[go: up one dir, main page]

CN120099402A - A smelting process for nickel-chromium-iron based alloy - Google Patents

A smelting process for nickel-chromium-iron based alloy Download PDF

Info

Publication number
CN120099402A
CN120099402A CN202510187512.1A CN202510187512A CN120099402A CN 120099402 A CN120099402 A CN 120099402A CN 202510187512 A CN202510187512 A CN 202510187512A CN 120099402 A CN120099402 A CN 120099402A
Authority
CN
China
Prior art keywords
furnace
oxygen
nitrogen
molten steel
blowing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202510187512.1A
Other languages
Chinese (zh)
Inventor
吕爱强
祁庆花
李国洲
刘林
王旭明
王炳正
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Lanzhou Lanshi Superalloy New Materials Co ltd
Original Assignee
Lanzhou Lanshi Superalloy New Materials Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Lanzhou Lanshi Superalloy New Materials Co ltd filed Critical Lanzhou Lanshi Superalloy New Materials Co ltd
Priority to CN202510187512.1A priority Critical patent/CN120099402A/en
Publication of CN120099402A publication Critical patent/CN120099402A/en
Pending legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/0056—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 using cored wires
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/0075—Treating in a ladle furnace, e.g. up-/reheating of molten steel within the ladle
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/06—Deoxidising, e.g. killing
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/064—Dephosphorising; Desulfurising
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/068—Decarburising
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/10—Handling in a vacuum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/04—Making ferrous alloys by melting
    • C22C33/06—Making ferrous alloys by melting using master alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/52—Ferrous alloys, e.g. steel alloys containing chromium with nickel with cobalt
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Treatment Of Steel In Its Molten State (AREA)

Abstract

The invention discloses a smelting process of nickel-chromium-iron-based alloy, which adopts an EAF arc furnace-LF furnace-VOD furnace-LF furnace-die casting process route to carry out smelting pouring of cast ingot, utilizes crude molten steel obtained by smelting all scrap steel of the arc furnace to carry out VOD vacuum oxygen blowing decarburization, uses nitrogen to replace nitrogen increase of chromium nitride iron and the like in the LF furnace, optimizes desulfurization and deoxidation control parameters of each furnace, finally controls Cr yield to be more than 99 percent and C to be less than 0.025 percent through a VOD oxygen blowing decarburization model, precisely controls nitrogen content of molten steel through an LF furnace nitrogen increase model, simultaneously controls oxygen in the molten steel to be less than 0.003 percent, and ensures that other chemical components meet standard requirements, thereby solving the problems that the nickel-chromium-iron-based alloy cannot be precisely controlled by adopting the arc furnace smelting and key elements.

Description

Smelting process of nickel-chromium-iron base alloy
Technical Field
The invention relates to the technical field of metallurgy, in particular to a smelting process of nickel-chromium-iron base alloy.
Background
The nickel-chromium-iron corrosion-resistant superalloy has good stress corrosion resistance and pitting corrosion resistance due to high Ni content and Cr content, has very wide application in the fields of photovoltaics, energy storage, power generation, petrifaction and the like, and medium plate materials with the thickness of more than 40mm for core barrel plates of optical storage equipment are dependent on Japanese and American imports for a long time.
At present, when smelting high chromium-nickel corrosion-resistant superalloy, a vacuum induction furnace is mainly adopted for smelting. The vacuum induction furnace smelting has high requirements on furnace burden, pure materials are needed, and the cost is high. The invention adopts the smelting method of scrap steel, electric furnace smelting, LF furnace, VOD furnace, LF furnace and die casting to produce the flat ingot, thereby providing convenience for directly rolling the subsequent flat ingot into the plate, providing raw materials with high purity on one hand, effectively utilizing the existing equipment on the other hand, reducing the production cost and improving the production efficiency.
Disclosure of Invention
The invention aims to provide a smelting process of nickel-chromium-iron-based alloy, which is characterized in that gas and decarburization in raw materials are removed through early-stage vacuum refining, nitrogen content in steel is accurately controlled through nitrogen blowing and nitrogen increasing at the bottom of a ladle in the later stage, and a refining slag system preparation device ensures deoxidization and desulfurizing agent inclusion removal effects, so that a flat cast ingot with high purity is obtained, and the requirement of high quality of raw materials for rolling a medium plate is met.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
A nickel-chromium-iron based alloy having a chemical composition optimized based on the SB-409 requirement in ASME SECII PartB, wherein the change in chemical composition directly affects the overall material properties. For the alloy, the alloy content is high, the added alloy amount is large, and meanwhile, the material is required to have good purity, good plasticity and toughness, so that the requirements on harmful elements such as S, P, H, O and gas elements are strict. The optimized chemical composition consists of ：C：0.04-0.10;Si：≤1.0;Mn：0.40-0.90;P：≤0.025;S：≤0.005;Ni：35.5-39.0;Cr：24.0-27.0;Co：0.38-0.47;Al：≤0.15;Nb:0.50-0.70; parts by mass of gas element H less than or equal to 0.0003, O less than or equal to 0.0030, N0.16-0.25 and Fe and inevitable impurity in balance. .
The smelting process route of the nickel-chromium-iron-based alloy comprises the steps of smelting in an EAF arc furnace, adjusting in an LF furnace, vacuum oxygen blowing and decarburization in a VOD furnace, nitrogen blowing and nitrogen increasing in the LF furnace, deoxidizing, desulfurizing and die casting. The method comprises the following specific steps:
1) EAF electric arc furnace smelting
Scrap steel is smelted by an EAF arc furnace, wherein the scrap steel is 2535NB return material accounting for 60 percent (mass fraction) +N08810 return material accounting for 20 percent (mass fraction), the rest furnace burden is chromium metal, electrolytic nickel and electrolytic cobalt alloy which are used for adjusting components, 15-20kg/t lime is added to the furnace bottom before charging, 3-5kg/t fluorite is added to the furnace bottom, after furnace burden is melted down, argon is adopted to stir evenly melting pool components and temperature, cr and molten steel components in ferrosilicon powder reducing slag are added according to the dosage of 1-2kg per ton molten steel, the mass ratio of C0.40-0.60 percent, P is less than or equal to 0.025 percent, si is less than or equal to 0.30 percent, mn is less than or equal to 0.8 percent, cr22.0-25.0 percent, ni35.0-37.0 percent, and the rest elements are not more than a control range, and the temperature is 1640-1660 ℃ and tapping (steel slag is the same).
2) LF furnace adjustment
The molten steel from the EAF electric arc furnace in the last step is fed into an LF furnace, the temperature is raised, electrolytic nickel, metallic chromium and electrolytic cobalt are sequentially added for component adjustment, meanwhile, 1.0-1.5kg/t of C powder and 0.5kg/t of aluminum particles are used for diffusion deoxidation, lime and fluorite are properly added for adjustment according to slag conditions, the mass ratio of the molten steel components is that C is 0.40-0.65%, P is less than or equal to 0.025%, si is less than or equal to 0.30%, mn is less than or equal to 0.80%, cr is 25.0-26.0%, ni is 36.5-37.2%, co is 0.38-0.45%, the rest elements do not exceed the control range, the temperature is 1640-1670 ℃, the ladle is lifted to a slag skimming area, and the slag skimming requirement is more than 90%.
3) VOD vacuum oxygen blowing decarburization
The steel ladle is hung to the temperature 1590-1610 ℃ of the VOD vacuum tank, the free space of the steel ladle is 800-1200mm, and the vacuum tank cover is closed for vacuumizing. When the vacuum degree reaches 25kPa, setting an oxygen lance to be 1200m away from the molten steel surface, beginning to blow oxygen, wherein the oxygen flow is 350Nm 3/h～450Nm3/h, the argon flow is 60 NL/min-80 NL/min, the vacuum degree is stabilized to 25-20kPa, the main oxygen blowing is that when the oxygen blowing amount reaches 0.25% of silicon, aluminum and carbon blown in the molten steel after theoretical calculation, the oxygen lance is lowered to 1100m away from the molten steel surface, the vacuum degree is reduced to 15kPa, the oxygen flow is 450Nm 3/h～550Nm3/h, the argon flow is 60 NL/min-80 NL/min, the vacuum degree is stabilized to 15-10kPa, the slow oxygen blowing is that the oxygen lance is lowered to 1050m away from the molten steel surface, the vacuum degree is reduced to 8kPa, the oxygen flow is 550Nm 3/h～450Nm3/h, the argon flow is 70 NL/min-90 NL/min, the vacuum degree is stabilized to 8-2kPa, when the oxygen concentration E-0 is higher than the highest, the CO and CO 2 concentration generates an intersection point, the oxygen blowing is stopped, the vacuum is continued to be reduced to 67Pa, the pressure is maintained to 15 Pa, the oxygen maintaining is maintained, the vacuum is carried out, the vacuum is reduced to be 70 NL/80/min, and the vacuum is reduced to 5 kg/kg, and the vacuum is required to be 5kg, and the weight of high-quality slag is reduced to be 5kg, and the vacuum slag is required to be 5 kg. Vacuum is pumped to the vacuum tank cover and the pressure is maintained for 20min under 67 Pa. After the whole process is finished, the C element content of the molten steel is less than 0.025%, and the molten steel is hoisted to a slag removing area for removing slag and then enters an LF furnace.
4) LF nitrogen blowing nitrogen increasing, deoxidizing and desulfurizing
The ladle enters an LF furnace, nitrogen is blown into the bottom of the ladle, 10kg/t of premelting slag, 6kg/t of lime, 3kg/t of fluorite and 1kg/t of aluminum particles and 1kg/t of calcium silicate powder are added in batches to carry out diffusion deoxidation, nitrogen is added, the nitrogen flow is 50Nm 3/h, the nitrogen adding speed is 0.0030 percent/min, the temperature control range is 1580-1620 ℃, the nitrogen adding is combined with the initial nitrogen content of molten steel to be within the specified range of the weight percent of the components, the nitrogen blowing is stopped and is switched into argon, the slag is kept for more than 30 minutes after the slag is in off-white or white, calcium treatment is carried out according to the calcium silicate wire fed by 2m/t, ferroboron is added according to the mass ratio of molten steel of 0.005%, the argon flow is 30-40NL/min, the soft blowing is more than or equal to 20 minutes, and all the element components accord with the weight percent of each component, and the temperature is 1480-1500 ℃;
5) And die casting, namely hanging the ladle to a pouring station for pouring by a ladle car.
In the VOD furnace vacuum oxygen blowing decarburization step, when the carbon blowing of the main oxygen blowing reaches 0.25%, the oxygen amount is 50% of the total theoretical oxygen blowing amount.
In the steps of nitrogen blowing, nitrogen increasing, deoxidizing and desulfurizing of LF, added ferroboron is wrapped by iron sheet and inserted into molten steel.
In the vacuum oxygen blowing decarburization step of the VOD furnace, the vacuumizing is less than 67Pa, the pressure maintaining process is divided into front and rear sections, wherein the argon flow is 70-90L/min for the first 10min, and the argon flow is 20-40L/min for the second 10 min.
The invention has the beneficial effects that the invention aims to provide the preferable components and the smelting process of the nickel-chromium-iron-based alloy, and adopts the mode of an EAF furnace, an LF furnace, a VOD furnace and an LF furnace to smelt the nickel-chromium-iron-based corrosion-resistant superalloy, and each element can be accurately controlled in place in the smelting process, and the smelting qualification rate is more than 98 percent; the temperature of molten steel before entering a VOD furnace is controlled to be 1590-1610 ℃, the chemical reaction of the VOD furnace releases heat, the temperature of the molten steel after the VOD furnace can reach 1680 ℃, the reduction slag can be added at high temperature for reduction and deoxidation after the VOD furnace, the C content is effectively controlled not to exceed the standard, the VOD furnace can reduce the adding of chromium nitride iron by adopting a nitrogen blowing mode at the bottom of a ladle, avoid the excessive temperature reduction of the molten steel, solve the problem of excessive carbon content caused by the power transmission and carburetion of an electrode, and remarkably reduce the smelting cost by adjusting the height of an oxygen lance, the flow rate of oxygen, the flow rate of argon and the vacuum degree, the minimum C element after the VOD furnace is smelted, the oxidation amount of Cr element is less, the Cr yield reaches more than 98%, the C element reaches the standard requirement and reduces the oxidation of Cr element by adopting a nitrogen blowing mode at the bottom of the ladle, the problem of exceeding the standard carbon content caused by the power transmission and the carburetion of the nitrogen is solved, and the nitrogen adding precision is high by a nitrogen adding model.
Detailed Description
The present invention will be described in further detail below.
The Ni-Cr-Fe base alloy contains ：C：0.04-0.10;Si：≤1.0;Mn：0.40-0.90;P：≤0.025;S：≤0.005;Ni：35.5-39.0;Cr：24.0-27.0;Co：0.38-0.47;Al：≤0.15;Nb:0.50-0.70; gas element (H) less than or equal to 0.0003 wt%, O less than or equal to 0.0030 wt%, N0.16-0.25 wt% and Fe and inevitable impurities for the rest.
The smelting process of the nickel-chromium-iron-based alloy comprises the steps of preparing the nickel-chromium-iron-based alloy, adopting an EAF electric arc furnace smelting, LF furnace adjustment, VOD furnace vacuum oxygen blowing decarburization, LF furnace nitrogen blowing nitrogen increasing, deoxidization, desulfurization and die casting process route to smelt and pour a flat steel ingot to form a square blank; the method comprises the following specific steps:
1) EAF electric arc furnace smelting
Charging is carried out according to the amount of molten steel in one furnace of 30t, waste steel is smelted in an EAF arc furnace, the proportion of waste steel is 2535NB, the proportion of return material is 60% +N08810, the proportion of return material is 20%, the balance of furnace burden is metallic chromium and electrolytic nickel, electrolytic cobalt alloy is used for adjusting components, 450kg of lime and 90kg of fluorite are added to the furnace bottom before charging, and argon is adopted for stirring the components and the temperature of a molten pool after the furnace burden is melted. Cr in 30kg of ferrosilicon powder reducing slag is added, so that the alloy yield is improved. Molten steel components of C0.48%, P0.019%, si0.25%, mn0.47%, cr24.0%, ni36.9%, and other elements not exceeding the control range, temperature of 16658 ℃ and tapping (same steel slag).
2) LF furnace adjustment
The molten steel from the EAF arc furnace is fed into an LF furnace for mainly heating and component adjustment, 30kg of C powder and 15kg of aluminum particles are added in three batches for diffusion deoxidation, and 100kg of lime and 20kg of fluorite are added appropriately according to slag conditions for adjustment. The alloy is added with electrolytic nickel, metallic chromium and electrolytic cobalt in sequence, the molten steel contains C0.54%, P0.020%, si0.28%, mn less than or equal to 0.80%, cr25.0-26.0%, ni36.5-37.2%, co0.38-0.45%, the rest elements are not more than the control range, the temperature is 1668 ℃, the ladle is hoisted to a slag-raking area for slag raking, and the slag raking is more than 90%.
4) VOD vacuum oxygen blowing decarburization
The ladle is hung to the VOD vacuum tank at 1610 ℃, the free space of the ladle is 1050mm, and the vacuum tank cover is closed for vacuumizing. When the vacuum degree reaches 25kPa, setting an oxygen lance to be 1200m away from the molten steel surface, starting to blow oxygen, wherein the oxygen flow is 350Nm 3/h～450Nm3/h, the argon flow is 70NL/min, the vacuum degree is stabilized to 25-20kPa, the main oxygen blowing is that when the oxygen blowing amount reaches 0.25 percent of silicon, aluminum and carbon in molten steel after theoretical calculation (50 percent of the total theoretical oxygen blowing amount), the oxygen lance is lowered to 1100m away from the molten steel surface, the vacuum degree is lowered to 15kPa, the oxygen flow is 450Nm 3/h～550Nm3/h, the argon flow is 70NL/min, the vacuum degree is stabilized to 15-10kPa, the slow oxygen blowing is lowered to be 1050m away from the molten steel surface, the oxygen flow is lowered to 8kPa, the argon flow is 80NL/min, the vacuum degree is stabilized to 8-2kPa, when the oxygen concentration potential E.0 is reached, the tail gas temperature is remarkably lowered to the highest value (an inflection point appears), the CO and CO 2 concentration generates an intersection point, the oxygen blowing is stopped, vacuum is continuously pumped to 11Pa, the vacuum carbon deoxidization is continuously carried out for 15min, the vacuum carbon deoxidization is carried out at 70 MPa, the vacuum degree is stabilized to 15-10kPa, the vacuum degree is reduced to be 8 Nm, the oxygen flow is 550Nm, the oxygen flow is reduced to be 80 Nm 3/h～450Nm3/h, the vacuum degree is 80NL/min, the vacuum degree is 8, the oxygen concentration is 8-20 kPa, the oxygen concentration is higher than 3, and the oxygen concentration is 5-20kPa, and the oxygen concentration is 50, and the oxygen concentration and the vacuum degree and the vacuum oxygen is 50. Vacuum is pumped to 11Pa by closing the vacuum tank cover, and the pressure is maintained for 20min (the argon flow is 80L/min for the first 10min and the argon flow is 20L/min for the second 10 min). After the whole process is finished, the C element content of the molten steel is 0.013 percent, and the ladle is hoisted to a slag removing area for removing slag and then enters an LF furnace.
4) LF nitrogen blowing nitrogen increasing, deoxidizing and desulfurizing
Molten steel enters a ladle of an LF furnace to be subjected to bottom blowing of nitrogen, 300kg of premelting slag, 180kg of lime and 90kg of fluorite are added for slagging, 30kg of aluminum particles and 30kg of silicon-calcium powder are added in batches for diffusion deoxidation. Nitrogen adding, namely, nitrogen flow rate is 50Nm 3/h, nitrogen adding speed is 0.0030 percent/min, temperature control range is 1580-1620 ℃, nitrogen adding is carried out by combining the initial nitrogen content of molten steel of 0.0512 percent to 0.2327 percent, nitrogen consumption is 58Nm 3, nitrogen utilization rate is 72 percent, and nitrogen stopping blowing is switched into argon. After the slag forms off-white or white, the slag is kept for more than 30 minutes, and is subjected to calcium treatment by feeding a calcium silicate wire according to 60 m. Adding ferroboron (iron sheet for wrapping and inserting molten steel) 6kg. Argon flow is 30-40NL/min, and soft blowing is more than or equal to 20min. All the elements are C0.056%, si0.39%, mn0.58%, P0.016%, S0.0009%, ni37.2%, cr24.8%, co0.42%, al0.042%, nb0.61%, gas element [ H ]0.0003%, O0.0027%, N0.2098% and temperature 1492 deg.C, and the ladle is hoisted to a pouring station ladle car for pouring.
By adopting the smelting method, after the smelted material VOD comes out, C is 0.013%, cr is 25.0%, the rest elements meet the requirements, not only C meets the requirements, but also reserves space for the subsequent LF electrode carburetion, and the yield of Cr is 99.2%, so that the expected requirements are met, the nitrogen content of molten steel can be accurately controlled by blowing nitrogen through a nitrogen increasing model, ferrochrome nitride is not needed to be added, the final tapping component is C0.056%, si0.39%, mn0.58%, P0.016%, S0.0009, ni37.2%, cr24.8%, co0.42%, al0.042%, nb0.61%, gas element [ H ]0.0003%, O ]0.0027%, [ N ]0.2105% and all meet the standard requirements.
The alloy ingot obtained by the method of the invention is subjected to thermal processing, forming and heat treatment, and then 2 groups of samples are taken for respectively performing performance detection, wherein the performance detection comprises room temperature yield strength (Rp 0.2), tensile strength (Rm) and elongation (A), 590 ℃ high temperature yield strength (Rp 0.2), hardness (HBW), grain size and intergranular corrosion test, and the performance meets and is superior to the standard requirements, and the detection results are as follows:
A first group of samples having a room temperature yield strength (Rp 0.2) of 365MPa, a tensile strength (Rm) of 720MPa and an elongation (A) of 51%, a high temperature yield strength (Rp 0.2) of 182MPa at 590 ℃ and a Hardness (HBW) of 170, a grain size of 3.5 grade, an intergranular corrosion by the ferric sulfate-sulfuric acid solution method, and an average corrosion rate of 0.083mm/a;
the second group of samples had a room temperature yield strength (Rp 0.2) of 360MPa, a tensile strength (Rm) of 722MPa and an elongation (A) of 51%, a 590 ℃ high temperature yield strength (Rp 0.2) of 185MPa, a Hardness (HBW) of 171, a grain size of 3.5 grade, and an average corrosion rate of 0.086mm/a by the iron sulfate-sulfuric acid solution method.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims (5)

1. A smelting process for Ni-Cr-Fe-base alloy includes such steps as smelting in Electric Arc Furnace (EAF), regulating LF furnace, vacuum oxygen blowing decarbonization in VOD furnace, nitrogen blowing, deoxidization, desulfurizing and die casting, and contains gas element (H) less than or equal to 0.0003, O less than or equal to 0.0030, N less than or equal to 0.16-0.25, fe and inevitable impurities.
2. The smelting process of the nickel-chromium-iron-based alloy according to claim 1, wherein the process route comprises the following specific steps:
1) EAF electric arc furnace smelting
Scrap steel is smelted by an EAF arc furnace, wherein the scrap steel is 2535NB, the return material accounts for 60% +N08810, the return material accounts for 20%, the rest furnace burden is chromium metal, electrolytic nickel and electrolytic cobalt, 15-20kg/t of lime and 3-5kg/t of fluorite are added to the bottom of the furnace before charging, argon is adopted to stir evenly the molten pool composition and the temperature after the furnace burden is melted, cr in ferrosilicon powder reducing slag is added according to the dosage of 1-2kg per ton of molten steel, the mass ratio of the molten steel composition is C0.40-0.60%, P is less than or equal to 0.025%, si is less than or equal to 0.30%, mn is less than or equal to 0.8%, cr22.0-25.0%, ni35.0-37.0%, the rest elements are not more than a control range, the temperature is 1640-1660 ℃, and the steel slag is the same;
2) LF furnace adjustment
The molten steel from the EAF arc furnace in the last step is fed into an LF furnace, heated, electrolytic nickel, metallic chromium and electrolytic cobalt are added in sequence for component adjustment, meanwhile, 1.0-1.5kg/t of C powder and 0.5kg/t of aluminum particles are used for diffusion deoxidation, lime and fluorite are properly added according to slag conditions for adjustment, the molten steel components with the mass ratio of C of 0.40-0.65%, P of less than or equal to 0.025%, si of less than or equal to 0.30%, mn of less than or equal to 0.80%, cr of 25.0-26.0%, ni of 36.5-37.2%, co of 0.38-0.45% and the rest elements of no more than a control range, and the temperature of 1640-1670 ℃ are used for hanging steel ladle to a slag skimming area, and the skimming requirement of more than 90%;
VOD furnace vacuum oxygen blowing decarburization
Hanging the steel ladle to VOD, vacuum the temperature of the tank is 1590-1610 ℃, the free space of the steel ladle is 800-1200mm, and vacuum is pumped by closing the vacuum tank cover; pre-blowing oxygen, namely setting an oxygen lance to be 1200m away from the molten steel surface when the vacuum degree reaches 25kPa, starting to blow oxygen, wherein the oxygen flow is 350Nm 3/h～450Nm3/h, the argon flow is 60 NL/min-80 NL/min, and the vacuum degree is stabilized to 25-20kPa; when the oxygen blowing amount reaches 0.25 percent of the theoretical calculation of the silicon, aluminum and carbon in the molten steel after blowing, the oxygen lance is lowered to 1100m from the molten steel surface, the vacuum degree is reduced to 15kPa, the oxygen flow rate is 450Nm 3/h～550Nm3/h, the argon flow rate is 60 NL/min-80 NL/min, and the vacuum degree is stabilized to 15-10kPa; slowly blowing oxygen, namely lowering the vacuum degree to 8kPa, reducing the oxygen flow to 550Nm 3/h～450Nm3/h, stabilizing the vacuum degree to 8-2kPa, stopping blowing oxygen when the oxygen concentration potential E-0 is reduced and the tail gas temperature is obviously lower than the highest value (inflection point appears), generating the intersection point by CO and CO 2 concentration, continuously vacuumizing to less than 67Pa, maintaining the pressure for 15min, carrying out vacuum carbon deoxidation at the stage, wherein the argon flow is 70-80NL/min, reducing the Ar flow to 60-80L/min after the air break, adding reducing slag, namely 5kg/t of premelting slag, 17kg/t of lime, 5kg/t of fluorite, 6kg/t of deoxidizer Al cake, 2kg/t of CaSi block and 1kg/t of industrial silicon, adding niobium-iron alloy according to Nb content requirement to adjust Nb in the molten steel to the specified range of the weight percentage of the component of claim 1, closing the vacuum pot cover to be vacuumized to less than 67Pa, 20min, maintaining the C content of the molten steel to be less than 0.025 after the whole process is finished, hanging the steel ladle to a slag removing area for removing slag;
4) Nitrogen blowing, nitrogen increasing, deoxidizing and desulfurizing for LF furnace
The ladle enters an LF furnace, nitrogen is blown at the bottom of the ladle, pre-melted slag 10kg/t, lime 6kg/t and fluorite 3kg/t are added for slagging, aluminum particles 1kg/t and calcium silicate powder 1kg/t are added in batches for diffusion deoxidation, nitrogen is added, the nitrogen flow is 50Nm 3/h, the nitrogen adding speed is 0.0030 percent/min, the temperature control range is 1580-1620 ℃, the nitrogen adding is carried out by combining the initial nitrogen content of molten steel to the weight percent of the component of claim 1, the nitrogen stopping and switching into argon, the slag is kept for more than 30 minutes after the slag is in an off-white or white state, calcium treatment is carried out by feeding a calcium silicate wire according to the 2m/t, ferroboron is added according to the mass ratio of molten steel of 0.005%, the argon flow is 30-40NL/min, the soft blowing is more than or equal to 20min, and all the element components of the composition of claim 1 meet the weight percent of the component of claim 1, and the temperature is 1480-1500 ℃;
5) And die casting, namely hanging the ladle to a pouring station for pouring by a ladle car.
3. The process for smelting a nichrome as claimed in claim 2, wherein in the step of vacuum oxygen blowing decarburization in the VOD furnace, the oxygen amount is 50% of the total theoretical oxygen blowing amount when the carbon of the main oxygen blowing is 0.25%.
4. The smelting process of nickel-chromium-iron base alloy according to claim 2, wherein in the LF nitrogen-blowing nitrogen-increasing, deoxidizing and desulfurizing steps, added ferroboron is covered with iron sheet and inserted into molten steel.
5. The smelting process of the nickel-chromium-iron-based alloy according to claim 2, wherein in the step of vacuum oxygen blowing decarburization of the VOD furnace, the vacuumizing is less than 67Pa, the pressure maintaining process is divided into front and rear sections, wherein the argon flow is 70-90L/min for the first 10min, and the argon flow is 20-40L/min for the second 10 min.
CN202510187512.1A 2025-02-20 2025-02-20 A smelting process for nickel-chromium-iron based alloy Pending CN120099402A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202510187512.1A CN120099402A (en) 2025-02-20 2025-02-20 A smelting process for nickel-chromium-iron based alloy

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202510187512.1A CN120099402A (en) 2025-02-20 2025-02-20 A smelting process for nickel-chromium-iron based alloy

Publications (1)

Publication Number Publication Date
CN120099402A true CN120099402A (en) 2025-06-06

Family

ID=95889262

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202510187512.1A Pending CN120099402A (en) 2025-02-20 2025-02-20 A smelting process for nickel-chromium-iron based alloy

Country Status (1)

Country Link
CN (1) CN120099402A (en)

Similar Documents

Publication Publication Date Title
CN105177215B (en) Efficient production process of high aluminum-alloy-content structure round steel
CN113957338A (en) Magnesium-containing 45 steel and preparation process thereof
CN114480987A (en) Rare earth-containing NM600 wear-resistant steel plate and preparation method thereof
CN114807730A (en) Nickel-free copper-phosphorus series weather-resistant steel casting blank
CN113215476A (en) Method for producing industrial pure iron
CN114381672B (en) Smelting and continuous casting manufacturing method of martensite high-wear-resistance steel plate
CN117965840B (en) Converter phosphorus controlled smelting method for low temperature steel and production method of high quality low temperature steel
CN114107826B (en) Nickel-based high-temperature alloy and preparation method thereof
CN108893682B (en) Die steel billet and preparation method thereof
EP3674424B1 (en) Smelting method for ultra-low carbon 13cr stainless steel
CN117467822A (en) A low-cost RH ultra-low carbon silicon steel smelting method
CN115125430A (en) Nitrogen-containing wind power gear steel and nitrogen increasing method thereof
CN117604194B (en) A vacuum consumable electrode for 300M steel and its Al-free deoxidation and refining method
CN118007012B (en) 05Cr17Ni4Cu4Nb stainless steel ingot for ultrathin diaphragm ship power equipment and preparation method and application thereof
CN117230376B (en) Electrode for producing 300M steel and preparation method and application thereof
CN118547133A (en) Refining method of structural steel for reducing diffusion deoxidizer
CN116121629B (en) Preparation method of gear steel 18CrNiMo7-6
CN117230360A (en) Preparation method of single-vacuum 300M steel
CN114395656B (en) A low-cost and stable casting production method of weathering steel based on thin slab
CN117965920A (en) Smelting method of UNS NO6025 alloy
CN120099402A (en) A smelting process for nickel-chromium-iron based alloy
CN120758784B (en) Smelting method for refining size of invar alloy inclusion and invar alloy
CN118516598B (en) Nitrogen addition control method and preparation method of high nitrogen silicon deoxidized steel and high nitrogen silicon deoxidized steel
CN117778866B (en) Preparation method of martensitic stainless steel
CN116254451B (en) Manufacturing method of steel ingot for spent fuel dry storage container and forging

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination