CN113151732A - High-strength high-temperature-resistant and low-temperature-resistant special gold steel and manufacturing process thereof - Google Patents
High-strength high-temperature-resistant and low-temperature-resistant special gold steel and manufacturing process thereof Download PDFInfo
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Abstract
The invention disclosesA special alloy steel with high strength and toughness, high temperature resistance and low temperature resistance and a manufacturing process are provided, which are mainly used for manufacturing gear shafts, turbine shafts and compressor blades of airplanes; large ship crankshafts and steering engine tail shafts; a turbonator rotor, impeller or blade; high-end equipment such as high-speed railway axles, hot rolls in the steel industry, shafts and gears in high-speed heavy load, and high-strength and high-toughness, corrosion resistance, low temperature resistance and the like required in ocean petrochemical equipment. The steel has the main properties after high-temperature tempering at the temperature of more than or equal to 650 ℃: the bss is more than or equal to 1250N/mm2，Бb≥1390N/mm2，αku≥150J/cm2(ii) a At-60 ℃: alpha ku is more than or equal to 120J/cm2(ii) a Compared with the yield strength and toughness of (4340) steel widely applied in the United states, the yield strength and toughness of the steel are respectively improved by 33.2 percent and 34.7 percent; compared with the BBs of the steam turbine moving blade steel 1Cr12Ni3Mo2VN, the yield is improved by 39.36 percent, and the alpha ku is improved by 54.7 percent; compared with the BBs of the titanium alloy blade (TC11) of the airplane steam compressor, the impact toughness is improved by 25.6 percent, and the final tempering or aging strengthening temperature is improved by more than 120 ℃. If one thousand tons of export can earn $ 2.28 million.
Description
Technical Field
The present invention belongs to the field of special alloy steel for metal material. In particular to a special alloy steel with high strength and toughness, high temperature resistance and low temperature resistance and a manufacturing process, which are mainly used for manufacturing equipment with the working temperature of: the high-speed or heavy-load train shaft, the airplane compressor blades, the gear shaft of a tank, the crankshaft of a large ship, the rotor shaft of a generator, the blades, and high-end equipment such as a hot roller, a shield annular composite cutter ring in the ocean petrochemical engineering and metallurgical industry are required to have high strength, good toughness, heat resistance, low temperature resistance, no fracture and long service life under strong dynamic heavy load.
Technical Field
In the prior art field of the world, due to different industries and application conditions, the varieties, brands and standards of metal materials are as many as a book, but the performance data of each steel grade is original and lagged before the steel grade of the invention; therefore, the invention has comprehensive leading and decay-destroying substitution in various industries. There is now a general serious inadaptation of the 011-16A special steel and the prior art as follows:
1. the inadaptability of 011-16A and the prior art on equipment in the high-speed rail industry is as follows:
the speed of the train is increased, and higher technical performance requirements are provided for wheel steel, high-speed bearings, axle steel and the like. The area is not large in most countries abroad, the temperature difference change of the air temperature is not large, and only certain 1-2 performance data are required to be in a set range when the material is used; the temperature of south and north of China is greatly different in winter, for example, the temperature of south is 15 ℃ in winter and the temperature of black dragon river in north is nearly-60 ℃; when the speed is 400KM/h and the total full load of the train (12 cars) is about (300) 350 tons, the 104 wheels with phi 800mm, the axle with phi 180mm and the matched bearing (104) must be synchronously rotated at ultra high speed (44.21 circles/second); the interior of the penetrating connection part of the two ends of the axle and the bearing inevitably generates strong circular kinetic frictional heat, the long-term working temperature of the axle is 500-600 ℃, and the instantaneous working temperature is even higher; the outside of the heat exchanger is strongly blown and moved airflow for heat dissipation; in severe winter, most exposed parts of the axle must bear the test of freezing and embrittlement at-20-60 ℃ in severe cold wind; the train is started or stopped, and the strong impact on the axle is necessarily generated, particularly the impact is larger when the train is braked emergently in normal running. In view of the above, the quenching and tempering of parts such as high-speed train shafts or other shafts, gears and the like under similar working conditions are performed according to GB/T3077-1999: when the tempering is carried out at 500-630 ℃, the axle inevitably loses the mechanical property during tempering in actual use and cannot bear the freezing embrittlement action at-60 ℃, and the result is undoubtedly that the axle is cracked frequently or the axle neck is fused due to the burning loss of the bearing at high temperature, and even the major accident of broken axle derailment is caused.
The steel has higher yield strength (785-2But the impact toughness is seriously insufficient at normal temperature [ alpha ku ═ 78-98) J/cm2Indexes of low temperature toughness and heat resistance at high temperature (i.e., thermal strength) cannot be found in the existing standards.
It has recently been proposed to manufacture high speed train axles from 40CrNi2Mo (also known as 4340 steel). 4340 steel is a steel grade of the united states with good hardenability, heat treatability and workability; the historical process and the performance of the method mainly comprise two types:
(1) oil cooling is adopted for quenching at 850 ℃, tempering is carried out at 200 ℃, and the steel is used as super-strong steel, and the main performance data is as follows: BBs ═ N/mm (1580-2，Бb＝(1920-2060)N/mm2，αku＝(55-75)J/cm2。
(2) Quenching at 900 ℃ by oil cooling, tempering at 413 ℃ and the BBs is more than or equal to 1260N/mm2，Бb≥1540N/mm2，αkv(-60℃)＝56J/cm2(the term "literature data"). It is mainly used for manufacturing a beam of a subsonic light aircraft, an undercarriage, a crankshaft of an aircraft engine, a middle-size and small-size rocket shell and the like.
Because the 4340 steel and the Chinese 40CrNiMoA contain elementsIn terms of the amount of nickel (Ni) only, the difference is 0.4%, if the N i content of 4340 steel is lower limit, the 4340 steel and 40CrNiMoA are considered to be the same steel type, according to GB/T3077-1999, when liquid fire is carried out at 850 ℃ and tempering is carried out at 600 ℃, the normal temperature performance is as follows: the bps is more than or equal to 835N/mm2，Бb≥980N/mm2，αku≥98J/cm2(ii) a Therefore, the high-speed train shaft with the speed per hour of 350KM-400KM made of 4340 steel still cannot meet the requirement of practical application conditions in China.
2. The inadaptability of the 011-16A special steel and the prior art on metallurgical industry equipment is as follows:
the Wu steel and the Deyang duplex or Shanghai Bao steel adopt a (phi 750 multiplied by 3465mm, G is 8355 kg/piece) hot roll made of 50CrN iMo or 60CrMnMo, and the surface of the hot roll is cracked or broken frequently in the hot rolling process and is not wear-resistant; frequent production stop, replacement and repair; after careful analysis: the quenching temperature zone of 50CrNi MoA or 60CrMnMo is at (840-860) DEG C, and the performance is poor after tempering at (600-650) DEG C; its BBs ═ N/mm (441-2，αku＝31J/cm2(ii) a But they will be subjected to heat conduction at (1080-; instantaneous air quenching occurs along with the rotary displacement after several seconds of hot rolling; the two traditional steels have no cold and hot fatigue resistance, and have no combined phase of anti-cracking, high temperature resistance or wear-resistant elements; so it is less resistant to heat and wear, and the tendency to crack or break is a necessary consequence of material design errors!
3. The inadaptability of 011-16A special steel and the prior art on equipment in the mine industry is as follows:
(1) crusher hammer shaft [ Φ 140 (outer diameter) × 1166 (length) or Φ 140 × 2332, manufactured by 35CrMoV or 40CrNi2Mo, unit: mm ] in many factories such as Gangxi Li pond cement plant, Hubei Ge State dam cement plant, Shanghai Hushan mountain cement plant in Jiangxi, the grinding groove with the depth of 6-15mm is commonly arranged on the phi 140 surface, and the grinding groove needs to be replaced for 2-4 times per month; in addition, the production stop accident that the hammer head flies down to break the separation grid plate due to the fracture of the hammer shaft occurs occasionally; the root causes are as follows: at the moment, the centrifugal shearing force of each hammer head to the hammer shaft reaches (259603-303407) N, and very strong crushing impact is accompanied at any time; this fact is sufficient to show that: the surface hardness, yield strength, impact toughness and the like of the hammer shaft are seriously insufficient.
(2) In Shanghai heavy machinery plant, 37Si Mn2MoV or 42CrMo is adopted for phi 1250 × 1250 birotors manufactured by Yushan mine of Zhejiang Jiangshan cement plant to resist damage (64 ten thousand yuan/pair), because the main shaft (phi 330 × phi 240 × phi 2670) is heavy: (1235 kg/piece) breaks causing production downtime; the Luoyang mining machinery plant adopts 42CrMo or 35CrMoV to break the main shaft (L is 5950, G is 5150kg) by connecting three pieces one by one for 2 meters phi and 2.4 meters hammer manufactured by Guangxi Li pond cement plant, 28 ten thousand yuan/piece, and obviously bending occurs in less than 3 days of installation and can not be used; causing the plant to shut down for more than 30 days; the reason for the breakage or bending of the main shaft is that the yield strength and impact toughness of the material are too low to have the application condition of violent impact crushing!
4. The inadaptability of the 011-16A special steel institute and the prior art on petrochemical industry equipment is as follows:
the hollow eccentric crank shaft (material: ZG40Cr) and the matched gear shaft (phi 320 multiplied by 2260mm, 795 kg/piece) of the F1200 and F1600 slurry pumps manufactured by Russia in 2002 by landification are made of the following materials: 40CrN i MoA or 42CrMo), when the crankshaft is transported to northwest Li industry (50 ℃ below zero), the crankshaft is started to rotate still or the noise is harsh, a plurality of cast crankshafts crack, and a gear shaft is bent and cannot be used for returning goods; the fundamental reasons are that the impact toughness and low-temperature toughness of the selected material are seriously insufficient, and the improper heat treatment of the material causes unstable or cold-brittle or weak deformation of the metallographic structure.
5. The inadaptability of the 011-16A special steel and the prior art on steam power generation and aviation equipment is summarized as follows: watch (1)
By careful analysis, it is evident that:
1. the general tempering temperature of main parts and components of the existing turbonator is below 650 ℃, and the yield strength (bos) and the impact toughness (alpha ku) are seriously insufficient, so that the main parts and the components are difficult to adapt to a generator set with the power temperature of 560-650 ℃;
2. although expensive high-temperature-resistant alloy, titanium alloy and high-alloy steel are adopted by the blades of the airplane compressor, the final tempering or aging strengthening temperature is below 620 ℃, and the impact toughness is very low; they are difficult to adapt to flight conditions where the air compressor outlet temperature is 560 ℃ to 650 ℃ or higher.
3. The yield strength of the 011-16A special steel is more than or equal to 1250N/mm when the tempering temperature TC is more than or equal to 650 DEG C2And the impact toughness alpha ku is more than or equal to 150J/cm2Even at-60 ℃ the impact toughness alpha ku (-60 ℃) is not less than 120J/cm2(ii) a And the furnace preparation cost is far lower than GH4169.TC11, Cr 11N i2W2MoV and 25Cr2Ni4MoV) the 011-16A special steel has wide applicability; the application of the 011-16A special steel inevitably and effectively expands the capacity of the steam turbine generator unit or prolongs the service life of the unit; for the compressor blade of the airplane, the service life of the compressor blade can be prolonged, and the flying speed of the airplane can be properly improved.
Disclosure of Invention
The purpose of the invention is: provides a steel sheet having, after tempering at 650 ℃ or higher: high strength (BBs is more than or equal to 1250N/mm)2，Бb≥1390N/mm2) (ii) a High toughness alpha ku is more than or equal to 150J/cm2And low temperature resistance: alpha ku (-60 ℃) is more than or equal to 120J/cm2The special alloy steel fully meets the world first-class technical high-speed train axle, the large ship crankshaft and the steering engine tail shaft which work under the dynamic heavy load at the working temperature of between 630 and 60 ℃; the high-strength and high-toughness composite cutter ring has the advantages of high strength, toughness and low-temperature resistance required by high-end equipment in ocean petrochemical industry, long service life and low cost.
Another purpose of the invention is to provide a manufacturing process of the special alloy steel with high toughness, high temperature resistance and low temperature resistance.
In order to achieve the purpose, the inventor respectively removes land of Lanzhou Qilian mountain, Hubei Dangyang, Xiangfan, Zhejiang Jiangshan, Shangxi Shanghao, Henan Xinyang, Guangxi Li pond, Nanning, Guizhou Guiyang, Hunan Heyang and the like in 11 months from 2007, and respectively places the railway train axles or industrial and mining (mainly cement plants) of various types in the railway in the places of Hunan Henan Heyang and the likeThe hammer shaft in the large hammer crusher with the diameter of 2m multiplied by 2m used in the open air is subjected to technical measurement of equipment disassembly and analysis of fracture reasons in an application field. The hammer shaft is fixedly connected between the left end disc and the right end disc by end face bolts, the middle of the hammer shaft passes through four hammer disc holes, each large hammer with the net weight of 120 kg and the linear speed of more than 38.54 m/s is hung on the hammer shaft, and the huge tangential function (E is MV) of each hammer is utilized2/2＝1/2×130×38.54296346.24J, breaking 1.5 m × 1.5 m of Daqingshi; therefore, the hammer shaft must have high yield strength and impact toughness, and good low-temperature toughness as the hammer shaft is operated in the open air; therefore, the use working conditions of the high-speed train shaft and the hammer shaft of the heavy hammer crusher are relatively close. From 2008 3 to 2012 6, 19 times of materials, process design and furnace preparation, smelting, casting blank and forging, and 24 different heat treatments and processing, performance detection and analysis, wherein the materials have no rest even in thirty years and the first year after more than five years of day, night and night; with full success at 7/28/2011. Four batches (48 pieces in number) of hammer shafts are developed for Zhejiang river cement factories and Shangfu chicken cement factories in Jiangxi successively, the effect of using the hammer shafts by users is good, the service life is about one year, and the passive situation that the original hammer shafts are broken at three places to five places and are frequently stopped and replaced is thoroughly changed. The business searches and searches for the detection performance data twice in 2011, 8, month and 28 and 2012, 7, month and 2 (search number: J12163) confirm that: reach the leading level at home and abroad; in order to prevent technical leakage, further improve the BBs and weldability, 8-furnace research and test are carried out, and the global technical performance data is searched for in 2019, 5, 13 and 13 days (new search number: Q19029), so that the advanced level is achieved. The total cost reaches 2326.76 ten thousand yuan, no country money is spent,
the invention adopts the following technical measures: the method is technically characterized in that C, Mn, Cr and N i are used as main elements, and a small amount of W, Mo, V, Zr, Nb and N elements are added; after the manufacturing process provided by the invention is implemented, the steel has excellent normal temperature, high temperature and low temperature performances; the manufacturing method has completely satisfied the manufacturing of high-speed train shafts, large-scale ship crankshafts, generator rotor blades, airplane compressor blades and other high-end equipment and parts of the world first-class level.
The alloy steel comprises the following chemical components in percentage by weight: the formula is characterized by comprising the following chemical components in percentage by weight:
carbon (C): 0.28-0.42; silicon (S i): 0.25-0.55; manganese (Mn): 0.35-0.65;
chromium (Cr): 0.65-1.1; (nickel) N i: 1.7-2.4; tungsten (W): 0.55-0.85;
molybdenum (Mo): 0.4-0.75; vanadium (V): 0.2-0.45; niobium (Nb): 0.15-0.35;
zirconium (Zr) is less than or equal to 0.2; nitrogen (N) is less than or equal to 0.16; phosphorus (P) is less than or equal to 0.015; sulfur (S) is less than or equal to 0.015; iron (Fe): 92.09-95.08, and at least one of the four elements of tungsten (W), niobium (Nb), chromium (Cr) and nitrogen (N) is not zero, and the rest is iron (Fe).
In the present invention, a part of carbon (C) is dissolved in α -Fe to form a ferrite solid solution and Fe forms cementite (Fe)3C) C also forms alloy carbides with the excess alloying elements dissolved in ferrite: VC, ZrC, NbC, WC and Mo2C、Mn7C3、Cr7C3Etc.; and also dissolve in cementite (Fe)3C) The alloy elements of (a) together form an alloy cementite with a complex lattice: (Fe. Cr)3C、(Fe·Mn)3C、(Fe·Mo)3C、(Fe·W)3C、(Fe·Cr)23C6、(Fe·Mo)23C6、(Fe·W)23C6、(Fe·V)3C. Etc.; they strongly impede the growth of high temperature austenite grains and promote the finest grains after heat treatment: grain size of 30 um or less2In order to have both sufficient strength and good impact toughness, the carbon content is controlled to be between 0.28% and 0.42% in the present invention.
Silicon (S i), when the Si content is less than or equal to 0.85%, the silicon is completely dissolved in the ferrite, the strength of the ferrite is strongly improved, and the toughness change is very small; when the content is more than 0.85%, the toughness is remarkably reduced; however, Si not only improves the tempering stability, but also increases the fluidity of molten steel and improves the casting performance. Therefore, the content of Si in the present invention is controlled between 0.25% and 0.55%.
Manganese (Mn) is an important element for improving strength, toughness, low temperature resistance and increasing the fluidity of molten steel, and in addition, Mn can form MnS with impurities S to be removed by slag, so Mn has the functions of molten steel purification and automatic impurity removal. In ferrite, when the Mn content is > 0.9%, impact toughness thereof is drastically reduced. In order to achieve the strengthening effect and not to reduce the toughness, the Mn content is controlled between 0.35 percent and 0.65 percent.
Chromium (Cr), molybdenum (Mo), some of which are dissolved in ferrite to form alloy ferrite alpha-Fe (Cr), alpha-Fe (Mo); another part forms fine, dispersed stable alloy carbides: cr (chromium) component7C3、Mo2C; and a part dissolved in cementite (Fe)3C) In the same way, the alloy cementite is stabilized in a fine, dispersed, diffused state: (Fe. Cr)3C、(Fe·Mo)3C、(Fe·Cr)23C6The phases exist in the grain boundary and among the grain boundaries of the high-temperature austenite, except that the growth of austenite grains is hindered, a good foundation is laid for obtaining a uniform fine grain sorbite structure after quenching and tempering, so that the strength, the hardness, the wear resistance and the high-temperature oxidation resistance of the high-temperature austenite are obviously improved, meanwhile, Cr and Mo also have the function of enabling a C curve to be shifted to the right so as to obviously improve the hardenability, when the content of Cr element is less than or equal to 1.2 percent, the strength and the impact toughness of the high-temperature austenite are increased along with the increase of Cr content, so the content of Cr in the high-temperature austenite is controlled between 0.65 percent and 1.1 percent; the addition of Mo improves the tempering stability and avoids high-temperature tempering brittleness; meanwhile, the addition of Mo improves the high-temperature resistance strength of the forged or rolled steel; in welding, Mo shows good crack resistance. Therefore, the content of Mo should be controlled between 0.4% and 0.75%.
Tungsten (W) when W is contained<At 3%, the strength and hardness of the steel increase with the W content, but the toughness is 245J/cm2Down to 49J/cm2Especially when the W content is>1.2 percent, the toughness is obviously reduced, and the addition of W, Mo with a proper amount not only effectively improves the strength and the tempering stability and strongly inhibits the tempering brittleness, but also effectively improves the hot strength and the wear resistance of the steel of the invention because of the formation of WC and WN, so that the W content in the steel of the invention is determined to be within the range of 0.55 to 0.85 percent in order to not greatly reduce the toughness.
When Ni (Ni) is less than 3%, the strength, toughness and low-temperature toughness of the steel are all increased with the increase of Ni content. When the content of the N i-containing steel exceeds 3%, the normal temperature toughness of the steel tends to be reduced, so that not only the strengthening effect is achieved, but also the organic combination of all elements is planned, and meanwhile, the cost is considered, and the N i-containing amount is controlled within the range of 1.7-2.4%.
Vanadium (V), V and C form dispersed, fine and extremely hard Vanadium Carbides (VC) and (V)2C) It exists in and between the grain boundaries of high-temperature austenite, and strongly hinders the growth of austenite grains; when the V content is 0.04-0.1%, and the temperature is 912-960 ℃, the austenite crystal grain changes slightly, so the addition of V can obviously refine the martensite crystal after quenching or the sorbite structure after high-temperature tempering. The strength, toughness, anti-explosion property, high-temperature resistance and low-temperature toughness of the steel are greatly improved. In the invention, the other alloy elements are organically combined, and the content of V is determined as follows: 0.2 to 0.45 percent.
Zirconium (Zr), niobium (Nb), Zr, Nb and C exist in grain boundaries and among grain boundaries of high-temperature austenite as dispersed and fine zirconium carbide (ZrC) and niobium carbide (NbC), so that the growth of the grains is effectively prevented, and the hardenability, the tempering stability, the weldability of the finished product and the high-temperature strength are enhanced. In order to obtain fine-grained high-strength sorbite and have high heat resistance and impact toughness, the invention confirms that the content of Nb is 0.15-0.35 percent, and the content of Zr is less than or equal to 0.2 percent.
Nitrogen (N), with trace amounts of N, which forms VN, ZrN, NbN, Nb, respectively, in an extremely active manner with V, Zr, Nb and Cr, Mo, W added to the steel according to the invention2N、WN、Cr2N, CrN, MoN, thereby reducing the percentage content of carbon; these dispersed and fine N-compounds exist in and between the grain boundaries of the high-temperature austenite, and strongly inhibit the growth of the grains; the addition of N not only improves the hardenability, the strength and the heat resistance, but also increases the weldability and the intercrystalline corrosion resistance, and the action effect of each element is comprehensively considered, so the content of N is determined to be less than or equal to 0.16 percent.
Phosphorus (P) and P tend to reduce the plasticity and toughness of the steel at room temperature and promote C, Mn segregation during the crystallization of the steel, so that the P content is determined to be less than or equal to 0.015%.
Sulphur (S), S is present in the steel in the form of FeS and MnS. MnS enters slag, but FeS and Fe can generate eutectic with low melting point and are distributed on grain boundaries, so that the binding force between the grain boundaries is weakened, and the steel is easy to break when stressed in a hot state, so that the content of S in the invention is controlled within the range of less than or equal to 0.015 percent.
In the invention, because the amount of S, P impurities is very small, the selection amount of S i, Mn, Mo, W, V and Nb is in the range of not only not reducing the toughness but also improving the strength, and the addition amount of Cr, N i, Mo, W, V, Zr, Nb and N not only improves the strength, but also greatly improves the impact toughness and low-temperature toughness, especially various alloy carbides and alloy cementites: VC, ZrC, WC, NbC, Mo2C、Mn7C3、(Fe.Cr)3C、(Fe.Mn)3C、(Fe.Mo)3C、(Fe.W)3C、(Fe.V)3C、(Fe.Nb)3C, etc., as well as various trace nitrides: VN, ZrN, NbN, WN, MoN, Cr2N and the like, and the carbides and nitrides which are difficult to decompose at high temperature are dispersed in and among the grain boundaries of the high-temperature austenite in the form of particles, so that the growth of crystal grains is strongly hindered, the quenching temperature and the tempering temperature of the austenite of the steel are obviously improved, the strength, the hardness, the wear resistance and the impact toughness of the fine-grain sorbite obtained after high-temperature tempering are strongly enhanced, and the high heat-resistant strength is still maintained at the high temperature of 500 ℃ and 630 ℃; the addition of Mo and Zr fully improves the forging and rolling properties of the steel, and Mo, W, V, Nb and the like improve the tempering stability and simultaneously effectively inhibit the tempering brittleness, so the steel has good forging property, hot workability and processability and shows excellent strength, toughness, low-temperature toughness and good heat resistance,
the special steel of the invention requires to adopt a vacuum electric furnace or an electric arc furnace with a temperature controller to carry out furnace preparation smelting according to the chemical composition specification; the stokehole component analysis must adopt the direct-reading analyzer of the spectrum, the ingot mould needed should be made in advance, and oven dry; and adopting AL as final deoxidation treatment. The electric furnace for heat treatment is also required to be provided with a temperature controller and an automatic process curve scanner; the specific production process without vacuum degassing equipment is as follows:
1. casting of a cast steel ingot: the tapping temperature is 1635-1600 ℃, when the chemical components are qualified, the molten steel is quickly poured into a ladle and is quickly and continuously blown with argon for 5-8 minutes, and when the temperature of the molten steel is 1560-1460 ℃, the molten steel is quickly poured into an ingot mold and is slowly cooled along with the ingot mold.
2. Annealing of the ingot casting failure: when the cast steel ingot is cooled to 380-430 ℃, the cast steel ingot is transferred into an electric furnace with the furnace temperature of 400 ℃, after the temperature is equalized for 3-5 hours, the temperature is slowly raised to 650-720 ℃, the temperature t is kept, namely the straight diameter or the thickness of the ingot blank is mmX (14-16) hours/100 mm, and the ingot blank is taken out of the furnace and cooled in air after being cooled to 200 ℃ along with the furnace.
3. And carrying out electroslag remelting on the ingot blank, and embedding the remelted ingot into dry sand or dry lime powder for slow cooling after demolding.
4. Annealing the remelted ingot: heating the ingot blank to 650-720 ℃, and keeping the temperature for: t is the diameter or thickness mm of the steel part x (12-16) hours/100 mm; cooling to 200 ℃ or below with the furnace, discharging and air cooling;
5. forging and heating temperature of steel billet: 1160-1260 ℃; the initial forging temperature is less than or equal to 1200 ℃, and the final forging temperature is more than or equal to 870 ℃.
6. Annealing temperature of forged steel: 650-720 ℃, heat preservation time: t is the diameter or thickness mm x (8-12) hours/100 mm of the steel part; when the temperature is cooled to be less than or equal to 250 ℃ along with the furnace, discharging the steel from the furnace and air cooling the steel.
7. Tempering: quenching at 860-950 ℃, and keeping the temperature for: t is the diameter or thickness mm x (1.4-2.5) hours/100 mm of the steel part; tempering: heating and heat preservation time at 650-720 ℃: t is (15-60) minutes + diameter or thickness mm of steel piece x 1.2 min/mm;
the steel of the present invention produced according to the above method achieves satisfactory technical and economic effects.
The invention relates to a high-strength high-temperature-resistant and low-temperature-resistant special steel (011-6A) product performance, and the analogy of the final heat treatment process temperature and the main mechanical performance of top-grade products in the prior various industries: watch (2)
Note: the performance of the 011-6A special steel is far superior to the top-grade product performance of various industries and superior to any steel grade in GB/T3077-1999 and the current standards in foreign countries; all the data of 011-6A have CMA reports; military and civil products are widely applied; the cost is high; the large-scale impact crushing hammer skin main shaft for manufacturing mines by using the hammer skin main shaft is not damaged for many years and is favored by users.
Compared with the prior art, the invention has the performance advantage of incomparable ratio in multiple industries, so the invention has wide applicability and can obtain great social and comprehensive economic benefits.
1. The invention has the technical performance advantages that:
(1) after the steel is tempered at the temperature of more than or equal to 650 ℃, the metallographic structure is sorbite, and the crystal grain is I-9 grade; at normal temperature: BBs ═ N/mm (1256-2，Бb＝(1395-1448)N/mm2，αku2＝(150-176)J/cm2And still has very good low-temperature resistance toughness at-60 ℃: alpha ku2＝(120-148)J/cm2(ii) a At +500 ℃, the thermal intensity of BBR (+500 ℃) is (851-2It can meet the performance requirements of making high-speed train axle and mechanical equipment in high and cold area, large-scale surface naval vessel and deep-water submarine engine crankshaft, airplane, tank gear shaft, generator rotor main shaft and marine petrochemical equipment.
(2) Compared with the prior 40Cr steel which is most widely applied to high-end equipment1Ni2Mo (us 4340) only after high temperature tempering at 600 ℃ at its normal temperature: BBs 835N/mm2，Бb＝980N/mm2，αku2The yield Strength (BBs) of 98J is increased by 33.2%, and the toughness at normal temperature is alpha ku2Is more than 40Cr1Ni2The Mo steel is improved by 34.7 percent.
(3) Compared with 25CrNi generator rotor steel4MoV's boost of 53.2%, and alpha ku2But is 25CrNi41.485 times of MoV; compared with 1Cr generator blade steel12Ni3Mo2VN was increased by 39.36% for the back-fire BBs only at 566 ℃, alpha ku2But is 1Cr12Ni3Mo22.205 times VN;
(4) compared with an airplane compressor titanium alloy blade (TC11), the steel 011-6A of the invention is aged at 530 [ ([ Bass ═ 930N/mm ])2，αku＝30J/cm2]The improvement of the ababs is 25.6 percent, and the alpha ku is improved by 400 percent;
2. popularization and transformation prospect and obvious social environment-friendly economic benefit
(1) The total of 26 provinces (including autonomous regions) and 4 direct prefectures according to the administrative region division in China.
The Beijing railway administration has a bus 2601 (with air-conditioned bus 1672); while Zhengzhou railway administration has 1710 rows of passenger cars; the Shanghai railway office comprises 4289 lines of passenger cars and 1102 lines of trucks; the Wuhan railway administration has 3301 columns of passenger cars.
The above-mentioned four major railroads have 11901 columns (2975 columns per station on average) and 1102 columns (Shanghai-only). The other 15 large railway offices in China are calculated according to 1200 rows (including 200 rows of trucks) of passenger trains and goods trains in each office, and then 19 large railway offices and 16 railway substations are arranged in China. The method comprises the following steps of (1) sharing passenger lists: 11901+15 × 1000 is 26901 (column), one third of which is 8967 is listed as a high speed train; and (4) additionally loading: 2201+15 × 200 ═ 4102 (columns).
Each heavy load truck comprises 40 wagons, and each wagon is provided with 4 axles; each locomotive head uses 4 axles; the number of axles of 4102 heavy load trucks is (40+1) × 4 × 4102 ═ 672728 (one); the high-speed rail express train generally has 12 carriages, each carriage uses 4 pieces of shaft and each locomotive uses 4 pieces of shaft, so that the total axle consumption of 8967 train high-speed rail express trains is (12+1) × 4 × 8967 ═ 466284 (pieces); according to the existing train axle dimension chart: length × (maximum outer diameter at both ends) × (2376 × Φ 256(mm), the rolled stock size is: 2500X Φ 270(mm), blank weight per axis at this time: g is 1.124 ton, if the axles of heavy-duty trains and high-speed trains are replaced every 3 months (actually, the train inspection and axle replacement are frequent), the steel consumption of the axles of the two trains is as follows: (672728+466284) pieces x 1.124T/piece x 4 times/year 510 (ten thousand tons)/year, if import axles are used, dollars are required: 510 million tons × 14/7.0 is 1020 (hundred million dollars), and converted to renminbi is 7140 (hundred million yuan). If the high-strength, high-toughness, low-temperature-resistant and high-temperature-resistant special steel developed by the company is adoptedThe two types of train shafts and other related shafts are manufactured and replaced once a year, and the product contains tax: 5.0 ten thousand yuan per T (RMB) is implemented, only 127.5 ten thousand tons of steel are needed at most every year, and the required axle purchase cost (RMB) is only 127.5 ten thousand tons per year × 5.0 ten thousand yuan per T637.5 (billion yuan). Only by one, the method can obtain the following significant economic benefits and social benefits for the country: (1) saving the purchase cost of the axle: 7140-637.5 ═ 6502.5 (one hundred million yuan); (2) reducing the steel for the axle: 510-127.5 ═ 382.5 (ten thousand tons); (3) saving steel-making energy consumption (reduced to standard coal): 382.5 ten thousand tons × 605kg/T ═ 231.4125 (ten thousand tons); (4) water conservation: 382.5 ten thousand/T is multiplied by 4.1 m3T x 1 ton/m31568.2 (ten thousand tons); (5) reduction of SO2Discharge capacity: 3825000T × 1.63 kg/T6234.75 (ton); (6) the iron ore mining cost, smelting cost, forging cost, heat treatment cost, mechanical processing cost (including processing electricity), loading and unloading cost and transportation cost (the transportation distance is 500KM) of the steel are reduced; this sum is: [ (200+2400+1900+2000+2400+ 20X 2+ 2X 2). times.500]yuan/T × 3825000T 342.108 (one hundred million yuan).
In addition, the comprehensive pollution to the society (such as processing, transportation noise, fly ash, waste storage and the like) can be greatly reduced; more importantly, the steel of the invention completely ensures the safe operation of high-speed rail train shafts and various high-load mechanical equipment or equipment in the environment similar to the severe cold region with large natural temperature difference or (-60 ℃).
Drawings
FIG. 1 is a schematic view of a metallographic photographed piece of forged quenched and tempered steel, showing a sorbite structure and showing I-9 grade crystal grains.
Detailed Description
The corresponding test data and process execution temperatures of the steel of the invention for the forged steel in the three specific embodiments are respectively listed as follows:
glue ball component (%) table (3) for implementing steel three-furnace of the invention
The process temperature for carrying out the three-furnace process of the melting and forging production of the cast steel of the invention [ unit: centigrade (T deg. C) ] table (4)
The steel forging blank annealing and the quenching and tempering process of the rough machined part and the mechanical properties [ the chemical components are the same as those in the table (3) ] are implemented in the table (5)
The specific implementation process is as follows: according to the steel components of the invention, three furnaces of the steel of the invention are smelted by adopting a 3-ton electric arc furnace, and the steelmaking temperature is as follows in sequence: 1660 deg.C, 1640 deg.C, 1650 deg.C; the transferred ladle argon blowing temperature is respectively as follows: 1630 ℃, 1600 ℃ and 1620 ℃; the casting temperature corresponds to: 1470 deg.C, 1520 deg.C, 1490 deg.C; the annealing temperature of the ingot blank is as follows: furnace cooling is carried out for the temperature of 650 ℃, 690 ℃ and 720 ℃ for 48 hours; two (phi 340 multiplied by 2170mm) ingot blanks per furnace are respectively: electroslag remelting is carried out at 1580 ℃, 1600 ℃ and 1620 ℃; the size of each re-melted ingot blank is as follows: annealing at 700 deg.C, 680 deg.C, 650 deg.C after 350 × 350 × 1600(mm), respectively, and holding time per furnace: t is 50 hours, and the steel is taken out of the furnace and cooled in air after being cooled to 200 ℃.
In order to ensure the quality of the steel forged shaft, one of two re-melted ingots annealed in each furnace is peeled and cut, and the sizes after polishing are respectively as follows: 348X 1580mm (the other piece of the remelted ingot is left for use). Heating the three-furnace remelting ingot blank to 1250 ℃, 1200 ℃ and 1180 ℃ respectively, discharging and forging, wherein the initial section temperature is respectively; 1200 ℃, 1170 ℃, 1150 ℃ and the final forging temperature are respectively as follows: 880 ℃, 870 ℃ and 890 ℃; forging steel billet size: phi 156 is multiplied by 10000mm, and the forged dry sand or dry lime is buried and cooled.
Stress-relief annealing of forged steel at the following temperatures: keeping the temperature at 700 ℃, 700 ℃ and 670 ℃ for 16 hours, cooling to 250 ℃ along with the furnace, and then discharging and air cooling; and sawing three pieces of forged steel with phi 156 multiplied by 10000mm into 4 sections, wherein the size of each section is as follows: Φ 156 × 2340 mm.
Rough turning and tempering: annealing three furnaces of 156X 2340mm of forged blank (per one time)Furnace 4 section), the equal rough turning is: phi 150 multiplied by 2340mm, quenching and tempering are carried out in sequence, and the quenching temperatures are respectively corresponding to: 950 ℃, 860 ℃ and 900 ℃, the tempering temperature is 720 ℃, 690 ℃ and 660 ℃ in sequence, and the heating and heat preservation time is 210 minutes; thereafter, finish-machined to form phi 140-0.2A strong impact hammer shaft of a heavy hammer crusher with a size of 2332 mm; meanwhile, the mechanical property detection at normal temperature and the low-temperature toughness detection at minus 60 ℃ are carried out on the same furnace test piece of each furnace hammer shaft body, the detection of the thermal strength at plus 500 ℃ is added to a part of the test piece, and the metallographic structure analysis is also carried out (see attached figure 1). The detection unit comprises: the Wuhan metal material test and detection center of the general company of the Zhonghai, the Wuhan iron and Steel design research institute, and the like. In order to improve the wear resistance of the surface of the hammer shaft, the three furnace hammer shafts are stabilized at 600 ℃, ion nitriding is carried out at 570 ℃, and the surface hardness HRC is respectively as follows: 55.8, 56.7, 57.6; the using effect of the product is highly praised by users such as Shanghao in Jiangxi and Guangxi Li pond.
Claims (2)
1. The special alloy steel with high strength, toughness, high temperature resistance and low temperature resistance is characterized by comprising the following chemical components in percentage by weight:
carbon: 0.28-0.42; silicon: 0.25-0.55; manganese: 0.35-0.65;
chromium: 0.65-1.1; nickel: 1.7-2.4; tungsten: 0.55-0.85;
molybdenum: 0.4-0.75; vanadium: 0.2-0.45; niobium: 0.15-0.35;
zirconium is less than or equal to 0.2; nitrogen is less than or equal to 0.16; phosphorus is less than or equal to 0.015; sulfur is less than or equal to 0.015; iron: 92.09-95.08, and at least one of the four elements of tungsten, niobium, chromium and nitrogen in the above components is not zero, and the rest is iron.
2. The process for the production of a high-toughness high-temperature-resistant and low-temperature-resistant special alloy steel according to claim 1, without vacuum degassing equipment, comprises the following steps:
(1) casting of steel ingots: the steel-making temperature is 1660-1630 ℃, when the temperature of the molten steel is 1635-1600 ℃, the molten steel is quickly poured into a steel ladle and continuously argon is blown for 5-8 minutes, when the temperature of the molten steel in the steel ladle is 1560-1460 ℃, the molten steel is quickly poured into an ingot mold and is cooled along with the mold;
(2) annealing of the ingot casting failure: when the ingot blank is cooled to 380-430 ℃, the ingot is transferred into an electric furnace with the furnace temperature of 400 ℃, the ingot blank is heated to 650-720 ℃ after the temperature is equalized for 3-5 hours, and the heat preservation time is as follows: t is the diameter or thickness of the ingot blank mm x (14-16) hours/100 mm; discharging the steel after furnace cooling is less than or equal to 200 ℃;
(3) electroslag remelting: carrying out electroslag remelting on the annealed ingot blank, and embedding the remelted ingot into dry sand or dry lime in time for slow cooling after demolding;
(4) annealing the remelted ingot: heating the remelted ingot to 650-720 ℃, and keeping the temperature for: t is the diameter or thickness of the ingot blank, namely mmX (12-16) hours/100 mm, and when the temperature is cooled to be less than or equal to 200 ℃ along with the furnace, the ingot blank is taken out of the furnace and cooled by air;
(5) forging and heating temperature of the remelting ingot blank: 1160-1260 ℃; the initial forging temperature is less than or equal to 1200 ℃, and the non-forging temperature is more than or equal to 870 ℃;
(6) annealing temperature of forged steel billet: 650-720 ℃, heat preservation time: t is the diameter or thickness mm x (8-12) hours/100 mm of the steel part; when the temperature is cooled to be less than or equal to 250 ℃ along with the furnace, discharging the steel from the furnace and air cooling the steel;
(7) tempering: quenching at 860-950 ℃, and keeping the temperature for: t is the diameter or thickness mm x (1.4-2.5) hours/100 mm of the steel part; tempering: heating and heat preservation time at 650-720 ℃: t ═ 15-60 minutes + diameter or thickness mm of the steel part x 1.2 min/mm.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115449591A (en) * | 2022-08-31 | 2022-12-09 | 山西太钢不锈钢股份有限公司 | Preparation method of steel for low-oxygen subway axle |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1067206A2 (en) * | 1999-07-09 | 2001-01-10 | Hitachi, Ltd. | Steam turbine blade, and steam turbine and steam turbine power plant using the same |
| CN1957101A (en) * | 2004-05-21 | 2007-05-02 | 工业钢克鲁梭公司 | Steel with high mechanical strength and wear resistance |
| CN103334052A (en) * | 2013-06-18 | 2013-10-02 | 上海大学 | High-thermal conductivity high-abrasion resistance hot stamping die steel and preparation method thereof |
-
2020
- 2020-01-07 CN CN202010012531.8A patent/CN113151732A/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1067206A2 (en) * | 1999-07-09 | 2001-01-10 | Hitachi, Ltd. | Steam turbine blade, and steam turbine and steam turbine power plant using the same |
| CN1957101A (en) * | 2004-05-21 | 2007-05-02 | 工业钢克鲁梭公司 | Steel with high mechanical strength and wear resistance |
| CN103334052A (en) * | 2013-06-18 | 2013-10-02 | 上海大学 | High-thermal conductivity high-abrasion resistance hot stamping die steel and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 刘俊尧, 中国铁道出版社 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115449591A (en) * | 2022-08-31 | 2022-12-09 | 山西太钢不锈钢股份有限公司 | Preparation method of steel for low-oxygen subway axle |
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