High-strength stainless steel material and preparation method thereof

Abstract

The invention discloses a high-strength stainless steel material and a preparation method thereof. The stainless steel material comprises the following chemical components in percentage by weight: less than or equal to 0.02% of C, less than or equal to 0.4% of Mn, less than or equal to 0.4% of Si, 12-12.5% of Cr, 9.00-9.50% of Ni, less than or equal to 0.005% of S, less than or equal to 0.035% of P, less than or equal to 0.015% of N, 1.0-1.2% of Ti, 4.0-4.2% of Mo, 0.20-0.40% of Al and the balance of Fe and inevitable impurities. The invention discloses a manufacturing method of high-strength stainless steel, which prepares a high-titanium controlled-aluminum high-strength stainless steel alloy through design of chemical component content of materials, AOD (argon oxygen decarburization) smelting control and development of a casting process and a heat treatment technology.

Description

Technical Field

[0001] The invention belongs to the field of alloy materials, and in particular relates to a method for manufacturing a high-strength austenitic stainless steel material. Background Art

[0002] Austenitic stainless steel is a common stainless steel material. Austenitic stainless steel is widely used in aerospace, marine engineering, nuclear power and other fields due to its stable organizational structure, good corrosion resistance and processing performance. However, compared with martensitic stainless steel, austenitic stainless steel has obvious deficiencies in tensile strength. In order to improve the strength of austenitic stainless steel, there are currently two commonly used technical directions. The first is to increase the C% and N% content in steel, but the increase in C% and N% content leads to a decrease in the corrosion resistance and processing performance of austenitic stainless steel. The second is to prepare austenitic materials with high nickel content (such as iron-nickel base, nickel base), but due to the high nickel content, the manufacturing cost is much higher than that of common austenitic stainless steel.

[0003] Continuous casting is a common casting mode for austenitic stainless steel due to its high yield rate and high casting efficiency. However, titanium-containing austenitic stainless steel (Ti% ≧0.2%) is very easy to clog the water nozzle during the continuous casting process, so titanium-containing austenitic stainless steel is generally cast by die casting. Due to the strong active characteristics of titanium element, austenitic stainless steel with high titanium content (Ti% ≧0.5%) reacts chemically with oxides such as SiO2 in the protective slag at high temperatures during the casting process, resulting in a decrease in the titanium content in the surface layer of the ingot, and denaturing the protective slag, resulting in a large number of defects on the surface of the ingot. Such defects are caused by insufficient lubrication due to the denaturation of the protective slag. The defects on the surface of the ingot are often deep and difficult to remove by grinding, resulting in a very high scrap rate for the finished round steel. Summary of the invention

[0004] Purpose of the invention: In view of the deficiencies in the prior art, the present invention proposes a high-strength stainless steel material and a preparation method thereof. By designing the chemical composition of the high-titanium-controlled aluminum stainless steel material, a mold casting protective slag suitable for the high-titanium stainless steel material is developed, and a high-strength high-titanium and high-molybdenum-controlled aluminum stainless steel material is produced through solution heat treatment and tempering heat treatment.

[0005] Technical solution: The high-strength stainless steel material described in the present invention comprises the following chemical components in weight percentage: C: ≤0.02%, Mn: ≤0.4%, Si: ≤0.4%, Cr: 12-12.5%, Ni: 9.00-9.50%, S: ≤0.005%, P: ≤0.035%, N: ≤0.015%, Ti: 1.0-1.2%, Mo: 4.0-4.2%, Al: 0.20-0.40%, the balance is Fe and unavoidable impurities.

[0006] In some embodiments, the following chemical compositions are included by weight: C: ≤0.02%, Mn: ≤0.3%, Si: ≤0.4%, Cr: 12.1-12.4%, Ni: 9.00-9.20%, S: ≤0.005%, P: ≤0.035%, N: ≤0.014%, Ti: 1.0-1.1%, Mo: 4.0-4.2%, Al: 0.20-0.30%, the balance is Fe and unavoidable impurities.

[0007] In some embodiments, the following chemical compositions are included by weight: C: 0.02%, Mn: 0.3%, Si: 0.4%, Cr: 12.2%, Ni: 9.03%, S: 0.005%, P: 0.030%, N: ≤ 0.013%, Ti: 1.0%, Mo: 4.1%, Al: 0.28%, and the balance is Fe and inevitable impurities.

[0008] On the other hand, the present invention also discloses a method for preparing a high-strength stainless steel material, comprising the following steps: S1, batching → electric furnace → AOD furnace → LF furnace: During the AOD furnace smelting process, calcium oxide is used to make slag during the decarburization period; after the decarburization process is completed, the slag is pulled into the reduction process, and barium oxide is used to make slag for reduction. Argon gas is used for low-pressure blowing throughout the reduction stage; S2, Die Casting → 16-inch billet: Molten steel is cast by die casting method, using high titanium stainless steel protective slag; S3, billet opening → 180mm×180mm billet → hot rolling → Φ90mm round steel → solution heat treatment → water cooling → tempering heat treatment.

[0009] In some embodiments, the protective slag for high titanium-containing stainless steel comprises the following chemical components in weight percentage: C: 1-2%, SiO2: 32-34%, CaO: 35-37%, Al2O3: 15-16%, Na2CO3: 1.5-2.5%, F: 1-1.5%, MgO: 0.5-1.5%, Fe2O3: 2-3%, TiO: 5-6.5%.

[0010] In some embodiments, the protective slag for high titanium-containing stainless steel comprises the following chemical components in weight percentage: C: 1.5-2%, SiO2: 33-34%, CaO: 36-37%, Al2O3: 15-15.5%, Na2CO3: 2.0-2.5%, F: 1.0-1.5%, MgO: 0.5-1.0%, Fe2O3: 2.5-3%, TiO: 5-6%.

[0011] In some embodiments, the protective slag for high titanium-containing stainless steel comprises the following chemical components in weight percentage: C: 1.8%, SiO2: 33.5%, CaO: 36.6%, Al2O3: 15.1%, Na2CO3: 2.1%, F: 1.2%, MgO: 0.8%, Fe2O3: 2.8%, TiO: 6.1%.

[0012] In some embodiments, during the casting process, a paper ring made of thick kraft paper is placed at the casting port. When casting starts, the paper ring burns rapidly at high temperature to generate smoke, which reduces the oxygen content in the area and inhibits the oxidation of Ti during the casting process.

[0013] In some embodiments, after hot rolling to Φ90 mm round steel, the round steel is subjected to solution heat treatment at a solution temperature of 1050-1150° C., charged into a hot furnace, kept warm for 40 minutes, and then water-cooled.

[0014] In some embodiments, after the water cooling is completed, the round steel is tempered at a tempering temperature of 450-500° C., the steel is fed into a hot furnace, kept at this temperature for 6 hours, and then water-cooled.

[0015] Beneficial effects: The beneficial effects of the present invention are as follows: 1. The present invention prepares high-strength austenitic stainless steel material by designing the chemical composition of the material and the production process without increasing the nickel content, carbon content and nitrogen content, with low cost and simple production process; 2. The present invention develops a protective slag for high-titanium content stainless steel die casting, which effectively inhibits the chemical reaction between titanium in molten steel and oxides such as protective slag SiO2 under high-temperature casting, improves the surface quality of steel ingots, reduces the amount of grinding of steel ingots, and improves the production yield rate; 3. In addition, the mold slag is adjusted to increase the viscosity of the mold slag, so that the mold slag has a proper viscosity under high-temperature casting of high-titanium steel. During the casting process, a paper ring made of thick kraft paper is placed at the casting port. At the beginning of casting, the paper ring burns rapidly at high temperature to produce a large amount of gas, which reduces the oxygen content in the area and inhibits the oxidation of titanium and aluminum during the casting process. Compared with the previous use of argon rings, which requires special equipment and special argon pipeline technology, this method has low cost, simple operation and good effect; 4. Through the method of solution heat treatment and then tempering aging heat treatment, titanium, molybdenum and aluminum are fully dispersed in the material to form a strengthening phase of the material and improve the tensile strength of the material. DETAILED DESCRIPTION

[0016] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as "center", "up", "down", "left", "right", "inside" and "outside" are the directions or positional relationships shown, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0018] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example 1

[0019] A high-strength stainless steel material comprises the following chemical components in weight percentage: C: 0.02%, Mn: 0.3%, Si: 0.4%, Cr: 12.2%, Ni: 9.03%, S: 0.005%, P: 0.030%, N: 0.013%, Ti: 1.0%, Mo: 4.1%, Al: 0.28%, and the balance is Fe and inevitable impurities.

[0020] The method for preparing the above-mentioned high-strength stainless steel material comprises the following steps: S1, batching → electric furnace → AOD furnace → LF furnace: During the AOD furnace smelting process, calcium oxide is used to make slag during the decarburization period; after the decarburization process is completed, the slag is pulled into the reduction process, and barium oxide is used to make slag for reduction. Argon gas is used for low-pressure blowing throughout the reduction stage; S2, Die Casting → 16-inch Steel Billet: Molten steel is cast by die casting method, using high titanium stainless steel protective slag, the high titanium stainless steel protective slag includes the following chemical components in weight percentage: C: 1.8%, SiO2: 33.5%, CaO: 36.6%, Al2O3: 15.1%, Na2CO3: 2.1%, F: 1.2%, MgO: 0.8%, Fe2O3: 2.8%, TiO: 6.1%.

[0021] The protective slag is partially adjusted on the basis of conventional austenitic stainless steel die casting protective slag. First, the protective slag basicity is increased from 0.9 to 1.1, the Al2O3 content is increased, and TiO is added to inhibit the chemical reaction between titanium and aluminum and the protective slag during the casting process. In addition, the F and C contents are adjusted to increase the viscosity of the protective slag, so that the protective slag has a proper viscosity under high-temperature casting of high-titanium steel. During the casting process, a paper ring made of thick kraft paper is placed at the casting port. At the beginning of casting, the paper ring burns rapidly at high temperature and produces a large amount of gas, which reduces the oxygen content in the area and inhibits the oxidation of titanium and aluminum during the casting process. Compared with the previous use of argon rings, which requires special equipment and special argon pipeline technology, this method is low-cost, simple to operate and has good results.

[0022] During the casting process, a paper ring made of thick kraft paper is placed at the casting port. At the beginning of casting, the paper ring burns rapidly at high temperature to produce smoke, which reduces the oxygen content in the area and inhibits the oxidation of Ti during the casting process.

[0023] S3, billet opening → 180mm×180mm billet → hot rolling → Φ90mm round steel → solution heat treatment → water cooling → tempering heat treatment: Among them, after the billet is opened to 180mm×180mm billet, the four edges and corners of the billet are ground into an arc shape.

[0024] After hot rolling to Φ90mm round steel, the round steel is subjected to solution heat treatment at a solution temperature of 1087℃. The round steel is fed into a hot furnace and kept warm for 40 minutes before being water-cooled.

[0025] After water cooling, the round steel is tempered at a tempering temperature of 458°C, fed into a hot furnace, and water-cooled after 6 hours of heat preservation.

[0026] Take samples at 1 / 2 radius of the material for tensile testing. Example 2

[0027] A high-strength stainless steel material comprises the following chemical components in weight percentage: C: 0.18%, Mn: 0.3%, Si: 0.4%, Cr: 12.8%, Ni: 9.02%, S: 0.005%, P: 0.035%, N: 0.015%, Ti: 1.0%, Mo: 4.1%, Al: 0.26%, and the balance is Fe and inevitable impurities.

[0028] The method for preparing the above-mentioned high-strength stainless steel material comprises the following steps: S1, batching → electric furnace → AOD furnace → LF furnace: During the AOD furnace smelting process, calcium oxide is used to make slag during the decarburization period; after the decarburization process is completed, the slag is pulled into the reduction process, and barium oxide is used to make slag for reduction. Argon gas is used for low-pressure blowing throughout the reduction stage; S2, Die Casting → 16-inch Steel Billet: Molten steel is cast by die casting method, using high titanium stainless steel protective slag, the high titanium stainless steel protective slag includes the following chemical components in weight percentage: C: 1.5%, SiO2: 33.4%, CaO: 36.8%, Al2O3: 15.6%, Na2CO3: 2.5%, F: 1.4%, MgO: 0.8%, Fe2O3: 2.5%, TiO: 5.5%.

[0029] The protective slag is partially adjusted on the basis of conventional austenitic stainless steel die casting protective slag. First, the protective slag basicity is increased from 0.9 to 1.1, the Al2O3 content is increased, and TiO is added to inhibit the chemical reaction between titanium and aluminum and the protective slag during the casting process. In addition, the F and C contents are adjusted to increase the viscosity of the protective slag, so that the protective slag has a proper viscosity under high-temperature casting of high-titanium steel. During the casting process, a paper ring made of thick kraft paper is placed at the casting port. At the beginning of casting, the paper ring burns rapidly at high temperature and produces a large amount of gas, which reduces the oxygen content in the area and inhibits the oxidation of titanium and aluminum during the casting process. Compared with the previous use of argon rings, which requires special equipment and special argon pipeline technology, this method is low-cost, simple to operate and has good results.

[0030] During the casting process, a paper ring made of thick kraft paper is placed at the casting port. At the beginning of casting, the paper ring burns rapidly at high temperature to produce smoke, which reduces the oxygen content in the area and inhibits the oxidation of Ti during the casting process.

[0031] S3, billet opening → 180mm×180mm billet → hot rolling → Φ90mm round steel → solution heat treatment → water cooling → tempering heat treatment: Among them, after the billet is opened to 180mm×180mm billet, the four edges and corners of the billet are ground into an arc shape.

[0032] After hot rolling to Φ90mm round steel, the round steel is subjected to solution heat treatment at a solution temperature of 1135℃, fed into a hot furnace, kept warm for 40 minutes and then water-cooled.

[0033] After water cooling, the round steel is tempered at a tempering temperature of 475°C, fed into a hot furnace, and water-cooled after 6 hours of heat preservation.

[0034] Take samples at 1 / 2 radius of the material for tensile testing. Example 3

[0035] A high-strength stainless steel material comprises the following chemical components in weight percentage: C: 0.02%, Mn: 0.4%, Si: 0.4%, Cr: 12.4%, Ni: 9.25%, S: 0.004%, P: 0.035%, N: 0.010%, Ti: 1.2%, Mo: 4.1%, Al: 0.20%, and the balance is Fe and inevitable impurities.

[0036] The method for preparing the above-mentioned high-strength stainless steel material comprises the following steps: S1, batching → electric furnace → AOD furnace → LF furnace: During the AOD furnace smelting process, calcium oxide is used to make slag during the decarburization period; after the decarburization process is completed, the slag is pulled into the reduction process, and barium oxide is used to make slag for reduction. Argon gas is used for low-pressure blowing throughout the reduction stage; S2, Die Casting → 16-inch Steel Billet: Molten steel is cast by die casting method, using high titanium stainless steel protective slag, the high titanium stainless steel protective slag includes the following chemical components in weight percentage: C: 1.6%, SiO2: 32.5%, CaO: 36.8%, Al2O3: 15.6%, Na2CO3: 2.1%, F: 1.2%, MgO: 1.3%, Fe2O3: 2.8%, TiO: 6.1%.

[0037] The protective slag is partially adjusted on the basis of conventional austenitic stainless steel die casting protective slag. First, the protective slag basicity is increased from 0.9 to 1.1, the Al2O3 content is increased, and TiO is added to inhibit the chemical reaction between titanium and aluminum and the protective slag during the casting process. In addition, the F and C contents are adjusted to increase the viscosity of the protective slag, so that the protective slag has a proper viscosity under high-temperature casting of high-titanium steel. During the casting process, a paper ring made of thick kraft paper is placed at the casting port. At the beginning of casting, the paper ring burns rapidly at high temperature and produces a large amount of gas, which reduces the oxygen content in the area and inhibits the oxidation of titanium and aluminum during the casting process. Compared with the previous use of argon rings, which requires special equipment and special argon pipeline technology, this method is low-cost, simple to operate and has good results.

[0038] During the casting process, a paper ring made of thick kraft paper is placed at the casting port. At the beginning of casting, the paper ring burns rapidly at high temperature to produce smoke, which reduces the oxygen content in the area and inhibits the oxidation of Ti during the casting process.

[0039] S3, billet opening → 180mm×180mm billet → hot rolling → Φ90mm round steel → solution heat treatment → water cooling → tempering heat treatment: Among them, after the billet is opened to 180mm×180mm billet, the four edges and corners of the billet are ground into an arc shape.

[0040] After hot rolling to Φ90mm round steel, the round steel is subjected to solution heat treatment at a solution temperature of 1130℃, fed into a hot furnace, kept warm for 40 minutes and then water-cooled.

[0041] After water cooling, the round steel is tempered at a tempering temperature of 490°C, fed into a hot furnace, and water-cooled after 6 hours of heat preservation.

[0042] Take samples at 1 / 2 radius of the material for tensile testing. Example 4

[0043] A high-strength stainless steel material comprises the following chemical components in weight percentage: C: 0.02%, Mn: 0.3%, Si: 0.4%, Cr: 12.5%, Ni: 9.48%, S: 0.005%, P: 0.033%, N: 0.014%, Ti: 1.2%, Mo: 4.1%, Al: 0.40%, and the balance is Fe and inevitable impurities.

[0044] The method for preparing the above-mentioned high-strength stainless steel material comprises the following steps: S1, batching → electric furnace → AOD furnace → LF furnace: During the AOD furnace smelting process, calcium oxide is used to make slag during the decarburization period; after the decarburization process is completed, the slag is pulled into the reduction process, and barium oxide is used to make slag for reduction. Argon gas is used for low-pressure blowing throughout the reduction stage; S2, Die Casting → 16-inch Steel Billet: Molten steel is cast by die casting method, using high titanium stainless steel protective slag, the high titanium stainless steel protective slag includes the following chemical components in weight percentage: C: 1.8%, SiO2: 32.5%, CaO: 36.6%, Al2O3: 15.8%, Na2CO3: 2.4%, F: 1.2%, MgO: 1.0%, Fe2O3: 2.6%, TiO: 6.1%.

[0045] The protective slag is partially adjusted on the basis of conventional austenitic stainless steel die casting protective slag. First, the protective slag basicity is increased from 0.9 to 1.1, the Al2O3 content is increased, and TiO is added to inhibit the chemical reaction between titanium and aluminum and the protective slag during the casting process. In addition, the F and C contents are adjusted to increase the viscosity of the protective slag, so that the protective slag has a proper viscosity under high-temperature casting of high-titanium steel. During the casting process, a paper ring made of thick kraft paper is placed at the casting port. At the beginning of casting, the paper ring burns rapidly at high temperature and produces a large amount of gas, which reduces the oxygen content in the area and inhibits the oxidation of titanium and aluminum during the casting process. Compared with the previous use of argon rings, which requires special equipment and special argon pipeline technology, this method is low-cost, simple to operate and has good results.

[0046] During the casting process, a paper ring made of thick kraft paper is placed at the casting port. At the beginning of casting, the paper ring burns rapidly at high temperature to produce smoke, which reduces the oxygen content in the area and inhibits the oxidation of Ti during the casting process.

[0047] S3, billet opening → 180mm×180mm billet → hot rolling → Φ90mm round steel → solution heat treatment → water cooling → tempering heat treatment: Among them, after the billet is opened to 180mm×180mm billet, the four edges and corners of the billet are ground into an arc shape.

[0048] After hot rolling to Φ90mm round steel, the round steel is subjected to solution heat treatment at a solution temperature of 1140℃, fed into a hot furnace, kept warm for 40 minutes and then water-cooled.

[0049] After water cooling, the round steel is tempered at a tempering temperature of 480°C, fed into a hot furnace, and water-cooled after 6 hours of heat preservation.

[0050] Take samples at 1 / 2 radius of the material for tensile testing.

[0051] The test results are shown in Table 1.

[0052] Table 1: Test results

[0053] The present invention prepares high-strength austenitic stainless steel material without increasing the nickel content, carbon content and nitrogen content by designing the chemical composition of the material and the production process, and has low cost and simple production process. The present invention develops protective slag for high-titanium content stainless steel die casting, which effectively inhibits the chemical reaction of titanium in molten steel with oxides such as protective slag SiO2 under high-temperature casting, improves the surface quality of the steel ingot, reduces the amount of grinding of the steel ingot, and improves the production yield.

[0054] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A high-strength stainless steel material, characterized in that: The chemical composition includes the following weight percentages: C: ≤0.02%, Mn: ≤0.4%, Si: ≤0.4%, Cr: 12-12.5%, Ni: 9.00-9.50%, S: ≤0.005%, P: ≤0.035%, N: ≤0.015%, Ti: 1.0-1.2%, Mo: 4.0-4.2%, Al: 0.20-0.40%, the balance is Fe and unavoidable impurities.

2. A high-strength stainless steel material according to claim 1, characterized in that: The chemical composition includes the following weight percentages: C: ≤0.02%, Mn: ≤0.3%, Si: ≤0.4%, Cr: 12.1-12.4%, Ni: 9.00-9.20%, S: ≤0.005%, P: ≤0.035%, N: ≤0.014%, Ti: 1.0-1.1%, Mo: 4.0-4.2%, Al: 0.20-0.30%, the balance is Fe and unavoidable impurities.

3. A high-strength stainless steel material according to claim 1, characterized in that: The chemical composition includes the following weight percentages: C: 0.02%, Mn: 0.3%, Si: 0.4%, Cr: 12.2%, Ni: 9.03%, S: 0.005%, P: 0.030%, N: ≤ 0.013%, Ti: 1.0%, Mo: 4.1%, Al: 0.28%, and the balance is Fe and inevitable impurities.

4. A method for preparing a high-strength stainless steel material according to any one of claims 1 to 3, characterized in that: The steps include: S1, batching → electric furnace → AOD furnace → LF furnace: During the AOD furnace smelting process, calcium oxide is used to make slag during the decarburization period; after the decarburization process is completed, the slag is pulled into the reduction process, and barium oxide is used to make slag for reduction. Argon gas is used for bottom blowing throughout the reduction stage; S2, Die Casting → 16-inch billet: Molten steel is cast using the die casting pouring method, using protective slag specially developed by the project team for high-titanium stainless steel; S3, billet opening → 180mm×180mm billet → hot rolling → Φ90mm round steel → solution heat treatment → water cooling → tempering heat treatment → water cooling.

5. The method for preparing a high-strength stainless steel material according to claim 4 is characterized in that: The protective slag for high titanium-containing stainless steel comprises the following chemical components in weight percentage: C: 1-2%, SiO2: 32-34%, CaO: 35-37%, Al2O3: 15-16%, Na2CO3: 1.5-2.5%, F: 1-1.5%, MgO: 0.5-1.5%, Fe2O3: 2-3%, TiO: 5-6.5%.

6. The method for preparing a high-strength stainless steel material according to claim 5, characterized in that: The protective slag for high titanium-containing stainless steel comprises the following chemical components in weight percentage: C: 1.5-2%, SiO2: 33-34%, CaO: 36-37%, Al2O3: 15-15.5%, Na2CO3: 2.0-2.5%, F: 1.0-1.5%, MgO: 0.5-1.0%, Fe2O3: 2.5-3%, TiO: 5-6%.

7. The method for preparing a high-strength stainless steel material according to claim 6, characterized in that: The protective slag for high titanium-containing stainless steel comprises the following chemical components in weight percentage: C: 1.8%, SiO2: 33.5%, CaO: 36.6%, Al2O3: 15.1%, Na2CO3: 2.1%, F: 1.2%, MgO: 0.8%, Fe2O3: 2.8%, TiO: 6.1%.

8. The method for preparing a high-strength stainless steel material according to claim 4 is characterized in that: During the casting process, a paper ring made of thick kraft paper is placed at the casting port. At the beginning of casting, the paper ring burns rapidly at high temperature to produce smoke, which reduces the oxygen content in the area and inhibits the oxidation of Ti during the casting process.

9. The method for preparing a high-strength stainless steel material according to claim 4, characterized in that: After hot rolling to Φ90mm round steel, the round steel is subjected to solution heat treatment at a solution temperature of 1050-1150℃, fed into a hot furnace, kept warm for 40 minutes and then water-cooled.

10. The method for preparing a high-strength stainless steel material according to claim 4, characterized in that: After water cooling, the round steel is tempered at a tempering temperature of 450-500°C. The hot furnace is charged and kept warm for 6 hours before water cooling.

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