CN104593692A - Heat-resistant cast austenitic stainless steel with excellent high-temperature comprehensive properties - Google Patents
Heat-resistant cast austenitic stainless steel with excellent high-temperature comprehensive properties Download PDFInfo
- Publication number
- CN104593692A CN104593692A CN201410814709.5A CN201410814709A CN104593692A CN 104593692 A CN104593692 A CN 104593692A CN 201410814709 A CN201410814709 A CN 201410814709A CN 104593692 A CN104593692 A CN 104593692A
- Authority
- CN
- China
- Prior art keywords
- heat
- stainless steel
- austenitic stainless
- resistant cast
- high temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
- C22C33/06—Making ferrous alloys by melting using master alloys
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
Abstract
The invention belongs to the technical field of new materials, and provides a heat-resistant cast austenitic stainless steel with excellent high-temperature comprehensive properties, which is mainly used in automobile engine exhaust system components of which the exhaust temperature exceeds 1000 DEG C, including exhaust manifolds, turbine casings and the like. The heat-resistant cast austenitic stainless steel comprises the following alloy components in percentage by mass: 0.1%-0.6% of C, 0.1%-0.5% of N, 0.4%-1.5% of Si, less than 1.5% of Mn, 17.5%-22.5% of Cr, 8.0%-13.0% of Ni, 1.0%-3.0% of Nb, less than 5.0% of W, less than 6.5% of Mo and the balance of matrix element Fe and impurity elements, including less than 0.04% of P, less than 0.03% of S, less than 0.04% of O and less than 0.05% of Al. The heat-resistant austenitic stainless steel is produced by a casting method without later-period heat treatment, and has the advantages of lower production cost, higher temperature resistance and higher durability as compared with like heat-resistant cast steel.
Description
Technical field
The invention belongs to new material technology field, relate to a kind of heat-resistant cast austenitic stainless steel with excellent high temperature over-all properties, be mainly used in the automobile engine exhaust system parts of exhaust temperature more than 1000 DEG C, comprise exhaust manifold, turbine case etc.
Background technology
The tail gas of motor vehicle emission is one of important source of pollution of urban atmospheric pollution.In recent years China's haze weather occurs again and again, and government can not restrain oneself the environmental protection pressure of national haze everywhere again.From 1 day July in 2011, all Light-Duty Gasoline Vehicle, pure gas fuel vehicle and dual-purpose fuel cars not meeting state four standard-required, must not sell and register.From 1 day January in 2015, state three diesel vehicle product must not be sold.At the beginning of 2013, " suggestion about strengthening ic engine industry energy-saving and emission-reduction " that general office of State Council of the People's Republic of China issues is pointed out, by 2015,60% of economic IC engine product Xu Zhan whole society oil engine product recoverable amount, compared with 2010, fuel of internal combustion engine rate of consumption reduces by 6% ~ 10%, realizes saving commodity fuel oil 2,000 ten thousand tons, reduces CO
2discharge 6,200 ten thousand tons, reduce NO
xdischarge 10%, adopts alternative fuel to save commodity fuel oil 1,500 ten thousand tons.Turbocharging technology is the important technical that can reach the automobile emissions standards that world community government is formulated.Turbo-supercharger utilizes the exhaust flue gas streams of engine to promote turbine wheel high speed rotating, drives compressor impeller high speed rotating simultaneously, makes the air velocity by pneumatic plant and pressure increase, and then improve engine air-fuel ratio.Turbo-charging is a gordian technique promoting engine performance and reduce energy consumption of vehicles and discharge, and the advantage possessed has: 1. fuel efficiency is higher.Compared with the naturally aspirated petrol engine of equivalent specifications, the fuel efficiency of turbo supercharging gasoline engine can improve and reaches 20%.And compared with naturally aspirated engine, the fuel efficiency of the turbo-charging diesel motor of equal rated output can improve and reaches 40%.2. performance is more excellent.Turbo-charging significantly improves power and the moment of torsion of engine, lifting vehicle response speed and safety performance.3. more clean, more environmental protection.Turbosupercharged engine can utilize the emission from engine, makes engine combustion more clean, and reduces size of engine under the prerequisite not damaging performance, reduces CO simultaneously
2and NO
xquantity discharged.
The use of turbo-supercharger, although can improve fuel efficiency, reduces CO
2discharge, but also improve tail gas exhaust temperature simultaneously.Compare traditional natural airbreathing motor, the exhaust temperature of turbo supercharging gasoline engine is increased to 1050 DEG C from 850 DEG C, and parts self-temperature can be heated to 950 ~ 1000 DEG C.The Service Environment of turbo-supercharger sums up, and mainly comprises: (1) starts, flame-out and variable-speed operation phase temperature rises sharply rapid drawdown; (2) when steady state operation phase is long, high-temperature hot exposes; (3) burn into oxidizing atmosphere.Exhaust system component prolonged heat exposure in oxidizing gas and air, and will stand the cold cycling repeatedly that the running of engine and stopping cause in this high temperature range.Therefore, exhaust system component must have higher holds warm ability and endurance quality, and has longer service life at the corresponding temperature.
Traditional engine exhaust system parts are all by heat resisting iron or heat-resistant cast ferrite stainless steel making.Although heat resisting iron is showing relatively high intensity lower than when 900 DEG C, when temperature is higher than 900 DEG C, the anti-oxidant and Thermal cracking ability of these materials declines, and shows heat-resisting ability deficiency.And heat-resistant cast ferritic stainless steel intensity when temperature is more than 950 DEG C also declines especially obvious.The performance requriements that these traditional materials have improve after cannot having met employing turbocharging technology.Nickel base superalloy has very excellent mechanical behavior under high temperature, is widely used in aircraft industry, and as the turbine blade etc. of aircraft engine, but the cost of nickel-base material is relatively high, cannot be widely used in motor car engine and exhaust system component thereof.Therefore, design, the lower cost materials developed for the manufacture of new work engine exhaust system component becomes extremely urgent.Heat-resistant cast austenitic stainless steel is under high-temperature service condition, and its mechanical property is obviously better than heat-resistant cast ferritic stainless steel, and cost is far below nickel-base high-temperature alloy material.Adopt casting technique, without the need to the thermal treatment process such as solid solution, timeliness in advance, manufacturing cost can be reduced further.Therefore, the heat-resistant cast austenitic stainless steel preferred material that can design as novel material, develop.
At present, a kind of heat resistance cast austenitic stainless CF8C-Plus (United States Patent (USP) has been developed jointly in U.S.'s Oak Ridge National Laboratory and Caterpillar technique center, patent No. US7153373B2, publication date on December 26th, 2006, patent name Heat and corrosion resistant cast CF8C stainless steel with improved high temperature strength and ductility).This cast steel nickel content, lower than 15% (massfraction), has lower production cost; And have higher high-temperature service performance at 700 ~ 850 DEG C, especially excellent Properties of High Temperature Creep, is thus successfully applied to the exhaust manifold of diesel motor.But petrolic exhaust temperature is generally than diesel motor height about 200 DEG C, and thus CF8C-Plus still can not be applied to exhaust system of gasoline engine parts safely and reliably.Simultaneously, FDAC metal group develops a kind of high chrome high-nickel heat-resistant cast austenitic stainless steel (United States Patent (USP), patent No. US8241558B2, publication date on 08 14th, 2012, patent name High-Cr, high-Ni, heat-resistant, austenitic cast steel and exhaust equipment members formed thereby; Chinese patent, patent No. CN100537814C, patent name " high Cr high-ni austenitic heat-resistant cast steel and the exhaust system part be made up of it ", publication date on 09 09th, 2009), there is higher high-temperature service performance, especially thermal fatigue property, can meet the service demand of exhaust temperature more than 1000 DEG C.But the Ni content of this cast steel is more than 20% (massfraction), and thus its production cost is higher, be not suitable for using in energy-saving and emission-reduction and Eco-power motor car engine.
Therefore, by adding trace alloying element and strict control Ni content, the heat-resistant cast austenitic stainless steel designing, develop a kind of low-cost and high-performance is very necessary.Novel material should possess the over-all propertieies such as good mechanical behavior under high temperature, antioxidant property, temperature-room type plasticity.
Summary of the invention
The object of the present invention is to provide a kind of high-temperature comprehensive property excellent, and the heat-resistant cast austenitic stainless steel that W metal content is few, economy is high.The high-temperature comprehensive property of this cast steel contains the high-temperature behaviors such as high-temperature yield strength, creep-resistant property, high temperature oxidation resistance, thermal fatigue resistance and the room-temperature property such as temperature-room type plasticity, room temperature low cycle fatigue.This cast steel is mainly used in the automobile engine exhaust system parts of exhaust temperature more than 1000 DEG C, comprises exhaust manifold, turbine case etc.
20Cr-10Ni system heat-resistant cast austenitic stainless steel described in US Patent No. 7153373B2, although cannot meet the service condition of exhaust temperature more than 1000 DEG C, the metallic element Ni content that price is relatively expensive is less; And the 25Cr-20Ni system heat-resistant cast austenitic stainless steel described in US Patent No. 8241558B2, although thermotolerance, endurance quality are comparatively excellent under the condition of exhaust temperature more than 1000 DEG C, W metal content is more.Therefore, the present inventor is by adjusting kind and the compositing range of alloying element, based on 20Cr-10Ni system heat-resistant cast austenitic stainless steel, can obtain when research reduces W metal content to thermotolerance, weather resistance beneficial effect and suitable with 25Cr-20Ni system hold warm ability and endurance quality.
From previous experiments result, add non-metallic element N, even then W metal poor 20Cr-10Ni system also can obtain stable single phase austenite matrix, and be combined with Nb the precipitated phase formed and can play precipitation strength effect, improve the mechanical property such as high temperature creep and thermal fatigue relatively significantly.But the interpolation of a large amount of N, can promote Cr
23c
6, Cr
2the precipitation of the rich Cr carbonitride such as N, makes the poor Cr of austenitic matrix, and then reduces antioxidant property.Therefore, the present inventor has the cast steel composition compositing range of best heat-resisting and endurance quality in order to find out, carry out deeply studying widely, draw following neodoxy: (1) is in order to ensure basic resistance toheat, as hot strength, oxidation resistent susceptibility, while increase N content, the content of the main alloy element such as C, Si, Mn, Cr, Ni is limited in proper range separately; (2) in order to ensure precipitation and the dispersion-strengthened action of sufficient Nb (C, N) precipitated phase, with the addition of the Nb more much higher than tradition forging stainless steel, and being limited in proper range; (3) in order to improve high-temperature creep life-span and thermal fatigue life, on other occasions containing W and/or Mo; (4) in order to while increase N, control the content of microtexture and precipitated phase, not only specify the main alloy element such as C, Si, Mn, Cr, Ni, Nb, W, Mo content separately, and the total amount of restriction (C+N).
The present invention realizes by following technical scheme:
A kind of heat-resistant cast austenitic stainless steel with excellent high temperature over-all properties of the present invention, its chemical composition is calculated as C:0.1% ~ 0.6%, N:0.1% ~ 0.5%, Si:0.4% ~ 1.5%, below Mn:1.5%, Cr:17.5% ~ 22.5%, Ni:8.0% ~ 13.0%, Nb:1.0% ~ 3.0%, below W:5.0%, below Mo:6.5% according to massfraction, remaining as matrix element Fe and below impurity element P:0.04%, below S:0.03%, below O:0.04%, below Al:0.05%.
Further, the described heat-resistant cast austenitic stainless steel with excellent high temperature over-all properties, its characteristic component is calculated as C:0.2% ~ 0.5%, N:0.1% ~ 0.4%, Si:0.5% ~ 1.0%, Mn:0.5% ~ 1.5%, Cr:18.5% ~ 21.5%, Ni:9.0% ~ 12.0%, Nb:1.5% ~ 2.5% according to massfraction, remaining as matrix element Fe and below impurity element P:0.04%, below S:0.03%, below O:0.04%, below Al:0.05%.
Further, the described heat-resistant cast austenitic stainless steel with excellent high temperature over-all properties, its characteristic component is calculated as C:0.2% ~ 0.5%, N:0.1% ~ 0.4%, Si:0.5% ~ 1.0%, Mn:0.5% ~ 1.5%, Cr:18.5% ~ 21.5%, Ni:9.0% ~ 12.0%, Nb:1.5% ~ 2.5%, W:1.0% ~ 5.0% according to massfraction, remaining as matrix element Fe and below impurity element P:0.04%, below S:0.03%, below O:0.04%, below Al:0.05%.
Further, the described heat-resistant cast austenitic stainless steel with excellent high temperature over-all properties, its characteristic component is calculated as C:0.2% ~ 0.5%, N:0.1% ~ 0.4%, Si:0.5% ~ 1.0%, Mn:0.5% ~ 1.5%, Cr:18.5% ~ 21.5%, Ni:9.0% ~ 12.0%, Nb:1.5% ~ 2.5%, Mo:2.0% ~ 6.5% according to massfraction, remaining as matrix element Fe and below impurity element P:0.04%, below S:0.03%, below O:0.04%, below Al:0.05%.
Further, the described heat-resistant cast austenitic stainless steel with excellent high temperature over-all properties, is characterized in that: the total content scope of (C+N) is: 0.2% ~ 0.8%.
The step of preparation process of Heat resisting cast steel of the present invention is as follows:
(1) metallic substance such as highly purified Fe, Cr, Ni, C, Nb, W, Mo, Si, Mn and nitrided ferro-chromium alloy is taken by composition proportion;
(2) the above-mentioned high purity metal material that takes and nitrided ferro-chromium alloy are put into vacuum induction furnace crucible, be evacuated to 5 × 10
-2below Pa, then pours into a mould after 20 ~ 30 minutes 1500 ~ 1550 DEG C of meltings, can obtain heat-resistant cast austenitic stainless steel ingot.
Heat-resistant cast austenitic stainless steel of the present invention is compared with the cast steel of the same type of immediate development, Ni content is lower than 15% (massfraction), there is lower production cost, and its high-temperature yield strength, high temperature fatigue performance are obviously promoted, and high-temperature oxidation resistance, temperature-room type plasticity etc. remain on suitable level or slightly promote.Particularly, at 1000 DEG C, under 50MPa condition, the high-temperature creep life-span of heat-resistant cast austenitic stainless steel of the present invention far exceedes commercial alloy CF8C-Plus.This shows, the more similar heat-resistance stainless steel of heat-resistant cast austenitic stainless steel of the present invention, what have lower production cost and Geng Gao holds warm ability and endurance quality, is a kind of heat resistance cast austenitic stainless, effectively can improves vehicle fuel efficiency of combustion and tail gas clean-up ability.
Accompanying drawing explanation
Fig. 1 is the typical metallographic microstructure of business cast steel CF8C-Plus.
Fig. 2 is the typical metallographic microstructure of heat-resistant cast austenitic stainless steel embodiment 4 of the present invention.
Fig. 3 is the typical metallographic microstructure of heat-resistant cast austenitic stainless steel embodiment 5 of the present invention.
Fig. 4 be heat-resistant cast austenitic stainless steel embodiment of the present invention at 1000 DEG C, the creep curve recorded under 50MPa condition.
Embodiment
[1] chemical composition of Heat resisting cast steel
First, the reason for specifying heat-resistant cast austenite stainless steel chemical composition of the present invention is described in detail.The content " % " of following element refers to massfraction, unless otherwise.
(1)Cr：17.5％～22.5％
Cr is requisite a kind of element in heat-resisting austenite cast steel, of crucial importance to raising Alloy Anti oxidation susceptibility, simultaneously by the precipitation of appropriate Cr carbide, improves the hot strength of cast steel to a certain extent.Be on active service at 1000 DEG C and above temperature, in cast steel, Cr content at least needs 15.0%.If but Cr content is more than 30.0%, the σ phase of a large amount of carbide and fragility can be separated out, the plasticity of severe exacerbation cast steel.Therefore, Cr content is set to 17.5% ~ 22.5%, and preferable range is 18.5% ~ 21.5%.
(2)Ni：8.0％～13.0％
Ni with Cr is the same, and being requisite a kind of element in heat-resisting austenite cast steel, is important austenite former, can effectively stablize cast steel austenitic matrix, and improve castability.In order to ensure the castability of thin-section casting, the lower limit of Ni content is set to 8.0%.When Ni content is more than 13.0%, the effect of Ni reaches capacity, and the cost that only surplus cast steel is high.Therefore, Ni content is set to 8.0% ~ 13.0%.Consider from Financial cost, Ni content preferable range is 9.0% ~ 12.0%.
(3)C：0.1％～0.6％
C can not only improve the solution strengthening ability of cast steel substrate, also by forming nascent or secondary carbide, forming precipitation strength, improving cast steel hot strength.In addition, C can improve the mobility (castability) of cast steel liquation, and forms eutectic carbides by being combined with Nb, improves castability and the hot strength of cast steel further.In order to effectively play respective action, C content is at least 0.1%.But when C content higher than 0.6% time, too much eutectic carbides and other carbide can be formed, reduce plasticity and the processing characteristics of cast steel.Therefore, C content is set to 0.1% ~ 0.6%, and preferable range is 0.2% ~ 0.5%.
(4)N：0.1％～0.5％
N is strong austenite former, can stablize the austenitic matrix of Heat resisting cast steel, improves its hot strength.N can fining austenite grains effectively, especially have the foundry goods of complicated shape, and these parts is not usually by forging processing.Tiny crystal grain can not only improve the plasticity of material, and solves the problem of the low processing characteristics of chromium nickel heat-resisting austenite cast steel.N can reduce the velocity of diffusion of C, thus slows down or stop the agglomeration of carbide.Therefore, N is the important element improving alloy plasticity.
The interpolation of trace N element just can significantly improve cast steel hot strength, creep-resistant property, thermal fatigue resistance and temperature-room type plasticity.But, when N content is more than 0.5%, a large amount of nitride can be separated out, as Cr
2n, makes cast steel become fragile; Reduce the Cr content of solid solution in matrix simultaneously, cast steel antioxidant property is worsened.And too much N can produce the defects such as pore in castingprocesses, reduce the intensity of cast steel.Therefore, N content is set to 0.1% ~ 0.5%, and preferable range is 0.1% ~ 0.4%.
In austenite cast steel, the effect of C and N is similar, is all strong austenite former, and is all easy to form compound with Nb.If the total amount of C and N is too low in cast steel, in austenite cast steel, there will be the brittlement phase such as σ, Alloy At Room Temperature plasticity and high temperature creep property are worsened.If the total amount of C and N is too high in cast steel, a large amount of precipitation and the alligatoring of carbonitride can be promoted, be unfavorable for temperature-room type plasticity and the high temperature creep property of cast steel equally.Therefore, the total amount of (C+N) is set to 0.2% ~ 0.8%.
(5)Nb：1.0％～3.0％
Nb by forming tiny carbonitride with C, N, thus improves hot strength and the creep life of Heat resisting cast steel, improves the antioxidant property of cast steel by suppressing the Carbide Precipitation of Cr simultaneously.And Nb also improves the castability of thin-walled exhaust manifold parts by forming eutectic carbides.Therefore, the lower limit of Nb content is set to 1.0%.But too much the interpolation of Nb can cause crystal boundary separates out a large amount of eutectic carbidess, makes Heat resisting cast steel become fragile, serious its hot strength of reduction and plasticity.Therefore, Nb content is set to 1.0% ~ 3.0%, and preferable range is 1.5% ~ 2.5%.
(6) below W:5%
W is one of main alloy element improving Heat resisting cast steel mechanical behavior under high temperature.But the interpolation of excessive W can promote Cr
23c
6etc. the precipitation of rich Cr carbide, worsen the antioxidant property of cast steel.And excessive W also can promote the precipitation of σ phase, reduce high-temp plastic and the thermal fatigue property of cast steel.Therefore, W content is set to less than 5.0%, and preferable range is 1.0% ~ 5.0%.
(7)Mo：6.5％
Mo can improve the corrosion resistance of cast steel effectively, is also one of main alloy element improving Heat resisting cast steel mechanical behavior under high temperature simultaneously.But when Mo content is more than 6.5%, a large amount of carbide and intermetallic phase can be separated out, the plasticity of severe exacerbation cast steel.Therefore, Mo content is set to less than 6.5%, and preferable range is less than 2.0% ~ 6.5%.
(8)Si：0.4％～1.5％
Si can improve the antioxidant property of cast steel effectively, and reductor required when being cast steel melting.Appropriate Si can improve cast steel casting performance, but when content is too much, can affect the stability of austenitic matrix, and and then the castability of reduction cast steel.Therefore, Si content should control 0.4% ~ 1.5%, preferred content 0.5% ~ 1.0%.
(9) below Mn:1.5%
Mn is austenite former, is solid-solution in the hot strength that can improve matrix in austenitic matrix.Reductor required when Mn is also cast steel melting and sweetening agent.But too much Mn precipitate can reduce the antioxidant property of cast steel.Therefore, Mn content should control below 1.5%, and preferable range is 0.5% ~ 1.5%.
(10) impurity element
According to current result of study of the present invention, the content of Al needs strict control.Although Al is reductor important in molten alloy process, can be combined with O and forms Al
2o
3precipitate.But Al also has very strong binding ability with N simultaneously, form AlN, reduce the N content of effective solid solution in matrix.And AlN is a kind of hard crisp phase, the temperature-room type plasticity of excessive precipitation meeting severe exacerbation cast steel and Properties of High Temperature Creep.Therefore, Al content should control below 0.05%.If O content can be effectively controlled, then can reduce the interpolation of Al as far as possible when smelting.
O in cast steel is not only with Al
2o
3, SiO
2exist Deng oxide form, also easily form pore.Because the existence containing a large amount of Cr, O in nickel heat-resistant cast austenitic stainless steel in high chromium of the present invention can make a large amount of Cr form Cr
2o
3.These oxide compounds and pore make cast steel easily ftracture, and reduce its intensity, plasticity and processing characteristics.And the content of Heat resisting cast steel of the present invention to Al has done strict restriction, thus considers from metallurgical angle, the content of O also must do corresponding restriction.Therefore, the content of O should control below 0.04%.
P is the major impurity element in current high chromium of the present invention in nickel heat-resistant cast austenitic stainless steel, is mixed into from raw material.Because P is easily at grain boundary segregation, reduce the toughness of cast steel, therefore, its content must control low as far as possible, below 0.04%.
S is also the major impurity element in Heat resisting cast steel, is mixed into from raw material.S, easily at grain boundary segregation, preferentially forms MnS with Mn, reduces the Mn content of effective solid solution in matrix.Therefore, S content should control below 0.03%.
[2] the evaluation experimental method of Heat resisting cast steel performance
Below the benchmark test method of heat-resistant cast austenitic stainless steel of the present invention is described in detail.
(1) room temperature and drawing by high temperature
Cut sample from embodiment, through being machined to gauge length 25mm, the standard round bar tension specimen of diameter 5mm, carries out tensile tests at room according to GB/T228.1-2010 standard respectively, and GB/T 4338-2006 standard carries out 1000 DEG C of tensile test at high temperature.
(2) creep experiments under high temperature
Cut sample from embodiment, through being machined to gauge length 25mm, the standard round bar creep sample of diameter 5mm, according to GB/T 2039-2012 standard at 1000 DEG C, carries out creep experiments under high temperature under 50MPa condition.
(3) room temperature and high temperature low-cycle fatigue
Cut sample from embodiment, through being machined to gauge length 30mm, the standard round bar fatiguespecimen of diameter 6.5mm, carries out room temperature respectively according to GB/T 15248-2008 standard and 950 DEG C of low cycle fatigue are tested.Wherein, the range of strain of room temperature fatigue experiment select be ± 0.3% and ± 0.6%, the range of strain selection of high temperature fatigue experiment is ± 0.6% and ± 0.8%.
(4) high temperature oxidation experiment
Cut sample from embodiment, and be processed into the thin slice of 10 × 10 × 2mm, then after polishing, put into crucible weigh, then put into heat treatment furnace, take out after beat exposure 150h at 950 DEG C and weigh.Twice weight subtracts each other the oxidation increment be measured by this experiment.
The present invention is set forth in more detail, so that those skilled in the art understand advantages and features of the invention by following examples.But the present invention also can't help these embodiments and limited.
Table 1 is depicted as the alloying constituent of embodiment and commercial alloy CF8C-Plus.Wherein embodiment 1 ~ 14 is the heat-resistant cast austenitic stainless steels in defined composition range of the present invention, and its step of preparation process is:
(1) metallic substance such as highly purified Fe, Cr, Ni, C, Nb, W, Mo, Si, Mn and nitrided ferro-chromium alloy is taken by composition proportion;
(2) the above-mentioned high purity metal material that takes and nitrided ferro-chromium alloy are put into vacuum induction furnace crucible, be evacuated to 5 × 10
-2below Pa, then pours into a mould after 20 ~ 30 minutes 1500 ~ 1550 DEG C of meltings, can obtain heat-resistant cast austenitic stainless steel ingot.
Commercial alloy CF8C-Plus shown in table 1, is provided by Ford of the U.S..Commercial alloy CF8C-Plus is the heat-resistant cast austenitic stainless steel that the Ni content described in US Patent No. 7153373B2 is effectively controlled.The comparision contents of the alloying elements such as C, Nb, W, Mo of this cast steel is low, and the comparision contents of Mn is high.Fig. 1 is its typical metallographic microstructure.Table 2 is depicted as the Evaluation results of embodiment and commercial alloy.
Embodiment 1 ~ 4 is containing N and not containing the cast steel of W, Mo, wherein the metallographic microstructure of embodiment 4 as shown in Figure 2.Embodiment 1 ~ 4 is at 1000 DEG C, and the high-temperature creep life-span under 50MPa condition is apparently higher than commercial alloy CF8C-Plus, and its high temperature low-cycle fatigue life-span and high temperature oxidation increment meet the service condition of exhaust system.
Embodiment 5 ~ 7 is containing N, W and not containing the cast steel of Mo, wherein the metallographic microstructure of embodiment 5 as shown in Figure 3.Embodiment 5 ~ 7 is at 1000 DEG C, and the high-temperature creep life-span under 50MPa condition is apparently higher than commercial alloy CF8C-Plus, and its room temperature, high temperature low-cycle fatigue life-span and high temperature oxidation increment meet the service condition of exhaust system.
Embodiment 8 ~ 10 is containing N, Mo and not containing the cast steel of W, it is at 1000 DEG C, and the high-temperature creep life-span under 50MPa condition is apparently higher than commercial alloy CF8C-Plus, and its room temperature low-cycle fatigue life meets the service condition of exhaust system.
The chemical composition (mass percent) of table 1 embodiment
| Sequence number | Fe | Cr | Ni | Nb | C | Si | Mn | N | W | Mo |
| Embodiment 1 | Bal. | 20.35 | 9.86 | 2.08 | 0.43 | 0.60 | 1.01 | 0.29 | - | - |
| Embodiment 2 | Bal. | 20.91 | 9.60 | 2.16 | 0.21 | 0.86 | 0.95 | 0.22 | - | - |
| Embodiment 3 | Bal. | 21.32 | 9.88 | 2.18 | 0.23 | 0.92 | 0.95 | 0.36 | - | - |
| Embodiment 4 | Bal. | 19.68 | 10.12 | 2.09 | 0.29 | 0.80 | 0.93 | 0.15 | - | - |
| Embodiment 5 | Bal. | 20.38 | 9.18 | 2.14 | 0.49 | 0.70 | 0.95 | 0.30 | 1.20 | - |
| Embodiment 6 | Bal. | 21.25 | 10.08 | 2.31 | 0.44 | 0.67 | 0.89 | 0.26 | 3.14 | - |
| Embodiment 7 | Bal. | 21.40 | 9.88 | 2.32 | 0.40 | 0.60 | 0.81 | 0.27 | 4.87 | - |
| Embodiment 8 | Bal. | 21.24 | 10.12 | 2.30 | 0.39 | 0.73 | 0.87 | 0.33 | - | 2.10 |
| Embodiment 9 | Bal. | 21.18 | 10.13 | 2.34 | 0.42 | 0.74 | 0.86 | 0.29 | - | 4.08 |
| Embodiment 10 | Bal. | 21.28 | 10.14 | 2.37 | 0.42 | 0.72 | 0.86 | 0.30 | - | 6.15 |
| CF8C-Plus | Bal. | 19.5 | 12.3 | 0.63 | 0.13 | 0.64 | 4.2 | 0.3 | - | 0.34 |
The Evaluation results of table 2 embodiment and commercial alloy.
Claims (6)
1. one kind has the heat-resistant cast austenitic stainless steel of excellent high temperature over-all properties, its chemical composition is calculated as C:0.1% ~ 0.6%, N:0.1% ~ 0.5%, Si:0.4% ~ 1.5%, below Mn:1.5%, Cr:17.5% ~ 22.5%, Ni:8.0% ~ 13.0%, Nb:1.0% ~ 3.0%, below W:5.0%, below Mo:6.5% according to massfraction, remaining as matrix element Fe and below impurity element P:0.04%, below S:0.03%, below O:0.04%, below Al:0.05%.
2. the heat-resistant cast austenitic stainless steel with excellent high temperature over-all properties according to claim 1, its characteristic component is calculated as C:0.2% ~ 0.5%, N:0.1% ~ 0.4%, Si:0.5% ~ 1.0%, Mn:0.5% ~ 1.5%, Cr:18.5% ~ 21.5%, Ni:9.0% ~ 12.0%, Nb:1.5% ~ 2.5% according to massfraction, remaining as matrix element Fe and below impurity element P:0.04%, below S:0.03%, below O:0.04%, below Al:0.05%.
3. the heat-resistant cast austenitic stainless steel with excellent high temperature over-all properties according to claim 1, its characteristic component is calculated as C:0.2% ~ 0.5%, N:0.1% ~ 0.4%, Si:0.5% ~ 1.0%, Mn:0.5% ~ 1.5%, Cr:18.5% ~ 21.5%, Ni:9.0% ~ 12.0%, Nb:1.5% ~ 2.5%, W:1.0% ~ 5.0% according to massfraction, remaining as matrix element Fe and below impurity element P:0.04%, below S:0.03%, below O:0.04%, below Al:0.05%.
4. the heat-resistant cast austenitic stainless steel with excellent high temperature over-all properties according to claim 1, its characteristic component is calculated as C:0.2% ~ 0.5%, N:0.1% ~ 0.4%, Si:0.5% ~ 1.0%, Mn:0.5% ~ 1.5%, Cr:18.5% ~ 21.5%, Ni:9.0% ~ 12.0%, Nb:1.5% ~ 2.5%, Mo:2.0% ~ 6.5% according to massfraction, remaining as matrix element Fe and below impurity element P:0.04%, below S:0.03%, below O:0.04%, below Al:0.05%.
5. the heat-resistant cast austenitic stainless steel with excellent high temperature over-all properties according to claim 1, is characterized in that: the total content scope of (C+N) is: 0.2% ~ 0.8%.
6. the preparation technology with the heat-resistant cast austenitic stainless steel of excellent high temperature over-all properties according to any one of Claims 1 to 5, is characterized in that comprising the following steps:
(1) metallic substance such as highly purified Fe, Cr, Ni, C, Nb, W, Mo, Si, Mn and nitrided ferro-chromium alloy is taken by composition proportion;
(2) the above-mentioned high purity metal material that takes and nitrided ferro-chromium alloy are put into vacuum induction furnace crucible, be evacuated to 5 × 10
-2below Pa, then pours into a mould after 20 ~ 30 minutes 1500 ~ 1550 DEG C of meltings, can obtain heat-resistant cast austenitic stainless steel ingot.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410814709.5A CN104593692B (en) | 2014-12-24 | 2014-12-24 | A kind of heat-resistant cast austenitic stainless steel with excellent high temperature combination property |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410814709.5A CN104593692B (en) | 2014-12-24 | 2014-12-24 | A kind of heat-resistant cast austenitic stainless steel with excellent high temperature combination property |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104593692A true CN104593692A (en) | 2015-05-06 |
| CN104593692B CN104593692B (en) | 2017-01-04 |
Family
ID=53119741
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410814709.5A Active CN104593692B (en) | 2014-12-24 | 2014-12-24 | A kind of heat-resistant cast austenitic stainless steel with excellent high temperature combination property |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104593692B (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105970116A (en) * | 2016-05-30 | 2016-09-28 | 苏州双金实业有限公司 | Steel being good in plastic property |
| CN107761010A (en) * | 2017-10-17 | 2018-03-06 | 中国华能集团公司 | A kind of tube material with excellent high temperature stabilized soil pavement and preparation method thereof |
| US10927439B2 (en) | 2018-05-30 | 2021-02-23 | Garrett Transportation I Inc | Stainless steel alloys, turbocharger components formed from the stainless steel alloys, and methods for manufacturing the same |
| EP3816317A1 (en) * | 2019-10-30 | 2021-05-05 | Garrett Transportation I Inc. | Stainless steel alloys, turbocharger components formed from the stainless steel alloys, and methods for manufacturing the same |
| CN113106355A (en) * | 2021-03-11 | 2021-07-13 | 湖南恒基粉末科技有限责任公司 | High-hardness 316L stainless steel and preparation method and application thereof |
| CN113862562A (en) * | 2021-09-09 | 2021-12-31 | 中车戚墅堰机车车辆工艺研究所有限公司 | Antioxidant high-creep cast austenitic heat-resistant stainless steel and preparation method thereof |
| CN114032448A (en) * | 2020-09-29 | 2022-02-11 | 西峡县众德汽车部件有限公司 | Cast steel material for automobile turbocharger shell |
| WO2022218444A1 (en) * | 2021-05-24 | 2022-10-20 | 大冶特殊钢有限公司 | Method for smelting high-temperature alloy with ultrahigh n content in vim furnace |
| CN115341136A (en) * | 2016-07-29 | 2022-11-15 | 三菱制钢株式会社 | Heat-resistant casting |
| CN115637393A (en) * | 2022-10-28 | 2023-01-24 | 鞍钢集团矿业有限公司 | Austenitic heat-resistant steel for chain grate link and preparation method thereof |
| CN115852256A (en) * | 2022-12-09 | 2023-03-28 | 哈尔滨汽轮机厂有限责任公司 | Application of ZG06Cr19Ni10 stainless steel with high ferrite content in preparation of low-voltage nuclear power guide vane |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01154848A (en) * | 1987-12-12 | 1989-06-16 | Nippon Steel Corp | Production of austenitic stainless steel having excellent seawater resistance |
| JPH07278759A (en) * | 1994-04-14 | 1995-10-24 | Hitachi Metals Ltd | Austenitic heat resistant cast steel, excellent in strength at high temperature and machinability, and exhaust system parts made thereof |
| JP2000054081A (en) * | 1998-08-10 | 2000-02-22 | Kawasaki Steel Corp | Austenitic stainless steel sheet free from uneven surface gloss, and its manufacture |
| JP2002256400A (en) * | 2001-02-27 | 2002-09-11 | Hitachi Ltd | Highly corrosion resistant and high strength austenitic stainless steel and production method therefor |
| JP2012082488A (en) * | 2010-10-13 | 2012-04-26 | Sumitomo Metal Ind Ltd | Austenitic stainless steel excellent in adhesion to film |
-
2014
- 2014-12-24 CN CN201410814709.5A patent/CN104593692B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01154848A (en) * | 1987-12-12 | 1989-06-16 | Nippon Steel Corp | Production of austenitic stainless steel having excellent seawater resistance |
| JPH07278759A (en) * | 1994-04-14 | 1995-10-24 | Hitachi Metals Ltd | Austenitic heat resistant cast steel, excellent in strength at high temperature and machinability, and exhaust system parts made thereof |
| JP2000054081A (en) * | 1998-08-10 | 2000-02-22 | Kawasaki Steel Corp | Austenitic stainless steel sheet free from uneven surface gloss, and its manufacture |
| JP2002256400A (en) * | 2001-02-27 | 2002-09-11 | Hitachi Ltd | Highly corrosion resistant and high strength austenitic stainless steel and production method therefor |
| JP2012082488A (en) * | 2010-10-13 | 2012-04-26 | Sumitomo Metal Ind Ltd | Austenitic stainless steel excellent in adhesion to film |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105970116A (en) * | 2016-05-30 | 2016-09-28 | 苏州双金实业有限公司 | Steel being good in plastic property |
| CN115341136A (en) * | 2016-07-29 | 2022-11-15 | 三菱制钢株式会社 | Heat-resistant casting |
| CN107761010A (en) * | 2017-10-17 | 2018-03-06 | 中国华能集团公司 | A kind of tube material with excellent high temperature stabilized soil pavement and preparation method thereof |
| CN107761010B (en) * | 2017-10-17 | 2019-06-14 | 中国华能集团公司 | A kind of tube material and preparation method thereof with excellent high temperature stabilized soil pavement |
| US10927439B2 (en) | 2018-05-30 | 2021-02-23 | Garrett Transportation I Inc | Stainless steel alloys, turbocharger components formed from the stainless steel alloys, and methods for manufacturing the same |
| EP3816317A1 (en) * | 2019-10-30 | 2021-05-05 | Garrett Transportation I Inc. | Stainless steel alloys, turbocharger components formed from the stainless steel alloys, and methods for manufacturing the same |
| US11725266B2 (en) | 2019-10-30 | 2023-08-15 | Garrett Transportation I Inc. | Stainless steel alloys, turbocharger components formed from the stainless steel alloys, and methods for manufacturing the same |
| CN114032448A (en) * | 2020-09-29 | 2022-02-11 | 西峡县众德汽车部件有限公司 | Cast steel material for automobile turbocharger shell |
| CN113106355A (en) * | 2021-03-11 | 2021-07-13 | 湖南恒基粉末科技有限责任公司 | High-hardness 316L stainless steel and preparation method and application thereof |
| WO2022218444A1 (en) * | 2021-05-24 | 2022-10-20 | 大冶特殊钢有限公司 | Method for smelting high-temperature alloy with ultrahigh n content in vim furnace |
| CN113862562A (en) * | 2021-09-09 | 2021-12-31 | 中车戚墅堰机车车辆工艺研究所有限公司 | Antioxidant high-creep cast austenitic heat-resistant stainless steel and preparation method thereof |
| CN113862562B (en) * | 2021-09-09 | 2023-12-05 | 中车戚墅堰机车车辆工艺研究所有限公司 | Antioxidant high-creep cast austenitic heat-resistant stainless steel and preparation method thereof |
| CN115637393A (en) * | 2022-10-28 | 2023-01-24 | 鞍钢集团矿业有限公司 | Austenitic heat-resistant steel for chain grate link and preparation method thereof |
| CN115852256A (en) * | 2022-12-09 | 2023-03-28 | 哈尔滨汽轮机厂有限责任公司 | Application of ZG06Cr19Ni10 stainless steel with high ferrite content in preparation of low-voltage nuclear power guide vane |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104593692B (en) | 2017-01-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104593692B (en) | A kind of heat-resistant cast austenitic stainless steel with excellent high temperature combination property | |
| JP3936849B2 (en) | Ferrite-based spheroidal graphite cast iron and exhaust system parts using the same | |
| CN110724861B (en) | High-performance aluminum alloy engine cylinder cover and casting method thereof | |
| JP6768929B2 (en) | Ferritic stainless steel with excellent high-temperature wear resistance, manufacturing method of ferritic stainless steel sheet, exhaust parts, high-temperature sliding parts, and turbocharger parts | |
| CN108842082B (en) | A kind of Fe-Ni base cast superalloy and preparation method thereof | |
| CN105603260A (en) | High-temperature-resistant turbocharger turbine wheel | |
| CN113862562B (en) | Antioxidant high-creep cast austenitic heat-resistant stainless steel and preparation method thereof | |
| CN102168211B (en) | High-temperature-resistant cobalt-based alloy for heat-resistant heel block of steel rolling heating furnace | |
| CN116445679A (en) | Manufacturing method of yttrium-containing ultrapure high-chromium ferritic stainless steel master alloy | |
| CN102605214A (en) | Novel nickel-base alloy for vent valve of combustion engine | |
| KR20130130490A (en) | Ferritic spheroidal cast iron for exhaust system | |
| CN1670406A (en) | Seal ring for turbocharger of internal combustion engine and its manufacturing method | |
| JP2543417B2 (en) | Valve steel | |
| CN109536781B (en) | High-purity low-inclusion nickel-based powder high-temperature alloy and preparation method and application thereof | |
| CN1032599C (en) | Nickel-saving heat-resisting steel | |
| CN112853207B (en) | Heat-resistant steel for turbocharger assembly and smelting method thereof | |
| JPH0686642B2 (en) | Heat resistant spheroidal graphite cast iron | |
| JPH0359967B2 (en) | ||
| JPS62142745A (en) | Heat-resistant spheroidal graphite cast iron | |
| CN117965963A (en) | High-performance engine valve and preparation process thereof | |
| JPS6233744A (en) | Heat-resistant cast steel | |
| CN110527892A (en) | Low expansion superalloy and preparation method thereof | |
| CN116479346A (en) | Heat-resistant cast steel for turbine shell of gasoline engine turbocharger and preparation method thereof | |
| CN1095424A (en) | Austenite high-temperature anti-carburization steel | |
| JPH06136487A (en) | Engine valve |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |