CN111154961A - Method for manufacturing shaft forging and shaft forging manufactured by same - Google Patents
Method for manufacturing shaft forging and shaft forging manufactured by same Download PDFInfo
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- CN111154961A CN111154961A CN201911426271.2A CN201911426271A CN111154961A CN 111154961 A CN111154961 A CN 111154961A CN 201911426271 A CN201911426271 A CN 201911426271A CN 111154961 A CN111154961 A CN 111154961A
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- 238000005242 forging Methods 0.000 title claims abstract description 199
- 238000000034 method Methods 0.000 title claims abstract description 71
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 35
- 238000001816 cooling Methods 0.000 claims abstract description 80
- 238000010438 heat treatment Methods 0.000 claims abstract description 55
- 239000004576 sand Substances 0.000 claims abstract description 50
- 229910000831 Steel Inorganic materials 0.000 claims description 45
- 239000010959 steel Substances 0.000 claims description 45
- 238000004321 preservation Methods 0.000 claims description 30
- 230000007547 defect Effects 0.000 abstract description 27
- 229910052739 hydrogen Inorganic materials 0.000 abstract description 17
- 239000001257 hydrogen Substances 0.000 abstract description 17
- 238000005265 energy consumption Methods 0.000 abstract description 12
- 239000007789 gas Substances 0.000 abstract description 8
- 238000009792 diffusion process Methods 0.000 abstract description 7
- 238000010583 slow cooling Methods 0.000 abstract description 4
- 230000002349 favourable effect Effects 0.000 abstract 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 abstract 1
- 241000519995 Stachys sylvatica Species 0.000 description 34
- 230000000052 comparative effect Effects 0.000 description 19
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 13
- 238000001514 detection method Methods 0.000 description 10
- 230000000694 effects Effects 0.000 description 7
- 239000002893 slag Substances 0.000 description 6
- 150000002431 hydrogen Chemical class 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910000851 Alloy steel Inorganic materials 0.000 description 2
- 238000003723 Smelting Methods 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- YZCKVEUIGOORGS-UHFFFAOYSA-N Hydrogen atom Chemical compound [H] YZCKVEUIGOORGS-UHFFFAOYSA-N 0.000 description 1
- 229910000617 Mangalloy Inorganic materials 0.000 description 1
- QFGIVKNKFPCKAW-UHFFFAOYSA-N [Mn].[C] Chemical compound [Mn].[C] QFGIVKNKFPCKAW-UHFFFAOYSA-N 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 229910052729 chemical element Inorganic materials 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 238000002592 echocardiography Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 239000002932 luster Substances 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
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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
- C21D7/00—Modifying the physical properties of iron or steel by deformation
- C21D7/13—Modifying the physical properties of iron or steel by deformation by hot working
-
- 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
-
- 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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/28—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for plain shafts
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Forging (AREA)
Abstract
The invention provides a method for manufacturing a shaft forging, which is characterized in that the drawing-out and upsetting times, sequence, drawing-out ratio and upsetting ratio in the forging process are strictly controlled, and the conventional fluctuating isothermal slow cooling process is replaced by the air cooling and sand cooling heat treatment process, so that the method is favorable for the diffusion of internal stress, is not easy to deform and can play a role in hydrogen diffusion, the shaft forging without white point defects can be manufactured without a large gas heating furnace, the production cost and energy consumption are reduced, and the production efficiency is improved.
Description
Technical Field
The invention relates to the technical field of metal material forging, in particular to a method for manufacturing a shaft forging and the shaft forging manufactured by the method.
Background
White spots are cracks formed by hydrogen in the steel under the effect of post-forging stress, and are harmful defects to the product. When white spots are found on the product, the product produced by the raw material of the same smelting furnace is scrapped, and the white spots are easy to appear on steel with high white spot tendency, such as carbon manganese steel, alloy steel and the like with low carbon content.
CN109457118A discloses a method for reducing white spots in 10Ni3MnCuAl steel, which starts with the selection of electroslag remelting slag, determines the formula of the slag, combines the baking means for smelting the slag, selects a high-purity graphite crucible to bake the slag in advance, and reacts hydrogen brought by air suction in the storage process of the slag with graphite so as to well remove the hydrogen in the slag in advance, thereby relieving the white spot phenomenon of the 10Ni3MnCuAl steel to a certain extent.
CN105543644A discloses a manufacturing process of gear steel SCM822H, which also solves the problem of white spots in forgings by controlling chemical components, needs a furnace for annealing and tempering treatment, and has high energy consumption and low heat treatment efficiency.
Among them, the 18CrNiMo7-6 steel is a steel grade with strong white spot sensitivity, which is easy to have white spot defects in the forged steel, especially the large-size forged flat steel is more sensitive in rainy season. The white spots are a crack defect generated by hydrogen in steel under the action of stress, the hydrogen dissolved in molten steel is remained in a solid solution formed in the steel when a steel ingot is solidified and is in a supersaturated state, atomic hydrogen is converted into molecular hydrogen when the cooling speed is high in the cooling process after hot working, hydrogen molecules which are not released exist between grain boundaries, and extremely high pressure is generated in the steel to form cracks. The white spots of the alloy steel have bright color and luster, and the carbon steel is darker. The average diameter of the white spots varies from a few millimeters to tens of millimeters. The presence of white spots has a very adverse effect on the properties of the steel, which reduces the mechanical properties of the steel, cracks the parts during heat treatment quenching, and breaks the parts during use.
A heat treatment process after rolling isothermal slow cooling forging is generally adopted after forging to prevent white point defects.
The process comprises the following steps:
(1) heating the large-scale gas heating furnace to 450-550 ℃ for waiting;
(2) after the shaft forging piece is forged, isothermal treatment is carried out for 3 hours at the temperature of 630-650 ℃ in the furnace;
(3) then furnace cooling to 280-320 ℃, and preserving heat for 6 hours;
(4) then heated to 930 deg.C; preserving the heat for 10 hours;
(5) discharging, cooling to 280-320 ℃, and keeping the temperature in the furnace for 6 hours;
(6) then heating to 600 ℃, and preserving the heat for 20 hours;
(7) and (5) cooling the furnace to 400 ℃, discharging and air cooling.
However, the method needs a large-scale gas heating furnace, so that the treatment cost is high and the production efficiency is low.
CN102424934A discloses a method for achieving the dual purposes of narrow hardenability band, qualified grain size and grain size durability by strictly controlling the narrow range of chemical elements C, Mn, Nb, Al and N which have great influence on the hardenability and the grain size of steel, thereby solving the problem of white point defect of 18CrNiMo7-6 steel, but the method needs to strictly control the composition of raw materials and ingredients, has larger limitation, and has complex forging process and heat treatment process steps, and is difficult to popularize and use.
Therefore, a method for manufacturing the shaft forging with low energy consumption and simple operation is urgently needed to be developed, and the problem of white point defects of the existing forging is solved in a low energy consumption and high efficiency mode.
Disclosure of Invention
In view of the problems in the prior art, the invention provides a method for manufacturing a shaft forging, wherein a steel ingot is subjected to three times of drawing, two times of upsetting and two times of heating, and the drawing and upsetting forging ratios are controlled to be combined with the heat treatment process of air cooling and sand cooling after forging, so that white spots in the shaft forging can be eliminated, a good hydrogen diffusion effect is achieved, the shaft forging without the white spot defect can be manufactured without a large gas heating furnace, the production cost and the energy consumption are reduced, and the production efficiency is improved; the shaft forging prepared by the method has no white point defect, and the strength and the performance are better improved.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a method of manufacturing a shaft forging, the method comprising the steps of:
(1) the steel ingot is subjected to first fire forging and second fire forging in sequence to obtain a forged blank;
the first hot forging sequentially comprises: the first heating and heat preservation, the first drawing, the first upsetting and the second drawing are carried out; wherein the first drawing has a draw ratio of 1.8-2.2, the first upsetting has a upsetting ratio of 2.1-2.3, and the second drawing has a draw ratio of 2-2.3;
the second hot forging sequentially comprises the following steps: heating and preserving heat for the second time, upsetting for the second time and drawing out for the third time; wherein the upsetting ratio of the second upsetting is 2.1-2.3, and the drawing ratio of the third drawing is 2.1-2.3;
(2) and sequentially carrying out air cooling and sand cooling on the forging stock to obtain the shaft forging.
The method for manufacturing the shaft forging strictly controls the drawing-out and upsetting times, sequence, drawing-out ratio and upsetting ratio in the forging process, wherein the drawing-out for the first time can effectively break as-cast structure and forge the defects of internal holes; the strip-shaped plastic inclusions in the core part of the blank can be broken into smaller impurities through the second upsetting, and the impurities can be drawn into dispersed particles through the second drawing process, so that the effect of white spots can be eliminated to a certain extent, and the distribution and diffusion of hydrogen are facilitated; meanwhile, the method adopts the heat treatment process of air cooling and sand cooling to replace the conventional fluctuating isothermal slow cooling process, can achieve the effects of further removing stress, preventing white spots, preventing hydrogen embrittlement, improving the structure and the like, can prepare the shaft forging without the white spot defect without a large-scale gas heating furnace, reduces the production cost and energy consumption, and improves the production efficiency.
The first drawing ratio in step (1) of the present invention is 1.8 to 2.2, and may be, for example, 1.80, 1.82, 1.84, 1.85, 1.86, 1.88, 1.90, 1.92, 1.95, 1.98, 2.00 or 2.20.
The upset ratio of the first upset is 2.1 to 2.3, and may be, for example, 2.10, 2.12, 2.15, 2.17, 2.18, 2.20, 2.22, 2.24, 2.25, 2.28 or 2.30.
The second drawing ratio is 2 to 2.3, and may be, for example, 2.00, 2.02, 2.04, 2.05, 2.07, 2.08, 2.09, 2.10, 2.12, 2.14, 2.15, 2.18, 2.20, 2.22, 2.24, 2.25, 2.28, or 2.30.
The second upsetting ratio is 2.1 to 2.3, and may be, for example, 2.10, 2.12, 2.15, 2.17, 2.18, 2.20, 2.22, 2.24, 2.25, 2.28 or 2.30.
The third drawing ratio is 2.1 to 2.3, and may be, for example, 2.10, 2.12, 2.15, 2.17, 2.18, 2.20, 2.22, 2.24, 2.25, 2.28 or 2.30.
In the invention, the drawing ratio and the upsetting ratio of each time are strictly controlled in the range, and partial white spots and stress can be eliminated in the forging process, so that the finally prepared shaft forging has no white spot defect and has good application value.
Preferably, the first drawing ratio in the first hot forging in the step (1) is 1.9-2.1.
Preferably, the upsetting ratio of the first upsetting is 2.2 to 2.3.
Preferably, the second drawing has a drawing ratio of 2.1-2.2.
Preferably, the upsetting ratio of the second upsetting in the second hot forging in the step (1) is 2.1-2.2.
Preferably, the third drawing ratio is 2.2-2.3.
Preferably, the finish forging temperature of the first hot forging in the step (1) is 860 to 890 ℃, and may be 860 ℃, 862 ℃, 865 ℃, 868 ℃, 870 ℃, 872 ℃, 875 ℃, 880 ℃, 882 ℃, 885 ℃, 888 ℃ or 890 ℃, preferably 870 to 880 ℃.
Preferably, the temperature of the first heating and heat preservation is 1200 to 1240 ℃, for example 1200 ℃, 1205 ℃, 1210 ℃, 1215 ℃, 1220 ℃, 1225 ℃, 1230 ℃, 1235 ℃ or 1240 ℃, preferably 1210 to 1230 ℃.
Preferably, the first heating and heat preservation time is 4-6 h, for example, 4h, 4.2h, 4.5h, 4.8h, 5.0h, 5.2h, 5.5h, 5.8h or 6.0h, preferably 4.5-5.5 h.
The heating and heat preservation time in the invention only needs 4-6 h, the stress in the steel ingot can be well relieved, compared with the prior art which needs heat preservation for 8-12 h, the energy consumption is reduced, and the time is saved.
Preferably, the finish forging temperature of the second hot forging in the step (1) is 860 to 890 ℃, and may be 860 ℃, 862 ℃, 865 ℃, 868 ℃, 870 ℃, 872 ℃, 875 ℃, 880 ℃, 882 ℃, 885 ℃, 888 ℃ or 890 ℃, preferably 870 to 880 ℃.
Preferably, the temperature of the second heating and heat preservation is 1200 to 1240 ℃, for example 1200 ℃, 1205 ℃, 1210 ℃, 1215 ℃, 1220 ℃, 1225 ℃, 1230 ℃, 1235 ℃ or 1240 ℃, preferably 1215 to 1230 ℃.
Preferably, the time for the second heating and heat preservation is 4 to 6 hours, for example, 4 hours, 4.2 hours, 4.5 hours, 4.8 hours, 5.0 hours, 5.2 hours, 5.5 hours, 5.8 hours or 6.0 hours, preferably 4.3 to 5.7 hours.
The heating and heat preservation time in the invention only needs 4-6 h, the stress in the steel ingot can be well relieved, compared with the prior art which needs heat preservation for 8-12 h, the energy consumption is reduced, and the time is saved.
The time and temperature of the first heating and heat preservation and the second heating and heat preservation can be the same or different, so that the stress can be relieved well.
Preferably, the material of the steel ingot in the step (1) is 18CrNiMo 7-6.
The material of the steel ingot is 18CrNiMo7-6, and the 18CrNiMo7-6 steel is a steel grade with strong white point sensitivity, so that the shaft forging without white point defects can be obtained after the manufacturing method provided by the invention is adopted, and the industrial application value is high.
Preferably, the diameter of the forged blank obtained in the step (1) is 400-500 mm, for example, 400mm, 405mm, 410mm, 415mm, 420mm, 425mm, 430mm, 435mm, 440mm, 445mm, 450mm, 455mm, 460mm, 465mm, 470mm, 475mm, 480mm, 485mm, 490mm, 495mm or 500mm, preferably 420-480 mm.
Aiming at the problem that white spots are easily generated due to the fact that a forged piece with the diameter of 400-500 mm is large in diameter, large in stress and large in temperature difference between forged pieces, the method provided by the invention is particularly suitable for the shaft forged piece with the diameter of 400-500 mm, and the shaft forged piece with the diameter of 400-500 mm and without white spot defects can be manufactured by a high-efficiency low-energy-consumption method.
Preferably, the temperature of the surface of the forged blank after the air cooling in the step (2) is 300 to 400 ℃, and for example, 300 ℃, 305 ℃, 310 ℃, 315 ℃, 320 ℃, 325 ℃, 330 ℃, 335 ℃, 340 ℃, 345 ℃, 350 ℃, 355 ℃, 360 ℃, 365 ℃, 370 ℃, 375 ℃, 380 ℃, 385 ℃, 390 ℃, 395 ℃ or 400 ℃, preferably 320 to 380 ℃.
The temperature of the surface of the forged blank after air cooling is 300-400 ℃, because the hydrogen embrittlement phenomenon of the steel blank is easy to occur, particularly about 200 ℃, a sand cooling mode with a slower cooling speed is needed after the air cooling is carried out to 300-400 ℃.
Preferably, the sand cooling comprises: and burying the forging stock in a sand body for sand cooling.
Preferably, the thickness of the sand body covering forging stock is 100-200 mm, for example, 100mm, 105mm, 110mm, 115mm, 120mm, 125mm, 130mm, 135mm, 140mm, 145mm, 150mm, 155mm, 160mm, 165mm, 170mm, 175mm, 180mm, 185mm, 190mm, 195mm or 200mm, preferably 120-180 mm.
The thickness of the sand body covering the forging stock is 100-200 mm, the cooling speed of the steel billet can be ensured, excessive growth of crystal grains can be better prevented, and the stress diffusion is more facilitated.
Preferably, the temperature of the sand body in the sand cooling is 80-140 ℃, for example, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃ or 140 ℃, preferably 90-120 ℃.
The temperature of the sand body is preferably 80-140 ℃, a more proper cooling speed is provided for the billet, and white spots and hydrogen embrittlement are more effectively prevented.
Preferably, the temperature of the surface of the sand-cooled forged blank is 150 to 180 ℃, and for example, may be 150 ℃, 152 ℃, 155 ℃, 158 ℃, 160 ℃, 162 ℃, 165 ℃, 168 ℃, 170 ℃, 172 ℃, 175 ℃, 178 ℃ or 180 ℃, preferably 160 to 170 ℃.
The temperature of the surface of the steel billet after sand cooling is preferably 150-180 ℃, white spots can be effectively prevented while the cooling efficiency is guaranteed, and the production efficiency and the product quality are improved.
Preferably, the sand cooling in the step (2) is followed by an operation of taking the forging stock out of the sand and performing air cooling again.
Preferably, the final cooling temperature of the secondary air cooling is room temperature.
As a preferred technical scheme of the invention, the method comprises the following steps:
(1) sequentially forging the 18CrNiMo7-6 steel ingot by a first fire forging and a second fire forging to obtain a forging stock with the diameter of 400-500 mm;
the first hot forging sequentially comprises: the first heating and heat preservation, the first drawing, the first upsetting and the second drawing are carried out; wherein the drawing-out ratio of the first drawing-out is 1.8-2.2, the upsetting ratio of the first upsetting is 2.1-2.3, the drawing-out ratio of the second drawing-out is 2-2.3, the finish forging temperature of the first hot forging is 860-890 ℃, the temperature of the first heating and heat preservation is 1200-1240 ℃, and the time is 4-6 hours;
the second hot forging sequentially comprises the following steps: heating and preserving heat for the second time, upsetting for the second time and drawing out for the third time; wherein the upsetting ratio of the second upsetting is 2.1-2.3, the drawing ratio of the third drawing is 2.1-2.3, the finish forging temperature of the second hot forging is 860-890 ℃, the temperature of the second heating and heat preservation is 1200-1240 ℃, and the time is 4-6 h;
(2) and air-cooling the forging stock until the temperature of the surface of the forging stock is 300-400 ℃, burying the forging stock in sand at 80-140 ℃, sand-cooling until the temperature of the surface of the forging stock is 150-180 ℃, taking out the forging stock from the sand, and air-cooling again to room temperature to obtain the shaft forging piece, wherein the thickness of the sand body covering the forging stock is 100-200 mm.
In a second aspect, the invention provides a shaft forging obtained by the method of the first aspect.
The shaft forging piece manufactured by the method provided by the invention has the advantages that the local stress is well eliminated, white spots and hydrogen embrittlement phenomena are avoided, the structure is uniform, the strength is high, and the application prospect is good.
Compared with the prior art, the invention has at least the following beneficial effects:
(1) the method for manufacturing the shaft forging piece has the advantages of stress relief, white point prevention and hydrogen embrittlement prevention by three times of drawing, twice upsetting and twice heating, controlling the drawing and upsetting forging ratios and combining with air cooling and sand cooling processes;
(2) the method for manufacturing the shaft forging provided by the invention adopts the combined process of air cooling and sand cooling to replace the conventional fluctuating isothermal slow cooling process, and the shaft forging without white point defects can be manufactured without a large-scale gas heating furnace, so that the production cost and the energy consumption are reduced, and the production efficiency is improved;
(3) the shaft forging piece manufactured by the manufacturing method provided by the invention has no white point defect and hydrogen embrittlement phenomenon, and has long service time and high application value.
Drawings
FIG. 1 is an ultrasonic flaw detection spectrum of a shaft forging produced in example 1 of the present invention.
FIG. 2 is an ultrasonic flaw detection spectrum of a shaft forging produced in comparative example 1 of the present invention.
Detailed Description
The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.
The present invention is described in further detail below. The following examples are merely illustrative of the present invention and do not represent or limit the scope of the claims, which are defined by the claims.
First, an embodiment
Example 1
The present embodiment provides a method of manufacturing a shaft forging, the method including the steps of:
(1) first-time forging: heating the 18CrNiMo7-6 steel ingot to 1200 ℃, and preserving heat for 5 h; after heat preservation is finished, sequentially carrying out primary drawing on the steel ingot, wherein the drawing ratio is 2.0, carrying out primary upsetting, the upsetting ratio is 2.2, carrying out secondary drawing, the drawing ratio is 2.2, and the finish forging temperature is 860 ℃;
(2) second-time forging: heating the forged piece subjected to the first hot forging again to 1240 ℃, and preserving heat for 6 hours; sequentially carrying out secondary upsetting on the steel ingot after heat preservation is finished, wherein the upsetting ratio is 2.2, carrying out tertiary drawing, the drawing ratio is 2.2, and the finish forging temperature is 860 ℃, so as to obtain a forging stock with the diameter of 420 mm;
(3) and (3) heat treatment: and air-cooling the forging stock until the temperature of the surface of the forging stock is 320 ℃, burying the forging stock in 80 ℃ sand, cooling the sand until the temperature of the surface of the forging stock is 180 ℃, taking out the forging stock from the sand, and air-cooling the forging stock to room temperature again to obtain the shaft forging piece, wherein the thickness of the sand body covering the forging stock is 150 mm.
The shaft forging manufactured by the embodiment is detected by using a defect echo method of ultrasonic flaw detection, a used instrument is a digital ultrasonic flaw detector CTS-2020, an ultrasonic flaw detection spectrogram is shown in fig. 1, and in the workpiece detection process, except for two waveforms of a surface echo B and a bottom echo D, a defect wave is not detected in the middle, which shows that the shaft forging manufactured by the embodiment has no white point defect and has high application value.
Example 2
The present embodiment provides a method of manufacturing a shaft forging, the method including the steps of:
(1) first-time forging: heating the 18CrNiMo7-6 steel ingot to 1240 ℃, and preserving heat for 6 h; after heat preservation is finished, sequentially carrying out primary drawing on the steel ingot, wherein the drawing ratio is 2.2, carrying out primary upsetting, the upsetting ratio is 2.3, carrying out secondary drawing, the drawing ratio is 2.3, and the finish forging temperature is 890 ℃;
(2) second-time forging: heating the forged piece subjected to the first hot forging again to 1240 ℃, and preserving heat for 4 hours; sequentially carrying out secondary upsetting on the steel ingot after heat preservation, wherein the upsetting ratio is 2.3, carrying out tertiary drawing, the drawing ratio is 2.3, and the finish forging temperature is 880 ℃, so as to obtain a forging stock with the diameter of 460 mm;
(3) and (3) heat treatment: and (3) air-cooling the forging stock to the temperature of 330 ℃ on the surface of the forging stock, burying the forging stock in 120 ℃ sand, cooling the sand to the temperature of 175 ℃ on the surface of the forging stock, taking out the forging stock from the sand, and air-cooling the forging stock to room temperature again to obtain the shaft forging, wherein the thickness of the sand body covering the forging stock is 200 mm.
Example 3
The present embodiment provides a method of manufacturing a shaft forging, the method including the steps of:
(1) first-time forging: heating the 18CrNiMo7-6 steel ingot to 1240 ℃, and preserving heat for 6 h; after heat preservation is finished, sequentially carrying out primary drawing on the steel ingot, wherein the drawing ratio is 2.2, carrying out primary upsetting, the upsetting ratio is 2.3, carrying out secondary drawing, the drawing ratio is 2.3, and the finish forging temperature is 880 ℃;
(2) second-time forging: heating the forged piece subjected to the first hot forging to 1200 ℃ again, and preserving heat for 6 hours; sequentially carrying out secondary upsetting on the steel ingot after heat preservation, wherein the upsetting ratio is 2.3, carrying out third drawing, the drawing ratio is 2.3, and the finish forging temperature is 875 ℃ to obtain a forging stock with the diameter of 500 mm;
(3) and (3) heat treatment: and air-cooling the forging stock until the temperature of the surface of the forging stock is 370 ℃, burying the forging stock in 140 ℃ sand, cooling the sand until the temperature of the surface of the forging stock is 170 ℃, taking out the forging stock from the sand, and air-cooling the forging stock to room temperature again to obtain the shaft forging, wherein the thickness of the sand body covering the forging stock is 100 mm.
Example 4
This example provides a method of manufacturing a shaft forging, which is the same as example 1 except that "the temperature of sand-cooling to the surface of the forging stock is 180" is replaced with "the temperature of sand-cooling to the surface of the forging stock is 150" in step (3).
Example 5
This example provides a method of manufacturing a shaft forging, which is the same as example 1 except that "the temperature of sand-cooling to the surface of the forging stock is 180" is replaced with "the temperature of sand-cooling to the surface of the forging stock is 160" in step (3).
Example 6
This example provides a method of manufacturing a shaft forging, which is the same as example 1 except that "the temperature of sand-cooling to the surface of the forging stock is 180" is replaced with "the temperature of sand-cooling to the surface of the forging stock is 170" in step (3).
Second, comparative example
Comparative example 1
This comparative example provides a method of manufacturing a shaft forging, which is the same as example 1 except that the second hot forging in step (2) is not performed.
The shaft forging piece manufactured by the comparative example is detected by using a defect echo method of ultrasonic flaw detection, a used instrument is a digital ultrasonic flaw detector CTS-2020, an ultrasonic flaw detection spectrogram is shown in figure 2, and as can be seen from the figure, besides two waveforms of a surface echo B and a bottom echo D, a plurality of defect waves F are arranged in the middle of a detection waveform, which shows that the shaft forging piece has white point defects, so that one part of ultrasonic waves meets the white point defects and returns to form defect echoes.
Comparative example 2
This comparative example provides a method of producing a shaft forging, which is the same as example 1 except that "the upset ratio at first upsetting is 2.2" in step (1) is replaced with "the upset ratio at first upsetting is 1.7".
Comparative example 3
This comparative example provides a method of manufacturing a shaft forging, which has the same specific steps and parameters as those of example 1, except that the parameters of upsetting and elongation of the first hot forging in step (1) and the second hot forging in step (2) were adjusted.
The steps (1) to (2) specifically include:
(1) first-time forging: heating the 18CrNiMo7-6 steel ingot to 1200 ℃, and preserving heat for 5 h; after heat preservation is finished, sequentially carrying out primary drawing on the steel ingot, wherein the drawing ratio is 1.8, carrying out primary upsetting, the upsetting ratio is 2.5, carrying out secondary drawing, the drawing ratio is 2.4, and the finish forging temperature is 860 ℃;
(2) second-time forging: heating the forged piece subjected to the first hot forging again to 1240 ℃, and preserving heat for 6 hours; and (3) sequentially carrying out secondary upsetting on the steel ingot after heat preservation is finished, wherein the upsetting ratio is 2.5, carrying out tertiary drawing, the drawing ratio is 2.0, and the finish forging temperature is 860 ℃, so as to obtain a forging stock with the diameter of 420 mm.
Comparative example 4
This comparative example provides a method of manufacturing a shaft forging, which is the same as example 1 except that the sand cooling in step (3) was replaced with air cooling to room temperature.
The step (3) specifically comprises the following steps:
(3) and cooling the forging stock by air cooling until the temperature of the surface of the forging stock is room temperature to obtain the shaft forging.
Third, test and results
The test method comprises the following steps: the shaft forgings obtained in the above examples and comparative examples were tested by the flaw echo method of ultrasonic flaw detection, and the probability of white point generation is shown in table 1.
TABLE 1
From table 1, the following points can be seen:
(1) from the comprehensive examples 1-6, the invention can be known that the ultrasonic flaw detection result of the prepared shaft forging piece shows that the probability of generating white spots is 0 by strictly controlling the drawing-out and upsetting times, sequence, drawing-out ratio and upsetting ratio in the forging process and controlling the air cooling and sand cooling processes, the shaft forging piece without white spot defects can be prepared without a large-scale gas heating furnace, and the energy consumption and the production cost are reduced;
(2) it can be known from the comprehensive examples 1 and comparative examples 1 to 3 that, in the example 1, the probability of generating white spots of the shaft forging prepared in the example 1 is 0, and the probability of generating white spots in the comparative examples 1, 2 and 3 is respectively 20%, 5% and 10% by controlling the forging process strictly, so that the effect of the white spots can be eliminated, the hydrogen distribution and diffusion are facilitated, and the shaft forging without the white spots is obtained by controlling the forging process strictly, by controlling the steps, the sequence and the parameters of upsetting and drawing in the forging process within a certain range, omitting the second fire forging compared with the comparative example 1, and adjusting the first upsetting ratio to 1.7 and the parameters of drawing and upsetting integrally in the comparative example 2;
(3) it can be seen from the combination of the embodiment 1 and the comparative example 4 that the process of air cooling, sand cooling and air cooling is adopted in the embodiment 1, compared with the process of directly air cooling to room temperature in the comparative example 4, the probability of generating white spots of the shaft forging prepared in the embodiment 1 is 0, and the probability of generating white spots in the comparative example 4 is as high as 50 percent, so that the invention selects the process of combining air cooling and sand cooling on the basis of controlling the forging process, and the shaft forging without white spot defects can be prepared without a large gas heating furnace.
In conclusion, the method for manufacturing the shaft forging piece, provided by the invention, has the advantages that the hydrogen diffusion effect can be well realized by strictly controlling the forging process and combining the heat treatment process of air cooling, sand cooling and air cooling, the shaft forging piece without white point defects is obtained, the strength of the shaft forging piece is improved, the energy consumption is reduced, and the industrial application value is higher.
The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must be implemented depending on the above detailed structural features. It should be understood by those skilled in the art that any modifications of the present invention, equivalent substitutions of selected components of the present invention, additions of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.
Claims (10)
1. A method of manufacturing a shaft forging, comprising the steps of:
(1) the steel ingot is subjected to first fire forging and second fire forging in sequence to obtain a forged blank;
the first hot forging sequentially comprises: the first heating and heat preservation, the first drawing, the first upsetting and the second drawing are carried out; wherein the first drawing has a draw ratio of 1.8-2.2, the first upsetting has a upsetting ratio of 2.1-2.3, and the second drawing has a draw ratio of 2-2.3;
the second hot forging sequentially comprises the following steps: heating and preserving heat for the second time, upsetting for the second time and drawing out for the third time; wherein the upsetting ratio of the second upsetting is 2.1-2.3, and the drawing ratio of the third drawing is 2.1-2.3;
(2) and sequentially carrying out air cooling and sand cooling on the forging stock to obtain the shaft forging.
2. The method according to claim 1, wherein the first drawing ratio in the first hot forging in the step (1) is 1.9 to 2.1;
preferably, the upsetting ratio of the first upsetting is 2.2-2.3;
preferably, the second drawing has a drawing ratio of 2.1-2.2.
3. The method according to claim 1 or 2, wherein the upset ratio of the second upset in the second hot forging of step (1) is 2.1 to 2.2;
preferably, the third drawing ratio is 2.2-2.3.
4. A method according to any one of claims 1 to 3, wherein the finish forging temperature of the first hot forging of step (1) is 860 to 890 ℃, preferably 870 to 880 ℃;
preferably, the temperature of the first heating and heat preservation is 1200-1240 ℃, and preferably 1210-1230 ℃;
preferably, the time for the first heating and heat preservation is 4-6 hours, and preferably 4.5-5.5 hours.
5. The method according to any one of claims 1 to 4, wherein the finish forging temperature of the second hot forging of step (1) is 860 to 890 ℃, preferably 870 to 880 ℃;
preferably, the temperature of the second heating and heat preservation is 1200-1240 ℃, and preferably 1215-1230 ℃;
preferably, the time of the second heating and heat preservation is 4-6 hours, and preferably 4.3-5.7 hours.
6. The method according to any one of claims 1 to 5, wherein the steel ingot in the step (1) is 18CrNiMo 7-6;
preferably, the diameter of the forged blank obtained in the step (1) is 400-500 mm, and preferably 420-480 mm.
7. The method according to any one of claims 1 to 6, wherein the temperature of the surface of the forged blank after the air cooling in the step (2) is 300 to 400 ℃, preferably 320 to 380 ℃;
preferably, the sand cooling comprises: burying the forging stock in a sand body for sand cooling;
preferably, the thickness of the sand body covering forging stock is 100-200 mm, and preferably 120-180 mm;
preferably, the temperature of the sand body in the sand cooling is 80-140 ℃, and preferably 90-120 ℃;
preferably, the temperature of the surface of the sand-cooled forging stock is 150-180 ℃, and preferably 160-170 ℃.
8. The method according to any one of claims 1 to 7, further comprising an operation of taking out the forging stock from the sand and performing air cooling again after the sand cooling in the step (2);
preferably, the final cooling temperature of the secondary air cooling is room temperature.
9. A method according to any one of claims 1 to 8, characterized in that the method comprises the steps of:
(1) sequentially forging the 18CrNiMo7-6 steel ingot by a first fire forging and a second fire forging to obtain a forging stock with the diameter of 400-500 mm;
the first hot forging sequentially comprises: the first heating and heat preservation, the first drawing, the first upsetting and the second drawing are carried out; wherein the drawing-out ratio of the first drawing-out is 1.8-2.2, the upsetting ratio of the first upsetting is 2.1-2.3, the drawing-out ratio of the second drawing-out is 2-2.3, the finish forging temperature of the first hot forging is 860-890 ℃, the temperature of the first heating and heat preservation is 1200-1240 ℃, and the time is 4-6 hours;
the second hot forging sequentially comprises the following steps: heating and preserving heat for the second time, upsetting for the second time and drawing out for the third time; wherein the upsetting ratio of the second upsetting is 2.1-2.3, the drawing ratio of the third drawing is 2.1-2.3, the finish forging temperature of the second hot forging is 860-890 ℃, the temperature of the second heating and heat preservation is 1200-1240 ℃, and the time is 4-6 h;
(2) and air-cooling the forging stock until the temperature of the surface of the forging stock is 300-400 ℃, burying the forging stock in sand at 80-140 ℃, sand-cooling until the temperature of the surface of the forging stock is 150-180 ℃, taking out the forging stock from the sand, and air-cooling again to room temperature to obtain the shaft forging piece, wherein the thickness of the sand body covering the forging stock is 100-200 mm.
10. A shaft forging obtained by the method of any one of claims 1 to 9.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112620560A (en) * | 2020-12-02 | 2021-04-09 | 南京迪威尔高端制造股份有限公司 | 18CrNiMo7-6 gear forging and manufacturing method and detection method for overcoming subcutaneous defects of forging |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005226150A (en) * | 2004-02-16 | 2005-08-25 | Daido Steel Co Ltd | Annealing method of tool steel, production method of annealed material for tool steel, annealed material for tool steel, tool steel using the same and tool |
| CN104525808A (en) * | 2014-11-13 | 2015-04-22 | 重庆长征重工有限责任公司 | Blank making method for 42CrMoA axial forging |
| CN104841823A (en) * | 2015-05-25 | 2015-08-19 | 无锡市派克重型铸锻有限公司 | Forging process for improving 1Cr11Ni2W2MoV forging grain size |
| CN105969962A (en) * | 2016-06-02 | 2016-09-28 | 溧阳市金昆锻压有限公司 | Control process of gear steel strip-shaped structure |
| CN106040938A (en) * | 2016-06-02 | 2016-10-26 | 溧阳市金昆锻压有限公司 | Combined die for forging gear shaft through moulding bed and forging technology |
| CN106077415A (en) * | 2016-08-24 | 2016-11-09 | 江苏金源高端装备股份有限公司 | A kind of Forging Technology of nuclear island spindle |
| CN108907049A (en) * | 2018-06-08 | 2018-11-30 | 陕西宏远航空锻造有限责任公司 | A kind of forging method improving spy's TC4 titanium alloy structure property |
| CN109127973A (en) * | 2017-09-29 | 2019-01-04 | 贵州安大航空锻造有限责任公司 | Cr13 type martensitic stain less steel heavy wall height cylinder ring forging forming method |
-
2019
- 2019-12-31 CN CN201911426271.2A patent/CN111154961B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005226150A (en) * | 2004-02-16 | 2005-08-25 | Daido Steel Co Ltd | Annealing method of tool steel, production method of annealed material for tool steel, annealed material for tool steel, tool steel using the same and tool |
| CN104525808A (en) * | 2014-11-13 | 2015-04-22 | 重庆长征重工有限责任公司 | Blank making method for 42CrMoA axial forging |
| CN104841823A (en) * | 2015-05-25 | 2015-08-19 | 无锡市派克重型铸锻有限公司 | Forging process for improving 1Cr11Ni2W2MoV forging grain size |
| CN105969962A (en) * | 2016-06-02 | 2016-09-28 | 溧阳市金昆锻压有限公司 | Control process of gear steel strip-shaped structure |
| CN106040938A (en) * | 2016-06-02 | 2016-10-26 | 溧阳市金昆锻压有限公司 | Combined die for forging gear shaft through moulding bed and forging technology |
| CN106077415A (en) * | 2016-08-24 | 2016-11-09 | 江苏金源高端装备股份有限公司 | A kind of Forging Technology of nuclear island spindle |
| CN109127973A (en) * | 2017-09-29 | 2019-01-04 | 贵州安大航空锻造有限责任公司 | Cr13 type martensitic stain less steel heavy wall height cylinder ring forging forming method |
| CN108907049A (en) * | 2018-06-08 | 2018-11-30 | 陕西宏远航空锻造有限责任公司 | A kind of forging method improving spy's TC4 titanium alloy structure property |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112620560A (en) * | 2020-12-02 | 2021-04-09 | 南京迪威尔高端制造股份有限公司 | 18CrNiMo7-6 gear forging and manufacturing method and detection method for overcoming subcutaneous defects of forging |
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