Z2CN19-10 +N2 forge piece for nuclear power and manufacturing method of Z2CN19-10 +N2 forge piece

Abstract

The invention provides a Z2CN19-10 + N2 forge piece for nuclear power, which is prepared from the following components in percentage by weight: 0.01 to 0.02 percent of C, 0.90 to 1.00 percent of Si, 1.90 to 2.00 percent of Mn, less than or equal to 0.030 percent of P, less than or equal to 0.015 percent of S, 18.50 to 20.00 percent of Cr, 9.00 to 10.00 percent of Ni, 0.90 to 1.00 percent of Cu, less than or equal to 0.0015 percent of Bi, 0.05 to 0.08 percent of N, 0.04 to 0.05 percent of Co, 0.05 to 0.08 percent of Nb, 0.07 to 0.10 percent of Ta and the balance of iron. The invention further provides a manufacturing method of the Z2CN19-10 + N2 forge piece for nuclear power. The Z2CN19-10 + N2 forge piece for nuclear power, provided by the invention, has relatively good intergranular corrosion resistance and hardenability.

Description

Technical Field

[0001] The invention belongs to the field of alloy forging, and specifically relates to a Z2CN19-10+N2 forging for nuclear power and a manufacturing method thereof. Background Art

[0002] Austenitic stainless steel has excellent corrosion resistance. Its production and usage account for about 70% of the total production and usage of stainless steel. It has many application fields, including machinery manufacturing, petrochemical, aerospace, medical equipment, etc. Common grades such as F304 and F316 are austenitic stainless steel. Z2CN19-10+N2 is also one of the austenitic stainless steels. It has excellent mechanical properties, corrosion resistance, organizational stability, good high-temperature mechanical properties, and neutron irradiation resistance. Therefore, it is widely used in key equipment in nuclear power plants, such as the internal components, injection boxes and supporting parts in the nuclear island reactor. These equipment are in harsh environments such as high temperature and high pressure, neutron irradiation, and fluid scouring for a long time, so the performance requirements of the material are extremely high. Austenitic stainless steel has many advantages, but it has a tendency to intergranular corrosion under certain conditions. The existing Z2CN19-10+N2 for nuclear power also has the problem of intergranular corrosion tendency. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a Z2CN19-10+N2 forging for nuclear power, which has good intergranular corrosion resistance and hardenability.

[0004] In order to solve the above technical problems, the technical solution of the present invention is:

[0005] A Z2CN19-10+N2 forging for nuclear power consists of the following components by weight percentage: C 0.01-0.02%, Si 0.90-1.00%, Mn 1.90-2.00%, P≤0.030%, S≤0.015%, Cr18.50-20.00%, Ni9.00-10.00%, Cu 0.90-1.00%, Bi≤0.0015%, N 0.05-0.08%, Co 0.04-0.05%, Nb0.05-0.08%, Ta 0.07-0.10%, and the remainder is iron.

[0006] Another technical problem to be solved by the present invention is to provide a method for manufacturing the Z2CN19-10+N2 forgings for nuclear power.

[0007] To solve the above technical problems, the technical solution is:

[0008] A method for manufacturing a Z2CN19-10+N2 forging for nuclear power, comprising the following steps:

[0009] S1. Electric furnace smelting: Prepare the raw materials by weight percentage, place the raw materials in an electric furnace, and smelt until the temperature reaches 1570-1610°C to obtain molten steel;

[0010] S2 refining outside the furnace: the molten steel obtained in step S1 is placed in a LF furnace, refined for 50-70min, vacuum degassing for 25-35min, and then cast into an ingot billet;

[0011] S3. Electroslag remelting: The steel ingot obtained in step S2 is placed in an electroslag furnace and electroslag remelted to obtain an electroslag ingot;

[0012] S4 forging: The electroslag ingot obtained in step S3 is subjected to upsetting and drawing by a hydraulic press to obtain a forging;

[0013] S5. Heat treatment: The forging obtained in step S4 is subjected to solution treatment and then placed in a cooling pool and quenched to room temperature to obtain a Z2CN19-10+N2 forging for nuclear power;

[0014] S6. Testing: Perform physical and chemical testing and nondestructive testing on the Z2CN19-10+N2 forgings for nuclear power obtained in step S5.

[0015] Furthermore, in step S2 of the present invention, argon protection is used throughout the refining outside the furnace, and the vacuum degree during vacuum degassing is 15-25 Pa; the temperature of the molten steel during pouring is 1400-1450°C.

[0016] Furthermore, in step S3 of the present invention, during the electroslag remelting process, the melting rate is 7-10 kg / min and the cooling rate is 10-15° C. / h.

[0017] Furthermore, in step S4 of the present invention, the cutting ratio of the ingot head of the electroslag ingot billet is 6%, the cutting ratio of the ingot tail of the electroslag ingot billet is 3%, the initial forging temperature is 1160-1200°C, the final forging temperature is 780-820°C, and the total forging ratio is ≥3.

[0018] Furthermore, in step S5 of the present invention, the solution treatment is carried out in an industrial resistance furnace, the temperature of the solution treatment is 1070-1090° C., and the holding time is calculated as 1.6 min / mm.

[0019] Furthermore, in step S6 of the present invention, during quenching, the cooling pool is filled with a coolant, which is composed of the following components by weight percentage: 8-10% C3-glycidyloxypropylmethyldiethoxysilane, 5-8% sodium 3-bromopropane sulfonate, 2-4% triethanolamine, 3-5% propylene glycol monobutyl ether, and the rest water.

[0020] Furthermore, the steps for preparing the cooling liquid of the present invention are as follows:

[0021] Prepare each component according to weight percentage, add C3-glycidyloxypropylmethyldiethoxysilane and propylene glycol monomethyl ether into water, stir until mixed evenly, then add 3-bromopropane sodium sulfonate and triethanolamine, and continue stirring for 1-2 hours to obtain a coolant.

[0022] Furthermore, in the step of preparing the cooling liquid of the present invention, the stirring speed is 100-200 rpm.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1) Reducing the carbon content can effectively improve the intergranular corrosion resistance of austenitic stainless steel. Therefore, the present invention appropriately reduces the carbon content on the basis of ensuring the strength of the material.

[0025] 2) For austenitic stainless steel, the appropriate addition of nitrogen can stabilize the austenite structure, improve the strength and corrosion resistance of the material, and the nitrogen element affects the precipitation process of chromium carbide during sensitization treatment, increasing the chromium concentration at the grain boundary. At the same time, nitrogen has an inhibitory effect on the segregation of phosphorus at the grain boundary, thereby improving the material's resistance to intergranular corrosion. Therefore, the present invention appropriately increases the nitrogen content and controls it to 0.05-0.08%.

[0026] 3) The essence of intergranular corrosion is chromium depletion at the grain boundaries. Reducing the number of grain boundaries inside the material can improve the material's resistance to intergranular corrosion. A grain size of 2-4 can both meet the material's mechanical requirements and reduce the material's tendency to intergranular corrosion. Therefore, the present invention controls the material's grain size to be 2-4 during the forging process.

[0027] 4) The present invention optimizes the solution treatment process of the material to ensure sufficient heat penetration, so that other phases in the material can be fully dissolved into austenite, which is beneficial to improving the material's resistance to intergranular corrosion.

[0028] 5) The present invention uses a coolant composed of C3-glycidyloxypropylmethyldiethoxysilane, 3-sodium bromopropane sulfonate, triethanolamine, propylene glycol monobutyl ether and water during quenching. The coolant has good stability and resistance to quenching cracking and can effectively improve the hardenability of forgings. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below in conjunction with specific embodiments. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention but are not intended to limit the present invention.

[0030] Example 1

[0031] Z2CN19-10+N2 forgings for nuclear power are composed of the following components in weight percentage: C 0.01%, Si0.95%, Mn 1.96%, P 0.028%, S 0.014%, Cr 18.80%, Ni 9.60%, Cu 0.94%, Bi0.0014%, N 0.06%, Co 0.04%, Nb 0.07%, Ta 0.08%, and the rest is iron.

[0032] The manufacturing method of embodiment 1 comprises the following steps:

[0033] S1. Electric furnace smelting: prepare raw materials according to weight percentage, place the raw materials in an electric furnace, and smelt until the temperature reaches 1590°C to obtain molten steel;

[0034] S2. Refining outside the furnace: The whole process is protected by argon gas. The molten steel obtained in step S1 is placed in a LF furnace. After refining for 60 min, it is vacuum degassed for 30 min and then cast into a steel ingot. The vacuum degree during vacuum degassing is 20 Pa. The temperature of the molten steel during casting is 1425 ° C.

[0035] S3 electroslag remelting: The steel ingot obtained in step S2 is placed in an electroslag furnace for electroslag remelting to obtain an electroslag ingot. During the electroslag remelting process, the melting rate is 9kg / min and the cooling rate is 15°C / h;

[0036] S4. Forging: The electroslag ingot obtained in step S3 is subjected to upsetting and drawing by a hydraulic press to obtain a forging, the cutting ratio of the electroslag ingot head is 6%, the cutting ratio of the electroslag ingot tail is 3%, the initial forging temperature is 1180°C, the final forging temperature is 800°C, and the total forging ratio is 3.1;

[0037] S5. Heat treatment: The forging obtained in step S4 is subjected to solution treatment in an industrial resistance furnace at a temperature of 1080°C and a holding time of 1.6 min / mm, and then placed in a cooling pool for quenching to room temperature to obtain a Z2CN19-10+N2 forging for nuclear power. During quenching, a coolant is contained in the cooling pool, and the coolant is composed of the following components by weight percentage: 9% C3-glycidyloxypropylmethyldiethoxysilane, 7% sodium 3-bromopropane sulfonate, 3% triethanolamine, 4% propylene glycol monobutyl ether, and the remainder water;

[0038] S6. Testing: Perform physical and chemical testing and nondestructive testing on the Z2CN19-10+N2 forgings for nuclear power obtained in step S5.

[0039] The steps of preparing the coolant are as follows:

[0040] The components were prepared according to weight percentage, C3-glycidyloxypropylmethyldiethoxysilane and propylene glycol monomethyl ether were added into water, stirred at 150 rpm until uniformly mixed, then 3-bromopropane sodium sulfonate and triethanolamine were added, and stirring was continued for 1.5 h to obtain a coolant.

[0041] Example 2

[0042] Z2CN19-10+N2 forgings for nuclear power are composed of the following components in weight percentage: C 0.02%, Si 0.90%, Mn 1.98%, P 0.030%, S 0.014%, Cr 18.50%, Ni 10.00%, Cu 0.98%, Bi 0.0015%, N 0.05%, Co 0.05%, Nb 0.08%, Ta 0.09%, and the rest is iron.

[0043] The manufacturing method of embodiment 2 comprises the following steps:

[0044] S1. Electric furnace smelting: prepare raw materials by weight percentage, place the raw materials in an electric furnace, and smelt until the temperature reaches 1570°C to obtain molten steel;

[0045] S2. Refining outside the furnace: The whole process is protected by argon gas. The molten steel obtained in step S1 is placed in a LF furnace. After refining for 70 min, it is vacuum degassed for 35 min and then cast into a steel ingot. The vacuum degree during vacuum degassing is 15 Pa; the temperature of the molten steel during casting is 1400 ℃;

[0046] S3. Electroslag remelting: The steel ingot obtained in step S2 is placed in an electroslag furnace to obtain an electroslag ingot. During the electroslag remelting process, the melting rate is 7kg / min and the cooling rate is 14°C / h.

[0047] S4. Forging: The electroslag ingot obtained in step S3 is subjected to upsetting and drawing by a hydraulic press to obtain a forging, the cutting ratio of the electroslag ingot head is 6%, the cutting ratio of the electroslag ingot tail is 3%, the initial forging temperature is 1160°C, the final forging temperature is 780°C, and the total forging ratio is 3;

[0048] S5. Heat treatment: The forging obtained in step S4 is subjected to solution treatment in an industrial resistance furnace at a temperature of 1070°C and a holding time of 1.6 min / mm, and then placed in a cooling pool for quenching to room temperature to obtain a Z2CN19-10+N2 forging for nuclear power. During quenching, a coolant is contained in the cooling pool, and the coolant is composed of the following components by weight percentage: 8% C3-glycidyloxypropylmethyldiethoxysilane, 8% sodium 3-bromopropane sulfonate, 2.5% triethanolamine, 5% propylene glycol monobutyl ether, and the remainder water;

[0049] S6. Testing: Perform physical and chemical testing and nondestructive testing on the Z2CN19-10+N2 forgings for nuclear power obtained in step S5.

[0050] The steps of preparing the coolant are as follows:

[0051] The components were prepared according to weight percentage, C3-glycidyloxypropylmethyldiethoxysilane and propylene glycol monomethyl ether were added into water, and after stirring at 100 rpm until the mixture was uniformly mixed, 3-bromopropane sodium sulfonate and triethanolamine were added, and stirring was continued for 2 hours to obtain a coolant.

[0052] Example 3

[0053] Z2CN19-10+N2 forgings for nuclear power are composed of the following components in weight percentage: C 0.015%, Si 1.00%, Mn 1.90%, P 0.029%, S 0.015%, Cr 20.00%, Ni 9.30%, Cu 1.00%, Bi 0.0015%, N 0.08%, Co 0.04%, Nb 0.05%, Ta 0.07%, and the rest is iron.

[0054] The manufacturing method of embodiment 3 comprises the following steps:

[0055] S1. Electric furnace smelting: prepare raw materials by weight percentage, place the raw materials in an electric furnace, and smelt until the temperature reaches 1580°C to obtain molten steel;

[0056] S2. Refining outside the furnace: The whole process is protected by argon. The molten steel obtained in step S1 is placed in a LF furnace, refined for 55 min, and then vacuum degassed for 28 min, and then cast into a steel ingot. The vacuum degree during vacuum degassing is 25 Pa; the temperature of the molten steel during casting is 1420 ° C;

[0057] S3 electroslag remelting: The steel ingot obtained in step S2 is placed in an electroslag furnace for electroslag remelting to obtain an electroslag ingot. During the electroslag remelting process, the melting rate is 8kg / min and the cooling rate is 10°C / h;

[0058] S4. Forging: The electroslag ingot obtained in step S3 is subjected to upsetting and drawing by a hydraulic press to obtain a forging, the cutting ratio of the electroslag ingot head is 6%, the cutting ratio of the electroslag ingot tail is 3%, the initial forging temperature is 1170°C, the final forging temperature is 790°C, and the total forging ratio is 3.2;

[0059] S5. Heat treatment: The forging obtained in step S4 is subjected to solution treatment in an industrial resistance furnace at a temperature of 1075°C and a holding time of 1.6 min / mm, and then placed in a cooling pool for quenching to room temperature to obtain a Z2CN19-10+N2 forging for nuclear power. During quenching, the cooling pool is filled with a coolant, which is composed of the following components by weight percentage: 8.5% of C3-glycidyloxypropylmethyldiethoxysilane, 5% of 3-bromopropyl sodium sulfonate, 4% of triethanolamine, 3% of propylene glycol monobutyl ether, and the remainder of water;

[0060] S6. Testing: Perform physical and chemical testing and nondestructive testing on the Z2CN19-10+N2 forgings for nuclear power obtained in step S5.

[0061] The steps of preparing the coolant are as follows:

[0062] The components were prepared according to weight percentage, C3-glycidyloxypropylmethyldiethoxysilane and propylene glycol monomethyl ether were added into water, stirred at 200 rpm until uniformly mixed, then 3-bromopropane sodium sulfonate and triethanolamine were added, and stirring was continued for 1 hour to obtain a coolant.

[0063] Example 4

[0064] Z2CN19-10+N2 forgings for nuclear power are composed of the following components in weight percentage: C 0.02%, Si0.98%, Mn 2.00%, P 0.030%, S 0.015%, Cr 19.00%, Ni 9.00%, Cu 0.90%, Bi0.0014%, N 0.07%, Co 0.05%, Nb 0.06%, Ta 0.10%, and the rest is iron.

[0065] The manufacturing method of embodiment 4 comprises the following steps:

[0066] S1. Electric furnace smelting: prepare raw materials by weight percentage, place the raw materials in an electric furnace, and smelt until the temperature reaches 1610°C to obtain molten steel;

[0067] S2. Refining outside the furnace: The whole process is protected by argon. The molten steel obtained in step S1 is placed in a LF furnace. After refining for 50 min, it is vacuum degassed for 25 min and then cast into a steel ingot. The vacuum degree during vacuum degassing is 18 Pa. The temperature of the molten steel during casting is 1450 ° C.

[0068] S3 electroslag remelting: The steel ingot obtained in step S2 is placed in an electroslag furnace for electroslag remelting to obtain an electroslag ingot. During the electroslag remelting process, the melting rate is 10kg / min and the cooling rate is 10°C / h;

[0069] S4. Forging: The electroslag ingot obtained in step S3 is subjected to upsetting and drawing by a hydraulic press to obtain a forging, the cutting ratio of the electroslag ingot head is 6%, the cutting ratio of the electroslag ingot tail is 3%, the initial forging temperature is 1200°C, the final forging temperature is 820°C, and the total forging ratio is 3;

[0070] S5. Heat treatment: The forging obtained in step S4 is subjected to solution treatment in an industrial resistance furnace at a temperature of 1090°C and a holding time of 1.6 min / mm, and then placed in a cooling pool for quenching to room temperature to obtain a Z2CN19-10+N2 forging for nuclear power. During quenching, a coolant is contained in the cooling pool, and the coolant is composed of the following components by weight percentage: 10% C3-glycidyloxypropylmethyldiethoxysilane, 6% sodium 3-bromopropane sulfonate, 2% triethanolamine, 4.5% propylene glycol monobutyl ether, and the rest water;

[0071] S6. Testing: Perform physical and chemical testing and nondestructive testing on the Z2CN19-10+N2 forgings for nuclear power obtained in step S5.

[0072] The steps of preparing the coolant are as follows:

[0073] The components were prepared according to weight percentage, C3-glycidyloxypropylmethyldiethoxysilane and propylene glycol monomethyl ether were added into water, stirred at 150 rpm until uniformly mixed, then 3-bromopropane sodium sulfonate and triethanolamine were added, and stirring was continued for 1 hour to obtain a coolant.

[0074] Comparative Example 1

[0075] The composition of the forging is: C 0.021%, Si 0.95%, Mn 1.96%, P 0.028%, S 0.014%, Cr18.80%, Ni 9.60%, Cu 0.94%, Bi 0.0014%, N 0.06%, Co 0.04%, Nb 0.07%, Ta0.08%, and the rest is iron; its manufacturing method is the same as that of Example 1. The difference from Example 1 is that the content of the C element in Comparative Example 1 is higher than the range defined by the present invention.

[0076] Comparative Example 2

[0077] The composition of the forging is: C 0.01%, Si 0.95%, Mn 1.96%, P 0.028%, S 0.014%, Cr18.80%, Ni 9.60%, Cu 0.94%, Bi 0.0014%, N 0.049%, Co 0.04%, Nb 0.07%, Ta0.08%, and the rest is iron; the manufacturing method is the same as that of Example 1. The difference from Example 1 is that the content of the N element in Comparative Example 2 is lower than the range defined by the present invention.

[0078] Comparative Example 3

[0079] The composition of the forging is the same as that of Example 1. The difference from Example 1 is that step S5 does not include a solution treatment operation.

[0080] Comparative Example 4

[0081] The composition of the forging is the same as that of Example 1. The difference from Example 1 is that the coolant in the cooling pool is replaced with water in step S5.

[0082] Experimental Example 1: Intergranular Corrosion Resistance Test

[0083] The forgings prepared in Examples 1-4 and Comparative Examples 1-3 were evaluated for intergranular corrosion according to Method E in GB / T 4334-2008, and the intergranular corrosion performance in the sensitized state (sensitization treatment at 650° C. for 2 h) was measured. The test results are shown in Table 1.

[0084] Example 1 The intergranular corrosion performance in the sensitized state (sensitized at 650℃ for 2h) is qualified Example 2 The intergranular corrosion performance in the sensitized state (sensitized at 650℃ for 2h) is qualified Example 3 The intergranular corrosion performance in the sensitized state (sensitized at 650℃ for 2h) is qualified Example 4 The intergranular corrosion performance in the sensitized state (sensitized at 650℃ for 2h) is qualified Comparative Example 1 After sensitization at 650℃ for 2h, cracks due to intergranular corrosion were found. Comparative Example 2 After sensitization at 650℃ for 2h, cracks due to intergranular corrosion were found. Comparative Example 3 After sensitization at 650℃ for 2h, cracks due to intergranular corrosion were found.

[0085] Table 1

[0086] As can be seen from Table 1, the intergranular corrosion performance of Examples 1-4 in the sensitized state (sensitization treatment at 650°C for 2h) is qualified, indicating that the Z2CN19-10+N2 forgings for nuclear power prepared by the present invention have good intergranular corrosion resistance. Compared with Example 1, Comparative Examples 1, 2, and 3 all have cracks caused by intergranular corrosion after sensitization treatment at 650°C for 2h, indicating that the operations of reducing the C element content, increasing the N element content, and adding a solid solution treatment before quenching adopted by the present invention can effectively improve the intergranular corrosion resistance of the forgings.

[0087] Experimental Example 2: Hardenability Test

[0088] The forgings prepared in Examples 1-4 and Comparative Example 4 were tested for terminal hardenability according to GB / T 225-2006 “Terminal quenching test method for hardenability of steel (Jominy test)”. The test results are shown in Table 2.

[0089] Hardness 15mm from the quenched end (HRC) Example 1 33.5 Example 2 31.5 Example 3 33 Example 4 32.5 Comparative Example 4 28

[0090] Table 2

[0091] As can be seen from Table 2, the hardness of Examples 1-4 at 15 mm from the quenching end is relatively high, indicating that the Z2CN19-10+N2 forgings for nuclear power prepared by the present invention have good hardenability. Compared with Example 1, the hardness of Comparative Example 4 at 15 mm from the quenching end is reduced, indicating that the coolant used in the present invention can effectively improve the hardenability of the forging.

[0092] Experimental Example 3: Mechanical Properties Test

[0093] The Z2CN19-10+N2 forgings for nuclear power prepared in Examples 1-4 were subjected to room temperature tensile tests respectively. The room temperature tensile tests were carried out with reference to the provisions of MC1000. The sample size was φ10 mm. The test results are shown in Table 3.

[0094] Rp0.2(MPa) Rm(MPa) Specified value ≥210 520-800 Example 1 228 554 Example 2 222 543 Example 3 231 562 Example 4 225 550

[0095] Table 3

[0096] It can be seen from Table 3 that Rp0.2 and Rm of Examples 1-4 all meet the specified value requirements, indicating that the Z2CN19-10+N2 forgings for nuclear power prepared by the present invention have good mechanical properties.

[0097] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A Z2CN19-10+N2 forging for nuclear power, characterized in that: Calculated by weight percentage, it is composed of the following components: C 0.01-0.02%, Si 0.90-1.00%, Mn 1.90-2.00%, P≤0.030%, S≤0.015%, Cr 18.50-20.00%, Ni 9.00-10.00%, Cu 0.90-1.00%, Bi≤0.0015%, N 0.05-0.08%, Co 0.04-0.05%, Nb 0.05-0.08%, Ta 0.07-0.10%, and the rest is iron.

2. The method for manufacturing a Z2CN19-10+N2 forging for nuclear power according to claim 1, characterized in that: The following steps are involved: S1. Electric furnace smelting: Prepare the raw materials by weight percentage, place the raw materials in an electric furnace, and smelt until the temperature reaches 1570-1610°C to obtain molten steel; S2 refining outside the furnace: the molten steel obtained in step S1 is placed in a LF furnace, refined for 50-70min, vacuum degassing for 25-35min, and then cast into an ingot billet; S3. Electroslag remelting: The steel ingot obtained in step S2 is placed in an electroslag furnace and electroslag remelted to obtain an electroslag ingot; S4 forging: The electroslag ingot obtained in step S3 is subjected to upsetting and drawing by a hydraulic press to obtain a forging; S5. Heat treatment: The forging obtained in step S4 is subjected to solution treatment and then placed in a cooling pool and quenched to room temperature to obtain a Z2CN19-10+N2 forging for nuclear power; S6. Testing: Perform physical and chemical testing and nondestructive testing on the Z2CN19-10+N2 forgings for nuclear power obtained in step S5.

3. The method for manufacturing a Z2CN19-10+N2 forging for nuclear power according to claim 2, characterized in that: In the step S2, the whole refining process outside the furnace is protected by argon gas, and the vacuum degree during vacuum degassing is 15-25Pa; the temperature of the molten steel during pouring is 1400-1450°C.

4. The method for manufacturing a Z2CN19-10+N2 forging for nuclear power according to claim 2, characterized in that: In the step S3, during the electroslag remelting process, the melting rate is 7-10 kg / min and the cooling rate is 10-15° C. / h.

5. The method for manufacturing a Z2CN19-10+N2 forging for nuclear power according to claim 2, characterized in that: In the step S4, the cutting ratio of the ingot head of the electroslag ingot is 6%, the cutting ratio of the ingot tail of the electroslag ingot is 3%, the initial forging temperature is 1160-1200°C, the final forging temperature is 780-820°C, and the total forging ratio is ≥3.

6. The method for manufacturing a Z2CN19-10+N2 forging for nuclear power according to claim 2, characterized in that: In step S5, the solution treatment is performed in an industrial resistance furnace, the temperature of the solution treatment is 1070-1090° C., and the holding time is calculated as 1.6 min / mm.

7. The method for manufacturing a Z2CN19-10+N2 forging for nuclear power according to claim 2, characterized in that: In the step S6, during quenching, the cooling pool is filled with a coolant, which is composed of the following components by weight percentage: 8-10% C3-glycidyloxypropylmethyldiethoxysilane, 5-8% sodium 3-bromopropane sulfonate, 2-4% triethanolamine, 3-5% propylene glycol monobutyl ether, and the rest is water.

8. The method for manufacturing a Z2CN19-10+N2 forging for nuclear power according to claim 7, characterized in that: The preparation steps of the cooling liquid are: Prepare each component according to weight percentage, add C3-glycidyloxypropylmethyldiethoxysilane and propylene glycol monomethyl ether into water, stir until mixed evenly, then add 3-bromopropane sodium sulfonate and triethanolamine, and continue stirring for 1-2 hours to obtain a coolant.

9. The method for manufacturing a Z2CN19-10+N2 forging for nuclear power according to claim 8, characterized in that: In the step of preparing the cooling liquid, the stirring speed is 100-200 rpm.