阅读说明：本技术 一种核电设备用钢制环锻件的锻造方法 (Forging method of steel ring forging for nuclear power equipment ) 是由 承天洋 唐广林 孙峰 承刚 张伟 卢迅 汪凯 于 2019-11-06 设计创作，主要内容包括：本发明公开了一种核电设备用钢制环锻件的锻造方法,包括以下步骤：S1：采用电炉冶炼及炉外精炼制造钢锭；S2：第一次锻造；S3：第二次锻造；S4：锻后预热处理；S5：淬火；S6：回火;S7：产品力学性能检测；S8：无损检测按EN10228-3规定对产品进行超声波无损检测；S9：锻后精加工。(The invention discloses a forging method of a steel ring forging for nuclear power equipment, which comprises the following steps: s1: manufacturing steel ingots by electric furnace smelting and external refining; s2: forging for the first time; s3: forging for the second time; s4: preheating treatment after forging; s5: quenching; s6: tempering, S7: detecting the mechanical property of the product; s8: nondestructive testing the product according to EN 10228-3; s9: and (5) finishing after forging.)

1. A forging method of a steel ring forging for nuclear power equipment is characterized by comprising the following steps:

s1: the steel ingot is manufactured by adopting electric furnace smelting and external refining, wherein the chemical components are controlled in the following mass percent: c: less than or equal to 0.06 percent; si: less than or equal to 0.75 percent; mn: less than or equal to 1.55 percent; p: less than or equal to 0.030 percent; s: less than or equal to 0.015 percent; ni: 3.5-4.8%; cr: 12.0-15.0%; mo: 0.32-0.73%; n: 0.020-0.3%, and the balance of iron and non-removable impurities;

s2: the first forging, wherein the forging initial forging temperature is 1250 ℃, the finish forging temperature is 950 ℃, and the forging ratio of the main section part of the forging is more than or equal to 3.5;

s3: forging for the second time, wherein the forging initial forging temperature is 1250 ℃, the finish forging temperature is 900 ℃, and the forging ratio of the main section part of the forging is more than or equal to 3;

s4: preheating treatment after forging, heating at an initial temperature of more than or equal to 230 ℃, heating to 850 ℃ at a heating rate of more than or equal to 60 ℃/h, and keeping the temperature for 3 hours;

s5: quenching, namely heating to 930-1060 ℃, preserving heat for 4-5 hours, then carrying out water quenching for 360 seconds by adopting water with the water temperature of 20-45 ℃, and then carrying out oil cooling;

s6: tempering, namely firstly heating to 550-650 ℃, preserving heat for 2-3 hours, and then cooling in air;

s7: detecting the mechanical property of the product, taking the average value of 3 Charpy V-shaped notch samples, wherein the mechanical property of the samples accords with the requirement

Detecting unqualified products and carrying out heat treatment again, wherein the heat treatment times are not more than two;

s8: nondestructive testing the product according to EN 10228-3;

s9: and (5) finishing after forging.

2. The forging method of the steel ring forging for nuclear power equipment as claimed in claim 1, wherein the mechanical property detection in step S7 includes a tensile test, an impact test and a hardness test.

3. The forging method of the steel ring forging for the nuclear power equipment as claimed in claim 1, wherein the mechanical property detection in the step S7 meets the regulations of GB/T2975 mechanical property test and sampling position of steel and steel products and sample preparation.

4. The forging method of the steel ring forging for nuclear power equipment as claimed in claim 2, wherein the tensile test is performed according to GB/T228.1.

5. The forging method of the steel ring forging for nuclear power equipment as claimed in claim 2, wherein the impact test is performed according to the GB/T229 specification.

6. The forging method of the steel ring forging for nuclear power equipment as claimed in claim 2, wherein the hardness test is performed according to GB/T231.1.

Technical Field

The invention relates to a forging method of a steel ring forging for nuclear power equipment.

Background

The metal material for the nuclear power plant usually works under the working conditions of high temperature, high pressure, strong corrosion and strong irradiation, has extremely high requirements on the material, usually meets the requirements of various properties such as nuclear performance, mechanical property, chemical property, physical property, irradiation performance, process performance, economy and the like, and meets the requirements of special standard regulations, and the materials commonly used in the industry at present are carbon steel, alloy steel, stainless steel, nickel-based alloy and the like. However, the conventional forging method is adopted to treat the materials, so that the materials are difficult to forge, as-cast metallurgical defects such as segregation, porosity, shrinkage cavity and the like remain in the forged piece in different degrees, so that the forged piece generates larger stress concentration in the heat treatment process, the forged piece is cracked in the heat treatment process or the placing process after the heat treatment is finished, or the effective service life of the parts in service is reduced due to the existence of internal stress. In addition, the radiation resistance of the material is difficult to meet the requirement of the steel for nuclear power plants. Therefore, the method is particularly important for detecting the forged products of the forged forgings of nuclear power equipment.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a forging method of a steel ring forging for nuclear power equipment.

In order to achieve the purpose, the technical scheme of the invention is to design a forging method of a steel ring forging for nuclear power equipment, which comprises the following steps:

s1: the steel ingot is manufactured by adopting electric furnace smelting and external refining, wherein the chemical components are controlled in the following mass percent: c: less than or equal to 0.06 percent; si: less than or equal to 0.75 percent; mn: less than or equal to 1.55 percent; p: less than or equal to 0.030 percent; s: less than or equal to 0.015 percent; ni: 3.5-4.8%; cr: 12.0-15.0%; mo: 0.32-0.73%; n: 0.020-0.3%, and the balance of iron and non-removable impurities;

s2: the first forging, wherein the forging initial forging temperature is 1250 ℃, the finish forging temperature is 950 ℃, and the forging ratio of the main section part of the forging is more than or equal to 3.5;

s3: forging for the second time, wherein the forging initial forging temperature is 1250 ℃, the finish forging temperature is 900 ℃, and the forging ratio of the main section part of the forging is more than or equal to 3;

s4: preheating treatment after forging, heating at an initial temperature of more than or equal to 230 ℃, heating to 850 ℃ at a heating rate of more than or equal to 60 ℃/h, and keeping the temperature for 3 hours;

s5: quenching, namely heating to 930-1060 ℃, preserving heat for 4-5 hours, then carrying out water quenching for 360 seconds by adopting water with the water temperature of 20-45 ℃, and then carrying out oil cooling;

s6: tempering, namely firstly heating to 550-650 ℃, preserving heat for 2-3 hours, and then cooling in air;

s7: detecting the mechanical property of the product, taking the average value of 3 Charpy V-shaped notch samples, wherein the mechanical property of the samples accords with the requirement

，

Detecting unqualified products and carrying out heat treatment again, wherein the heat treatment times are not more than two;

s8: nondestructive testing the product according to EN 10228-3;

s9: and (5) finishing after forging.

In a further improvement, the mechanical property test in step S7 includes a tensile test, an impact test and a hardness test.

The further improvement is that the mechanical property detection product in the step S7 should meet the regulation of GB/T2975 steel and steel product mechanical property test and sampling position and sample preparation.

In a further development, the tensile test is carried out in accordance with GB/T228.1.

It is further improved that the impact test is performed according to the GB/T229 specification.

In a further development, the hardness test is carried out in accordance with GB/T231.1.

The invention has the advantages and beneficial effects that: the chromium content is increased, the corrosion resistance of the forge piece is improved, the nickel content is increased, the strength and the toughness of the forge piece are effectively improved, in addition, a new mechanical property detection method is adopted after the forge piece is forged, the forge piece completely meets the requirements of nuclear power metal, and the product quality is ensured.

Detailed Description

The following further describes embodiments of the present invention with reference to examples. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

The invention discloses a forging method of a steel ring forging for nuclear power equipment, which comprises the following steps:

s1: the steel ingot is manufactured by adopting electric furnace smelting and external refining, wherein the chemical components are controlled in the following mass percent: c: less than or equal to 0.06 percent; si: less than or equal to 0.75 percent; mn: less than or equal to 1.55 percent; p: less than or equal to 0.030 percent; s: less than or equal to 0.015 percent; ni: 3.5-4.8%; cr: 12.0-15.0%; mo: 0.32-0.73%; n: 0.020-0.3%, and the balance of iron and non-removable impurities;

s2: the first forging, wherein the forging initial forging temperature is 1250 ℃, the finish forging temperature is 950 ℃, and the forging ratio of the main section part of the forging is more than or equal to 3.5;

s3: forging for the second time, wherein the forging initial forging temperature is 1250 ℃, the finish forging temperature is 900 ℃, and the forging ratio of the main section part of the forging is more than or equal to 3;

s4: preheating treatment after forging, heating at an initial temperature of more than or equal to 230 ℃, heating to 850 ℃ at a heating rate of more than or equal to 60 ℃/h, and keeping the temperature for 3 hours;

s5: quenching, namely heating to 930-1060 ℃, preserving heat for 4-5 hours, then carrying out water quenching for 360 seconds by adopting water with the water temperature of 20-45 ℃, and then carrying out oil cooling;

s6: tempering, namely firstly heating to 550-650 ℃, preserving heat for 2-3 hours, and then cooling in air;

s7: detecting the mechanical property of the product, taking the average value of 3 Charpy V-shaped notch samples, wherein the mechanical property of the samples accords with the requirement

，

Detecting unqualified products and carrying out heat treatment again, wherein the heat treatment times are not more than two;

s8: nondestructive testing the product according to EN 10228-3;

s9: and (5) finishing after forging.

The quenching and tempering heat preservation time is ensured to be sufficient, the time is determined according to the section size of the forged piece, the mechanical property detection is carried out after the performance heat treatment of the ring forged piece is finished, the surface processing is carried out after the mechanical property detection is finished, the flaw detection inspection requirement is met, the formal ultrasonic flaw detection is carried out, the finish machining is arranged after the flaw detection is qualified, and the surface of the forged piece is free from visible harmful defects such as cracks, interlayers, folding, slag inclusion and the like. If the defect exists, the grinding is allowed to be eliminated, but the grinding part needs to be smoothly transited, and the removal depth does not exceed 80 percent of the allowance.

The mechanical property detection in the step S7 includes a tensile test, an impact test and a hardness test. The mechanical property detection product is required to meet the regulation of GB/T2975 steel and steel product mechanical property test and sampling position and sample preparation when in sampling, the tensile test is executed according to the regulation of GB/T228.1, the impact test is executed according to the regulation of GB/T229, and the hardness test is executed according to the regulation of GB/T231.1.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the technical principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.