High-purity iron-chromium-aluminum resistance alloy and manufacturing method thereof

Abstract

The invention discloses a high-purity iron-chromium-aluminum resistance alloy and a manufacturing method thereof, and relates to the technical field of metallurgy, and the pure iron-chromium-aluminum resistance alloy comprises the following chemical elements: less than or equal to 0.04% of C, 0.15-0.60% of Si, 0.35-0.85% of Mn, less than or equal to 0.015% of P, less than or equal to 0.008% of S, 22.00-27.00% of Cr, 0.2-1.50% of Mo, 0.2-3.00% of Co, 0.50-1.50% of Ti, 0.05-1.50% of any combination of Ce, Y, Zr and La, 4.00-7.00% 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.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, in particular to a high-purity iron-chromium-aluminum resistance alloy and a manufacturing 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℃, and are usually used in industrial electric furnaces, laboratory electric furnaces and household appliances. In particular, iron-based alloys have the advantages of high resistivity, good thermal stability, long service life, abundant resources and low cost. Under the same power, voltage and cross-sectional size of electric heating components, the amount of iron-based alloys is less than that of Ni-Cr alloys, and the price is cheap, the cost is only 1 / 3 of that of Ni-Cr alloys. At present, most companies use the process of vacuum induction furnace + electroslag remelting to produce 1300℃ high temperature resistant iron-chromium-aluminum products. The oxygen and nitrogen content in the products is high, and the intergranular bonding strength of the cast structure of the products is weak, the structure is brittle, and cracks are easily generated during thermal deformation. The product yield rate is low, which seriously restricts the market promotion of the product. In order to solve this technical problem, a high-purity iron-chromium-aluminum resistance alloy and a manufacturing method thereof are proposed. Summary of the invention

[0003] The object of the present invention is to provide a high-purity Fe-Cr-Al resistance alloy and a method for manufacturing the same, so as to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions: A high-purity iron-chromium-aluminum resistance alloy, the chemical element percentages of the pure iron-chromium-aluminum resistance alloy are: C: ≤0.04%, Si: 0.15-0.60%, Mn: 0.35-0.85%, P≤0.015%, S≤0.008%, Cr: 22.00%-27.00%, Mo: 0.2-1.50%, Co: 0.2-3.00%, Ti: 0.50-1.50%, any combination of Ce, Y, Zr, La: 0.05-1.50%, Al: 4.00-7.00%, and the rest are iron and impurity elements.

[0005] As a further solution of the present invention: the percentage of chemical elements in the pure iron-chromium-aluminum resistance alloy is: C: ≤0.03%, Si: 0.30-0.50%, Mn: 0.55-0.65%, P≤0.012%, S≤0.006%, Cr: 24.00%-25.00%, Mo: 0.4-1.30%, Co: 0.5-2.50%, Ti: 0.80-1.20%, any combination of Ce, Y, Zr, La: 0.08-1.20%, Al: 4.00-7.00%, 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 iron-chromium-aluminum resistance alloy are: C: ≤0.02%, Si: 0.35%, Mn: 0.60%, P≤0.010%, S≤0.005%, Cr: 24.50%, Mo: 0.80%, Co: 1.50%, Ti: 1.00%, any combination of Ce, Y, Zr, La: 1.00%, Al: 5.500%, and the rest are iron and impurity elements.

[0007] Another object of the present invention is to provide a method for preparing the subject, comprising the following steps: All alloys are polished to remove surface oxides and attachments, and the ingredients are prepared according to the preset proportions; All raw materials are charged and then vacuum induction treated to obtain castings, and the castings are quickly annealed; The casting is subjected to vacuum consumable melting treatment to obtain an intermediate casting, and the intermediate casting is subjected to tempering furnace annealing treatment.

[0008] As a further solution of the present invention: the intermediate casting is subjected to a heat treatment; The intermediate casting is subjected to a forging process to obtain a rod, and the rod is subjected to an annealing process.

[0009] As a further solution of the present invention: the step of charging all raw materials and then performing vacuum induction treatment to obtain castings, and performing rapid annealing treatment on the castings comprises: First melt at low power, melting time ≥ 4h, adjust the temperature to 1640℃-1680℃ after melting, stir + scouring time ≥ 45min, adjust the alloy composition after [O]+[N]≤100ppm, measure the temperature to 1650℃-1690℃ for steel casting; Demolding is done 20-45 minutes after pouring, followed by rapid annealing. During the entire melting process, the vacuum degree is ≤5Pa.

[0010] As a further solution of the present invention: the casting is subjected to vacuum consumable smelting treatment to obtain an intermediate casting, and the intermediate casting is subjected to tempering furnace annealing treatment, comprising: The normal melting rate of castings is 1-10.0kg / min, and the melting rate of the feeding section is 0.5-4kg / min; Demould the part 20-45 minutes after pouring, then quickly put it back into the furnace for annealing.

[0011] As a further solution of the present invention: the processes of rapid annealing and tempering furnace annealing are both: 800-850°C, and the holding time is calculated according to the formula T=K1*D, wherein K1 is the calculation coefficient, with a value of 0.0.2-5; D1 is the diameter of the casting.

[0012] As a further solution of the present invention: the heating treatment of the intermediate casting comprises: Heat to 800±10℃ at a heating rate of ≤100℃ / h, and keep warm for >60min. Then heat to 950℃-1150℃ at a heating rate of ≤120℃ / h. The keeping warm time is calculated according to the formula T=K*D, where K is the calculation coefficient, with a value of 0.0.2-2; D2 is the diameter of the intermediate casting.

[0013] As a further solution of the present invention: the annealing process is to heat the temperature to 650-700°C at a heating rate of ≤100°C / hour, and the holding time is calculated according to the formula T=K2*D, where K2 is the calculation coefficient, the value is 0.5-5; D is the rod diameter, and then cool to room temperature with the furnace to obtain a high-purity iron-chromium-aluminum resistance alloy rod Compared with the prior art, the beneficial effects of the present invention are as follows: a high-purity iron-chromium-aluminum alloy billet is prepared by a double vacuum process, wherein [O]+[N]≤100ppm; a high-temperature casting method is adopted to obtain a developed columnar crystal structure, which provides favorable conditions for vacuum self-consumption to stabilize the melting rate; a thicker fine equiaxed crystal zone is obtained by a slow and fast cooling self-consumption process, which provides a favorable outer layer constraint for forging deformation; rapid demolding is adopted after vacuum induction and vacuum self-consumption to avoid the formation of serious internal cracks in the steel ingot; a low-temperature deformation followed by high-temperature remelting is provided to provide a favorable internal crack welding + axial deformation + rapid cooling forging process to obtain uniform and sufficient deformation of the structure and avoid carbide precipitation, thereby obtaining a high-purity iron-chromium-aluminum resistance alloy rod. DETAILED DESCRIPTION

[0014] The technical solution of the present invention is further described in detail below in conjunction with specific implementation methods.

[0015] The invention provides a high-purity iron-chromium-aluminum resistance alloy. The chemical element percentages of the pure iron-chromium-aluminum resistance alloy are: C: ≤0.04%, Si: 0.15-0.60%, Mn: 0.35-0.85%, P≤0.015%, S≤0.008%, Cr: 22.00%-27.00%, Mo: 0.2-1.50%, Co: 0.2-3.00%, Ti: 0.50-1.50%, any combination of Ce, Y, Zr and La: 0.05-1.50%, Al: 4.00-7.00%, and the rest are iron and impurity elements.

[0016] In some embodiments, the percentages of chemical elements in the pure iron-chromium-aluminum resistance alloy are: C: ≤0.03%, Si: 0.30-0.50%, Mn: 0.55-0.65%, P≤0.012%, S≤0.006%, Cr: 24.00%-25.00%, Mo: 0.4-1.30%, Co: 0.5-2.50%, Ti: 0.80-1.20%, any combination of Ce, Y, Zr, La: 0.08-1.20%, Al: 4.00-7.00%, and the rest are iron and impurity elements.

[0017] In some embodiments, the percentages of chemical elements in the pure iron-chromium-aluminum resistance alloy are: C: ≤0.02%, Si: 0.35%, Mn: 0.60%, P≤0.010%, S≤0.005%, Cr: 24.50%, Mo: 0.80%, Co: 1.50%, Ti: 1.00%, any combination of Ce, Y, Zr, La: 1.00%, Al: 5.500%, and the rest are iron and impurity elements.

[0018] The present invention also provides a method for preparing a high-purity iron-chromium-aluminum resistance alloy, comprising the following steps: S1. Polish all alloys to remove surface oxides and attachments, and mix according to the preset ratio; S2, all raw materials are charged, and then vacuum induction treatment is performed to obtain castings, and the castings are quickly annealed; In some embodiments, the step S2, charging all raw materials, and then performing vacuum induction treatment to obtain a casting, and performing rapid annealing treatment on the casting, comprises: First melt at low power, melting time ≥ 4h, adjust the temperature to 1640℃-1680℃ after melting, stir + scouring time ≥ 45min, adjust the alloy composition after [O]+[N]≤100ppm, measure the temperature to 1650℃-1690℃ for steel casting; Demolding is done 20-45 minutes after pouring, followed by rapid annealing. During the entire melting process, the vacuum degree is ≤5Pa.

[0019] S3, subjecting the casting to vacuum consumable melting treatment to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing treatment.

[0020] In some embodiments, the step S3, subjecting the casting to vacuum consumable smelting to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing, comprises: The normal melting rate of castings is 1-10.0kg / min, and the melting rate of the feeding section is 0.5-4kg / min; Demould the part 20-45 minutes after pouring, then quickly put it back into the furnace for annealing.

[0021] The annealed intermediate casting is inspected and the shrinkage cavity defect at the shrinkage feeding end is removed.

[0022] In some embodiments, the processes of rapid annealing and tempering furnace annealing are both: 800-850°C, and the holding time is calculated according to the formula T=K1*D (where K1 is a calculation coefficient, with a value of 0.0.2-5; D1 is the diameter of the casting).

[0023] S4, heating the intermediate casting; In some embodiments, the step S4, heating the intermediate casting, comprises: Heat to 800±10℃ at a heating rate of ≤100℃ / h, and keep warm for >60min. Then heat to 950℃-1150℃ at a heating rate of ≤120℃ / h. The keeping warm time is calculated according to the formula T=K*D (where K is the calculation coefficient, with a value of 0.0.2-2; D2 is the diameter of the intermediate casting).

[0024] S5. Forging the intermediate casting to obtain a rod, and annealing the rod.

[0025] In some embodiments, the S5, forging the intermediate casting to obtain a rod, and annealing the rod, comprises: Forging by forging hammer or free forging, using upsetting forging, that is, upsetting along the axis of the consumable ingot; The material is made by two fires. The first fire is low-temperature deformation, and the second fire is returned to the furnace for heating; the first fire upsetting deformation is ≤30%, and then returned to the furnace for heating and insulation for ≥3h, and then the second upsetting is carried out to the required specifications of the bar.

[0026] The final forging temperature is strictly controlled between 700-750℃, and then air-cooled.

[0027] The annealing process is: heating to 650-700°C at a heating rate of ≤100°C / hour, the holding time is calculated according to the formula T=K2*D (where K2 is the calculation coefficient, with a value of 0.5-5; D is the rod diameter), and then cooling to room temperature with the furnace to obtain a high-purity iron-chromium-aluminum resistance alloy rod.

[0028] The present invention adopts a double vacuum (vacuum induction + vacuum consumable) 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 the vacuum consumable to stabilize the melting rate; adopts a slow and fast cooling consumable process to obtain a thicker fine equiaxed crystal zone, providing a favorable outer layer constraint for forging deformation; adopts rapid demolding after vacuum induction and vacuum consumable to avoid the formation of serious internal cracks in the steel ingot; adopts a low-temperature deformation followed by a high-temperature furnace return to provide a favorable internal crack welding + axial deformation + rapid cooling forging process to obtain uniform and sufficient deformation of the structure and avoid carbide precipitation, thereby obtaining a high-purity iron-chromium-aluminum resistance alloy rod.

[0029] Example 1 A high-purity iron-chromium-aluminum resistance alloy, the chemical element percentages of the pure iron-chromium-aluminum resistance alloy are: C: ≤0.04%, Si: 0.60%, Mn: 0.85%, P≤0.015%, S≤0.008%, Cr: 27.00%, Mo: 1.50%, Co: 3.00%, Ti: 1.50%, any combination of Ce, Y, Zr, La: 1.50%, Al: 7.00%, and the rest are iron and impurity elements.

[0030] The present invention also provides a method for preparing a high-purity iron-chromium-aluminum resistance alloy, comprising the following steps: S1. Polish all alloys to remove surface oxides and attachments, and mix according to the preset ratio; S2, all raw materials are charged, and then vacuum induction treatment is performed to obtain castings, and the castings are quickly annealed; In some embodiments, the step S2, charging all raw materials, and then performing vacuum induction treatment to obtain a casting, and performing rapid annealing treatment on the casting, comprises: First melt at low power, melting time ≥ 4h, adjust the temperature to 1680℃ after melting, stir + scouring time ≥ 45min, adjust the alloy composition after [O] + [N] ≤ 100ppm, measure the temperature to 1690℃ for steel casting; Demoulding is carried out 45 minutes after pouring, followed by rapid annealing. During the entire melting process, the vacuum degree is ≤5Pa.

[0031] S3, subjecting the casting to vacuum consumable melting treatment to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing treatment.

[0032] In some embodiments, the step S3, subjecting the casting to vacuum consumable smelting to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing, comprises: The normal melting rate of the casting is 10.0kg / min, and the melting rate of the feeding section is 4kg / min; Demould the part 45 minutes after pouring and then quickly put it back into the furnace for annealing.

[0033] The annealed intermediate casting is inspected and the shrinkage cavity defect at the shrinkage feeding end is removed.

[0034] In some embodiments, the processes of rapid annealing and tempering furnace annealing are both: 850°C, and the holding time is calculated according to the formula T=K1*D (where K1 is a calculation coefficient, with a value of 0.0.2-5; D1 is the diameter of the casting).

[0035] S4, heating the intermediate casting; In some embodiments, the step S4, heating the intermediate casting, comprises: Heat to 800±10℃ at a heating rate of ≤100℃ / h, and keep warm for >60min. Then heat to 950℃-1150℃ at a heating rate of ≤120℃ / h. The keeping warm time is calculated according to the formula T=K*D (where K is the calculation coefficient, with a value of 0.0.2-2; D2 is the diameter of the intermediate casting).

[0036] S5. Forging the intermediate casting to obtain a rod, and annealing the rod.

[0037] In some embodiments, the S5, forging the intermediate casting to obtain a rod, and annealing the rod, comprises: Forging by forging hammer or free forging, using upsetting forging, that is, upsetting along the axis of the consumable ingot; The material is made by two fires. The first fire is low-temperature deformation, and the second fire is returned to the furnace for heating; the first fire upsetting deformation is ≤30%, and then it is returned to the furnace for heating and insulation for ≥3h, and then the second upsetting is carried out to the required specifications of the bar.

[0038] The final forging temperature is strictly controlled between 750℃ and then air-cooled.

[0039] The annealing process is: heating to 700°C at a heating rate of ≤100°C / hour, the holding time is calculated according to the formula T=K2*D (where K2 is the calculation coefficient, with a value of 0.5-5; D is the rod diameter), and then cooling to room temperature with the furnace to obtain a high-purity iron-chromium-aluminum resistance alloy rod.

[0040] Example 2 A high-purity iron-chromium-aluminum resistance alloy, the chemical element percentages of the pure iron-chromium-aluminum resistance alloy are: C: ≤0.04%, Si: 0.15%, Mn: 0.35%, P≤0.015%, S≤0.008%, Cr: 22.00%, Mo: 0.2%, Co: 0.2%, Ti: 0.50%, any combination of Ce, Y, Zr, La: 0.05%, Al: 4.00%, and the rest are iron and impurity elements.

[0041] The present invention also provides a method for preparing a high-purity iron-chromium-aluminum resistance alloy, comprising the following steps: S1. Polish all alloys to remove surface oxides and attachments, and mix according to the preset ratio; S2, all raw materials are charged, and then vacuum induction treatment is performed to obtain castings, and the castings are quickly annealed; In some embodiments, the step S2, charging all raw materials, and then performing vacuum induction treatment to obtain a casting, and performing rapid annealing treatment on the casting, comprises: First melt at low power, melting time ≥ 4h, adjust the temperature to 164℃ after melting, stir + scouring time ≥ 45min, adjust the alloy composition after [O] + [N] ≤ 100ppm, measure the temperature to 1650℃ for steel casting; Demoulding is carried out 20 minutes after pouring, followed by rapid annealing. During the entire melting process, the vacuum degree is ≤5Pa.

[0042] S3, subjecting the casting to vacuum consumable melting treatment to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing treatment.

[0043] In some embodiments, the step S3, subjecting the casting to vacuum consumable smelting to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing, comprises: The normal melting rate of the casting is 1g / min, and the melting rate of the shrinkage section is 0.5kg / min; Demould the part 20 minutes after pouring and then quickly put it back into the furnace for annealing.

[0044] The annealed intermediate casting is inspected and the shrinkage cavity defect at the shrinkage feeding end is removed.

[0045] In some embodiments, the processes of rapid annealing and tempering furnace annealing are both: 800°C, and the holding time is calculated according to the formula T=K1*D (where K1 is a calculation coefficient, with a value of 0.0.2-5; D1 is the diameter of the casting).

[0046] S4, heating the intermediate casting; In some embodiments, the step S4, heating the intermediate casting, comprises: Heat to 800±10℃ at a heating rate of ≤100℃ / h, and keep warm for >60min. Then heat to 950℃ at a heating rate of ≤120℃ / h. The keeping warm time is calculated according to the formula T=K*D (where K is the calculation coefficient, with a value of 0.0.2-2; D2 is the diameter of the intermediate casting).

[0047] S5. Forging the intermediate casting to obtain a rod, and annealing the rod.

[0048] In some embodiments, the S5, forging the intermediate casting to obtain a rod, and annealing the rod, comprises: Forging by forging hammer or free forging, using upsetting forging, that is, upsetting along the axis of the consumable ingot; The material is made by two fires. The first fire is low-temperature deformation, and the second fire is returned to the furnace for heating; the first fire upsetting deformation is ≤30%, and then it is returned to the furnace for heating and insulation for ≥3h, and then the second upsetting is carried out to the required specifications of the bar.

[0049] The final forging temperature is strictly controlled within 700℃ and then air-cooled.

[0050] The annealing process is: heating to 650°C at a heating rate of ≤100°C / hour, the holding time is calculated according to the formula T=K2*D (where K2 is the calculation coefficient, with a value of 0.5-5; D is the rod diameter), and then cooling to room temperature with the furnace to obtain a high-purity iron-chromium-aluminum resistance alloy rod.

[0051] Example 3 A high-purity iron-chromium-aluminum resistance alloy, the chemical element percentages of the pure iron-chromium-aluminum resistance alloy are: C: ≤0.03%, Si: 0.50%, Mn: 0.65%, P≤0.012%, S≤0.006%, Cr: 25.00%, Mo: 1.30%, Co: 2.50%, Ti: 1.20%, any combination of Ce, Y, Zr, La: 1.20%, Al: 7.00%, and the rest are iron and impurity elements.

[0052] The present invention also provides a method for preparing a high-purity iron-chromium-aluminum resistance alloy, comprising the following steps: S1. Polish all alloys to remove surface oxides and attachments, and mix according to the preset ratio; S2, all raw materials are charged, and then vacuum induction treatment is performed to obtain castings, and the castings are quickly annealed; In some embodiments, the step S2, charging all raw materials, and then performing vacuum induction treatment to obtain a casting, and performing rapid annealing treatment on the casting, comprises: First melt at low power, melting time ≥ 4h, adjust the temperature to 1670℃ after melting, stir + scouring time ≥ 45min, adjust the alloy composition after [O] + [N] ≤ 100ppm, measure the temperature to 1680℃ for steel casting; Demoulding is carried out 40 minutes after pouring, followed by rapid annealing. During the entire melting process, the vacuum degree is ≤5Pa.

[0053] S3, subjecting the casting to vacuum consumable melting treatment to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing treatment.

[0054] In some embodiments, the step S3, subjecting the casting to vacuum consumable smelting to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing, comprises: The normal melting rate of the casting is 7kg / min, and the melting rate of the shrinkage section is 3kg / min; Demould the part 30 minutes after pouring and then quickly put it back into the furnace for annealing.

[0055] The annealed intermediate casting is inspected and the shrinkage cavity defect at the shrinkage feeding end is removed.

[0056] In some embodiments, the processes of rapid annealing and tempering furnace annealing are both: 840°C, and the holding time is calculated according to the formula T=K1*D (where K1 is a calculation coefficient, with a value of 0.0.2-5; D1 is the diameter of the casting).

[0057] S4, heating the intermediate casting; In some embodiments, the step S4, heating the intermediate casting, comprises: Heat to 800±10℃ at a heating rate of ≤100℃ / h, and keep warm for >60min. Then heat to 1100℃ at a heating rate of ≤120℃ / h. The keeping warm time is calculated according to the formula T=K*D (where K is the calculation coefficient, with a value of 0.0.2-2; D2 is the diameter of the intermediate casting).

[0058] S5. Forging the intermediate casting to obtain a rod, and annealing the rod.

[0059] In some embodiments, the S5, forging the intermediate casting to obtain a rod, and annealing the rod, comprises: Forging by forging hammer or free forging, using upsetting forging, that is, upsetting along the axis of the consumable ingot; The material is made by two fires. The first fire is low-temperature deformation, and the second fire is returned to the furnace for heating; the first fire upsetting deformation is ≤30%, and then returned to the furnace for heating and insulation for ≥3h, and then the second upsetting is carried out to the required specifications of the bar.

[0060] The final forging temperature is strictly controlled between 740℃ and then air-cooled.

[0061] The annealing process is: heating to 690°C at a heating rate of ≤100°C / hour, the holding time is calculated according to the formula T=K2*D (where K2 is the calculation coefficient, with a value of 0.5-5; D is the rod diameter), and then cooling to room temperature with the furnace to obtain a high-purity iron-chromium-aluminum resistance alloy rod.

[0062] Example 4 A high-purity iron-chromium-aluminum resistance alloy, the chemical element percentages of the pure iron-chromium-aluminum resistance alloy are: C: ≤0.03%, Si: 0.30%, Mn: 0.55%, P≤0.012%, S≤0.006%, Cr: 24.00%, Mo: 0.4%, Co: 0.5%, Ti: 0.80%, any combination of Ce, Y, Zr, La: 0.08%, Al: 4.00%, and the rest are iron and impurity elements.

[0063] The present invention also provides a method for preparing a high-purity iron-chromium-aluminum resistance alloy, comprising the following steps: S1. Polish all alloys to remove surface oxides and attachments, and mix according to the preset ratio; S2, all raw materials are charged, and then vacuum induction treatment is performed to obtain castings, and the castings are quickly annealed; In some embodiments, the step S2, charging all raw materials, and then performing vacuum induction treatment to obtain a casting, and performing rapid annealing treatment on the casting, comprises: First melt at low power, melting time ≥ 4h, adjust the temperature to 1650℃ after melting, stir + scouring time ≥ 45min, adjust the alloy composition after [O] + [N] ≤ 100ppm, measure the temperature to 1660℃ for steel casting; Demoulding is carried out 25 minutes after pouring, followed by rapid annealing. During the entire melting process, the vacuum degree is ≤5Pa.

[0064] S3, subjecting the casting to vacuum consumable melting treatment to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing treatment.

[0065] In some embodiments, the step S3, subjecting the casting to vacuum consumable smelting to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing, comprises: The normal melting rate of the casting is 3kg / min, and the melting rate of the shrinkage section is 1kg / min; Demould the part 25 minutes after pouring and then quickly put it back into the furnace for annealing.

[0066] The annealed intermediate casting is inspected and the shrinkage cavity defect at the shrinkage feeding end is removed.

[0067] In some embodiments, the processes of rapid annealing and tempering furnace annealing are both: 810°C, and the holding time is calculated according to the formula T=K1*D (where K1 is a calculation coefficient, with a value of 0.0.2-5; D1 is the diameter of the casting).

[0068] S4, heating the intermediate casting; In some embodiments, the step S4, heating the intermediate casting, comprises: Heat to 800±10℃ at a heating rate of ≤100℃ / h, and keep warm for >60min. Then heat to 1000℃ at a heating rate of ≤120℃ / h. The keeping warm time is calculated according to the formula T=K*D (where K is the calculation coefficient, with a value of 0.0.2-2; D2 is the diameter of the intermediate casting).

[0069] S5. Forging the intermediate casting to obtain a rod, and annealing the rod.

[0070] In some embodiments, the S5, forging the intermediate casting to obtain a rod, and annealing the rod, comprises: Forging by forging hammer or free forging, using upsetting forging, that is, upsetting along the axis of the consumable ingot; The material is made by two fires. The first fire is low-temperature deformation, and the second fire is returned to the furnace for heating; the first fire upsetting deformation is ≤30%, and then it is returned to the furnace for heating and insulation for ≥3h, and then the second upsetting is carried out to the required specifications of the bar.

[0071] The final forging temperature is strictly controlled between 710℃ and then air-cooled.

[0072] The annealing process is: heating to 660°C at a heating rate of ≤100°C / hour, the holding time is calculated according to the formula T=K2*D (where K2 is the calculation coefficient, with a value of 0.5-5; D is the rod diameter), and then cooling to room temperature with the furnace to obtain a high-purity iron-chromium-aluminum resistance alloy rod.

[0073] Example 5 A high-purity iron-chromium-aluminum resistance alloy, the chemical element percentages of the pure iron-chromium-aluminum resistance alloy are: C: ≤0.02%, Si: 0.35%, Mn: 0.60%, P≤0.010%, S≤0.005%, Cr: 24.50%, Mo: 0.80%, Co: 1.50%, Ti: 1.00%, any combination of Ce, Y, Zr, La: 1.00%, Al: 5.500%, and the rest are iron and impurity elements.

[0074] The present invention also provides a method for preparing a high-purity iron-chromium-aluminum resistance alloy, comprising the following steps: S1. Polish all alloys to remove surface oxides and attachments, and mix according to the preset ratio; S2, all raw materials are charged, and then vacuum induction treatment is performed to obtain castings, and the castings are quickly annealed; In some embodiments, the step S2, charging all raw materials, and then performing vacuum induction treatment to obtain a casting, and performing rapid annealing treatment on the casting, comprises: First melt at low power, melting time ≥ 4h, adjust the temperature to 1660℃ after melting, stir + scouring time ≥ 45min, adjust the alloy composition after [O] + [N] ≤ 100ppm, measure the temperature to 1670℃ for steel casting; Demoulding was carried out 35 minutes after pouring, followed by rapid annealing. During the entire melting process, the vacuum degree is ≤5Pa.

[0075] S3, subjecting the casting to vacuum consumable melting treatment to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing treatment.

[0076] In some embodiments, the step S3, subjecting the casting to vacuum consumable smelting to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing, comprises: The normal melting rate of the casting is 5.0kg / min, and the melting rate of the shrinkage section is 2kg / min; The mold was removed 35 minutes after pouring, and then quickly returned to the furnace for annealing.

[0077] The annealed intermediate casting is inspected and the shrinkage cavity defect at the shrinkage feeding end is removed.

[0078] In some embodiments, the processes of rapid annealing and tempering furnace annealing are both: 830°C, and the holding time is calculated according to the formula T=K1*D (where K1 is a calculation coefficient, with a value of 0.0.2-5; D1 is the diameter of the casting).

[0079] S4, heating the intermediate casting; In some embodiments, the step S4, heating the intermediate casting, comprises: Heat to 800±10℃ at a heating rate of ≤100℃ / h, and keep warm for >60min. Then heat to 1050℃ at a heating rate of ≤120℃ / h. The keeping warm time is calculated according to the formula T=K*D (where K is the calculation coefficient, with a value of 0.0.2-2; D2 is the diameter of the intermediate casting).

[0080] S5. Forging the intermediate casting to obtain a rod, and annealing the rod.

[0081] In some embodiments, the S5, forging the intermediate casting to obtain a rod, and annealing the rod, comprises: Forging by forging hammer or free forging, using upsetting forging, that is, upsetting along the axis of the consumable ingot; The material is made by two fires. The first fire is low-temperature deformation, and the second fire is returned to the furnace for heating; the first fire upsetting deformation is ≤30%, and then returned to the furnace for heating and insulation for ≥3h, and then the second upsetting is carried out to the required specifications of the bar.

[0082] The final forging temperature is strictly controlled between 730℃ and then air-cooled.

[0083] The annealing process is: heating to 670°C at a heating rate of ≤100°C / hour, the holding time is calculated according to the formula T=K2*D (where K2 is the calculation coefficient, with a value of 0.5-5; D is the rod diameter), and then cooling to room temperature with the furnace to obtain a high-purity iron-chromium-aluminum resistance alloy rod.

[0084] Example 6 This embodiment adopts a 1000kg vacuum induction furnace and a consumable furnace smelting process + a forging hammer to produce a preparation method for 0Cr26Al5.5 high-purity resistance alloy rod, which specifically includes the following steps: S1. Sandblast pure iron, metal chromium, metal molybdenum and metal cobalt, and then mix according to the chemical composition: 8-10g C per furnace, Si: 0.50%, Mn: 0.50%, Cr: 26.00%, Mo: 1.00%, Co: 0.85%, Ti: 0.85%, La+Zr: 0.20%, Al: 5.5%, and the rest are pure iron rods; S2, all raw materials are charged, and then vacuum induction treatment is performed to obtain castings, and the castings are quickly annealed; In some embodiments, the step S2, charging all raw materials, and then performing vacuum induction treatment to obtain a casting, and performing rapid annealing treatment on the casting, comprises: Heat the chute in a heating furnace at 1250°C for ≥2h; Charging in the crucible: small pieces of pure iron on the bottom, pure iron rods surrounding the crucible, and metal chromium, metal molybdenum, and metal cobalt loosely packed in the middle.

[0085] The S2, charging all raw materials, and then performing vacuum induction treatment to obtain castings, and performing rapid annealing treatment on the castings, also includes: (1) Evacuate the vacuum and start supplying power after the vacuum degree is ≤10pa; (2) Melt the metal at low power, adjust the temperature to 1660℃-1680℃ after melting, stir and refine for 60 minutes; test [O]+[N]≤90ppm; then add metal aluminum, silicon and manganese, add ferrotitanium after refining for 10 minutes, stir for 5 minutes, finally add rare earth lanthanum and zirconium, stir for 5 minutes, adjust the temperature to 1660℃-1680℃ for steel casting.

[0086] (3) After 25 minutes, the mold is removed and the product is quickly put back into the furnace for annealing. The annealing process in the furnace is as follows: the temperature is raised to 820°C at a heating rate of ≤100°C / hour, kept at this temperature for 3 hours, and then cooled to room temperature in the furnace.

[0087] S3, subjecting the casting to vacuum consumable melting treatment to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing treatment.

[0088] In some embodiments, the step S3, subjecting the casting to vacuum consumable smelting to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing, comprises: Put the induction ingot after surface polishing into the vacuum consumable furnace and evacuate. When the vacuum degree is less than 15pa, it starts to be consumable; Consumable process: the ingot melting rate is controlled at 2-3kg / min; the feeding stage rate is controlled at 1-1.5kg / min.

[0089] After cooling for 30 minutes, break the air, demould, and quickly put it back into the furnace for annealing.

[0090] Annealing treatment: the demoulding 0Cr26Al5.5 high-purity resistance alloy billet is quickly transferred to the adding furnace, heated to 820°C at a heating rate of ≤120°C / hour, kept at this temperature for 3h, and cooled to room temperature along with the furnace.

[0091] S4, heating the intermediate casting; In some embodiments, the step S4, heating the intermediate casting, comprises: Heat to 800±10℃ at a heating rate of 100℃ / h, keep warm for 150min, then heat to 1050±10℃ at a heating rate of ≤110℃ / h, and calculate the holding time according to the formula T=K*D (where K is the calculation coefficient, with a value of 0.0.2-2; D2 is the diameter of the intermediate casting).

[0092] S5. Forging the intermediate casting to obtain a rod, and annealing the rod.

[0093] In some embodiments, the S5, forging the intermediate casting to obtain a rod, and annealing the rod, comprises: First, it is upset by 15% in the axial direction, then returned to the furnace and heated to 1120±10℃, kept warm for 210min, and then continued to deform in the axial direction, forged to Φ125mm, and finally hammered to Φ120mm circle with a round hammer to obtain 0Cr26Al5.5 high-purity resistance alloy rod.

[0094] Example 7 This embodiment adopts a 1500kg vacuum induction furnace and a consumable furnace smelting process + a forging hammer to produce a preparation method for 0Cr25.5Al7 high-purity resistance alloy rod, which specifically includes the following steps: S1. Sandblast pure iron, metal chromium, metal molybdenum and metal cobalt, and then mix according to the chemical composition: C 10-12g per furnace, Si: 0.80%, Mn: 0.80%, Cr: 25.5.00%, Mo: 0.65%, Co: 0.50%, Ti: 0.65%, La+Ce: 0.15%, Al: 7%, and the rest are pure iron rods; S2, all raw materials are charged, and then vacuum induction treatment is performed to obtain castings, and the castings are quickly annealed; In some embodiments, the step S2, charging all raw materials, and then performing vacuum induction treatment to obtain a casting, and performing rapid annealing treatment on the casting, comprises: Heat the chute in a heating furnace at 1250°C for ≥2h; Charging in the crucible: small pieces of pure iron on the bottom, pure iron rods surrounding the crucible, and metal chromium, metal molybdenum, and metal cobalt loosely packed in the middle.

[0095] The S2, charging all raw materials, and then performing vacuum induction treatment to obtain castings, and performing rapid annealing treatment on the castings, also includes: (4) Evacuate the vacuum and start supplying power after the vacuum degree is ≤10pa; (5) Melt the metal at low power, adjust the temperature to 1660℃-1680℃ after melting, stir and refine for 60 minutes; test [O]+[N]≤90ppm; then add metal aluminum, silicon and manganese, add ferrotitanium after refining for 10 minutes, stir for 5 minutes, finally add rare earth lanthanum and zirconium, stir for 5 minutes, and adjust the temperature to 1650℃-1670℃ for steel casting.

[0096] (6) After 20 minutes, the mold is removed and the product is quickly put back into the furnace for annealing. The annealing process in the furnace is as follows: the temperature is raised to 820°C at a heating rate of ≤100°C / hour, kept at this temperature for 3 hours, and then cooled to room temperature in the furnace.

[0097] S3, subjecting the casting to vacuum consumable melting treatment to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing treatment.

[0098] In some embodiments, the step S3, subjecting the casting to vacuum consumable smelting to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing, comprises: Put the induction ingot after surface polishing into the vacuum consumable furnace and evacuate. When the vacuum degree is less than 15pa, it starts to be consumable; Consumable process: the ingot melting rate is controlled at 3.5-5.0kg / min; the feeding stage rate is controlled at 1-1.5kg / min.

[0099] After cooling for 20 minutes, break the air, demould, and quickly put it back into the furnace for annealing.

[0100] Annealing treatment: the demoulding 0Cr26Al5.5 high purity resistance alloy billet is quickly transferred to the adding furnace, heated to 840℃ at a heating rate of ≤120℃ / hour, kept at this temperature for 2h, and cooled to room temperature along with the furnace.

[0101] Conduct flaw detection on consumable ingots and remove defects such as shrinkage holes at the shrinkage-feeding end.

[0102] In some embodiments, the processes of rapid annealing and tempering furnace annealing are both: 830°C, and the holding time is calculated according to the formula T=K1*D (where K1 is a calculation coefficient, with a value of 0.0.2-5; D1 is the diameter of the casting).

[0103] S4, heating the intermediate casting; In some embodiments, the step S4, heating the intermediate casting, comprises: Heat to 800±10℃ at a heating rate of ≤80℃ / h, keep warm for 100min, then heat to 1080±10℃ at a heating rate of ≤100℃ / h, and calculate the holding time according to the formula T=K*D (where K is the calculation coefficient, with a value of 0.0.2-2; D2 is the diameter of the intermediate casting).

[0104] S5. Forging the intermediate casting to obtain a rod, and annealing the rod.

[0105] In some embodiments, the S5, forging the intermediate casting to obtain a rod, and annealing the rod, comprises: First, it is upset by 15% in the axial direction, then returned to the furnace and heated to 1140±10℃, kept warm for 150min, and then continued to deform in the axial direction, forged to Φ85mm, and finally hammered to Φ80mm with a round hammer to obtain 0Cr25.5Al7 high-purity resistance alloy rods.

[0106] 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 iron-chromium-aluminum resistance alloy, characterized in that: The percentage of chemical elements of the pure iron-chromium-aluminum resistance alloy is: C: ≤0.04%, Si: 0.15-0.60%, Mn: 0.35-0.85%, P≤0.015%, S≤0.008%, Cr: 22.00%-27.00%, Mo: 0.2-1.50%, Co: 0.2-3.00%, Ti: 0.50-1.50%, Ce, Y, Zr, La in any combination: 0.05-1.50%, Al:4.00-7.00%, the rest are iron and impurity elements.

2. The high-purity iron-chromium-aluminum resistance alloy according to claim 1, characterized in that: The percentages of chemical elements of the pure iron-chromium-aluminum resistance alloy are: C: ≤0.03%, Si: 0.30-0.50%, Mn: 0.55-0.65%, P≤0.012%, S≤0.006%, Cr: 24.00%-25.00%, Mo: 0.4-1.30%, Co: 0.5-2.50%, Ti: 0.80-1.20%, any combination of Ce, Y, Zr, La: 0.08-1.20%, Al: 4.00-7.00%, and the rest are iron and impurity elements.

3. The high-purity iron-chromium-aluminum resistance alloy according to claim 1, characterized in that: The percentages of chemical elements of the pure iron-chromium-aluminum resistance alloy are: C: ≤0.02%, Si: 0.35%, Mn: 0.60%, P≤0.010%, S≤0.005%, Cr: 24.50%, Mo: 0.80%, Co: 1.50%, Ti: 1.00%, any combination of Ce, Y, Zr, La: 1.00%, Al: 5.500%, and the rest are iron and impurity elements.

4. A method for preparing a high-purity Fe-Cr-Al resistance alloy as claimed in any one of claims 1 to 2, characterized in that: The steps include: All alloys are polished to remove surface oxides and attachments, and the ingredients are prepared according to the preset proportions; All raw materials are charged and then vacuum induction treated to obtain castings, and the castings are quickly annealed; The casting is subjected to vacuum consumable melting treatment to obtain an intermediate casting, and the intermediate casting is subjected to tempering furnace annealing treatment.

5. The method for preparing a high-purity Fe-Cr-Al resistance alloy according to claim 4, characterized in that: The preparation method also includes: Heat treatment of the intermediate casting; The intermediate casting is subjected to a forging process to obtain a rod, and the rod is subjected to an annealing process.

6. The method for preparing a high-purity Fe-Cr-Al resistance alloy according to claim 4, characterized in that: The method comprises charging all raw materials, performing vacuum induction treatment to obtain castings, and performing rapid annealing treatment on the castings, including: First melt at low power, melting time ≥ 4h, adjust the temperature to 1640℃-1680℃ after melting, stir + scouring time ≥ 45min, adjust the alloy composition after [O]+[N]≤100ppm, measure the temperature to 1650℃-1690℃ for steel casting; Demolding is done 20-45 minutes after pouring, followed by rapid annealing. During the entire melting process, the vacuum degree is ≤5Pa.

7. The method for preparing a high-purity Fe-Cr-Al resistance alloy according to claim 6, characterized in that: The method of subjecting the casting to vacuum consumable melting treatment to obtain an intermediate casting, and subjecting the intermediate casting to tempering furnace annealing treatment, comprises: The normal melting rate of castings is 1-10.0kg / min, and the melting rate of the feeding section is 0.5-4kg / min; Demould the part 20-45 minutes after pouring, then quickly put it back into the furnace for annealing.

8. The method for preparing a high-purity Fe-Cr-Al resistance alloy according to claim 7, characterized in that: The processes of rapid annealing and tempering furnace annealing are both: 800-850°C, and the holding time is calculated according to the formula T=K1*D, where K1 is the calculation coefficient, with a value of 0.0.2-5; D1 is the diameter of the casting.

9. The method for preparing a high-purity Fe-Cr-Al resistance alloy according to claim 5, characterized in that: The heating treatment of the intermediate casting comprises: Heat to 800±10℃ at a heating rate of ≤100℃ / h, and keep warm for >60min. Then heat to 950℃-1150℃ at a heating rate of ≤120℃ / h. The keeping warm time is calculated according to the formula T=K*D, where K is the calculation coefficient, with a value of 0.0.2-2; D2 is the diameter of the intermediate casting.

10. The method for preparing a high-purity Fe-Cr-Al resistance alloy according to claim 9, characterized in that: The annealing process is to heat the bar to 650-700°C at a heating rate of ≤100°C / hour, and the holding time is calculated according to the formula T=K2*D, where K2 is the calculation coefficient, with a value of 0.5-5; D is the bar diameter, and then the bar is cooled to room temperature in the furnace to obtain a high-purity iron-chromium-aluminum resistance alloy bar.