CN113198956A - Forging method of austenitic stainless steel with ultrahigh silicon content - Google Patents
Forging method of austenitic stainless steel with ultrahigh silicon content Download PDFInfo
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- CN113198956A CN113198956A CN202110392391.6A CN202110392391A CN113198956A CN 113198956 A CN113198956 A CN 113198956A CN 202110392391 A CN202110392391 A CN 202110392391A CN 113198956 A CN113198956 A CN 113198956A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
- B21J5/002—Hybrid process, e.g. forging following casting
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J1/00—Preparing metal stock or similar ancillary operations prior, during or post forging, e.g. heating or cooling
- B21J1/06—Heating or cooling methods or arrangements specially adapted for performing forging or pressing operations
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
- B21J5/06—Methods for forging, hammering, or pressing; Special equipment or accessories therefor for performing particular operations
- B21J5/08—Upsetting
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C30/00—Alloys containing less than 50% by weight of each constituent
- C22C30/02—Alloys containing less than 50% by weight of each constituent containing copper
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of silicon
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/001—Austenite
Abstract
The invention discloses a forging method of austenitic stainless steel with ultrahigh silicon content, belonging to the technical field of hot processing of materials. The method comprises the following steps: (1) demolding the cast ingot at high temperature; (2) homogenizing the ingot at 1150-1180 ℃ for 25-50 h; (3) the initial forging temperature is 1100-; (4) and (3) constant-temperature forging: forging deformation adopts a mode of combining upsetting and drawing; and after the forging, quick air cooling or spray cooling is required. The forged high-silicon austenitic stainless steel alloy bar can avoid hot cracks caused by precipitated phases in the forging process, has high structure uniformity, and can effectively improve the structure of a subsequent deformed product.
Description
Technical Field
The invention relates to the technical field of hot processing of materials, in particular to a forging method of austenitic stainless steel with ultrahigh silicon content.
Background
The high-silicon austenitic stainless steel has excellent corrosion resistance in high-temperature concentrated sulfuric acid, and is mainly used for manufacturing industrial equipment in a high-temperature concentrated sulfuric acid environment, such as a steel plate for a sulfuric acid absorption tower lining, a concentrated sulfuric acid cooler, a pump, a pipeline and the like. The higher the Si content in the high-silicon austenitic stainless steel, the better the corrosion resistance, and can be used in a more severe service environment. However, at present, deformation parts such as pipelines, plates, forgings and the like in domestic sulfuric acid manufacturing equipment are mostly composed of low-end high-silicon austenitic stainless steel with the Si content of less than 5 wt.%, and products and production technologies of high-performance high-silicon austenitic stainless steel with the Si content of more than 6.0 wt.% are mainly monopolized by foreign manufacturers. This is because if Si > 5.0 wt.%, a brittle phase precipitates when the alloy is solidified and precipitated, and the brittle phase cannot be completely eliminated by the homogenization treatment at high temperature. And when the temperature is lower than 900 ℃, brittle phases such as G phase and sigma phase are easy to precipitate in the high-silicon austenitic stainless steel structure, and the grain boundary strength of the alloy is seriously weakened. If the hot working process is unreasonable in design, cracks are easy to appear during forging, hot rolling, hot extrusion and hot perforation, so that products are scrapped, and the qualification rate is low. This is the main reason why hot-worked parts of high silicon austenitic stainless steels with Si > 5.0 wt.% are less used in domestic equipment in the sulfuric acid industry in our country.
The forging process is the first hot-pressing process of the high-silicon austenitic stainless steel hot-deformed product, and directly influences the success or failure and the quality of the subsequent hot-processed product. However, the forging production of high-silicon austenitic stainless steel products with Si content more than 5.0 wt.% has serious problems, mainly including forging cracks and low yield, and the application of the high-silicon austenitic stainless steel variety with Si content of 5.0-7.0 wt.% in sulfuric acid production equipment in China is severely restricted. Therefore, the forging method suitable for the 5.0-7.0 wt.% Si high-silicon austenitic stainless steel is developed, the problems of hot cracks and low yield in the forging process are solved, the performance and structure requirements of subsequent reprocessing are met, and the method is a key problem which is urgently needed to be solved when the high-silicon austenitic stainless steel is applied to domestic sulfuric acid production equipment.
Disclosure of Invention
Aiming at the difficult problems of difficult forging, easy cracking, low yield and the like of the high-silicon austenitic stainless steel, the invention provides a forging method of the austenitic stainless steel with ultrahigh silicon content, which solves the problems of cracking, low yield and the like of the high-silicon austenitic stainless steel, forges a high-silicon austenitic stainless steel forging blank with uniform structure, good compactness and no microcrack, and meets the requirements of subsequent processing such as subsequent hot extrusion, hot rolling, hot perforation and the like.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a forging method of an austenitic stainless steel with an ultra-high silicon content, which uses a forging hammer or a press to forge an ingot of the austenitic stainless steel with a Si content of 5.0-7.0 wt.%, the forging process comprising the following steps:
(1) selecting raw materials: the raw material selection comprises alloy component selection, a smelting method and high-temperature demoulding treatment.
Selecting alloy components: selecting the chemical components (wt.%) of the austenitic stainless steel with ultrahigh Si content: c: 0.015-0.050%; cr: 14.00 to 20.00 percent; ni: 15.00-22.00%; si: 5.00-7.00%; mn: 0.50-2.00%; s is less than 0.010 percent; p is less than 0.025 percent; mo: 0.50-2.00%; cu: 0.50-1.50%; al is less than 0.10 percent; n is less than 0.02 percent; the balance of Fe. Basically covers the mainstream high-silicon austenitic stainless steel varieties at home and abroad, such as Sandvik SX, Zecor, UNSS32615 and other brands.
The smelting method comprises the following steps: and adopting a method of vacuum induction or electric furnace combined electroslag remelting to smelt the austenitic stainless steel ingot with the Si content of 5.0-7.0%.
And (3) high-temperature demolding: the high Si content in the alloy causes the alloy to precipitate brittle phases when solidified, and if cooled to room temperature, extreme casting stresses accumulate in the ingot, which leads to easy breakage or microcracking during demoulding. Therefore, after smelting the high-silicon austenitic stainless steel, demoulding at the temperature of 600-800 ℃, and then entering a heat treatment furnace for homogenization treatment. If the cast steel ingot cannot be forged immediately after homogenization treatment, the steel ingot needs to be rapidly air-cooled or spray-cooled, so that a large amount of precipitated phases are prevented from being precipitated.
(2) Homogenizing a steel ingot: the steel ingot demoulded at the high temperature needs to immediately enter a heat treatment furnace with 800-.
(3) Preparing the initial forging temperature of the steel ingot: after the steel ingot is subjected to high-temperature homogenization treatment, the steel ingot cannot be immediately forged. Because at higher temperatures, the heat generated during forging causes grain boundary remelting phenomena in the alloy. Therefore, the steel ingot after the high-temperature homogenization treatment needs to be cooled to the initial forging temperature for heat preservation treatment, wherein the initial forging temperature is 1100-1140 ℃, and the heat preservation time is 2-4 hours. And (3) reheating to the initial forging temperature of 1100-1140 ℃ at the temperature rise speed of 100-150 ℃/h during the forging of the steel ingot which is subjected to the high-temperature homogenization treatment and is cooled in the step 2), and keeping the temperature for 2-4 h.
(4) And (3) constant-temperature forging: after the ingot is taken out of the furnace, if the surface temperature drops too fast, the brittle phase of the rapidly precipitated phase can cause surface cracking and extends inwards, so that it is necessary to ensure that the surface temperature of the ingot cannot drop too fast, not less than 1000 ℃. Therefore, after the steel ingot is discharged from the furnace, the surface of the steel ingot needs to be paved with electric heating heat preservation asbestos. In the forging deformation process, in order to break coarse columnar crystals and strengthen alloy element diffusion, forging in a mode of upsetting-combining drawing-out is needed. Forging, upsetting deformation is carried out along the axis of the blank, the deformation is 20-40%, then drawing back to the original length, the single reduction is 40-100mm, when the final forging temperature is lower than 1000 ℃, the blank is required to be heated to 1100-1140 ℃ in a furnace returning mode, and after heat preservation is carried out for 0.5-1h, forging is carried out.
(5) Cooling after forging: after the steel ingot is forged, a high-power fan is needed for rapid cooling by a phoenix or spray cooling, so that the precipitated phase is prevented from rapidly growing and being precipitated in large quantity.
The invention has the following advantages:
compared with the prior art, the forging method of the austenitic stainless steel with the ultrahigh Si content has the following advantages: by utilizing the forging method of the austenitic stainless steel with ultrahigh Si content, the austenitic stainless steel with high Si content of 5.0-7.0 wt.% can be forged, even if precipitated phases exist in the structure, the cracking defect can not be generated in the forging process, and the forging structure is compact and uniform. The method has the advantages of wide applicability, simple operation, low requirement on equipment, easy large-scale industrial production and high yield.
Drawings
FIG. 1 shows a forged structure of a 100kg high-silicon austenitic stainless steel ingot in example 1.
FIG. 2 is a structure of a crack site of a 100kg high-silicon austenitic stainless steel ingot in comparative example 1.
FIG. 3 shows the structure of the crack site of a 100kg high-silicon austenitic stainless steel ingot in comparative example 2.
FIG. 4 shows the structure of the crack site of the 100kg high-silicon austenitic stainless steel ingot in comparative example 3.
FIG. 5 shows the ingot forged structure of 1000kg of the high-silicon austenitic stainless steel of example 2.
FIG. 6 shows a steel ingot forged structure of 1000kg of the high-silicon austenitic stainless steel of example 3.
Detailed Description
The present invention will be described in detail with reference to examples.
The invention provides a forging method suitable for high-silicon austenitic stainless steel with 5.0-7.0 wt.% of Si content, which comprises the following specific forging processes:
1) preparing raw materials: selecting the chemical components (wt.%) of the austenitic stainless steel with ultrahigh Si content: c: 0.015-0.050%; cr14.00-20.00%; ni: 15.00-22.00%; 5.00 to 7.00 percent of Si; 0.50 to 2.00 percent of Mn; s is less than 0.010 percent; p is less than 0.025 percent; 0.50 to 2.00 percent of Mo; 0.50 to 1.50 percent of Cu; al is less than 0.10 percent; n is less than 0.02 percent; the balance of Fe.
And adopting a method of vacuum induction or electric furnace combined electroslag remelting to smelt the austenitic stainless steel with the Si content of 5.0-7.0 wt.%.
2) And (3) high-temperature demolding: after smelting of the high-silicon austenitic stainless steel is finished, demoulding is carried out at the temperature of 600-800 ℃, and the high-silicon austenitic stainless steel is put into a heat treatment furnace for homogenization treatment. If the cast steel ingot cannot be forged immediately after homogenization treatment, the steel ingot needs to be rapidly air-cooled or spray-cooled, so that a large amount of precipitated phases are prevented from being precipitated.
3) In the step 2), homogenizing a steel ingot: the steel ingot demoulded at the high temperature needs to immediately enter a heat treatment furnace with 800-.
4) Preparing the initial forging temperature of the steel ingot: and cooling the steel ingot after the high-temperature homogenization treatment to the initial forging temperature, and carrying out heat preservation treatment at the initial forging temperature of 1100-1140 ℃ for 2-4 hours. And (3) reheating the steel ingot which is subjected to the high-temperature homogenization treatment in the step 2) to the initial forging temperature of 1100-1140 ℃ at the temperature rising speed of 100-.
5) And (3) constant-temperature forging: after the steel ingot is discharged from the furnace, the surface of the steel ingot needs to be paved with electric heating heat preservation asbestos. Forging by adopting a mode of upsetting and drawing out. Forging, upsetting deformation is carried out along the axis of the blank, the deformation is 20-40%, then drawing back to the original length, the single reduction is 40-100mm, and when the final forging temperature is lower than 1000 ℃, the blank must be returned to the furnace and heated.
6) Cooling after forging: after the steel ingot is forged, a high-power fan is needed for rapid cooling by a phoenix or spray cooling, so that the precipitated phase is prevented from rapidly growing and being precipitated in large quantity.
Example 1 and comparative examples 1-3:
100kg of high-silicon austenitic stainless steel cast ingot is smelted by vacuum induction combined with protective atmosphere electroslag, and is poured into 4 steel ingots of 100kg, the diameter of the steel ingots is 165mm, and the height of the steel ingots is 610 mm. The chemical composition of 4 ingots is shown in table 1.
TABLE 1
After the steel ingot smelting is finished, the steel ingots of the embodiment 1, the comparative examples 2 and the comparative examples 3 are demoulded at 800 ℃, and immediately enter a heat treatment furnace at 800 ℃ for homogenization treatment. The steel ingot of comparative example 1 was cooled to room temperature and demolded, and the steel ingot of comparative example 1 broke when demolded. 2) Homogenizing a steel ingot: the steel ingot of example 1, the steel ingot of comparative example 2 and the steel ingot of comparative example 3 are firstly insulated at 800 ℃ for 1h, and then are heated to 1170 ℃ at the heating rate of 150 ℃/h for homogenization treatment. The homogenization treatment time of the steel ingot in example 1 and comparative examples 2 and 3 is 25h, after the homogenization treatment of the comparative example 2 is finished, the steel ingot is directly and rapidly forged on an air forging hammer, upsetting and cogging are firstly carried out along the axis of the ingot, the deformation is 25%, then the ingot is pulled back to the original length, and the core part of the ingot is cracked in the process of pulling and forging. After the homogenization treatment of the steel ingots in the embodiment 1 and the steel ingots in the comparative example 3 is finished, the temperature is reduced to the initial forging temperature of 1130 ℃, and the temperature is kept for 2 hours.
In example 1, after the initial forging temperature of the steel ingot is prepared, the whole steel ingot is immediately covered by heat-preservation asbestos, and in comparative example 3, the steel ingot is not coated with asbestos. Then quickly forging on an air forging hammer, upsetting and cogging along the axis of the blank firstly, wherein the deformation is 25%, and then drawing back to the original length. The forging temperature is lower than 1000 ℃, the steel is returned to the furnace and heated again, the heating temperature is 1130 ℃, and the heat preservation is carried out for 0.5 h; and (3) after the steel ingot is taken out of the furnace, forging for the second fire time, paving heat preservation cotton immediately after the steel ingot of the steel ingot in example 1 is taken out of the furnace, and upsetting the steel ingot of 2 steel ingots by 30% again without wrapping asbestos outside the steel ingot of comparative example 3, and then drawing out and forging the steel ingot into a round bar with the diameter of 80 mm. And after the steel ingot is forged, rapidly cooling the steel ingot by a high-power fan. No cracking behavior was observed on the surface of the steel ingot of example 1# steel. After surface finish ultrasonic flaw detection, the steel ingot of example 1 has no internal cracks and coarse crystal defects. Comparative example 3 micro-cracks occurred on both the surface and the core. The process effect profiles of examples and comparative examples are shown in Table 2, and the structures of the forged bars of examples and comparative examples are shown in FIGS. 1 to 4.
TABLE 2 Process profiles for the examples and comparative examples
| High temperature demolding | Homogenization treatment | Temperature preparation for forging | Constant temperature forging | Ingot state | |
| Example 1 | Demoulding at 800 DEG C | 1170℃×25h | Cooling to 1130 deg.C | Heat preservation pad | Intact |
| Comparative example 1 | Demoulding at room temperature | Cracking of | |||
| Comparative example 2 | Demoulding at 800 DEG C | 1170℃×25h | Forging at 1170 DEG C | Core cracking | |
| Comparative example 3 | Demoulding at 800 DEG C | 1170℃×25h | Cooling to 1130 deg.C | Not keeping warm | Surface cracking |
Example 2
1) Preparing raw materials: 1000kg of high-silicon austenitic stainless steel cast ingots are smelted by adopting an electric furnace combined with protective atmosphere electroslag, and the diameters of the steel ingots are 406mm respectively. The alloy comprises the following components (wt%): c: 0.043 percent; cr: 18.30 percent; ni: 22.20 percent; si: 5.20 percent; mn: 1.20 percent; s is less than 0.0015 percent; p: 0.012%; mo: 0.96 percent; cu: 1.30 percent; al is less than 0.10 percent; n is less than 0.02 percent; the balance of Fe. Demoulding at 800 ℃ after the steel ingot smelting is finished, and immediately entering a 800 ℃ heat treatment furnace for homogenization treatment.
2) Homogenizing a steel ingot: only steel ingots are firstly kept at 800 ℃ for 2h, and then are heated to 1150 ℃ at the heating rate of 120 ℃/h for homogenization treatment, wherein the homogenization treatment time is 30 h.
3) Preparing the initial forging temperature of the steel ingot: after the homogenization treatment is finished, the furnace temperature is reduced to 1100 ℃ of the initial forging temperature before forging, and the temperature is kept for 3 h.
4) And (3) constant-temperature forging: after the heated blank is discharged from a furnace, the whole steel ingot is immediately covered by heat-insulating asbestos, then the steel ingot is forged on a 3000t hydraulic press, upsetting and cogging are firstly carried out along the axis of the blank, the deformation is 33%, then straightening is carried out, and drawing-out forging is carried out according to a square-octagonal forging mode. The steel ingot is directly forged into a 300mm octagonal ingot blank. In the forging process, a temperature measuring gun is adopted for temperature monitoring, and the steel is immediately returned to the furnace and reheated when the temperature is lower than 1000 ℃.
5) Carrying out furnace returning and heating: when the temperature is lower than 1000 ℃, the steel ingot is returned to the furnace and heated to 1100 ℃ again, and the temperature is kept for 1 h.
6) And (3) second-time constant-temperature forging: and after the steel ingot is discharged from the furnace, immediately paving heat preservation cotton. And (3) upsetting the steel ingot by about 38 percent again, drawing out the steel ingot blank with the size of 200mm by a square-octagonal forging mode, then returning to the furnace and heating, and repeating the step 5.
7) And (3) performing constant-temperature forging for the third fire time: after the 200mm octagonal ingot blank is discharged from the furnace, the ingot blank must be covered with heat-insulating cotton for protection due to long length. Directly drawing out a finished round bar with the length of 120mm according to a rolling forging mode.
8) Cooling after forging: after the steel ingot is forged, a high-power fan is needed for spray cooling, so that the precipitated phases are prevented from growing rapidly and precipitating in a large amount.
No cracking occurred during the forging of 1000kg of the high silicon austenitic stainless steel ingot with 5.20 wt.% Si content, no internal cracks were found after surface finish ultrasonic flaw detection, and the forged bar structure is shown in FIG. 5.
Example 3
1) Preparing raw materials: 1000kg of high-silicon austenitic stainless steel ingot ingots with the diameters of 406mm are smelted by adopting an electric furnace combined with protective atmosphere electroslag. The alloy comprises the following components: c: 0.043 percent; cr: 13.60 percent; ni: 16.70 percent; si: 6.75 percent; mn: 1.16 percent; s is less than 0.0015 percent; p: 0.012%; mo: 0.96 percent; cu: 0.92 percent; al is less than 0.10 percent; n is less than 0.02 percent; the balance of Fe. Demoulding at 700 ℃ after the steel ingot smelting is finished, and immediately entering a 800 ℃ heat treatment furnace for homogenization treatment.
2) Homogenizing a steel ingot: the steel ingot is firstly kept at 800 ℃ for 2h, and then is heated to 1170 ℃ at the heating rate of 100 ℃/h for homogenization treatment, wherein the homogenization treatment time is 50 h.
3) Preparing the initial forging temperature of the steel ingot: after the homogenization treatment is finished, the furnace temperature is reduced to 1100 ℃ of the initial forging temperature before forging, and the temperature is kept for 4 h.
4) And (3) constant-temperature forging: after the heated blank is discharged from a furnace, the whole steel ingot is immediately covered by heat-insulating asbestos, then the steel ingot is forged on a 3000t hydraulic press, upsetting and cogging are firstly carried out along the axis of the blank, the deformation is 26%, then straightening is carried out, a square steel ingot is forged, and in the forging process, an electric heating asbestos pad is adopted to carry out heat insulation on the surface of the steel ingot. Directly forging into 300mm octagonal ingot blanks. And in the forging process, monitoring the surface temperature of the steel ingot by using a temperature measuring gun, and immediately returning to the furnace and reheating when the temperature is lower than 1000 ℃.
5) Carrying out furnace returning and heating: when the temperature is lower than 1000 ℃, the steel ingot is returned to the furnace and heated to 1100 ℃ again, and the temperature is kept for 1.5 h; .
6) And (3) second-time constant-temperature forging: and after the steel ingot is discharged from the furnace, immediately paving heat preservation cotton. And upsetting the steel ingot by about 40% again, and drawing out the steel ingot to an octagonal forging blank with the diameter of 200mm according to a square-octagonal forging mode. Then the furnace is returned to heat, and the step 5 is repeated.
7) And (3) performing constant-temperature forging for the third fire time: after the heat preservation is finished, the octagonal ingot blank is discharged from the furnace and must be protected by electric heating heat preservation cotton. And upsetting the steel ingot by about 35% again, and drawing out the steel ingot to an octagonal forging blank with the diameter of 120mm according to a square-octagonal forging mode.
8) Cooling after forging: after the steel ingot is forged, a high-power fan is needed for rapid cooling by a phoenix or spray cooling, so that the precipitated phase is prevented from rapidly growing and being precipitated in large quantity.
9) No cracking behavior occurs in the forging process of 1000kg of the high-silicon austenitic stainless steel ingot with the Si content of 6.75 wt.%, and no internal crack and coarse crystal defects are found after surface finish ultrasonic flaw detection. Metallographic analysis revealed that the forged structure was uniform, as shown in FIG. 6.
Claims (6)
1. A forging method of austenitic stainless steel with ultrahigh silicon content is characterized in that: the method uses a forging hammer or a press to forge an austenitic stainless steel ingot with the Si content of 5.0-7.0 wt.%, and the forging process comprises the following steps:
1) preparing raw materials: demoulding at the temperature of 600-800 ℃ after the smelting of the cast steel ingot is finished, and then putting the cast steel ingot into a heat treatment furnace for homogenization treatment according to the step (2);
2) homogenizing a steel ingot: the homogenization treatment temperature of the steel ingot is 1150-1180 ℃, and the heat preservation time is 25-50 h; cooling to the initial forging temperature after the steel ingot is subjected to homogenization treatment, if the cast steel ingot cannot be immediately forged after the homogenization treatment, rapidly air-cooling or spray-cooling the steel ingot, and reheating to the initial forging temperature at the temperature rising speed of 150 ℃/h of 100-;
3) preparing the initial forging temperature of the steel ingot: after the temperature of the steel ingot reaches the initial forging temperature of 1100-1140 ℃, the heat preservation time is 2-4 h;
4) and (3) constant-temperature forging: discharging the heated blank in the step 3) out of a furnace for forging deformation, wherein the forging is upsetting deformation along the axial direction of the blank, the deformation is 20-40%, then drawing back to original length, the single reduction in the drawing process is 40-100mm, and the final forging temperature is more than 1000 ℃;
5) forging for multiple times: carrying out upsetting, drawing and forging on the blank for multiple times according to the operation process of the step 4) until the required specification is reached;
6) cooling after forging: and after the steel ingot is forged, rapidly cooling by air or spraying.
2. The forging method of ultra-high silicon content austenitic stainless steel as set forth in claim 1, wherein: the austenitic stainless steel with the ultrahigh Si content comprises the following chemical components in percentage by weight:
c: 0.015-0.050%; cr: 14.00 to 20.00 percent; ni: 15.00-22.00%; si: 5.00-7.00%; mn: 0.50-2.00%; s is less than 0.010 percent; p is less than 0.025 percent; mo: 0.50-2.00%; cu: 0.50-1.50%; al is less than 0.10 percent; n is less than 0.02 percent; the balance of Fe.
3. The forging method of ultra-high silicon content austenitic stainless steel as set forth in claim 1, wherein: in the step 1), the cast steel ingot is smelted by adopting a method of vacuum induction or electric furnace combined electroslag remelting.
4. The forging method of ultra-high silicon content austenitic stainless steel as set forth in claim 1, wherein: in the step 2), the steel ingot homogenizing treatment process comprises the following steps: firstly, heating the steel ingot demoulded at high temperature to 800-850 ℃ in a heating furnace at the heating speed of 100-150 ℃/h, and preserving the heat for 2-4 hours; then heating to 1150-1180 ℃ at a heating rate of 100-150 ℃/h, and keeping the temperature for 25-50 h.
5. The forging method of ultra-high silicon content austenitic stainless steel as set forth in claim 1, wherein: and 4) in the forging deformation process, heat preservation treatment is carried out on the blank by adopting heat preservation asbestos or an electrically heated asbestos sleeve.
6. The forging method of ultra-high silicon content austenitic stainless steel as set forth in claim 1, wherein: in the forging process of the steps (4) - (5), when the temperature of the blank is lower than 1000 ℃, the blank is returned to the furnace and heated to 1100-1140 ℃, and after heat preservation is carried out for 0.5-1h, forging is carried out.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113909462A (en) * | 2021-10-14 | 2022-01-11 | 浙江久立特材科技股份有限公司 | Rapid hot demolding method for cast ingot |
| CN113953420A (en) * | 2021-09-10 | 2022-01-21 | 安徽强兴精锻有限公司 | Forging process of alloy steel for ball pin seat |
| CN114367615A (en) * | 2022-01-18 | 2022-04-19 | 山西太钢不锈钢股份有限公司 | Forging method of S32760 super duplex stainless steel ingot |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080107559A1 (en) * | 2005-04-11 | 2008-05-08 | Yoshitaka Nishiyama | Austenitic stainless steel |
| CN102605285A (en) * | 2011-01-25 | 2012-07-25 | 宝山钢铁股份有限公司 | Austenitic stainless steel and method for manufacturing same |
| CN106756628A (en) * | 2017-01-06 | 2017-05-31 | 江苏星火特钢有限公司 | A kind of silicon nitrogenous austenitic stainless steel high and preparation method thereof |
| CN109355558A (en) * | 2018-11-01 | 2019-02-19 | 中广核研究院有限公司 | Austenitic stainless steel and preparation method thereof, application |
| CN111774511A (en) * | 2020-05-18 | 2020-10-16 | 中北大学 | Forging method of iron-manganese-aluminum austenitic steel ingot |
-
2021
- 2021-04-13 CN CN202110392391.6A patent/CN113198956B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080107559A1 (en) * | 2005-04-11 | 2008-05-08 | Yoshitaka Nishiyama | Austenitic stainless steel |
| CN102605285A (en) * | 2011-01-25 | 2012-07-25 | 宝山钢铁股份有限公司 | Austenitic stainless steel and method for manufacturing same |
| CN106756628A (en) * | 2017-01-06 | 2017-05-31 | 江苏星火特钢有限公司 | A kind of silicon nitrogenous austenitic stainless steel high and preparation method thereof |
| CN109355558A (en) * | 2018-11-01 | 2019-02-19 | 中广核研究院有限公司 | Austenitic stainless steel and preparation method thereof, application |
| CN111774511A (en) * | 2020-05-18 | 2020-10-16 | 中北大学 | Forging method of iron-manganese-aluminum austenitic steel ingot |
Non-Patent Citations (1)
| Title |
|---|
| 陈思含: "6%Si高硅奥氏体不锈钢固溶处理过程中bcc相的演变机制研究", 《金属学报》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113953420A (en) * | 2021-09-10 | 2022-01-21 | 安徽强兴精锻有限公司 | Forging process of alloy steel for ball pin seat |
| CN113909462A (en) * | 2021-10-14 | 2022-01-11 | 浙江久立特材科技股份有限公司 | Rapid hot demolding method for cast ingot |
| CN114367615A (en) * | 2022-01-18 | 2022-04-19 | 山西太钢不锈钢股份有限公司 | Forging method of S32760 super duplex stainless steel ingot |
| CN114367615B (en) * | 2022-01-18 | 2023-07-14 | 山西太钢不锈钢股份有限公司 | Forging method of S32760 super duplex stainless steel ingot |
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