High-strength stainless steel casting and preparation method thereof

Abstract

The invention relates to the technical field of stainless steel materials, and provides a high-strength stainless steel casting and a preparation method thereof. The invention discloses a high-strength stainless steel casting which is composed of the following components in percentage by weight: less than or equal to 0.04% of C, 12%-13.5% of Cr, 3.0%-6.0% of Ni, 0.8%-1.2% of Mo, 0.20%-0.30% of Zr, 0.20%-0.30% of V, 0.01%-0.06% of N, 0.30%-0.45% of Si, 0.20%-0.50% of Mn and the balance of Fe and inevitable impurities. The weight contents of Cr, Mo, Zr and V meet the relational expression that Cr / (Mo + Zr + V) is more than 6 and less than or equal to 10. According to the technical scheme, the problem of low strength of stainless steel castings in related technologies is solved.

Description

Technical Field

[0001] This invention relates to the field of stainless steel materials technology, specifically to a high-strength stainless steel casting and its preparation method. Background Technology

[0002] Stainless steel castings are widely used in key fields such as petrochemicals, nuclear power, and automobiles due to their excellent corrosion resistance, good mechanical properties, and designability. However, as modern industrial equipment develops towards larger scale and higher efficiency, more stringent requirements are being placed on the strength of stainless steel castings.

[0003] For example, ball valves and automotive safety components operating under extreme conditions are prone to stress concentration, fatigue cracks, and even pressure failure and component breakage if their strength is insufficient. This could lead to major safety accidents or equipment malfunctions. Increasing strength can reduce these risks at their source. In addition, high-strength stainless steel castings do not require frequent maintenance or replacement during use, effectively reducing total lifecycle costs.

[0004] Therefore, it is necessary to propose a high-strength stainless steel casting and its preparation method. Summary of the Invention

[0005] This invention proposes a high-strength stainless steel casting and its preparation method, which solves the problem of low strength of stainless steel castings in related technologies.

[0006] The technical solution of the present invention is as follows: This invention proposes a high-strength stainless steel casting, which, by weight percentage, consists of the following components: C≤0.04%, Cr 12.0%~13.5%, Ni 3.0%~6.0%, Mo 0.8%~1.2%, Zr 0.20%~0.30%, V 0.20%~0.30%, N 0.01%~0.06%, Si 0.30%~0.45%, Mn 0.20%~0.50%, with the remainder being Fe and unavoidable impurities; the weight content of Cr, Mo, Zr, and V satisfies the relationship: 6<Cr / (Mo+Zr+V)≤10.

[0007] As a further technical solution, the weight contents of Cr, Mo, Zr, and V satisfy the relationship: Cr / (Mo+Zr+V)=8.

[0008] As a further technical solution, the weight contents of Mo, Zr, and V satisfy the following relationship: Mo:Zr:V=4:0.8~1.2:0.8~1.2.

[0009] As a further technical solution, the weight contents of Mo, Zr, and V satisfy the relationship: Mo:Zr:V=4:1:1.

[0010] This invention also proposes a method for preparing high-strength stainless steel castings, comprising the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; S4. After tempering, the semi-finished castings are used to obtain high-strength stainless steel castings.

[0011] As a further technical solution, in step S3, the annealing process is as follows: after heating to 750°C and holding for 45-60 minutes, the temperature is cooled to 650°C at a first cooling rate and held for 10-20 minutes, and then cooled to room temperature at a second cooling rate, wherein the first cooling rate is greater than the second cooling rate.

[0012] As a further technical solution, the heating rate to 750°C is 10~20°C / min.

[0013] As a further technical solution, the first cooling rate is 80~90℃ / min, and the second cooling rate is 50~60℃ / min.

[0014] The annealing process in this invention is generally divided into two stages. Compared with a single annealing process, the two-stage annealing process of this invention can better eliminate internal stress and improve the impact resistance of stainless steel castings.

[0015] As a further technical solution, in step S4, the tempering process involves heating to 550°C, holding at that temperature for 40-50 minutes, and then air-cooling to room temperature.

[0016] The working principle and beneficial effects of this invention are as follows: In this invention, Mo, Zr, and V are added to the composition of stainless steel castings, and the weight ratio of Cr, Mo, Zr, and V is specified, i.e., 6 < Cr / (Mo + Zr + V) ≤ 10, which can improve the tensile strength of stainless steel castings. The addition of Mo, Zr, and V and the limitation of their weight ratio allow Mo, Zr, and V to exert their synergistic effects in solid solution and grain refinement, thereby fully leveraging the strengthening effect of Cr and improving the tensile strength of stainless steel castings. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1 A high-strength stainless steel casting, by weight percentage, comprises the following components: C 0.04%, Cr 12%, Ni 3.0%, Mo 0.8%, Zr 0.20%, V 0.20%, N 0.01%, Si 0.30%, Mn 0.20%, with the remainder being Fe and unavoidable impurities; wherein the weight contents of Cr, Mo, Zr, and V satisfy the following relationships: Cr / (Mo+Zr+V)=10, Mo:Zr:V=4:1:1; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min and hold for 45min, then cool to 650℃ at a first cooling rate and hold for 20min, and then cool to room temperature at a second cooling rate of 80℃ / min and 60℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0019] Example 2 A high-strength stainless steel casting, by weight percentage, is composed of the following components: C 0.04%, Cr 12%, Ni 4.0%, Mo 1.0%, Zr 0.25%, V 0.25%, N 0.04%, Si 0.4%, Mn 0.4%, with the remainder being Fe and unavoidable impurities; wherein the weight contents of Cr, Mo, Zr, and V satisfy the following relationships: Cr / (Mo+Zr+V)=8, Mo:Zr:V=4:1:1; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min and hold for 45min, then cool to 650℃ at a first cooling rate and hold for 20min, and then cool to room temperature at a second cooling rate of 80℃ / min and 60℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0020] Example 3 A high-strength stainless steel casting, by weight percentage, comprises the following components: C 0.03%, Cr 13.5%, Ni 6.0%, Mo 1.2%, Zr 0.30%, V 0.30%, N 0.06%, Si 0.45%, Mn 0.50%, with the remainder being Fe and unavoidable impurities; wherein the weight contents of Cr, Mo, Zr, and V satisfy the following relationships: Cr / (Mo+Zr+V)=7.5, Mo:Zr:V=4:1:1; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 20℃ / min and hold for 60min, then cool to 650℃ at a first cooling rate and hold for 10min, and then cool to room temperature at a second cooling rate of 90℃ / min and 50℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 20℃ / min and held for 40 minutes, then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0021] Example 4 A high-strength stainless steel casting, by weight percentage, is composed of the following components: C 0.04%, Cr 12%, Ni 4.0%, Mo 0.8%, Zr 0.2%, V 0.2%, N 0.04%, Si 0.4%, Mn 0.4%, with the remainder being Fe and unavoidable impurities; wherein the weight contents of Cr, Mo, Zr, and V satisfy the following relationships: Cr / (Mo+Zr+V)=10, Mo:Zr:V=4:1:1; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min and hold for 45min, then cool to 650℃ at a first cooling rate and hold for 20min, and then cool to room temperature at a second cooling rate of 80℃ / min and 60℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0022] Example 5 A high-strength stainless steel casting, by weight percentage, is composed of the following components: C 0.04%, Cr 12%, Ni 4.0%, Mo 1.2%, Zr 0.3%, V 0.3%, N 0.04%, Si 0.4%, Mn 0.4%, with the remainder being Fe and unavoidable impurities; wherein the weight contents of Cr, Mo, Zr, and V satisfy the following relationships: Cr / (Mo+Zr+V)=20 / 3, Mo:Zr:V=4:1:1; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min and hold for 45min, then cool to 650℃ at a first cooling rate and hold for 20min, and then cool to room temperature at a second cooling rate of 80℃ / min and 60℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0023] Example 6 A high-strength stainless steel casting, by weight percentage, is composed of the following components: C 0.04%, Cr 12%, Ni 4.0%, Mo 1.0%, Zr 0.2%, V 0.3%, N 0.04%, Si 0.4%, Mn 0.4%, with the remainder being Fe and unavoidable impurities; wherein the weight contents of Cr, Mo, Zr, and V satisfy the following relationships: Cr / (Mo+Zr+V)=8, Mo:Zr:V=4:0.8:1.2; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min and hold for 45min, then cool to 650℃ at a first cooling rate and hold for 20min, and then cool to room temperature at a second cooling rate of 80℃ / min and 60℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0024] Example 7 A high-strength stainless steel casting, by weight percentage, comprises the following components: C 0.04%, Cr 12%, Ni 4.0%, Mo 1.0%, Zr 0.3%, V 0.2%, N 0.04%, Si 0.4%, Mn 0.4%, with the remainder being Fe and unavoidable impurities; wherein the weight contents of Cr, Mo, Zr, and V satisfy the following relationships: Cr / (Mo+Zr+V)=8, Mo:Zr:V=4:1.2:0.8; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min and hold for 45min, then cool to 650℃ at a first cooling rate and hold for 20min, and then cool to room temperature at a second cooling rate of 80℃ / min and 60℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0025] Example 8 A high-strength stainless steel casting, by weight percentage, comprises the following components: C 0.04%, Cr 12%, Ni 4.0%, Mo 1.0%, Zr 0.3%, V 0.2%, N 0.04%, Si 0.4%, Mn 0.4%, with the remainder being Fe and unavoidable impurities; wherein the weight contents of Cr, Mo, Zr, and V satisfy the following relationships: Cr / (Mo+Zr+V)=8, Mo:Zr:V=4:1.2:0.8; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min and hold for 45min, then cool to 650℃ at a first cooling rate and hold for 20min, and then cool to room temperature at a second cooling rate. The first cooling rate is 85℃ / min and the second cooling rate is 60℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0026] Example 9 A high-strength stainless steel casting, by weight percentage, comprises the following components: C 0.04%, Cr 12%, Ni 4.0%, Mo 1.0%, Zr 0.3%, V 0.2%, N 0.04%, Si 0.4%, Mn 0.4%, with the remainder being Fe and unavoidable impurities; wherein the weight contents of Cr, Mo, Zr, and V satisfy the following relationships: Cr / (Mo+Zr+V)=8, Mo:Zr:V=4:1.2:0.8; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min and hold for 45min, then cool to 650℃ at a first cooling rate and hold for 20min, and then cool to room temperature at a second cooling rate of 90℃ / min and 60℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0027] Example 10 A high-strength stainless steel casting, by weight percentage, comprises the following components: C 0.04%, Cr 12%, Ni 4.0%, Mo 1.0%, Zr 0.3%, V 0.2%, N 0.04%, Si 0.4%, Mn 0.4%, with the remainder being Fe and unavoidable impurities; wherein the weight contents of Cr, Mo, Zr, and V satisfy the following relationships: Cr / (Mo+Zr+V)=8, Mo:Zr:V=4:1.2:0.8; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min and hold for 45min, then cool to 650℃ at a first cooling rate and hold for 20min, and then cool to room temperature at a second cooling rate of 85℃ / min and 55℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0028] Example 11 A high-strength stainless steel casting, by weight percentage, comprises the following components: C 0.04%, Cr 12%, Ni 4.0%, Mo 1.0%, Zr 0.3%, V 0.2%, N 0.04%, Si 0.4%, Mn 0.4%, with the remainder being Fe and unavoidable impurities; wherein the weight contents of Cr, Mo, Zr, and V satisfy the following relationships: Cr / (Mo+Zr+V)=8, Mo:Zr:V=4:1.2:0.8; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min and hold for 45min, then cool to 650℃ at a first cooling rate and hold for 20min, and then cool to room temperature at a second cooling rate of 85℃ / min and 50℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0029] Example 12 A high-strength stainless steel casting, by weight percentage, comprises the following components: C 0.04%, Cr 12%, Ni 4.0%, Mo 1.0%, Zr 0.3%, V 0.2%, N 0.04%, Si 0.4%, Mn 0.4%, with the remainder being Fe and unavoidable impurities; wherein the weight contents of Cr, Mo, Zr, and V satisfy the following relationships: Cr / (Mo+Zr+V)=8, Mo:Zr:V=4:1.2:0.8; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min, hold for 45min, and then cool to room temperature at 85℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0030] Comparative Example 1 A high-strength stainless steel casting, by weight percentage, is composed of the following components: C 0.04%, Cr 12%, Ni 3.0%, N 0.01%, Si 0.30%, Mn 0.20%, with the remainder being Fe and unavoidable impurities; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min and hold for 45min, then cool to 650℃ at a first cooling rate and hold for 20min, and then cool to room temperature at a second cooling rate of 80℃ / min and 60℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0031] Comparative Example 2 A high-strength stainless steel casting, by weight percentage, is composed of the following components: C 0.04%, Cr 12%, Ni 3.0%, Mo 0.8%, N 0.01%, Si 0.30%, Mn 0.20%, with the remainder being Fe and unavoidable impurities; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min and hold for 45min, then cool to 650℃ at a first cooling rate and hold for 20min, and then cool to room temperature at a second cooling rate of 80℃ / min and 60℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0032] Comparative Example 3 A high-strength stainless steel casting, by weight percentage, is composed of the following components: C 0.04%, Cr 12%, Ni 3.0%, Zr 0.20%, N 0.01%, Si 0.30%, Mn 0.20%, with the remainder being Fe and unavoidable impurities; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min and hold for 45min, then cool to 650℃ at a first cooling rate and hold for 20min, and then cool to room temperature at a second cooling rate of 80℃ / min and 60℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0033] Comparative Example 4 A high-strength stainless steel casting, by weight percentage, is composed of the following components: C 0.04%, Cr 24%, Ni 3.0%, V 0.20%, N 0.01%, Si 0.30%, Mn 0.20%, with the remainder being Fe and unavoidable impurities; A method for preparing a high-strength stainless steel casting includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; The annealing process is as follows: heat to 750℃ at a heating rate of 10℃ / min and hold for 45min, then cool to 650℃ at a first cooling rate and hold for 20min, and then cool to room temperature at a second cooling rate of 80℃ / min and 60℃ / min. S4. The semi-finished casting is heated to 550℃ at a heating rate of 10℃ / min, held for 50 minutes, and then air-cooled to room temperature to obtain a high-strength stainless steel casting.

[0034] Experimental Example 1 The stainless steel castings prepared in Examples 1-7 and Comparative Examples 1-4 were processed according to GB / T 228.1. The 2021 standard "Metallic materials, tensile testing—Part 1: Test at room temperature" is used to test tensile strength, with a test rate of 0.008 s. 1 The test results are shown in Table 1 below.

[0035] Table 1. Results of tensile strength determination for Examples 1-7 and Comparative Examples 1-4

[0036] As shown in Table 1, the tensile strength of the stainless steel castings in Examples 1-7 of the present invention is higher than that in Comparative Examples 1-4, indicating that the weight content of Cr, Mo, Zr and V in the stainless steel castings of the present invention satisfies the relationship: 6 < Cr / (Mo + Zr + V) ≤ 10, which can improve the tensile strength of the stainless steel castings.

[0037] Experiment Example 2 The stainless steel castings obtained in Examples 7-12 were prepared in accordance with GB / T 229. The 2020 "Charpy Pendulum Impact Test Method for Metallic Materials" standard measures the absorbed energy KV2 at room temperature using a V-notch specimen and a 2mm pendulum edge. The test results are shown in Table 2.

[0038] Table 2. Impact resistance test results of Examples 7-12

[0039] By comparing the impact resistance results of Examples 7-11 and Example 12 in Table 2, it is shown that the limitation of the annealing process in this invention can improve the impact resistance of stainless steel castings.

[0040] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-strength stainless steel casting, characterized in that, By weight percentage, it consists of the following components: C≤0.04%, Cr 12%~13.5%, Ni 3.0%~6.0%, Mo 0.8%~1.2%, Zr 0.20%~0.30%, V 0.20%~0.30%, N 0.01%~0.06%, Si 0.30%~0.45%, Mn 0.20%~0.50%, with the remainder being Fe and unavoidable impurities; the weight contents of Cr, Mo, Zr, and V satisfy the relationship: 6<Cr / (Mo+Zr+V)≤10.

2. A high-strength stainless steel casting according to claim 1, characterized in that, The weight contents of Cr, Mo, Zr, and V satisfy the following relationship: Cr / (Mo+Zr+V)=8.

3. A high-strength stainless steel casting according to claim 1, characterized in that, The weight contents of Mo, Zr, and V satisfy the following relationship: Mo:Zr:V = 4:0.8~1.2:0.8~1.

2.

4. A high-strength stainless steel casting according to claim 3, characterized in that, The weight contents of Mo, Zr, and V satisfy the following relationship: Mo:Zr:V = 4:1:

1.

5. A method for preparing a high-strength stainless steel casting, used to prepare the high-strength stainless steel casting according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1. After mixing the ingredients according to the weight percentage composition of the high-strength stainless steel casting, the desired molten steel is obtained after melting and refining. S2. After pouring the molten steel, a billet is obtained; S3. After annealing the billet, a semi-finished casting is obtained; S4. After tempering, the semi-finished castings are used to obtain high-strength stainless steel castings.

6. The method for preparing a high-strength stainless steel casting according to claim 5, characterized in that, In step S3, the annealing process is as follows: after heating to 750°C and holding for 45-60 minutes, the temperature is cooled to 650°C at a first cooling rate and held for 10-20 minutes, and then cooled to room temperature at a second cooling rate, wherein the first cooling rate is greater than the second cooling rate.

7. The method for preparing a high-strength stainless steel casting according to claim 6, characterized in that, The heating rate to 750°C is 10~20°C / min.

8. The method for preparing a high-strength stainless steel casting according to claim 6, characterized in that, The first cooling rate is 80~90℃ / min, and the second cooling rate is 50~60℃ / min.

9. The method for preparing a high-strength stainless steel casting according to claim 5, characterized in that, In step S4, the tempering process involves heating to 550°C, holding at that temperature for 40-50 minutes, and then air-cooling to room temperature.

10. The method for preparing a high-strength stainless steel casting according to claim 9, characterized in that, The heating rate to 550°C is 10~20°C / min.

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