furnace at 1400℃ for a holding time of ≥2h; When loading the crucible, a small piece of pure iron is placed on the bottom, pure iron rods are placed around the crucible, and carbon, metallic nickel, metallic chromium, metallic cobalt are loosely placed in the middle.

[0031] S3, performing vacuum induction melting of various raw materials in the crucible to obtain annealed castings; In some embodiments, the step S3, performing vacuum induction melting of various raw materials in the crucible to obtain a casting that has been annealed, comprises: Evacuate the vacuum, and start to supply power after the vacuum degree is ≤10pa; Melt the metal at low power for 5-7h. After melting, adjust the temperature to 1620℃, stir and refine for 80 minutes; test [O]+[N]≤85ppm; then add aluminum, silicon and manganese with argon filling, add ferrotitanium after refining for 8-12min, stir for 6 minutes, finally add rare earth lanthanum and zirconium, stir for 6 minutes, adjust the temperature to 1530℃ for steel casting; After 50 minutes, the mold is broken and quickly put back into the furnace for the first annealing process.

[0032] The first furnace annealing process includes heating to 900°C at a heating rate of ≤80°C / hour, keeping the temperature for 5 hours, and cooling to room temperature along with the furnace.

[0033] S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece; In some embodiments, the step S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece, comprises: The induction ingot after the casting surface is polished is loaded into the vacuum consumable furnace and evacuated; the consumable process starts when the vacuum degree is less than 15pa; the consumable process is that the melting rate of the ingot body is controlled at 10kg / min; the feeding stage rate is controlled at 3kg / min; After the self-consumable process is completed, the mold is broken after cooling for 90 minutes, and then quickly put back into the furnace for the second annealing process to obtain the intermediate part.

[0034] Among them, the second furnace annealing process quickly transfers the demoulding consumable ingot to the adding furnace, heats it to 900°C at a heating rate of ≤100°C / hour, keeps it warm for 6 hours, and cools it to room temperature with the furnace to obtain the intermediate part.

[0035] S5. The intermediate piece is rolled to obtain a bar.

[0036] In some embodiments, the step S5, rolling the intermediate piece to obtain a bar, comprises: Heat to 800±10℃ at a heating rate of 60℃ / h, keep warm for 180min, then heat to 1200±10℃ at a heating rate of 100℃ / h, keep warm for 300min, then take out of the furnace; The total number of deformation passes is 19, and the billet specification is 215mm×215mm square billet. The deformation from the billet to the first 4 passes is ≤5%, and the deformation from the 8th to the 11th pass is 22%. The final rolling temperature is 980℃-1050℃; The 4-stand continuous rolling mill is used, and the last two stands are Φ180mm finishing stands. The rolling speed is 1.8-2.3m / S, and the final rolling temperature is between 750℃. Φ180mm bars are rolled out, and then air-cooled while moving on the chain cooling bed; The temperature was raised to 700°C at a heating rate of 60°C / h and kept at a temperature for 210 minutes. The steel was then taken out of the furnace and straightened when the temperature dropped to 500°C. After passing the flaw detection, a high-purity nickel-chromium-iron resistance alloy rod was obtained.

[0037] Example 2 A high-purity nickel-chromium-iron resistance alloy: the percentage of chemical elements of the pure nickel-chromium-iron resistance alloy is: C: <0.05%, Si: 0.80%, Mn: 0.50%, P≤0.015%, S≤0.008%, Ni: 35%, Cr: 18.00%%, Co: 0.5%, Ti: 0.10%, La+Zr: 0.05%, Al: 0.100%, and the rest are iron and impurity elements.

[0038] A method for preparing a high-purity nickel-chromium-iron resistance alloy comprises the following steps: S1. Sandblasting pure iron, metallic nickel, metallic chromium and metallic cobalt, and then batching them according to their chemical components; S2, preheating the chute, and loading the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible; In some embodiments, the step S2, preheating the chute and loading the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible, comprises: Heat the chute in a heating furnace at 100°C for a holding time of ≥2h; When loading the crucible, a small piece of pure iron is placed on the bottom, pure iron rods are placed around the crucible, and carbon, metallic nickel, metallic chromium, metallic cobalt are loosely placed in the middle.

[0039] S3, performing vacuum induction melting of various raw materials in the crucible to obtain annealed castings; In some embodiments, the step S3, performing vacuum induction melting of various raw materials in the crucible to obtain a casting that has been annealed, comprises: Evacuate the vacuum, and start to supply power after the vacuum degree is ≤10pa; Melt the metal at low power for 5-7h. After melting, adjust the temperature to 1600℃, stir and refine for 60 minutes; test [O]+[N]≤85ppm; then add metal aluminum, silicon and manganese with argon filling, add ferrotitanium after refining for 8min, stir for 4 minutes, finally add rare earth lanthanum and zirconium, stir for 4 minutes, adjust the temperature to 1520℃ for steel casting; After 40 minutes, the mold is broken and quickly put back into the furnace for the first annealing process.

[0040] The first furnace annealing process includes heating to 800°C at a heating rate of ≤80°C / hour, keeping the temperature for 4 hours, and cooling to room temperature along with the furnace.

[0041] S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece; In some embodiments, the step S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece, comprises: The induction ingot after the casting surface is polished is loaded into the vacuum consumable furnace and evacuated; the consumable process starts when the vacuum degree is less than 15pa; the consumable process is that the melting rate of the ingot body is controlled at 8kg / min; the feeding stage rate is controlled at 2.5kg / min; After the self-consumable process is completed, the mold is broken after cooling for 70 minutes, and then quickly put back into the furnace for the second annealing process to obtain the intermediate part.

[0042] Among them, the second furnace annealing process quickly transfers the demoulding consumable ingot to the adding furnace, heats it to 800°C at a heating rate of ≤100°C / hour, keeps it warm for 4h, and cools it to room temperature with the furnace to obtain the intermediate part.

[0043] S5. The intermediate piece is rolled to obtain a bar.

[0044] In some embodiments, the step S5, rolling the intermediate piece to obtain a bar, comprises: Heat to 800±10℃ at a heating rate of 60℃ / h, keep warm for 180min, then heat to 1200±10℃ at a heating rate of 100℃ / h, keep warm for 300min, then take out of the furnace; The total number of deformation passes is 19, and the billet specification is 215mm×215mm square billet. The first 4 passes from billet opening are deformed with a deformation amount of ≤5%, and the 8th to 11th passes are deformed with a large deformation of 22%, and the final rolling temperature is 980℃; The 4-stand continuous rolling mill is used, and the last two stands are Φ180mm finishing stands. The rolling speed is 1.8m / S, and the final rolling temperature is between 730-750℃. Φ180mm bars are rolled out, and then air-cooled while moving on the chain cooling bed; The temperature was raised to 650°C at a heating rate of 60°C / h and kept at a temperature for 210 minutes. The steel was then taken out of the furnace and straightened when the temperature dropped to 350°C. After passing the flaw detection, a high-purity nickel-chromium-iron resistance alloy rod was obtained.

[0045] Example 3 A high-purity nickel-chromium-iron resistance alloy: the percentage of chemical elements of the pure nickel-chromium-iron resistance alloy is: C: <0.03%, Si: 1.50%, Mn: 1.30%, P≤0.010%, S≤0.006%, Ni: 43%, Cr: 22.00%, Co: 2.10%, Ti: 0.40%, La+Zr: 2.00%, Al: 0.50%, and the rest are iron and impurity elements.

[0046] A method for preparing a high-purity nickel-chromium-iron resistance alloy comprises the following steps: S1. Sandblasting pure iron, metallic nickel, metallic chromium and metallic cobalt, and then batching them according to their chemical components; S2, preheating the chute, and loading the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible; In some embodiments, the step S2, preheating the chute and loading the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible, comprises: Heat the chute in a heating furnace at 1300°C for a holding time of ≥2h; When loading the crucible, a small piece of pure iron is placed on the bottom, pure iron rods are placed around the crucible, and carbon, metallic nickel, metallic chromium, metallic cobalt are loosely placed in the middle.

[0047] S3, performing vacuum induction melting of various raw materials in the crucible to obtain annealed castings; In some embodiments, the step S3, performing vacuum induction melting of various raw materials in the crucible to obtain a casting that has been annealed, comprises: Evacuate the vacuum, and start to supply power after the vacuum degree is ≤10pa; Melt the metal at low power for 6.5 hours. After melting, adjust the temperature to 1620℃ and stir + refine for 75 minutes. Test [O]+[N]≤85ppm. Then add aluminum, silicon and manganese with argon filling. After refining for 9-11 minutes, add ferrotitanium and stir for 5.5 minutes. Finally, add rare earth lanthanum and zirconium and stir for 5.5 minutes. Adjust the temperature to 1530℃ for steel casting. After 47 minutes, the mold is broken and quickly put back into the furnace for the first annealing process.

[0048] The first furnace annealing process includes heating to 870°C at a heating rate of ≤80°C / hour, keeping the temperature for 5 hours, and cooling to room temperature along with the furnace.

[0049] S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece; In some embodiments, the step S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece, comprises: The induction ingot after the casting surface is polished is loaded into the vacuum consumable furnace and evacuated; the consumable process starts when the vacuum degree is less than 15pa; the consumable process is that the melting rate of the ingot body is controlled at 9.5kg / min; the feeding stage rate is controlled at 2.9kg / min; After the self-consumable process is completed, the mold is broken after cooling for 85 minutes, and then quickly put back into the furnace for the second annealing process to obtain the intermediate part.

[0050] Among them, the second furnace annealing process quickly transfers the demoulding consumable ingot to the adding furnace, heats it to 870°C at a heating rate of ≤100°C / hour, keeps it warm for 5.5h, and cools it to room temperature with the furnace to obtain the intermediate part.

[0051] S5. The intermediate piece is rolled to obtain a bar.

[0052] In some embodiments, the step S5, rolling the intermediate piece to obtain a bar, comprises: Heat to 800±10℃ at a heating rate of 60℃ / h, keep warm for 180min, then heat to 1200±10℃ at a heating rate of 100℃ / h, keep warm for 300min, then take out of the furnace; The total number of deformation passes is 19, and the billet specification is 215mm×215mm square billet. The first 4 passes are deformed with a deformation of ≤5%, and the 8th to 11th passes are deformed with a large deformation of 22%, and the final rolling temperature is 1050℃; The 4-stand continuous rolling mill is used, and the last two stands are Φ180mm finishing stands. The rolling speed is 2.3m / S, and the final rolling temperature is between 730-750℃. Φ180mm bars are rolled out, and then air-cooled while moving on the chain cooling bed; The temperature was raised to 700°C at a heating rate of 60°C / h and kept at a temperature for 210 minutes. The steel was then taken out of the furnace and straightened when the temperature dropped to 500°C. After passing the flaw detection, a high-purity nickel-chromium-iron resistance alloy rod was obtained.

[0053] Example 4 A high-purity nickel-chromium-iron resistance alloy: the percentage of chemical elements of the pure nickel-chromium-iron resistance alloy is: C: <0.03%, Si: 1.10%, Mn: 0.65%, P≤0.010%, S≤0.006%, Ni: 37%, Cr: 19.00%%, Co: 0.9%, Ti: 0.20%, La+Zr: 0.15%, Al: 0.20%, and the rest are iron and impurity elements.

[0054] A method for preparing a high-purity nickel-chromium-iron resistance alloy comprises the following steps: S1. Sandblasting pure iron, metallic nickel, metallic chromium and metallic cobalt, and then batching them according to their chemical components; S2, preheating the chute, and loading the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible; In some embodiments, the step S2, preheating the chute and loading the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible, comprises: Heat the chute in a heating furnace at 1100°C for a holding time of ≥2h; When loading the crucible, a small piece of pure iron is placed on the bottom, pure iron rods are placed around the crucible, and carbon, metallic nickel, metallic chromium, metallic cobalt are loosely placed in the middle.

[0055] S3, performing vacuum induction melting of various raw materials in the crucible to obtain annealed castings; In some embodiments, the step S3, performing vacuum induction melting of various raw materials in the crucible to obtain a casting that has been annealed, comprises: Evacuate the vacuum, and start to supply power after the vacuum degree is ≤10pa; Melt the metal at low power for 5.5 hours. After melting, adjust the temperature to 1600℃, stir and refine for 65 minutes; test [O]+[N]≤85ppm; then add aluminum, silicon and manganese with argon filling, add ferrotitanium after refining for 9 minutes, stir for 4.5 minutes, finally add rare earth lanthanum and zirconium, stir for 4.5 minutes, adjust the temperature to 1520℃ for steel casting; After 43 minutes, the mold is broken and quickly put back into the furnace for the first annealing process.

[0056] The first furnace annealing process includes heating to 830°C at a heating rate of ≤80°C / hour, keeping the temperature for 4 hours, and cooling to room temperature along with the furnace.

[0057] S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece; In some embodiments, the step S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece, comprises: The induction ingot after the casting surface is polished is loaded into the vacuum consumable furnace and evacuated; the consumable process starts when the vacuum degree is less than 15pa; the consumable process is that the melting rate of the ingot body is controlled at 8.5kg / min; the feeding stage rate is controlled at 2.6kg / min; After the self-consumable process is completed, the mold is broken after cooling for 75 minutes, and then quickly put back into the furnace for the second annealing process to obtain the intermediate part.

[0058] Among them, the second furnace annealing process quickly transfers the demoulding consumable ingot to the adding furnace, heats it to 830°C at a heating rate of ≤100°C / hour, keeps it warm for 4.5h, and cools it to room temperature with the furnace to obtain the intermediate part.

[0059] S5. The intermediate piece is rolled to obtain a bar.

[0060] In some embodiments, the step S5, rolling the intermediate piece to obtain a bar, comprises: Heat to 800±10℃ at a heating rate of 60℃ / h, keep warm for 180min, then heat to 1200±10℃ at a heating rate of 100℃ / h, keep warm for 300min, then take out of the furnace; The total number of deformation passes is 19, and the billet specification is 215mm×215mm square billet. The first 4 passes from billet opening are deformed with a deformation amount of ≤5%, and the 8th to 11th passes are deformed with a large deformation of 22%, and the final rolling temperature is 980℃; The 4-stand continuous rolling mill is used, and the last two stands are Φ180mm finishing stands. The rolling speed is 1.8-2.3m / S, and the final rolling temperature is between 730℃. Φ180mm bars are rolled out, and then air-cooled while moving on the chain cooling bed; The temperature was raised to 650°C at a heating rate of 60°C / h and kept at a temperature for 210 minutes. The steel was then taken out of the furnace and straightened when the temperature dropped to 350°C. After passing the flaw detection, a high-purity nickel-chromium-iron resistance alloy rod was obtained.

[0061] Example 5 A high-purity nickel-chromium-iron resistance alloy: the percentage of chemical elements of the pure nickel-chromium-iron resistance alloy is: C: <0.02%, Si: 1.30%, Mn: 0.10%, P≤0.008%, S≤0.006%, Ni: 40%, Cr: 21.00%, Co: 1.50%, Ti: 0.35%, La+Zr: 1.30%, Al: 0.35%, and the rest are iron and impurity elements.

[0062] A method for preparing a high-purity nickel-chromium-iron resistance alloy comprises the following steps: S1. Sandblasting pure iron, metallic nickel, metallic chromium and metallic cobalt, and then batching them according to their chemical components; S2, preheating the chute, and placing the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible; In some embodiments, the step S2, preheating the chute and loading the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible, comprises: Heat the chute in a heating furnace at 1200°C for a holding time of ≥2h; When loading the crucible, a small piece of pure iron is placed on the bottom, pure iron rods are placed around the crucible, and carbon, metallic nickel, metallic chromium, metallic cobalt are loosely placed in the middle.

[0063] S3, performing vacuum induction melting of various raw materials in the crucible to obtain annealed castings; In some embodiments, the step S3, performing vacuum induction melting of various raw materials in the crucible to obtain a casting that has been annealed, comprises: Evacuate the vacuum, and start to supply power after the vacuum degree is ≤10pa; Melt the metal at low power for 6 hours. After melting, adjust the temperature to 1610℃ and stir + refine for 70 minutes. Test [O]+[N]≤85ppm. Then add aluminum, silicon and manganese with argon filling. After refining for 10 minutes, add titanium iron and stir for 5 minutes. Finally, add rare earth lanthanum and zirconium and stir for 5 minutes. Adjust the temperature to 1525℃ for steel casting. After 45 minutes, the mold is broken and quickly put back into the furnace for the first annealing process.

[0064] The first furnace annealing process includes heating to 850°C at a heating rate of ≤80°C / hour, keeping the temperature for 4.5 hours, and cooling to room temperature along with the furnace.

[0065] S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece; In some embodiments, the step S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece, comprises: The induction ingot after the casting surface is polished is loaded into the vacuum consumable furnace and evacuated; the consumable process starts when the vacuum degree is less than 15pa; the consumable process is that the melting rate of the ingot body is controlled at 9kg / min; the feeding stage rate is controlled at 2.7kg / min; After the self-consumable process is completed, the mold is broken after cooling for 70-90 minutes, and then quickly put back into the furnace for the second annealing process to obtain the intermediate part.

[0066] Among them, the second furnace annealing process quickly transfers the demoulding consumable ingot to the adding furnace, heats it to 850°C at a heating rate of ≤100°C / hour, keeps it warm for 5h, and cools it to room temperature with the furnace to obtain the intermediate part.

[0067] S5. The intermediate piece is rolled to obtain a bar.

[0068] In some embodiments, the step S5, rolling the intermediate piece to obtain a bar, comprises: Heat to 800±10℃ at a heating rate of 60℃ / h, keep warm for 180min, then heat to 1200±10℃ at a heating rate of 100℃ / h, keep warm for 300min, then take out of the furnace; The total number of deformation passes is 19, and the billet specification is 215mm×215mm square billet. The deformation from the billet to the first 4 passes is ≤5%, and the deformation from the 8th to the 11th pass is 22%. The final rolling temperature is 980℃-1050℃; The 4-stand continuous rolling mill is used, and the last two stands are Φ180mm finishing stands. The rolling speed is 1.8-2.3m / S, and the final rolling temperature is between 730-750℃. Φ180mm bars are rolled out, and then air-cooled while moving on the chain cooling bed; The temperature is raised to 650-700°C at a heating rate of 60°C / h, and the heat preservation time is 210 minutes. Then it is taken out of the furnace, and straightened when the temperature drops to 350-500°C. The flaw detection is qualified to obtain high-purity nickel-chromium-iron resistance alloy rods.

[0069] Example 6 A high-purity nickel-chromium-iron resistance alloy: the chemical element percentages of the pure nickel-chromium-iron resistance alloy are: C: 0.015%, Ni: 38%, Si: 1.10%, Mn: 0.65%, Cr: 18.00%, Co: 1.20%, Ti: 0.25%, La+Zr: 0.20%, Al: 0.5%, and the balance is Fe and impurity elements.

[0070] A method for preparing a high-purity nickel-chromium-iron resistance alloy comprises the following steps: S1. Sandblasting pure iron, metallic nickel, metallic chromium and metallic cobalt, and then batching them according to their chemical components; S2, preheating the chute, and loading the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible; In some embodiments, the step S2, preheating the chute and loading the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible, comprises: Heat the chute in a heating furnace at 1200°C for a holding time of ≥2h; When loading the crucible, a small piece of pure iron is placed on the bottom, pure iron rods are placed around the crucible, and carbon, metallic nickel, metallic chromium, metallic cobalt are loosely placed in the middle.

[0071] S3, performing vacuum induction melting of various raw materials in the crucible to obtain annealed castings; In some embodiments, the step S3, performing vacuum induction melting of various raw materials in the crucible to obtain a casting that has been annealed, comprises: Evacuate the vacuum, and start to supply power after the vacuum degree is ≤10pa; Melt the metal at low power for 6 hours. After melting, adjust the temperature to 1610℃ and stir + refine for 70 minutes. Test [O]+[N]≤85ppm. Then add aluminum, silicon and manganese with argon filling. After refining for 10 minutes, add titanium iron and stir for 5 minutes. Finally, add rare earth lanthanum and zirconium and stir for 5 minutes. Adjust the temperature to 1525℃ for steel casting. After 45 minutes, the mold is broken and quickly put back into the furnace for the first annealing process.

[0072] The first furnace annealing process includes heating to 850°C at a heating rate of ≤80°C / hour, keeping the temperature for 4.5 hours, and cooling to room temperature along with the furnace.

[0073] S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece; In some embodiments, the step S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece, comprises: The induction ingot after the casting surface is polished is loaded into the vacuum consumable furnace and evacuated; the consumable process starts when the vacuum degree is less than 15pa; the consumable process is that the melting rate of the ingot body is controlled at 9kg / min; the feeding stage rate is controlled at 2.7kg / min; After the self-consumable process is completed, the mold is broken after cooling for 70-90 minutes, and then quickly put back into the furnace for the second annealing process to obtain the intermediate part.

[0074] Among them, the second furnace annealing process quickly transfers the demoulding consumable ingot to the adding furnace, heats it to 850°C at a heating rate of ≤100°C / hour, keeps it warm for 5h, and cools it to room temperature with the furnace to obtain the intermediate part.

[0075] S5. The intermediate piece is rolled to obtain a bar.

[0076] In some embodiments, the step S5, rolling the intermediate piece to obtain a bar, comprises: Heat to 800±10℃ at a heating rate of 60℃ / h, keep warm for 180min, then heat to 1200±10℃ at a heating rate of 100℃ / h, keep warm for 300min, then take out of the furnace; The total number of deformation passes is 19, and the billet specification is 215mm×215mm square billet. The deformation from the billet to the first 4 passes is ≤5%, and the deformation from the 8th to the 11th pass is 22%. The final rolling temperature is 980℃-1050℃; The 4-stand continuous rolling mill is used, and the last two stands are Φ180mm finishing stands. The rolling speed is 1.8-2.3m / S, and the final rolling temperature is between 730-750℃. Φ180mm bars are rolled out, and then air-cooled while moving on the chain cooling bed; The temperature is raised to 650-700°C at a heating rate of 60°C / h, and the heat preservation time is 210 minutes. Then it is taken out of the furnace, and straightened when the temperature drops to 350-500°C. The flaw detection is qualified to obtain high-purity nickel-chromium-iron resistance alloy rods.

[0077] Example 7 A high-purity nickel-chromium-iron resistance alloy: the chemical element percentages of the pure nickel-chromium-iron resistance alloy are: C: 0.012%, Ni: 40%, Si: 1.50%, Mn: 1.5%, Cr: 20.00%, Co: 2.00%, Ti: 0.40%, La+Zr: 0.15%, Al: 0.45%, and the balance is Fe and impurity elements.

[0078] A method for preparing a high-purity nickel-chromium-iron resistance alloy comprises the following steps: S1. Sandblasting pure iron, metallic nickel, metallic chromium and metallic cobalt, and then batching them according to their chemical components; S2, preheating the chute, and loading the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible; In some embodiments, the step S2, preheating the chute and loading the prepared pure iron, metallic nickel, metallic chromium, and metallic cobalt into the crucible, comprises: Heat the chute in a heating furnace at 1200°C for a holding time of ≥2h; When loading the crucible, a small piece of pure iron is placed on the bottom, pure iron rods are placed around the crucible, and carbon, metallic nickel, metallic chromium, metallic cobalt are loosely placed in the middle.

[0079] S3, performing vacuum induction melting of various raw materials in the crucible to obtain annealed castings; In some embodiments, the step S3, performing vacuum induction melting of various raw materials in the crucible to obtain a casting that has been annealed, comprises: Evacuate the vacuum, and start to supply power after the vacuum degree is ≤10pa; Melt the metal at low power for 6 hours. After melting, adjust the temperature to 1610℃ and stir + refine for 70 minutes. Test [O]+[N]≤85ppm. Then add aluminum, silicon and manganese with argon filling. After refining for 10 minutes, add titanium iron and stir for 5 minutes. Finally, add rare earth lanthanum and zirconium and stir for 5 minutes. Adjust the temperature to 1525℃ for steel casting. After 45 minutes, the mold is broken and quickly put back into the furnace for the first annealing process.

[0080] The first furnace annealing process includes heating to 850°C at a heating rate of ≤80°C / hour, keeping the temperature for 4.5 hours, and cooling to room temperature along with the furnace.

[0081] S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece; In some embodiments, the step S4, performing vacuum consumable treatment on the casting to obtain an intermediate piece, comprises: The induction ingot after the casting surface is polished is loaded into the vacuum consumable furnace and evacuated; the consumable process starts when the vacuum degree is less than 15pa; the consumable process is that the melting rate of the ingot body is controlled at 9kg / min; the feeding stage rate is controlled at 2.7kg / min; After the self-consumable process is completed, the mold is broken after cooling for 70-90 minutes, and then quickly put back into the furnace for the second annealing process to obtain the intermediate part.

[0082] Among them, the second furnace annealing process quickly transfers the demoulding consumable ingot to the adding furnace, heats it to 850°C at a heating rate of ≤100°C / hour, keeps it warm for 5h, and cools it to room temperature with the furnace to obtain the intermediate part.

[0083] S5. The intermediate piece is rolled to obtain a bar.

[0084] In some embodiments, the step S5, rolling the intermediate piece to obtain a bar, comprises: Heat to 800±10℃ at a heating rate of 60℃ / h, keep warm for 180min, then heat to 1200±10℃ at a heating rate of 100℃ / h, keep warm for 300min, then take out of the furnace; The total number of deformation passes is 19, and the billet specification is 215mm×215mm square billet. The deformation from the billet to the first 4 passes is ≤5%, and the deformation from the 8th to the 11th pass is 22%. The final rolling temperature is 980℃-1050℃; The 4-stand continuous rolling mill is used, and the last two stands are Φ180mm finishing stands. The rolling speed is 1.8-2.3m / S, and the final rolling temperature is between 730-750℃. Φ180mm bars are rolled out, and then air-cooled while moving on the chain cooling bed; The temperature is raised to 650-700°C at a heating rate of 60°C / h, and the heat preservation time is 210 minutes. Then it is taken out of the furnace, and straightened when the temperature drops to 350-500°C. The flaw detection is qualified to obtain high-purity nickel-chromium-iron resistance alloy rods.

[0085] The present invention adopts a double vacuum process to prepare a high-purity iron-chromium-aluminum alloy billet, wherein [O]+[N]≤100ppm; adopts a high-temperature casting method to obtain a developed columnar crystal structure, providing favorable conditions for vacuum self-consumption to stabilize the melting rate; adopts rapid demoulding after vacuum induction and vacuum self-consumption to avoid serious internal cracks in the steel ingot; adopts a rough rolling mill large deformation + continuous rolling + rapid cooling process to obtain uniform and sufficient deformation of the structure and avoid carbide precipitation, and has high production efficiency.

[0086] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A high purity nickel-chromium-iron resistance alloy, characterized in that: The chemical element percentages of the pure nickel-chromium-iron resistance alloy are: C: <0.05%, Si: 0.80-1.80%, Mn: 0.50-1.50%, P≤0.015%, S≤0.008%, Ni: 35-45%, Cr: 18.00%-23.00%, Co: 0.5-2.50%, Ti: 0.10-0.60%, La+Zr: 0.05-2.50%, Al: 0.10-0.60%, and the rest are iron and impurity elements.

2. The high-purity nickel-chromium-iron resistance alloy according to claim 1, characterized in that: The percentages of chemical elements of the pure nickel-chromium-iron resistance alloy are: C: <0.03%, Si: 1.10-1.50%, Mn: 0.65-1.30%, P≤0.010%, S≤0.006%, Ni: 37-43%, Cr: 19.00%-22.00%, Co: 0.9-2.10%, Ti: 0.20-0.40%, La+Zr: 0.15-2.00%, Al: 0.20-0.50%, and the rest are iron and impurity elements.

3. The high-purity nickel-chromium-iron resistance alloy according to claim 1, characterized in that: The percentages of chemical elements of the pure nickel-chromium-iron resistance alloy are: C: <0.02%, Si: 1.30%, Mn: 0.10%, P≤0.008%, S≤0.006%, Ni: 40%, Cr: 21.00%, Co: 1.50%, Ti: 0.35%, La+Zr: 1.30%, Al: 0.35%, and the rest are iron and impurity elements.

4. A method for preparing a high-purity nickel-chromium-iron resistance alloy as claimed in any one of claims 1 to 3, characterized in that: The steps include: Pure iron, nickel, chromium and cobalt are sandblasted and then batched according to chemical composition; Preheat the chute and put the prepared pure iron, metal nickel, metal chromium and metal cobalt into the crucible; Perform vacuum induction melting of various raw materials in the crucible to obtain annealed castings; The casting is subjected to a vacuum consumable treatment to obtain an intermediate piece.

5. The method for preparing the high-purity nickel-chromium-iron resistance alloy according to claim 4, characterized in that: The preparation method further comprises: rolling the intermediate piece to obtain a bar.

6. The method for preparing the high-purity nickel-chromium-iron resistance alloy according to claim 4, characterized in that: The method of preheating the chute and placing the prepared pure iron, metal nickel, metal chromium and metal cobalt into the crucible comprises: Heat the chute in a heating furnace at 1000℃-1400℃, and keep warm for ≥2h; When loading the crucible, a small piece of pure iron is placed on the bottom, pure iron rods are placed around the crucible, and carbon, metallic nickel, metallic chromium, metallic cobalt are loosely placed in the middle.

7. The method for preparing the high-purity nickel-chromium-iron resistance alloy according to claim 4, characterized in that: The vacuum induction melting of various raw materials in the crucible to obtain the annealed castings includes: Evacuate the vacuum, and start to supply power after the vacuum degree is ≤10pa; Melt the metal at low power for 5-7h. After melting, adjust the temperature to 1600℃-1620℃, stir and refine for 60-80 minutes; test [O]+[N]≤85ppm; then add metal aluminum, silicon and manganese with argon filling, add ferrotitanium after refining for 8-12min, stir for 4-6 minutes, finally add rare earth lanthanum and zirconium, stir for 4-6 minutes, adjust the temperature to 1520℃-1530℃ for steel casting; After 40-50 minutes, the mold is broken and quickly put back into the furnace for the first annealing process.

8. The method for preparing the high-purity nickel-chromium-iron resistance alloy according to claim 7, characterized in that: The first furnace annealing process includes heating to 800-900°C at a heating rate of ≤80°C / hour, keeping the temperature for 4-5h, and cooling to room temperature along with the furnace.

9. The method for preparing a high-purity nickel-chromium-iron resistance alloy according to claim 4, characterized in that: The method of subjecting the casting to vacuum consumable treatment to obtain the intermediate piece comprises: The induction ingot after the casting surface is polished is loaded into the vacuum consumable furnace and evacuated; the consumable process starts when the vacuum degree is less than 15pa; the consumable process is that the melting rate of the ingot body is controlled at 8-10kg / min; the feeding stage rate is controlled at 2.5-3kg / min; After the self-consumable process is completed, the mold is broken after cooling for 70-90 minutes, and then quickly put back into the furnace for the second annealing process to obtain the intermediate part.

10. The method for preparing a high-purity nickel-chromium-iron resistance alloy according to claim 9, characterized in that: In the second furnace annealing process, the demoulding consumable ingot is quickly transferred to the adding furnace, heated to 800-900℃ at a heating rate of ≤100℃ / hour, kept at this temperature for 4-6h, and cooled to room temperature with the furnace to obtain the intermediate part.