Smelting method of high-titanium nickel-based alloy

Abstract

The invention discloses a smelting method of a high-titanium nickel-based alloy, which comprises AOD furnace smelting and VOD furnace smelting, in the decarburization stage 1, the vacuum degree is 190-210 mbar, the oxygen blowing amount is 900-1100 m < 3 >, the oxygen supply intensity is 28-32 m < 3 > / h / t, the oxygen lance position is 1500-1700 mm, and the steel ladle bottom argon blowing supply intensity is 3-5 Nl / min / t; in the second decarburization stage, the vacuum degree is 90-110 mbar, the oxygen blowing amount is 350-450 m < 3 >, the oxygen supply intensity is 24-26 m < 3 > / h / t, the oxygen lance position is 1200-1400 mm, and the steel ladle bottom argon blowing supply intensity is 5-7 Nl / min / t; in the third decarburization period, the vacuum degree is 10-30 mbar, the oxygen blowing amount is 250-350 m < 3 >, the oxygen supply intensity is 18-22 m < 3 > / h / t, the oxygen lance position is 900-1100 mm, and the steel ladle bottom argon blowing supply intensity is 7-9 Nl / min / t; in the boiling period, the vacuum degree is smaller than or equal to 1 mbar, the steel ladle bottom blowing argon supply intensity is 13-17 Nl / min / t, and the boiling time is 55-65 min; and in the reduction period, alloy auxiliary materials are added, and the reduction time is 25-35 min. According to the method, the contents of Al, Ti and N in the high-titanium nickel-based alloy are accurately controlled as follows: 0.10-0.20% of Al, 0.60-0.70% of Ti and less than or equal to 70ppm of N, so that efficient and stable production of the high-titanium nickel-based alloy is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a smelting method of a high-titanium nickel-based alloy. Background Art

[0002] Nickel-based alloys, especially high-titanium (titanium content ≥ 0.60%) precipitation-strengthened alloys, have excellent heat resistance, corrosion resistance, and good comprehensive mechanical properties, and are widely used in the fields of petrochemicals, energy and power, industrial and household heating elements, etc. This high-titanium nickel-based alloy is usually smelted in a vacuum induction furnace, remelted in a vacuum consumable furnace or an electroslag furnace, and hot-processed using casting and rolling processes. Its product quality is unstable, the production cost is high, and the yield rate and production efficiency are low, resulting in a prominent contradiction between supply and demand, which seriously restricts the widespread use and industrial production of this product. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a smelting method of a high-titanium nickel-based alloy, including AOD furnace smelting and VOD furnace smelting. After the AOD furnace taps out steel, the ladle is hoisted to the VOD furnace, the C content of the VOD furnace is controlled to be 0.60-0.80%, and the temperature of the VOD furnace is controlled to be 1540-1580°C. The VOD furnace smelting includes:

[0004] (1) VOD furnace evacuation and oxygen blowing decarburization. In the first stage of VOD furnace decarburization, the vacuum degree is controlled at 190-210 mbar and the oxygen blowing amount is controlled at 900-1100 mbar. 3 , oxygen supply intensity is controlled at 28~32m 3 / h / t, the oxygen lance position is controlled at 1500-1700mm, and the argon supply intensity of the ladle bottom blowing is controlled at 3-5Nl / min / t; in the second stage of decarburization in the VOD furnace, the vacuum degree is controlled at 90-110mbar, and the oxygen blowing amount is controlled at 350-450m 3 , oxygen supply intensity is controlled at 24~26m 3 / h / t, the oxygen lance position is controlled at 1200-1400mm, and the argon supply intensity of the ladle bottom blowing is controlled at 5-7Nl / min / t; in the third decarburization phase of the VOD furnace, the vacuum degree is controlled at 10-30mbar, and the oxygen blowing amount is controlled at 250-350m 3 , oxygen supply intensity is controlled at 18~22m 3 / h / t, oxygen lance position is controlled at 900~1100mm, and argon supply intensity of ladle bottom blowing is controlled at 7~9Nl / min / t;

[0005] (2) After the third decarburization phase of the VOD furnace is completed, the VOD furnace enters the boiling phase, the vacuum is controlled to be ≤1mbar, the argon supply intensity of the ladle bottom blowing is controlled to be 13-17Nl / min / t, and the boiling time is controlled to be 55-65min;

[0006] (3) After the boiling period of the VOD furnace ends, it enters the VOD reduction period, and alloy auxiliary materials are added. The amount of alloy auxiliary materials added is controlled as follows: lime 18-22 kg / t, fluorite 2-4 kg / t, aluminum 9.5-10.5 kg / t, sponge titanium 7.5-8.5 kg / t, and the reduction time is controlled as 25-35 min;

[0007] (4) After the VOD reduction period, argon is blown from the bottom of the ladle to stir and cool it down to 1450-1470℃ before leaving the station. The ladle is then hoisted to the vertical bending continuous casting machine for casting. The interval time from leaving the VOD station to the start of casting on the vertical bending continuous casting machine is controlled to be 10-30 minutes.

[0008] Furthermore, in the above-mentioned high-titanium nickel-based alloy smelting method, the chemical composition of the high-titanium nickel-based alloy is as follows by mass percentage: C≤0.050%, Si≤0.50%, Mn≤1.0%, P≤0.030%, S≤0.030%, Cr: 19.5~23.5%, Ni: 38.0~46.0%, Mo: 2.5~3.5%, Cu: 1.5~3.0%, Al≤0.20%, Ti: 0.60~1.20%.

[0009] Furthermore, in the above-mentioned high-titanium nickel-based alloy smelting method, the contents of Al, Ti and N in the high-titanium nickel-based alloy are Al: 0.10-0.20%, Ti: 0.60-0.70%, and N≤70ppm.

[0010] The smelting method of the high-titanium nickel-based alloy of the present invention has the following advantages and beneficial effects:

[0011] The present invention aims at the smelting production of high-titanium nickel-based alloy with a titanium content of ≥0.60%. By innovatively designing a set of process parameters in a VOD furnace smelting process, the Al and Ti contents in the nickel-based alloy product are accurately controlled to Al: 0.10-0.20%, Ti: 0.60-0.70%, and the N content in the high-titanium nickel-based alloy product is greatly reduced to N≤70ppm, thereby realizing efficient and stable production of the high-titanium nickel-based alloy. The high-titanium nickel-based alloy product has stable quality, high yield rate and high production efficiency, and realizes the industrialized production of the high-titanium nickel-based alloy with a titanium content of ≥0.60%. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0013] The smelting method of the high titanium nickel-based alloy of the present invention comprises AOD furnace smelting and VOD furnace smelting. After the AOD furnace taps out steel, the ladle is hoisted to the VOD furnace. The C content of the VOD furnace at the station is controlled to be 0.60-0.80%, and the temperature of the VOD furnace at the station is controlled to be 1540-1580° C., wherein the VOD furnace smelting comprises:

[0014] (1) VOD furnace evacuation and oxygen blowing decarburization. In the first stage of VOD furnace decarburization, the vacuum degree is controlled at 190-210 mbar and the oxygen blowing amount is controlled at 900-1100 mbar. 3 , oxygen supply intensity is controlled at 28~32m 3 / h / t, the oxygen lance position is controlled at 1500-1700mm, and the argon supply intensity of the ladle bottom blowing is controlled at 3-5Nl / min / t; in the second stage of decarburization in the VOD furnace, the vacuum degree is controlled at 90-110mbar, and the oxygen blowing amount is controlled at 350-450m 3 , oxygen supply intensity is controlled at 24~26m 3 / h / t, the oxygen lance position is controlled at 1200-1400mm, and the argon supply intensity of the ladle bottom blowing is controlled at 5-7Nl / min / t; in the third decarburization phase of the VOD furnace, the vacuum degree is controlled at 10-30mbar, and the oxygen blowing amount is controlled at 250-350m 3 , oxygen supply intensity is controlled at 18~22m 3 / h / t, the oxygen lance position is controlled at 900-1100mm, and the argon supply intensity of the ladle bottom blowing is controlled at 7-9Nl / min / t.

[0015] (2) After the third decarburization phase of the VOD furnace is completed, the VOD furnace enters the boiling phase, the vacuum degree is controlled to be ≤1mbar, the argon supply intensity of the ladle bottom blowing is controlled to be 13-17Nl / min / t, and the boiling time is controlled to be 55-65min.

[0016] (3) After the boiling period of the VOD furnace, it enters the VOD reduction period, and alloy auxiliary materials are added. The amount of alloy auxiliary materials added is controlled as follows: lime 18-22 kg / t, fluorite 2-4 kg / t, aluminum 9.5-10.5 kg / t, sponge titanium 7.5-8.5 kg / t, and the reduction time is controlled as 25-35 min.

[0017] (4) After the VOD reduction period, argon is blown from the bottom of the ladle to stir and cool it down to 1450-1470℃ before leaving the station. The ladle is then hoisted to the vertical bending continuous casting machine for casting. The interval time from leaving the VOD station to the start of casting on the vertical bending continuous casting machine is controlled to be 10-30 minutes.

[0018] By implementing the high-titanium nickel-based alloy smelting method of the present invention, the Al and Ti contents in the produced high-titanium nickel-based alloy product are precisely controlled to Al: 0.10-0.20%, Ti: 0.60-0.70%, and the N content in the high-titanium nickel-based alloy product is greatly reduced to N≤70ppm, thereby realizing the efficient and stable production of high-titanium nickel-based alloy with a titanium content ≥0.60%.

[0019] The following is a detailed description of the smelting method of the high titanium nickel-based alloy of the present invention in conjunction with specific embodiments. In the following embodiments of the present invention, the chemical composition of the high titanium nickel-based alloy is as follows by mass percentage: C≤0.050%, Si≤0.50%, Mn≤1.0%, P≤0.030%, S≤0.030%, Cr: 19.5-23.5%, Ni: 38.0-46.0%, Mo: 2.5-3.5%, Cu: 1.5-3.0%, Al≤0.20%, Ti: 0.60-1.20%.

[0020] Example 1

[0021] The smelting method of the high titanium nickel-based alloy of Example 1 comprises:

[0022] (1) After the AOD furnace taps out steel, the ladle is hoisted to the VOD furnace. The C content of the steel arriving at the VOD furnace is 0.64% and the temperature arriving at the VOD furnace is 1561°C.

[0023] (2) VOD furnace evacuation and oxygen blowing for decarburization. In the first phase of decarburization in the VOD furnace, the vacuum degree is 206 mbar and the oxygen blowing volume is 946 m 3 , oxygen supply intensity is 31m 3 / h / t, the oxygen lance position is 1610mm, and the argon supply intensity of the ladle bottom blowing is 4.1Nl / min / t; in the second stage of decarburization in the VOD furnace, the vacuum degree is 101mbar, and the oxygen blowing volume is 389m 3 , oxygen supply intensity is 25.2m 3 / h / t, the oxygen lance position is 1310mm, and the argon supply intensity of the ladle bottom blowing is 6.2Nl / min / t; in the third stage of decarburization in the VOD furnace, the vacuum degree is 21mbar, and the oxygen blowing volume is 312m 3 , oxygen supply intensity is 21.1m 3 / h / t, the oxygen lance position is 1021mm, and the argon supply intensity of the ladle bottom blowing is 8.1Nl / min / t.

[0024] (3) After the third decarburization phase of the VOD furnace is completed, the VOD furnace enters the boiling phase, the vacuum degree is 0.81 mbar, the argon gas supply intensity of the ladle bottom blowing is 15.1 Nl / min / t, and the boiling time is 61 min.

[0025] (4) After the boiling period of the VOD furnace, it enters the VOD reduction period, and alloy auxiliary materials are added. The amount of alloy auxiliary materials added is: lime 20.4kg / t, fluorite 3.2kg / t, aluminum 10.1kg / t, sponge titanium 8.2kg / t, and the reduction time is 31min.

[0026] (5) After the VOD reduction period, argon is blown from the bottom of the ladle to stir and cool it down to 1462℃ before it leaves the station. The ladle is then hoisted to the vertical bending continuous casting machine for casting. The interval from leaving the VOD station to the start of casting on the vertical bending continuous casting machine is 21 minutes.

[0027] In the high-titanium nickel-based alloy product produced by Example 1 of the present invention, the contents of Al, Ti and N are respectively Al: 0.16%, Ti: 0.63% and N: 62ppm, thereby achieving efficient and stable production of high-titanium nickel-based alloy with a titanium content ≥ 0.60%.

[0028] Example 2

[0029] The smelting method of the high titanium nickel-based alloy of Example 2 comprises:

[0030] (1) After the AOD furnace taps out steel, the ladle is hoisted to the VOD furnace. The C content of the steel arriving at the VOD furnace is 0.71% and the temperature arriving at the VOD furnace is 1558°C.

[0031] (2) VOD furnace evacuation and oxygen blowing for decarburization. In the first phase of decarburization in the VOD furnace, the vacuum degree is 198 mbar and the oxygen blowing volume is 1012 m 3 , oxygen supply intensity is 29m 3 / h / t, the oxygen lance position is 1580mm, and the argon supply intensity of the ladle bottom blowing is 3.9Nl / min / t; in the second phase of decarburization in the VOD furnace, the vacuum degree is 98mbar, and the oxygen blowing volume is 406m 3 , oxygen supply intensity is 24.8m 3 / h / t, the oxygen lance position is 1289mm, and the argon supply intensity of the ladle bottom blowing is 5.8Nl / min / t; in the third stage of decarburization in the VOD furnace, the vacuum degree is 19mbar, and the oxygen blowing volume is 328m 3 , oxygen supply intensity is 20.4m 3 / h / t, the oxygen lance position is 998mm, and the argon supply intensity of the ladle bottom blowing is 7.8Nl / min / t.

[0032] (3) After the third decarburization phase of the VOD furnace is completed, the VOD furnace enters the boiling phase, the vacuum degree is 0.71 mbar, the argon gas supply intensity of the ladle bottom blowing is 14.6 Nl / min / t, and the boiling time is 58 min.

[0033] (4) After the boiling period of the VOD furnace, it enters the VOD reduction period, and alloy auxiliary materials are added. The amount of alloy auxiliary materials added is: lime 19.6kg / t, fluorite 2.9kg / t, aluminum 9.8kg / t, sponge titanium 7.8kg / t, and the reduction time is 29min.

[0034] (5) After the VOD reduction period, argon is blown from the bottom of the ladle to stir and cool it down to 1458℃ before it leaves the station. The ladle is then hoisted to the vertical bending continuous casting machine for casting. The interval from the VOD leaving the station to the start of casting on the vertical bending continuous casting machine is 18 minutes.

[0035] In the high-titanium nickel-based alloy product produced by Example 2 of the present invention, the contents of Al, Ti, and N are respectively Al: 0.15%, Ti: 0.66%, and N: 58ppm, thereby achieving efficient and stable production of high-titanium nickel-based alloy with a titanium content ≥ 0.60%.

[0036] Example 3

[0037] The smelting method of the high titanium nickel-based alloy of Example 3 comprises:

[0038] (1) After the AOD furnace taps out steel, the ladle is hoisted to the VOD furnace. The C content of the steel arriving at the VOD furnace is 0.66% and the temperature arriving at the VOD furnace is 1563°C.

[0039] (2) VOD furnace evacuation and oxygen blowing for decarburization. In the first phase of decarburization in the VOD furnace, the vacuum degree is 206 mbar and the oxygen blowing volume is 988 m 3 , oxygen supply intensity is 32m 3 / h / t, the oxygen lance position is 1618mm, and the argon supply intensity of the ladle bottom blowing is 4.3Nl / min / t; in the second phase of decarburization in the VOD furnace, the vacuum degree is 97mbar, and the oxygen blowing volume is 396m 3 , oxygen supply intensity is 25.3m 3 / h / t, the oxygen lance position is 1308mm, and the argon supply intensity of the ladle bottom blowing is 6.1Nl / min / t; in the third stage of decarburization in the VOD furnace, the vacuum degree is 22mbar, and the oxygen blowing volume is 298m 3 , oxygen supply intensity is 19.9m 3 / h / t, the oxygen lance position is 1008mm, and the argon supply intensity of the ladle bottom blowing is 8.5Nl / min / t.

[0040] (3) After the third decarburization phase of the VOD furnace is completed, the VOD furnace enters the boiling phase, the vacuum degree is 0.89 mbar, the argon gas supply intensity of the ladle bottom blowing is 15.6 Nl / min / t, and the boiling time is 64 min.

[0041] (4) After the boiling period of the VOD furnace, it enters the VOD reduction period, and alloy auxiliary materials are added. The amount of alloy auxiliary materials added is: lime 20.2kg / t, fluorite 3.2kg / t, aluminum 10.3kg / t, sponge titanium 8.1kg / t, and the reduction time is 31min.

[0042] (5) After the VOD reduction period, argon is blown from the bottom of the ladle to stir and cool it down to 1462℃ before it leaves the station. The ladle is then hoisted to the vertical bending continuous casting machine for casting. The interval from leaving the VOD station to the start of casting on the vertical bending continuous casting machine is 23 minutes.

[0043] In the high-titanium nickel-based alloy product produced by Example 3 of the present invention, the contents of Al, Ti and N are respectively Al: 0.18%, Ti: 0.62% and N: 56ppm, thereby achieving efficient and stable production of high-titanium nickel-based alloy with a titanium content ≥ 0.60%.

[0044] In summary, the smelting method of the high-titanium nickel-based alloy of the present invention is aimed at the smelting production of high-titanium nickel-based alloy with a titanium content of ≥0.60%. By innovatively designing a set of process parameters in the VOD furnace smelting process, the Al and Ti contents in the nickel-based alloy product are precisely controlled to Al: 0.10-0.20%, Ti: 0.60-0.70%, and the N content in the high-titanium nickel-based alloy product is greatly reduced to N≤70ppm, thereby realizing efficient and stable production of high-titanium nickel-based alloy, and the high-titanium nickel-based alloy product has stable quality, high yield rate and high production efficiency, and realizes the industrial production of high-titanium nickel-based alloy with a titanium content of ≥0.60%.

[0045] It should be noted that, in this article, the term "comprise" or any other variation thereof is intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such article or device.

[0046] It should also be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the present invention.

Claims

1. A smelting method of a high-titanium nickel-based alloy, comprising AOD furnace smelting and VOD furnace smelting. After the AOD furnace taps out steel, the ladle is hoisted to the VOD furnace. The C content of the VOD furnace is controlled to be 0.60-0.80% and the temperature of the VOD furnace is controlled to be 1540-1580° C., characterized in that: VOD furnace smelting includes: (1) VOD furnace evacuation and oxygen blowing decarburization. In the first stage of VOD furnace decarburization, the vacuum degree is controlled at 190-210 mbar and the oxygen blowing amount is controlled at 900-1100 mbar. 3 , oxygen supply intensity is controlled at 28~32m 3 / h / t, the oxygen lance position is controlled at 1500-1700mm, and the argon supply intensity of the ladle bottom blowing is controlled at 3-5Nl / min / t; in the second stage of decarburization in the VOD furnace, the vacuum degree is controlled at 90-110mbar, and the oxygen blowing amount is controlled at 350-450m 3 , oxygen supply intensity is controlled at 24~26m 3 / h / t, the oxygen lance position is controlled at 1200-1400mm, and the argon supply intensity of the ladle bottom blowing is controlled at 5-7Nl / min / t; in the third decarburization phase of the VOD furnace, the vacuum degree is controlled at 10-30mbar, and the oxygen blowing amount is controlled at 250-350m 3 , oxygen supply intensity is controlled at 18~22m 3 / h / t, oxygen lance position is controlled at 900~1100mm, and argon supply intensity of ladle bottom blowing is controlled at 7~9Nl / min / t; (2) After the third decarburization phase of the VOD furnace is completed, the VOD furnace enters the boiling phase, the vacuum is controlled to be ≤1mbar, the argon supply intensity of the ladle bottom blowing is controlled to be 13-17Nl / min / t, and the boiling time is controlled to be 55-65min; (3) After the boiling period of the VOD furnace ends, it enters the VOD reduction period, and alloy auxiliary materials are added. The amount of alloy auxiliary materials added is controlled as follows: lime 18-22 kg / t, fluorite 2-4 kg / t, aluminum 9.5-10.5 kg / t, sponge titanium 7.5-8.5 kg / t, and the reduction time is controlled as 25-35 min; (4) After the VOD reduction period, argon is blown from the bottom of the ladle to stir and cool it down to 1450-1470℃ before leaving the station. The ladle is then hoisted to the vertical bending continuous casting machine for casting. The interval time from leaving the VOD station to the start of casting on the vertical bending continuous casting machine is controlled to be 10-30 minutes.

2. The smelting method of high titanium nickel-based alloy according to claim 1, characterized in that: The chemical composition of the high-titanium nickel-based alloy is as follows by mass percentage: C≤0.050%, Si≤0.50%, Mn≤1.0%, P≤0.030%, S≤0.030%, Cr: 19.5-23.5%, Ni: 38.0-46.0%, Mo: 2.5-3.5%, Cu: 1.5-3.0%, Al≤0.20%, Ti: 0.60-1.20%.

3. The smelting method of high titanium nickel-based alloy according to claim 2, characterized in that: The contents of Al, Ti and N in the high-titanium nickel-based alloy are Al: 0.10-0.20%, Ti: 0.60-0.70%, and N≤70ppm.