CN114289655A - Technology for eliminating ferrite of large-size austenitic stainless steel forging for high temperature - Google Patents
Technology for eliminating ferrite of large-size austenitic stainless steel forging for high temperature Download PDFInfo
- Publication number
- CN114289655A CN114289655A CN202111640724.9A CN202111640724A CN114289655A CN 114289655 A CN114289655 A CN 114289655A CN 202111640724 A CN202111640724 A CN 202111640724A CN 114289655 A CN114289655 A CN 114289655A
- Authority
- CN
- China
- Prior art keywords
- forging
- temperature
- equal
- technology
- ferrite
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000005242 forging Methods 0.000 title claims abstract description 147
- 229910000859 α-Fe Inorganic materials 0.000 title claims abstract description 35
- 238000005516 engineering process Methods 0.000 title claims abstract description 26
- 229910000963 austenitic stainless steel Inorganic materials 0.000 title claims abstract description 24
- 238000000034 method Methods 0.000 claims abstract description 42
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 40
- 239000010959 steel Substances 0.000 claims abstract description 40
- 238000010438 heat treatment Methods 0.000 claims abstract description 34
- 230000008569 process Effects 0.000 claims abstract description 26
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 15
- 238000003723 Smelting Methods 0.000 claims abstract description 8
- 239000006104 solid solution Substances 0.000 claims abstract description 8
- 238000001816 cooling Methods 0.000 claims abstract description 7
- 238000003754 machining Methods 0.000 claims abstract description 7
- 239000002994 raw material Substances 0.000 claims abstract description 7
- 239000000203 mixture Substances 0.000 claims abstract description 6
- 238000004321 preservation Methods 0.000 claims description 24
- 238000010304 firing Methods 0.000 claims description 13
- 229910052804 chromium Inorganic materials 0.000 claims description 6
- 229910052759 nickel Inorganic materials 0.000 claims description 6
- 230000002596 correlated effect Effects 0.000 claims description 5
- 238000005096 rolling process Methods 0.000 claims description 5
- 238000009987 spinning Methods 0.000 claims description 5
- 229910052750 molybdenum Inorganic materials 0.000 claims description 4
- 229910052710 silicon Inorganic materials 0.000 claims description 4
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 230000008030 elimination Effects 0.000 claims description 3
- 238000003379 elimination reaction Methods 0.000 claims description 3
- 239000012535 impurity Substances 0.000 claims description 3
- 229910052748 manganese Inorganic materials 0.000 claims description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims description 3
- 229910052717 sulfur Inorganic materials 0.000 claims description 3
- 230000001276 controlling effect Effects 0.000 claims description 2
- 238000011534 incubation Methods 0.000 claims description 2
- 230000000630 rising effect Effects 0.000 claims description 2
- 238000012546 transfer Methods 0.000 claims description 2
- 238000005204 segregation Methods 0.000 abstract description 8
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 7
- 230000007797 corrosion Effects 0.000 description 6
- 238000005260 corrosion Methods 0.000 description 6
- 239000011651 chromium Substances 0.000 description 5
- 238000001514 detection method Methods 0.000 description 5
- 229910001566 austenite Inorganic materials 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 3
- 239000000306 component Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000010587 phase diagram Methods 0.000 description 3
- 229910052708 sodium Inorganic materials 0.000 description 3
- 239000011734 sodium Substances 0.000 description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 206010070834 Sensitisation Diseases 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 229910052729 chemical element Inorganic materials 0.000 description 1
- 239000000110 cooling liquid Substances 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 239000008358 core component Substances 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000009863 impact test Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000008313 sensitization Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000007920 subcutaneous administration Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
Images
Landscapes
- Forging (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
The invention discloses a technology for eliminating ferrite of a large-size austenitic stainless steel forging for high temperature, which has the technical scheme key points that the technology comprises the following steps: step S1: smelting raw materials; step S2: forging and heating, comprising three steps: (1) preheating the forged piece in a furnace; (2) raising the temperature of the forge piece at a constant speed; (3) keeping the temperature of the forged piece; step S3: forging the forge piece, wherein the forging process comprises seven times of heating, and the step S4: heat treatment, comprising the following steps: (1) water treatment is carried out after forging; (2) performing mechanical rough machining on the forge piece; (3) solid solution process; step S5: the invention has the advantages of completely eliminating ferrite generated by composition segregation, uneven cooling speed and the like in the smelting process of a large steel ingot, improving various properties of the forging and prolonging the long service life of the forging.
Description
Technical Field
The invention relates to the technical field of stainless steel forging, in particular to a technology for eliminating ferrite of a large-size austenitic stainless steel forging for high temperature.
Background
Along with the development of comprehensive national power in China, the problem is that China has huge energy gaps, so that the requirement of the country on clean energy is increased day by day, and the independent manufacture of nuclear power heavy-duty container equipment powerfully ensures the energy safety of the country. Domestic nuclear power is developing towards a safer, more reliable and more efficient fourth-generation nuclear power reactor type, and the new reactor type puts higher requirements on equipment materials and mechanical properties. At present, the core component of the fourth generation nuclear reactor is mainly an austenitic stainless steel forging piece for high temperature. The component is in a liquid sodium cooling liquid, and in the high-temperature operation process, ferrite is transformed to generate a sodium corrosion phenomenon, so that nuclear power equipment is unstable in operation, and serious nuclear power accidents are caused.
The traditional austenitic stainless steel is a pure austenitic structure, the nickel equivalent is relatively improved, the chromium equivalent is reduced, carbides are easily separated out in the intergranular corrosion sensitization test process, a chromium-poor area is formed, the intergranular corrosion resistance is reduced, and the intergranular corrosion is unqualified. Secondly, no matter which smelting process is selected, the composition segregation exists in the process of molten steel casting and solidification, and the existence of the segregation enables the raw materials to locally form ferrite. For large-diameter steel ingots, whether electroslag ingots or electric furnace ingots, the local solidification rate is reduced during ingot casting, the segregation tendency of segregation elements is increased, ferrite is easily formed at the center of the steel ingot, and the ferrite is difficult to eliminate in the subsequent forging process.
Meanwhile, for the austenitic stainless steel forging piece used at high temperature, because strip-shaped ferrite exists in the austenitic steel structure, a large amount of hot cracks are easy to appear on the edge of the forging piece in the forging process. Therefore, how to solve the problem of the ferrite content of the austenitic stainless steel forging for high temperature affects the key operation safety factor of nuclear power equipment.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a technology for eliminating ferrite of a large-size forged piece made of austenitic stainless steel for high temperature, which has the advantages of completely eliminating the ferrite generated by composition segregation, uneven cooling speed and the like in the smelting process of a large steel ingot, improving various attributes of the forged piece and prolonging the long service life of the forged piece.
The technical purpose of the invention is realized by the following technical scheme:
a technology for eliminating ferrite of a high-temperature austenitic stainless steel large-specification forging is characterized by comprising the following steps:
step S1: smelting raw materials;
step S2: forging and heating, comprising three steps: (1) preheating the forged piece in a furnace; (2) raising the temperature of the forge piece at a constant speed; (3) keeping the temperature of the forged piece;
step S3: forging the forge piece, wherein the forging process comprises seven times of heating:
(1) the first fire time: the forging temperature is 1200-1230 ℃, the steel ingot is sequentially subjected to outer circle drawing and upsetting by light rolling, the final forging temperature is guaranteed to be more than or equal to 850 ℃, and then the forge piece is heated and kept warm;
(2) the second fire time: drawing out a forging piece at 1130-1160 ℃;
(3) the third fire time: upsetting the steel ingot, wherein the forging temperature is 1130-1160 ℃;
(4) the fourth fire time: drawing out a forging piece at 1140-1160 ℃;
(5) the fifth fire time: upsetting the steel ingot, wherein the forging temperature is 1140-1160 ℃;
(6) the sixth fire time: drawing out a forging piece at the forging temperature of 1120-1160 ℃;
(7) the seventh fire: upsetting a steel ingot by a flat plate, and then performing double-sided spinning upsetting at the forging temperature of 1120-1160 ℃;
step S4: heat treatment, comprising the following steps:
(1) water treatment after forging: and after the forging of the forge piece is finished, quickly introducing water, wherein the transport time is less than or equal to 90S, and cooling the forge piece to room temperature by water.
(2) Performing mechanical rough machining on the forge piece;
(3) solid solution process; the heat preservation time in the solid solution process is positively correlated with the thickness of the forged piece, and the heat preservation time of the forged piece with the thickness of 1mm is 1.5-2.4 min; after the heat preservation is finished, the mixture is taken out of the furnace and is quickly transferred into water, and the transfer time is less than or equal to 3 min;
step S5: and performing mechanical finish machining on the forging.
Further, in the step S2, (1) the forge piece is put into a furnace for preheating, and the temperature of the forge piece in the furnace is ensured to be less than or equal to 500 ℃; (2) controlling the temperature rising rate of the forge piece to be less than 150 ℃/H; (3) carrying out heat preservation by stages, wherein the heat preservation temperature of the first stage is 850 ℃; the second stage incubation temperature was 1230 ℃.
Further, in the first heating of the step S3, the drawing ratio of the forge piece is more than 1.3; the upsetting ratio is more than 2.0; in the process of heating and heat preservation of the forge piece, the method comprises the following steps: heating the steel ingot in a forging heating furnace at 1230 +/-15 ℃ for more than or equal to 90h, and heating in the second stage: and cooling the forging to 1160 +/-15 ℃ for heat preservation.
Furthermore, in the second firing of step S3, the finish forging temperature is not less than 850 ℃, the FM method is used for drawing, and the drawing ratio is more than 2.2.
Furthermore, in the third firing of the step S3, the final forging temperature is more than or equal to 850 ℃, the upper and lower flat plates are upset, and the upset ratio is more than 2.2.
Furthermore, in the fourth firing of the step S3, the finish forging temperature is more than or equal to 850 ℃, the upper and lower flat anvil method is used for drawing, and the drawing ratio is more than 2.2.
Furthermore, in the fifth firing of the step S3, the final forging temperature is more than or equal to 850 ℃, the upper and lower flat plates are upset, and the upset ratio is more than 2.2.
Furthermore, in the sixth firing of the step S3, the finish forging temperature is more than or equal to 850 ℃, the upper and lower flat anvil method is used for drawing, and the drawing ratio is more than 2.2.
Further, in the seventh firing of step S3, the finish forging temperature is not less than 800 ℃ and the total upset ratio is more than 4.5.
A large-size forged piece of austenitic stainless steel for high temperature use.
By adopting the technical scheme, the material comprises the following elements in percentage by weight: c: 0.04-0.05%, Mn: 1.5-1.9%, P: not more than 0.002%, S not more than 0.003%, Si: 0.2-0.5%, Cr: 17.1-17.6%, Ni: 11.5-12.5%, Mo: 2.5-3.0%, Cu: less than or equal to 0.1 percent, B: less than or equal to 0.0018 percent, V: 0.03-0.05%, Co: less than or equal to 0.05 percent, Nb + Ta: less than or equal to 0.15 percent, O: less than or equal to 35ppm, H: less than or equal to 5ppm, and the balance of Fe and impurities.
In conclusion, the invention has the following beneficial effects:
1. the forging temperature is set near the phase equilibrium temperature point of austenite phase and high-temperature ferrite phase, the high-temperature diffusion is carried out for a long time, the composition segregation is improved, simultaneously, the high-temperature ferrite is converted into austenite, the ferrite is effectively eliminated, the risk of forging cracking caused by the ferrite is reduced, and the sodium liquid corrosion resistance of the material forging under the high-temperature operation working condition is ensured due to the elimination of the ferrite, so that the product percent of pass is greatly improved.
2. According to the invention, the contents of C, Cr, Ni, Si, V, Mo and N are adjusted according to a phase diagram and the equivalent content of chromium and nickel, so that the raw materials are guaranteed to be pure austenite, and through an EF + AOD/VOD + ESR smelting process, the purity of the steel ingot is greatly improved, the gas content is accurately controlled, and the comprehensive mechanical property of the product is effectively improved.
3. According to the invention, through the forging high-temperature long-time heating step, the free ferrite structure in the steel ingot is effectively reduced, and the forging performance of the steel ingot is optimized;
4. according to the invention, by forging, high-temperature long-time heating and matching with multi-fire three-dimensional deformation, the component segregation can be reduced, and the residual ferrite can be effectively eliminated.
5. The forging method comprises seven heating times, wherein the first heating time enables the surface structure of the steel ingot to be changed into a forging state from an as-cast state, the subcutaneous defect is eliminated, and the hot processing performance of the steel ingot is guaranteed.
6. The invention improves the internal quality of the steel by multiple-fire-number large-deformation forging and large-forging-ratio deformation, and eliminates as-cast structure. The internal structure of the forging is uniform, and the anisotropy of the performance of the forging is eliminated.
7. The invention controls the heating and finish forging temperature between fire times and the deformation of each fire time to enable the grain size of the forged piece to be finer. The grain refinement of the forging can improve various properties such as toughness and fatigue resistance, thereby prolonging the service life;
8. in the performance heat treatment step, the internal structure is more uniform through high-temperature solid solution, the precipitated phase is fully solid-dissolved, the performance of the forge piece is improved, and the intergranular corrosion resistance is ensured.
Drawings
FIG. 1 is a schematic representation of the steps of a ferrite elimination technique for large size forgings of austenitic stainless steel for high temperature use;
fig. 2 is a simulation of the equilibrium temperature point of austenitic stainless steel for high temperature.
FIG. 3 is a microscopic micrograph of a forging.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the following detailed description of the present invention is provided with reference to the accompanying drawings and the detailed description. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are all used in a non-precise scale for the purpose of facilitating and distinctly aiding in the description of the embodiments of the present invention. To make the objects, features and advantages of the present invention comprehensible, reference is made to the accompanying drawings. It should be understood that the structures, ratios, sizes, and the like shown in the drawings and described in the specification are only used for matching with the disclosure of the specification, so as to be understood and read by those skilled in the art, and are not used to limit the implementation conditions of the present invention, so that the present invention has no technical significance, and any structural modification, ratio relationship change or size adjustment should still fall within the scope of the present invention without affecting the efficacy and the achievable purpose of the present invention.
Example 1:
a technology for eliminating ferrite of a large-specification austenitic stainless steel forging for high temperature comprises the following steps as shown in figure 1:
step S1: and (4) smelting the raw materials. Specifically, the raw material is subjected to EF + AOD/VOD + ESR treatment process. The forging comprises the following chemical elements in percentage by weight: c: 0.04-0.05%, Mn: 1.5-1.9%, P: not more than 0.002%, S not more than 0.003%, Si: 0.2-0.5%, Cr: 17.1-17.6%, Ni: 11.5-12.5%, Mo: 2.5-3.0%, Cu: less than or equal to 0.1 percent, B: less than or equal to 0.0018 percent, V: 0.03-0.05%, Co: less than or equal to 0.05 percent, Nb + Ta: less than or equal to 0.15 percent, O: less than or equal to 35ppm, H: less than or equal to 5ppm, and the balance of Fe and impurities. As shown in fig. 2, the actual chemical components of the steel ingot are fitted with a phase diagram by using Jmat software, and the equilibrium temperature point of the austenite phase and the high-temperature ferrite phase can be calculated from the phase diagram.
Step S2: forging and heating. The method specifically comprises the following steps: (1) preheating the forge piece in a furnace, and ensuring the temperature of the forge piece in the furnace to be less than or equal to 500 ℃; (2) raising the temperature of the forge piece at a constant speed, wherein the temperature raising rate of the forge piece is controlled to be less than 150 ℃/H; (3) the forging is subjected to heat preservation by stages, and the heat preservation temperature of the first stage is 850 ℃; the heat preservation temperature of the second stage is 1230 ℃, the heat preservation time of each heat preservation stage is positively correlated with the thickness of the steel ingot, and the steel ingot with the thickness of 100mm is heated for 1.5-2 hours.
Step S3: forging the forge piece, wherein the forging process comprises seven times of heating:
(1) the first fire time: the forging temperature is 1200 ℃, the steel ingot is sequentially subjected to slight rolling and external circle drawing and upsetting, the finish forging temperature is guaranteed to be more than or equal to 850 ℃, and the drawing ratio of the forge piece is more than 1.3; the upsetting ratio is more than 2.0. Then heating and heat preservation are carried out on the forged piece, and the method comprises the following steps: heating the steel ingot in a forging heating furnace at 1230 +/-15 ℃ for more than or equal to 90h, and heating in the second stage: and cooling the forging to 1160 +/-15 ℃ for heat preservation, wherein the heating time in the second stage is positively correlated with the thickness of the steel ingot, and the steel ingot with the thickness of 100mm is heated for 1.5-2 h.
(2) The second fire time: drawing out the forging piece at 1130 deg.c and final forging temperature not lower than 850 deg.c, and drawing out by FM process in the drawing out ratio higher than 2.2.
(3) The third fire time: upsetting the steel ingot, wherein the forging temperature is 1130 ℃, the finish forging temperature is more than or equal to 850 ℃, upsetting the upper flat plate and the lower flat plate, and the upsetting ratio is more than 2.2.
(4) The fourth fire time: drawing out the forging piece, wherein the forging temperature is 1140 ℃, the finish forging temperature is more than or equal to 850 ℃, drawing out by an upper and lower flat anvil method, and the drawing-out ratio is more than 2.2.
(5) The fifth fire time: upsetting the steel ingot, wherein the forging temperature is 1140 ℃, the final forging temperature is more than or equal to 850 ℃, upsetting the upper flat plate and the lower flat plate, and the upsetting ratio is more than 2.2.
(6) The sixth fire time: drawing out the forging piece, wherein the forging temperature is 1120 ℃, the finish forging temperature is more than or equal to 850 ℃, drawing out by an upper and lower flat anvil method, and the drawing-out ratio is more than 2.2.
(7) The seventh fire: upsetting a steel ingot by a flat plate, then carrying out double-sided spinning upsetting, wherein the forging temperature is 1120 ℃, the finish forging temperature is more than or equal to 800 ℃, and the total upsetting ratio is more than 4.5.
Step S4: heat treatment, comprising the following steps:
(1) water treatment after forging: after the forging of the forging piece is finished, the forging piece is quickly immersed in water, and the interval time from the discharging of the forging piece to the immersion of the forging piece is less than or equal to 3 min; the water temperature of the cooling water is less than or equal to 30 ℃, the forging is cooled in the flowing water, the transport time is less than or equal to 90S, and the forging is cooled to room temperature by water.
(2) And carrying out mechanical rough machining on the forge piece.
(3) Solid solution process; the heat preservation time in the solid solution process is positively correlated with the thickness of the forged piece, and the heat preservation time of the forged piece with the thickness of 1mm is 1.5-2.4 min; and (4) after the heat preservation is finished, discharging from the furnace and rapidly transferring into water, wherein the transferring time is less than or equal to 3 min.
Step S5: and performing mechanical finish machining on the forging.
Example 2:
the procedure differs from example 1 in that:
step S3: forging the forge piece, wherein the forging process comprises seven times of heating:
(1) the first fire time: the forging temperature is 1220 ℃, the steel ingot is sequentially subjected to slight rolling and external circle drawing and upsetting, the final forging temperature is guaranteed to be more than or equal to 850 ℃, and then the forge piece is heated and kept warm;
(2) the second fire time: drawing the forging to be long, wherein the forging temperature is 1140 ℃.
(3) The third fire time: and upsetting the steel ingot, wherein the forging temperature is 1140 ℃.
(4) The fourth fire time: drawing out the forging piece at 1150 deg.c.
(5) The fifth fire time: upsetting the steel ingot, wherein the forging temperature is 1150 ℃.
(6) The sixth fire time: drawing the forging to be long, wherein the forging temperature is 1140 ℃.
(7) The seventh fire: upsetting a steel ingot by a flat plate, then carrying out double-sided spinning upsetting, wherein the forging temperature is 1140 ℃.
Example 3:
the procedure differs from example 1 in that:
step S3: forging the forge piece, wherein the forging process comprises seven times of heating:
(1) the first fire time: the forging temperature is 1230 ℃, the steel ingot is sequentially subjected to light rolling and external circle drawing and upsetting, the final forging temperature is guaranteed to be more than or equal to 850 ℃, and then the forge piece is heated and kept warm;
(2) the second fire time: drawing the forging to length at 1160 ℃.
(3) The third fire time: upsetting the steel ingot, wherein the forging temperature is 1160 ℃.
(4) The fourth fire time: drawing the forging to length at 1160 ℃.
(5) The fifth fire time: upsetting the steel ingot, wherein the forging temperature is 1160 ℃.
(6) The sixth fire time: drawing the forging to length at 1160 ℃.
(7) The seventh fire: upsetting a steel ingot by a flat plate, and then performing double-sided spinning upsetting at the forging temperature of 1160 ℃.
Comprehensive mechanical detection of the forged piece:
experimental groups: two samples were randomly drawn from the examples as experimental groups. The standard is as follows: ASME SA-965.
1. And (3) impact test: the results are shown in Table 1.
TABLE 1
2. And (3) hardness detection: the results are shown in Table 2.
TABLE 2
3. And (3) detecting the room temperature performance: the results are shown in Table 3.
| Yield strength | Tensile strength | Elongation after fracture | Reduction of area | |
| Acceptance requirements | ≥226Mpa | ≥515Mpa | 35 | 35 |
| Experimental group 1 | 285.8 | 567.8 | 68.5 | 83.0 |
| Experimental group 2 | 288.7 | 570.9 | 67.5 | 83.0 |
TABLE 3
4. And (3) detecting the performance at 350 ℃: the results are shown in Table 4.
TABLE 4
4. Performance detection at 450 ℃: the results are shown in Table 5.
| Yield strength | Tensile strength | Elongation after fracture | Reduction of area | |
| Acceptance requirements | ≥121Mpa | ≥410Mpa | - | - |
| Experimental group 1 | 164.7 | 464.4 | 53.0 | 76.0 |
| Experimental group 2 | 159.3 | 464.4 | 53.0 | 76.0 |
TABLE 5
4. And (3) detecting the performance at 550 ℃: the results are shown in Table 6.
| Yield strength | Tensile strength | Elongation after fracture | Reduction of area | |
| Acceptance requirements | ≥116Mpa | ≥396Mpa | - | - |
| Experimental group 1 | 148.3 | 441.3 | 53.0 | 73.0 |
| Experimental group 2 | 156.6 | 445.9 | 56.5 | 75.0 |
TABLE 6
4. And (3) performance detection at 580 ℃: the results are shown in Table 7.
| Yield strength | Tensile strength | Elongation after fracture | Reduction of area | |
| Acceptance requirements | ≥114Mpa | ≥376Mpa | - | - |
| Experimental group 1 | 156.8 | 428.4 | 53.5 | 75.0 |
| Experimental group 2 | 152.2 | 422.0 | 56.0 | 76.0 |
TABLE 7
Microscopic detection of the forged piece:
magnification: 300 times.
And (4) conclusion: as shown in fig. 3, the ferrite content was 0% under an electron microscope of 300 times, and no cracks were seen in the alloy structure.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A technology for eliminating ferrite of a high-temperature austenitic stainless steel large-specification forging is characterized by comprising the following steps:
step S1: smelting raw materials;
step S2: forging and heating, comprising three steps: (1) preheating the forged piece in a furnace; (2) raising the temperature of the forge piece at a constant speed; (3) keeping the temperature of the forged piece;
step S3: forging the forge piece, wherein the forging process comprises seven times of heating:
(1) the first fire time: the forging temperature is 1200-1230 ℃, the steel ingot is sequentially subjected to outer circle drawing and upsetting by light rolling, the final forging temperature is guaranteed to be more than or equal to 850 ℃, and then the forge piece is heated and kept warm;
(2) the second fire time: drawing out a forging piece at 1130-1160 ℃;
(3) the third fire time: upsetting the steel ingot, wherein the forging temperature is 1130-1160 ℃;
(4) the fourth fire time: drawing out a forging piece at 1140-1160 ℃;
(5) the fifth fire time: upsetting the steel ingot, wherein the forging temperature is 1140-1160 ℃;
(6) the sixth fire time: drawing out a forging piece at the forging temperature of 1120-1160 ℃;
(7) the seventh fire: upsetting a steel ingot by a flat plate, and then performing double-sided spinning upsetting at the forging temperature of 1120-1160 ℃;
step S4: heat treatment, comprising the following steps:
(1) water treatment after forging: and after the forging of the forge piece is finished, quickly introducing water, wherein the transport time is less than or equal to 90S, and cooling the forge piece to room temperature by water.
(2) Performing mechanical rough machining on the forge piece;
(3) solid solution process; the heat preservation time in the solid solution process is positively correlated with the thickness of the forged piece, and the heat preservation time of the forged piece with the thickness of 1mm is 1.5-2.4 min; after the heat preservation is finished, the mixture is taken out of the furnace and is quickly transferred into water, and the transfer time is less than or equal to 3 min;
step S5: and performing mechanical finish machining on the forging.
2. The technology for eliminating the ferrite of the large-size austenitic stainless steel forging for high temperature according to claim 1, wherein the technology comprises the following steps: in the step S2, (1) placing the forge piece into a furnace for preheating, and ensuring that the temperature of the forge piece in the furnace is less than or equal to 500 ℃; (2) controlling the temperature rising rate of the forge piece to be less than 150 ℃/H; (3) carrying out heat preservation by stages, wherein the heat preservation temperature of the first stage is 850 ℃; the second stage incubation temperature was 1230 ℃.
3. The technology for eliminating the ferrite of the large-size austenitic stainless steel forging for high temperature according to claim 1, wherein the technology comprises the following steps: in the first firing of step S3, the drawing ratio of the forging is more than 1.3; the upsetting ratio is more than 2.0; in the process of heating and heat preservation of the forge piece, the method comprises the following steps: heating the steel ingot in a forging heating furnace at 1230 +/-15 ℃ for more than or equal to 90h, and heating in the second stage: and cooling the forging to 1160 +/-15 ℃ for heat preservation.
4. The technology for eliminating the ferrite of the large-size austenitic stainless steel forging for high temperature according to claim 1, wherein the technology comprises the following steps: in the second firing of step S3, the finish forging temperature is not less than 850 ℃, the FM method is used for drawing, and the drawing ratio is more than 2.2.
5. The technology for eliminating the ferrite of the large-size austenitic stainless steel forging for high temperature according to claim 1, wherein the technology comprises the following steps: in the third firing of step S3, the final forging temperature is more than or equal to 850 ℃, the upper and lower flat plates are upset, and the upset ratio is more than 2.2.
6. The technology for eliminating the ferrite of the large-size austenitic stainless steel forging for high temperature according to claim 1, wherein the technology comprises the following steps: in the fourth firing of step S3, the finish forging temperature is more than or equal to 850 ℃, the upper and lower flat anvil method is used for drawing, and the drawing ratio is more than 2.2.
7. The technology for eliminating the ferrite of the large-size austenitic stainless steel forging for high temperature according to claim 1, wherein the technology comprises the following steps: in the fifth firing of step S3, the final forging temperature is not less than 850 ℃, the upper and lower flat plates are upset, and the upset ratio is more than 2.2.
8. The technology for eliminating the ferrite of the large-size austenitic stainless steel forging for high temperature according to claim 1, wherein the technology comprises the following steps: in the sixth firing of step S3, the finish forging temperature is not less than 850 ℃, the upper and lower flat anvil method is used for drawing, and the drawing ratio is more than 2.2.
9. The technology for eliminating the ferrite of the large-size austenitic stainless steel forging for high temperature according to claim 1, wherein the technology comprises the following steps: in the seventh firing of step S3, the finish forging temperature is more than or equal to 800 ℃, and the total upsetting ratio is more than 4.5.
10. The forging prepared by the ferrite elimination technology of the austenitic stainless steel large-size forging for high temperature according to any one of claims 1-9, wherein the forging comprises the following components in percentage by weight: comprises the following elements in percentage by weight: c: 0.04-0.05%, Mn: 1.5-1.9%, P: not more than 0.002%, S not more than 0.003%, Si: 0.2-0.5%, Cr: 17.1-17.6%, Ni: 11.5-12.5%, Mo: 2.5-3.0%, Cu: less than or equal to 0.1 percent, B: less than or equal to 0.0018 percent, V: 0.03-0.05%, Co: less than or equal to 0.05 percent, Nb + Ta: less than or equal to 0.15 percent, O: less than or equal to 35ppm, H: less than or equal to 5ppm, and the balance of Fe and impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111640724.9A CN114289655B (en) | 2021-12-29 | 2021-12-29 | Ferrite elimination technology for austenitic stainless steel large-specification forge piece for high temperature |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111640724.9A CN114289655B (en) | 2021-12-29 | 2021-12-29 | Ferrite elimination technology for austenitic stainless steel large-specification forge piece for high temperature |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114289655A true CN114289655A (en) | 2022-04-08 |
| CN114289655B CN114289655B (en) | 2024-02-27 |
Family
ID=80971276
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111640724.9A Active CN114289655B (en) | 2021-12-29 | 2021-12-29 | Ferrite elimination technology for austenitic stainless steel large-specification forge piece for high temperature |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114289655B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005146303A (en) * | 2003-11-11 | 2005-06-09 | Sanyo Special Steel Co Ltd | Method for manufacturing curburized steel superior in grain-coarsening resistance after high temperature carburizing |
| JP2017013075A (en) * | 2015-06-26 | 2017-01-19 | 新日鐵住金株式会社 | Production method for martensitic stainless steel tube |
| CN111558680A (en) * | 2020-06-22 | 2020-08-21 | 无锡派克新材料科技股份有限公司 | Manufacturing method of large-section F53 solid forging |
| CN112024798A (en) * | 2020-08-25 | 2020-12-04 | 无锡继平锻造有限公司 | Forging and machining process of rear pipe forging for special ship |
| CN112893510A (en) * | 2021-03-05 | 2021-06-04 | 无锡继平锻造有限公司 | Forging and heat treatment process of marine corrosion-resistant pull rod duplex stainless steel forging |
| CN112941410A (en) * | 2021-01-29 | 2021-06-11 | 无锡市法兰锻造有限公司 | Method for controlling alpha phase content in austenitic stainless steel |
| CN113025793A (en) * | 2021-03-05 | 2021-06-25 | 无锡继平锻造有限公司 | High-purity fine-grain stainless steel forging and forging treatment process |
-
2021
- 2021-12-29 CN CN202111640724.9A patent/CN114289655B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005146303A (en) * | 2003-11-11 | 2005-06-09 | Sanyo Special Steel Co Ltd | Method for manufacturing curburized steel superior in grain-coarsening resistance after high temperature carburizing |
| JP2017013075A (en) * | 2015-06-26 | 2017-01-19 | 新日鐵住金株式会社 | Production method for martensitic stainless steel tube |
| CN111558680A (en) * | 2020-06-22 | 2020-08-21 | 无锡派克新材料科技股份有限公司 | Manufacturing method of large-section F53 solid forging |
| CN112024798A (en) * | 2020-08-25 | 2020-12-04 | 无锡继平锻造有限公司 | Forging and machining process of rear pipe forging for special ship |
| CN112941410A (en) * | 2021-01-29 | 2021-06-11 | 无锡市法兰锻造有限公司 | Method for controlling alpha phase content in austenitic stainless steel |
| CN112893510A (en) * | 2021-03-05 | 2021-06-04 | 无锡继平锻造有限公司 | Forging and heat treatment process of marine corrosion-resistant pull rod duplex stainless steel forging |
| CN113025793A (en) * | 2021-03-05 | 2021-06-25 | 无锡继平锻造有限公司 | High-purity fine-grain stainless steel forging and forging treatment process |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114289655B (en) | 2024-02-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112893510B (en) | Forging and heat treatment process of marine corrosion-resistant pull rod duplex stainless steel forging | |
| CN103352175B (en) | A kind of control nitrogen austenitic stainless steel and manufacture method thereof | |
| CN112695255B (en) | Preparation method of ferrite martensite steel clad tube | |
| CN113235030B (en) | Preparation method of large-size GH4169 high-temperature alloy bar | |
| CN113088790B (en) | C-Mn high-strength steel forging and heat treatment process for welded structural part | |
| CN109136653A (en) | For the nickel-base alloy of nuclear power generating equipment and its manufacturing method of hot rolled plate | |
| CN112024798A (en) | Forging and machining process of rear pipe forging for special ship | |
| CN110468348B (en) | 022Cr19Ni10 stainless steel flange for nuclear power station and manufacturing method thereof | |
| CN109402514A (en) | A kind of dedicated hot stamping die steel HS7 and preparation method thereof | |
| CN109112423A (en) | Special thick alloy-steel plate of a kind of superior low-temperature toughness and preparation method thereof | |
| CN113025793A (en) | High-purity fine-grain stainless steel forging and forging treatment process | |
| CN106756509B (en) | A kind of high-temperature alloy structural steel and its Technology for Heating Processing | |
| CN102409258B (en) | Structural homogeneity control method of boron-containing high strength hydrogen resistant brittle alloy | |
| CN113430455A (en) | High-strength austenitic stainless steel resistant to liquid lead (lead bismuth) corrosion and preparation method thereof | |
| CN113235014A (en) | High-performance silicon-containing ferrite/martensite steel | |
| CN110484836B (en) | Hafnium zirconium titanium molybdenum reinforced austenitic stainless steel and preparation method thereof | |
| CN115896419A (en) | Preparation method and application of GH2132 alloy bar | |
| CN115449595A (en) | Method for improving annealing structure uniformity of H13 hot work die steel | |
| CN113523164B (en) | Forging and heat treatment process for high-strength forging of marine rudder system | |
| KR101630403B1 (en) | Manufacture method of nuclear fuel component made of zirconium applied multi-stage cold rolling | |
| CN102059271A (en) | Manufacture method of seamless steel tube for (ultra-)supercritical boiler | |
| CN114289655B (en) | Ferrite elimination technology for austenitic stainless steel large-specification forge piece for high temperature | |
| CN115121993A (en) | Preparation method of high-performance nickel-based alloy welding wire | |
| CN114147156A (en) | Manufacturing method of ultralow-temperature 304L forge piece | |
| CN114032375A (en) | Processing method of super 13Cr stainless steel forged material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |