CN-121428388-B - Preparation method of ultrahigh-strength SF1900 steel vacuum consumable steel ingot

Abstract

The application relates to the technical field of ultrahigh-strength steel materials, and particularly discloses a preparation method of an ultrahigh-strength SF1900 steel vacuum consumable steel ingot. The application discloses a preparation method of an ultrahigh-strength SF1900 steel vacuum consumable steel ingot, which comprises the steps of vacuum induction smelting, protective atmosphere electroslag remelting and vacuum consumable remelting. The application realizes comprehensive optimization of purity, inclusion control, component uniformity and solidification structure by adopting a triple smelting process of a vacuum induction furnace, protective atmosphere electroslag and a vacuum consumable furnace, and improves consistency of solidification structure, macrosegregation and chemical component uniformity of the steel ingot.

Inventors

• Han shun
• LI JIANXIN
• WANG CHUNXU
• LI JIBAO
• LI YONG
• PANG XUEDONG
• SUN YONG
• YANG CHAO
• CAO YUXIAN
• LI XINYANG
• Geng Ruming
• WEN BO

Assignees

• 钢铁研究总院有限公司
• 抚顺特殊钢股份有限公司

Dates

Publication Date

20260508

Application Date

20251114

Claims (7)

1. 1. A preparation method of an ultrahigh-strength SF1900 steel vacuum consumable steel ingot is characterized by comprising the following steps of vacuum induction smelting, protective atmosphere electroslag remelting and vacuum consumable remelting in sequence; the process parameters of the protective atmosphere electroslag remelting are that slag materials are premelted slag, the slag system comprises, by weight, caF2, al2O3, mgO=60-70%, 15-25%, 8-12%, 3-7%, the melting speed is 5.0-7.0kg/h, and the protective atmosphere is Ar gas for protection; The vacuum consumable remelting process parameters are that the melting speed is 4.5-5.5kg/min, helium is filled for cooling during melting, the helium cooling starting stage is within 30min, the flow is increased from 0ml/min to 220-280ml/min, the heat sealing top stage is within 30min, and the flow is reduced from 220-280ml/min to 15-25ml/min; the chemical composition of the ultrahigh-strength SF1900 steel vacuum consumable steel ingot is ：C：0.14-0.25%,Ni：13.00-15.00%,Mo：1.00-2.00%,Cr：1.5-3.0%,Co：9.00-11.00%,Al：0.85-0.95%,Ti＜0.01%,Si：≤0.10%,Mn：≤0.10%,Cu≤0.05%,S≤0.0007%,P≤0.006%,O≤15PPm,N≤15PPm,, and the balance is Fe and unavoidable impurities according to the weight percentage.
2. 2. The preparation method of the ultrahigh-strength SF1900 steel vacuum consumable steel ingot, which is disclosed in claim 1, is characterized in that in the vacuum induction smelting step, raw materials comprise zero-number Ni or first-number Ni, metal Co, metal Cr, metal Mo, metal Al, low-carbon refined steel and carbon electrodes, wherein the ingot size of the electrodes is phi 550-660mm and 5000-6000kg.
3. 3. The method for preparing the ultrahigh-strength SF1900 steel vacuum consumable steel ingot, according to claim 1, wherein in the protective atmosphere electroslag remelting step, premelted slag is prepared from, by weight, caF2, al2O3, caO, mgO=62-67%, 16-23%, 9-11%, and 4-6%.
4. 4. The method for manufacturing a vacuum consumable steel ingot of ultra-high strength SF1900 steel according to claim 1, wherein the melting speed is 5.5-6.5kg/h in the protective atmosphere electroslag remelting step.
5. 5. The method for manufacturing a vacuum consumable steel ingot of ultra-high strength SF1900 steel according to claim 1, wherein the melting speed in the protective atmosphere electroslag remelting step is 5.7-6.2kg/h.
6. 6. The method for preparing the vacuum consumable steel ingot of ultrahigh strength SF1900 steel according to claim 1, wherein in the vacuum consumable remelting, the melting speed is 4.7-5.3kg/min, helium is filled for cooling during melting, the cooling start stage of helium is 30min, the flow is increased from 0ml/min to 240-260ml/min, the heat sealing top stage is 30min, and the flow is reduced from 240-260ml/min to 17-22ml/min.
7. 7. The method for manufacturing a vacuum consumable steel ingot for ultra-high strength SF1900 steel according to claim 1, wherein the chemical composition of the vacuum consumable steel ingot for ultra-high strength SF1900 steel is ：C：0.14-0.25%,Ni：13.00-15.00%,Mo：1.00-2.00%,Cr：1.5-3.0%,Co ：9.00-11.00%,Al：0.85-0.95%,Ti＜0.01%,Si：≤0.02%,Mn：≤0.02%,Cu≤0.05%,S≤0.0007%,P≤0.004%,O≤5PPm,N≤7PPm, and the balance of Fe and unavoidable impurities in weight percent.

Description

Preparation method of ultrahigh-strength SF1900 steel vacuum consumable steel ingot Technical Field The application relates to the technical field of ultrahigh-strength steel materials, in particular to a preparation method of an ultrahigh-strength SF1900 steel vacuum consumable steel ingot. Background The ultrahigh-strength SF1900 steel has ultrahigh strength, high toughness and high fatigue life. Currently, duplex smelting technology, namely vacuum induction smelting and protective atmosphere electroslag remelting or vacuum induction smelting and vacuum consumable remelting, is commonly adopted for smelting the ultrahigh-strength SF1900 steel for aviation. In the duplex smelting process of vacuum induction smelting and protective atmosphere electroslag remelting, the protective atmosphere electroslag remelting has unique advantages in desulfurization and inclusion removal, but is poor in steel purity, gas control and performance control in solidification structure. In the duplex smelting process of vacuum induction smelting and vacuum consumable remelting, the desulfurization capability and the denaturation effect of oxide inclusions in the remelting process are poor. Disclosure of Invention In order to solve the technical problems, the application provides a preparation method of an ultrahigh-strength SF1900 steel vacuum consumable steel ingot. The application provides a preparation method of an ultrahigh-strength SF1900 steel vacuum consumable steel ingot, which comprises the following steps of vacuum induction smelting, protective atmosphere electroslag remelting and vacuum consumable remelting in sequence; The process parameters of the protective atmosphere electroslag remelting are that slag materials are premelted slag, the slag system and the proportion thereof are CaF 2：Al2O3, mgO=60-70%, 15-25%, 8-12%, 3-7%, the melting speed is 5.0-7.0kg/h, and the protective atmosphere is protected by Ar gas; The vacuum consumable remelting process comprises the steps of filling helium for cooling during melting, wherein the melting speed is 4.5-5.5kg/min, the helium cooling starting stage is within 30min, the flow is increased from 0ml/min to 220-280ml/min, the heat sealing top stage is within 30min, and the flow is reduced from 220-280ml/min to 15-25ml/min. The smelting process of the ultrahigh-strength SF1900 steel provided by the application aims to smelt a novel ultrahigh-strength SF1900 steel consumable ingot with lower raw material cost, better hot processing performance and ultrahigh purity in industrial production. The success of smelting the ultrahigh-strength SF1900 steel by adopting a triple process of vacuum induction smelting, protective atmosphere electroslag remelting and vacuum consumable remelting can fill the blank of the smelting process of the ultrahigh-strength SF1900 steel in China and can also improve the metallurgical quality of the domestic ultrahigh-strength SF1900 steel. Preferably, the technological parameters of the vacuum induction smelting are that the total smelting temperature is 1500-1550 ℃, the refining temperature is 1520-1570 ℃, the tapping temperature is 1540-1570 ℃, the vacuum degree in the total smelting period is 20-40Pa, and the vacuum degree in the refining period is less than 3Pa and is maintained for more than 50 min. Preferably, in the vacuum induction melting step, the refining temperature=full melting temperature+ (10-20 ℃) and the tapping temperature=full melting temperature+ (30-40 ℃). In a specific embodiment, in the vacuum induction melting step, the total melting temperature is 1530 ℃, the refining temperature is 1545 ℃, the tapping temperature is 1565 ℃, the total melting period vacuum degree is 20-40Pa, and the refining period vacuum degree is 2Pa, and the temperature is kept for 100min. In a specific embodiment, in the vacuum induction melting step, the total melting temperature is 1535 ℃, the refining temperature is 1540 ℃, the tapping temperature is 1570 ℃, the total melting period vacuum degree is 20-40Pa, and the refining period vacuum degree is 2Pa, and the temperature is kept for 100min. In a specific embodiment, in the vacuum induction melting step, the full melting temperature is 1525 ℃, the refining temperature is 1550 ℃, the tapping temperature is 1570 ℃, the full melting period vacuum degree is 20-40Pa, and the refining period vacuum degree is 2Pa, and the temperature is kept for 100min. Preferably, in the vacuum induction smelting step, raw materials comprise zero-number Ni or first-number Ni, metal Co, metal Cr, metal Mo, metal Al, low-carbon refined steel and a carbon electrode, wherein the electrode is prepared in the vacuum induction smelting step, and the ingot size of the electrode is phi 550-600mm and 5000-6000kg. Preferably, in the protective atmosphere electroslag remelting step, the premelting slag comprises, by weight, caF 2：Al2O3, mgO=62-67%, 16-23%, 9-11% and 4-6% of CaO. In a specific embodiment, in the protective atmosphere elec