Production and forging process of high-strength large-section stainless steel

Abstract

The invention discloses a production forging process of high-strength large-section stainless steel, which relates to the technical field of stainless steel production, and comprises the following steps: blank preparation and rough forging: firstly preparing a steel billet required by stainless steel production, and then adding the prepared steel billet; iron, titanium, nickel, zinc, chromium, manganese, molybdenum, copper, silicon, niobium, nitrogen and carbon are prepared into steel billets according to a certain proportion, solution treatment is carried out, so that the structural components of the stainless steel are uniformly distributed, work hardening is eliminated, the corrosion resistance of the stainless steel is improved, then heat treatment is carried out on the stainless steel, the hardness of the stainless steel is reduced, the strength of the stainless steel is improved, and the stainless steel is higher in flexibility; and finally, the stainless steel subjected to heat treatment is subjected to fine treatment, the hydrogen embrittlement reaction of the stainless steel is eliminated through the fine treatment, the stainless steel is not prone to breakage in the machining process, the quality of the stainless steel is guaranteed, and the stainless steel is higher in strength, plasticity and corrosion resistance through mutual cooperation of the treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of stainless steel production, and particularly relates to a production forging process of high-strength large-section stainless steel. Background Art

[0002] Stainless steel, the full name of which is stainless acid-resistant steel, refers to a series of steel types with high chemical stability in air, water, aqueous solutions of salts, acids, and other corrosive media; it is an alloy steel containing more than 13% chromium, and some also contain other elements such as nickel and titanium. Due to its excellent performance, stainless steel is widely used in many fields such as construction, medical treatment, food, aviation, and industry.

[0003] However, due to the differences in the production process and material ratio of existing stainless steel, the strength of some stainless steel is insufficient, which does not meet the production conditions for certain products with high strength requirements. Moreover, the distribution of each component of stainless steel is not uniform enough, resulting in quality differences after producing related products. At the same time, this type of stainless steel is relatively brittle and prone to cracking during the production of related products, thus leading to product scrapping.

[0004] Therefore, a production forging process of high-strength large-section stainless steel is proposed to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a production forging process of high-strength large-section stainless steel to solve the problems of insufficient strength and uneven distribution of each component of existing stainless steel.

[0006] To achieve the above purpose, the present invention provides the following technical solution: A production forging process of high-strength large-section stainless steel, including the following steps:

[0007] S1: Preparation and rough forging of the blank: First, prepare the steel blank required for stainless steel production, and then heat the prepared steel blank. When heating, the heating temperature rises evenly. After the steel blank is heated to 800 degrees Celsius, it is kept warm for one hour, and then the steel blank is taken out for forging to form the steel blank. After the steel blank is forged into shape, it is placed in a heating device for heat preservation. After three hours of heat preservation, the next step is carried out;

[0008] S2: Fine forging and solution treatment of stainless steel: After heat preservation, take out the roughly forged stainless steel, and carry out fine forging through stamping equipment to stamp the stainless steel blank into the required size. After fine forging is completed, put the forged stainless steel into a heating device for heating. After heating to the set temperature, keep it warm for a period of time, and then take out the stainless steel and put it into a solid solution for rapid cooling. After solution treatment is completed, carry out the next operation;

[0009] S3: Heat treatment of stainless steel: After the billet is finely forged and solution-treated, it is placed in a heat treatment equipment for tempering. When performing the heat treatment of the billet, the billet needs to be heated to a set temperature in the heat treatment equipment and then held for a certain time. After the heat treatment is completed, it is allowed to cool naturally in the heat treatment equipment;

[0010] S4: Fine treatment of stainless steel: After the stainless steel is heat-treated, it is placed in a sandblasting device for sandblasting. After sandblasting, the stainless steel is put into an acidic solution for pickling. After pickling, the stainless steel is immersed in a coating solution for coating treatment. After coating treatment, wait for the stainless steel to dry completely. After drying is completed, the treated stainless steel is then put into a heating device, and the stainless steel is held at a constant temperature in a moving temperature for a period of time. After the treatment is completed, the stainless steel can be taken out;

[0011] S5: Determination of the strength of stainless steel: Before the stainless steel is finely forged and solution-treated, a part of the stainless steel is taken as a sample. After the stainless steel is treated, the treated stainless steel and the stainless steel before treatment are respectively subjected to strength tests and the strength data of the two are compared.

[0012] Preferably, the main components of the billet are iron, titanium, nickel, zinc, chromium, manganese, molybdenum, copper, silicon, niobium, nitrogen, and carbon. The percentages of each element of iron, titanium, nickel, zinc, chromium, manganese, molybdenum, copper, silicon, niobium, nitrogen, and carbon are 20% for iron, 5% for titanium, 4% for nickel, 22.8% for zinc, 20% for chromium, 5.5% for manganese, 0.3% for molybdenum, 1.5% for copper, 0.5% for silicon, 0.3% for niobium, 0.03% for nitrogen, and 0.07% for carbon.

[0013] Preferably, when the billet is finely forged and solution-treated, the heating temperature of the stainless steel is 1100 - 1200 degrees Celsius. When the stainless steel is heated, the heating temperature needs to rise evenly, and the rate of temperature rise is 300 - 400 degrees Celsius per hour. When the stainless steel is heated to the set temperature, the stainless steel is held at the set time for 1 - 2 hours. After heating is completed, the stainless steel is quickly put into a cooling medium for cooling.

[0014] Preferably, when the stainless steel is tempered, the tempering temperature of the stainless steel shall not exceed the AC1 line, and the heating temperature range is 600 - 650 degrees Celsius. After the stainless steel is heated to the specified temperature, the stainless steel is placed in a heating device and held for 8 - 10 hours. When the stainless steel is heated, the heating temperature needs to rise evenly, and the rate of temperature rise is 150 - 200 degrees Celsius per hour.

[0015] Preferably, when pickling the stainless steel, a mixed acid solution is used for pickling the stainless steel. Specifically, when operating, the components of the mixed acid solution adopted include pickling the steel billet with a mixed acid. The types of the mixed acid mainly include hydrofluoric acid, hydrochloric acid and nitric acid. The concentration of the hydrofluoric acid is 20%, the concentration of the hydrochloric acid is 25%, the concentration of the nitric acid is 16%, and the ratio of the hydrofluoric acid, hydrochloric acid and nitric acid is 1:1:1.

[0016] Preferably, after the stainless steel is coated, the coated and dried stainless steel needs to be placed in a heating device for continuous heating. When operating, the final heating temperature is 220 - 260 degrees Celsius. After heating to the set temperature, the stainless steel is placed in the heating device for heat preservation for 3 - 4 hours.

[0017] Preferably, when sandblasting the stainless steel, the sandblasting time is 12 - 14 hours. After sandblasting, the residual sand on its surface needs to be cleaned. After cleaning, it is first washed and dried, then processed again and then pickled. When pickling, the ratio of the mixed acid solution to water is 1:50, and the pickling time is 2 - 3 hours.

[0018] Preferably, after the stainless steel is sandblasted and before pickling after surface cleaning treatment, the surface of the stainless steel needs to be polished. After completion, the surface of the stainless steel is cleaned again. After cleaning is completed, pickling operation can be carried out.

[0019] Preferably, when the stainless steel is heat-treated, the air in the treatment device is discharged, and then nitrogen is filled into the heating device as a protective gas, and the stainless steel is heat-treated with nitrogen as the heating medium.

[0020] Preferably, when testing the strength of the stainless steel finished product and the untreated stainless steel sample, it needs to be detected under the same conditions. The weight and thickness of the stainless steel finished product and the untreated stainless steel sample are the same, and the detection temperature is the same. When detecting, the strength of the detection equipment increases at a uniform speed, and it is not advisable to adopt the method of first increasing the strength rapidly and then increasing the strength slowly. And the same testing device needs to be used during the test. The test data includes but is not limited to tensile strength and compressive strength.

[0021] In summary, the technical effects and advantages of the present invention:

[0022] In the present invention, a steel billet is made from iron, titanium, nickel, zinc, chromium, manganese, molybdenum, copper, silicon, niobium, nitrogen, and carbon in a certain proportion. After the steel billet is forged and formed, it is made into a stainless steel material through solution treatment, heat treatment, and fine treatment. During the above process, the solution treatment makes the organizational components of the stainless steel evenly distributed, eliminates work hardening at the same time, facilitates subsequent processing, and improves the corrosion resistance of the stainless steel. Then, the hardness of the stainless steel is reduced through heat treatment to increase the strength of the stainless steel, and the flexibility of the stainless steel is stronger. Finally, the heat-treated stainless steel is subjected to fine treatment, and the hydrogen embrittlement reaction of the stainless steel is eliminated through fine treatment, so that the stainless steel is not easily broken during the processing, ensuring the quality of the stainless steel. Through the cooperation of the above treatments, the stainless steel has higher strength, stronger plasticity and corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 It is a schematic diagram of the operation steps of a production forging process of a high-strength large-section stainless steel proposed by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0026] Example: Refer to Figure 1 A production forging process of a high-strength large-section stainless steel shown in the figure, including the following steps:

[0027] S1: Preparation and rough forging of the billet: First, prepare the steel billet required for stainless steel production, and then heat the prepared steel billet. When heating, the heating temperature rises evenly. After the steel billet is heated to 800 degrees Celsius, it is kept warm for one hour, and then the steel billet is taken out for forging to form the steel billet. After the steel billet is forged and formed, it is placed in a heating device for heat preservation. After three hours of heat preservation, the next step is carried out;

[0028] S2: Fine forging and solution treatment of stainless steel: After heat preservation, take out the roughly forged stainless steel, and perform fine forging through stamping equipment. Stamp the stainless steel billet into the required size. After fine forging is completed, put the forged stainless steel into a heating device for heating. After heating to the set temperature, keep it warm for a period of time. Then take out the stainless steel and put it into a solid solution for rapid cooling. After the solution treatment is completed, proceed to the next step;

[0029] S3: Heat treatment of stainless steel: After the steel billet is finely forged and solution-treated, place it in a heat treatment equipment for tempering treatment. When performing the heat treatment of the steel billet, it is necessary to heat the steel billet to the set temperature in the heat treatment equipment and then keep it warm. After the heat treatment is completed, let it cool naturally in the heat treatment equipment;

[0030] S4: Fine treatment of stainless steel: After the stainless steel is heat-treated, place it in a sandblasting device for sandblasting treatment. After sandblasting is completed, put the stainless steel into an acidic solution for pickling. After pickling is completed, immerse the stainless steel in a coating solution for coating treatment. After coating treatment, wait for the stainless steel to dry completely. After drying is completed, put the treated stainless steel into a heating device, and keep the stainless steel at a constant temperature in a moving temperature for a period of time. After the treatment is completed, the stainless steel can be taken out;

[0031] S5: Determination of the strength of stainless steel: Before the stainless steel is finely forged and solution-treated, take a part of the stainless steel as a sample. After the stainless steel is processed, perform strength tests on the processed stainless steel and the stainless steel before processing respectively, and compare the strength data of the two.

[0032] As a preferred implementation manner of this embodiment, the main components of the steel billet are iron, titanium, nickel, zinc, chromium, manganese, molybdenum, copper, silicon, niobium, nitrogen, and carbon. The percentages of each element of iron, titanium, nickel, zinc, chromium, manganese, molybdenum, copper, silicon, niobium, nitrogen, and carbon are 20% for iron, 5% for titanium, 4% for nickel, 22.8% for zinc, 20% for chromium, 5.5% for manganese, 0.3% for molybdenum, 1.5% for copper, 0.5% for silicon, 0.3% for niobium, 0.03% for nitrogen, and 0.07% for carbon.

[0033] As a preferred implementation manner of this embodiment, when the steel billet is finely forged and solution-treated, the heating temperature of the stainless steel is 1100 - 1200 degrees Celsius. When the stainless steel is heated, the heating temperature needs to rise evenly, and the rate of temperature rise is 300 - 400 degrees Celsius per hour. When the stainless steel is heated to the set temperature, keep the stainless steel at the set time for heat preservation for 1 - 2 hours. After heating is completed, quickly put the stainless steel into a cooling medium for cooling.

[0034] As a preferred implementation manner of this embodiment, when tempering the stainless steel, the tempering temperature of the stainless steel shall not exceed the AC1 line, and the heating temperature range is 600 - 650 degrees Celsius. After the stainless steel is heated to the specified temperature, the stainless steel is placed in a heating device and kept warm for 8 - 10 hours. When the stainless steel is heated, the heating temperature needs to rise evenly, and the rate of temperature rise is 150 - 200 degrees Celsius per hour.

[0035] As a preferred implementation manner of this embodiment, when pickling the stainless steel, a mixed acid solution is used to pickle the stainless steel. Specifically, the components of the mixed acid solution adopted include pickling the steel billet with a mixed acid. The types of the mixed acid mainly include hydrofluoric acid, hydrochloric acid, and nitric acid. The concentration of the hydrofluoric acid is 20%, the concentration of the hydrochloric acid is 25%, the concentration of the nitric acid is 16%, and the ratio of the hydrofluoric acid, hydrochloric acid, and nitric acid is 1:1:1.

[0036] As a preferred implementation manner of this embodiment, after the stainless steel is coated with a film, the stainless steel after the film is dried needs to be placed in a heating device and heated continuously. During this operation, the final heating temperature is 220 - 260 degrees Celsius. After heating to the set temperature, the stainless steel is placed in a heating device and kept warm for 3 - 4 hours.

[0037] As a preferred implementation manner of this embodiment, when sandblasting the stainless steel, the sandblasting time is 12 - 14 hours. After sandblasting, the residual sand on its surface needs to be cleaned. After cleaning, it is first washed and dried, then processed again and pickled. When pickling, the ratio of the mixed acid solution to water is 1:50, and the pickling time is 2 - 3 hours.

[0038] As a preferred implementation manner of this embodiment, after sandblasting the stainless steel, before cleaning its surface and before pickling treatment, the surface of the stainless steel needs to be polished. After completion, the surface of the stainless steel is cleaned again, and after cleaning is completed, pickling operation can be carried out.

[0039] As a preferred implementation manner of this embodiment, when heat-treating the stainless steel, the air in the treatment device is discharged, and then nitrogen is filled into the heating device as a protective gas, and the stainless steel is heat-treated with nitrogen as the heating medium.

[0040] As a preferred embodiment of this embodiment, when the strength test is carried out on the finished stainless steel product and the untreated stainless steel sample, it needs to be detected under the same conditions. The weight and thickness of the finished stainless steel product and the untreated stainless steel sample are the same, and the detection temperature is the same. During the detection, the strength of the detection equipment increases at a uniform speed. It is not advisable to adopt the method of first rapidly increasing the strength and then slowly increasing the strength. And the same testing device needs to be used during the test. The test data includes but is not limited to tensile strength and compressive strength.

[0041] Working principle of the present invention:

[0042] In the present invention, a steel billet is made from iron, titanium, nickel, zinc, chromium, manganese, molybdenum, copper, silicon, niobium, nitrogen, and carbon in a certain proportion. After the steel billet is forged and formed, it is made into stainless steel material through solution treatment, heat treatment, and fine treatment. During the above process, the solution treatment makes the tissue components of the stainless steel evenly distributed, eliminates work hardening at the same time, facilitates subsequent processing, and improves the corrosion resistance of the stainless steel. Then, the hardness of the stainless steel is reduced through heat treatment to improve the strength of the stainless steel, and the flexibility of the stainless steel is stronger. Finally, the heat-treated stainless steel is subjected to fine treatment to eliminate the hydrogen embrittlement reaction of the stainless steel, making the stainless steel not easy to break during the processing and ensuring the quality of the stainless steel. Through the cooperation of the above treatments, the stainless steel has higher strength, stronger plasticity and corrosion resistance.

[0043] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A production forging process for high-strength large-section stainless steel, characterized in that: The following steps are involved: S1: Billet preparation and rough forging: First, prepare the billet required for stainless steel production, then heat the prepared billet. During heating, the heating temperature rises evenly. After the billet is heated to 800 degrees Celsius, it is kept warm for one hour. Then, the billet is taken out for forging. After the billet is forged, it is placed in a heating device for heat preservation. After heat preservation for three hours, the next step is carried out. S2: Fine forging and solution treatment of stainless steel: After heat preservation, the roughly forged stainless steel is taken out and fine forged by stamping equipment to stamp the stainless steel billet into the required size. After fine forging is completed, the forged stainless steel is placed in a heating device for heating. After heating to the set temperature, it is kept warm for a period of time, and then the stainless steel is taken out and placed in a solid solution for rapid cooling. After the solution treatment is completed, the next step is carried out; S3: Heat treatment of stainless steel: After fine forging and solution treatment, the billet is placed in a heat treatment device for tempering. During the heat treatment of the billet, the billet needs to be heated to a set temperature in the heat treatment device and then kept warm. After the heat treatment is completed, it is allowed to cool naturally in the heat treatment device; S4 stainless steel fine treatment: After the stainless steel is heat treated, it is placed in a sandblasting device for sandblasting. After the sandblasting is completed, the stainless steel is placed in an acid solution for pickling. After the pickling is completed, the stainless steel is immersed in a coating solution for coating. After the coating treatment, the stainless steel is waited for to be completely dried. After the drying is completed, the treated stainless steel is placed in a heating device and placed in a moving temperature constant temperature treatment for a period of time. After the treatment is completed, the stainless steel can be taken out; S5: Determination of stainless steel strength: Before fine forging and solution treatment of stainless steel, take some stainless steel samples. After the stainless steel treatment is completed, perform strength tests on the treated stainless steel and the stainless steel before and after treatment respectively and compare the strength data of the two.

2. The production forging process of high-strength large-section stainless steel according to claim 1, characterized in that: The main components of the steel billet are iron, titanium, nickel, zinc, chromium, manganese, molybdenum, copper, silicon, niobium, nitrogen and carbon. The percentages of the elements are 20% for iron, 5% for titanium, 4% for nickel, 22.8% for zinc, 20% for chromium, 5.5% for manganese, 0.3% for molybdenum, 1.5% for copper, 0.5% for silicon, 0.3% for niobium, 0.03% for nitrogen and 0.07% for carbon.

3. The production forging process of high-strength large-section stainless steel according to claim 1, characterized in that: When the steel billet is subjected to fine forging and solution treatment, the stainless steel is heated to a temperature of 1100 to 1200 degrees Celsius. When the stainless steel is heated, the heating temperature needs to rise evenly, and the rate of temperature rise is 300 to 400 degrees Celsius per hour. When the stainless steel is heated to the set temperature, the stainless steel is kept warm for 1 to 2 hours in the set time. After the heating is completed, the stainless steel is quickly put into a cooling medium for cooling.

4. The production forging process of high-strength large-section stainless steel according to claim 1, characterized in that: When the stainless steel is tempered, the tempering temperature of the stainless steel shall not exceed the AC1 line, and the heating temperature range is 600 to 650 degrees Celsius. After the stainless steel is heated to the specified temperature, the stainless steel is placed in a heating device for insulation for 8 to 10 hours. When the stainless steel is heated, the heating temperature needs to rise evenly, and the temperature rise rate is 150 to 200 degrees Celsius per hour.

5. The production forging process of high-strength large-section stainless steel according to claim 1, characterized in that: When the stainless steel is pickled, a mixed acid solution is used to pickle the stainless steel. During the specific operation, the composition of the mixed acid solution includes pickling the steel billet with mixed acid. The types of mixed acid mainly include hydrofluoric acid, hydrochloric acid and nitric acid. The concentration of the hydrofluoric acid is 20%, the concentration of the hydrochloric acid is 25%, the concentration of the nitric acid is 16%, and the ratio of the hydrofluoric acid, hydrochloric acid and nitric acid is 1:1:

1.

6. A production forging process for high-strength large-section stainless steel according to claim 1, characterized in that: After the stainless steel is coated, the dried stainless steel needs to be placed in a heating device for further heating. During this operation, the final heating temperature is 220 to 260 degrees Celsius. After heating to the set temperature, the stainless steel is placed in the heating device for 3 to 4 hours to keep warm.

7. The production forging process of high-strength large-section stainless steel according to claim 1, characterized in that: When the stainless steel is sandblasted, the sandblasting time is 12 to 14 hours. After sandblasting, the residual sand on the surface needs to be cleaned. After cleaning, it is washed with water and dried, and then pickled again. During pickling, the ratio of mixed acid to water is 1:50, and the pickling time is 2 to 3 hours.

8. A production forging process for high-strength large-section stainless steel according to claim 7, characterized in that: After the stainless steel is sandblasted, its surface is cleaned and before pickling, the stainless steel surface needs to be polished. After completion, the stainless steel surface is cleaned again, and the pickling operation can be performed after cleaning.

9. The production forging process of high-strength large-section stainless steel according to claim 1, characterized in that: When the stainless steel is heat treated, the air in the treatment device is exhausted, and nitrogen is then filled into the heating device as a protective gas, and the stainless steel is heat treated using nitrogen as a heating medium.

10. The production forging process of high-strength large-section stainless steel according to claim 1, characterized in that: When the finished stainless steel product and the untreated stainless steel sample are subjected to strength tests, the tests need to be carried out under the same conditions, and the tested stainless steel product and the untreated stainless steel sample have the same weight, thickness, and test temperature. During the test, the strength of the testing equipment is increased at a uniform rate, and it is not appropriate to increase the strength quickly first and then slowly. The same testing device needs to be used during the test, and the test data include but are not limited to tensile strength and compressive strength.

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