CN101532075A - Method of increasing resistance to stress corrosion cracking of austenitic stainless steels - Google Patents
Method of increasing resistance to stress corrosion cracking of austenitic stainless steels Download PDFInfo
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- C21D1/26—Methods of annealing
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- C22C19/03—Alloys based on nickel or cobalt based on nickel
- C22C19/05—Alloys based on nickel or cobalt based on nickel with chromium
- C22C19/058—Alloys based on nickel or cobalt based on nickel with chromium without Mo and W
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- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
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- 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
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- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/001—Austenite
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/004—Dispersions; Precipitations
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/50—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for welded joints
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Abstract
A method of providing resistance to intergranular stress corrosion cracking in an alloy material, the method comprising sensitizing the alloy to form carbides (22), allowing the carbides to precipitate, and applying a heat treatment to replenish a chromium-depleted zone (24).
Description
Background of invention
[0001] the present invention relates in general to the method for alleviating stress corrosion crack in the austenite solid solution hardened stainless steel.
[0002] in the application of for example nuclear reactor, steam driven turbine or water deoxygenator, the high temperature in high purity water or the water/steam system becomes rodent environment, can bring negative impact to structured material by general corrosion or stress corrosion crack (SCC).For example, high-temperature water can make for example material generation stress corrosion SCC of stainless steel, Ni-Fe base alloy and nickel-base alloy.Under the existence of the environment of chloride under some corrosive atmosphere, particularly high temperature or sulfur-bearing hydrochlorate, when material stands to add or during remaining tension stress, SCC can take place.The difference that these stress can come from thermal expansion between the part or shrink, working pressure high relatively or that change, perhaps they can be the unrelieved stresss that various technology produced of carrying out in the production of part or system or the assembling process.Except stress, the remaining plastix strain that produces in part or system's production or the assembling process can make the easier generation of material SCC.For example, SCC can come from the unrelieved stress that metal treatment produced of welding, cold working and other hot machine.Stress corrosion crack also comprises the cracking that static state or Dynamic tension stress caused that acts on simultaneously with corrosion.Water chemistry, welding, thermal treatment and radiation all can increase the susceptibility of metal or alloy part counter stress corrosion cracking.
[0003] intergranular stress corrosion cracking (IGSCC) is the localization cracking, susceptible crystal boundary of material place in the erosion environment condition under it occurs in and loads.The sliding rank (slip step) of intergranular oxidizing reaction weakens crystal boundary, and crystal boundary opens and form the physics cracking under applied load then.The cracking development does not almost have or does not have the sign of viscous deformation, and partial destruction takes place probably.The generation of IGSCC usually needs three simultaneous conditions: materials chemistry is formed or the localized variation of crystal boundary microtexture, remnants or applied stress and be exposed in the corrosive atmosphere.All these key factors all can be facilitated the formation and development of stress corrosion crack.For example, a kind of common sensitization form is by due to the Thermal Cycle, and welding postcooling speed is slow, is enough to make rich chromium carbide to be separated out at the crystal boundary place.Separating out of carbide, the adjacent crystal boundary of exhausting chromium makes them no longer have erosion resistance to a certain degree.Therefore, in the time of in the presence of chemical corrosion water surrounding and tension stress, in the erosion-resisting material of script, at these crystal boundary places SCC may take place.
[0004] the IGSCC correlative study has produced the multiple remission method of handling these various inducements.A kind of alleviation is susceptible material stress corrosion rimose method in boiling water reactor for example, is by using hydrogen water chemistry (HWC), and this comprises in the reactor feedwater and adds hydrogen.The adding of hydrogen has reduced the level of oxidisability thing, for example dissolved oxygen and hydrogen peroxide, thus reduce the susceptibility of stress corrosion crack.Unfortunately, hydrogen water chemistry technology may need a large amount of hydrogen, with the stress corrosion crack susceptibility in the various parts of effective reduction to acceptable level.
[0005] with stainless steel, high chromium super stainless steel, Fe-Ni-base and Ni-base alloy and chromium component alloy, to obtain overall erosion resistance, if but the Cr add-on is not enough to keep stable oxide film in corrosive atmosphere, if perhaps microstructure change has produced low chromium concn zone, then this method can not be alleviated SCC.A problem is that these materials are unstable on possibility microtexture under its expection service temperature, perhaps may or weld to produce the microtexture of SCC susceptible through heat-treated.Alleviating the used a kind of method of SCC, is to add oxide compound continuously to strengthen or stabilizing element in corrosive atmosphere.The utilization of another kind method adds catalytic element (for example platinum), and producing hydrogen in corrosive atmosphere, hydrogen reduce free oxygen in water, reduce to minimum thereby it is corroded inducing action.A problem of this method is that it needs terminal user to participate in initiatively keeping the SCC mitigation strategy.In addition, it can produce partly or the operation bidirectional expense during equipment life.
[0006] therefore, still need novel method with the relieve stresses corrosion cracking.
The invention summary
[0007] herein disclosed is the method for resisting Fe-Ni-Cr alloy material intergranular stress corrosion cracking.
[0008] in one embodiment, the invention provides the method for antagonism Fe-Ni-Cr alloy material intergranular stress corrosion cracking, this method comprises that the Fe-Ni-Cr alloy material is carried out sensitization to be handled, form carbide precipitation at the grain boundary interfaces place, and near carbide precipitation, form poor chromium district, sensitization Fe-Ni-Cr alloy material is heated to certain temperature and time, chromium is diffused in the poor chromium district.
[0009] in another embodiment; the invention provides the treatment process that at the grain boundary interfaces place carbide precipitation is arranged and the sensitization Fe-Ni-Cr alloy material in poor chromium district is arranged near carbide precipitation; described method comprises: sensitization Fe-Ni-Cr alloy material is heated to certain temperature and time; chromium is diffused into the poor chromium district from the crystal grain matrix (grain matrix) of Fe-Ni-Cr alloy material, and wherein the resistivity to the intergranular stress corrosion cracking increases to some extent with respect to the sensitization Fe-Ni-Cr that does not have heating.
[0010] feature of part disclosed herein and method and benefit with reference to the following drawings with detailed description and included here embodiment, can be easier to understand.
The accompanying drawing summary
[0011] the following drawings, wherein the numbering of same element is identical, is illustrative purpose.
[0012] Fig. 1 is the synoptic diagram that improves alloy material stress corrosion crack resistivity method.
[0013] Fig. 2 illustrates after the solution annealing thermal treatment, does not have rich chromium carbide at the crystal boundary place of 800H alloy.
[0014] Fig. 3 illustrates after the sensitization thermal treatment, has rich chromium carbide to separate out at the crystal boundary place of 800H alloy.
Detailed Description Of The Invention
[0015] the present invention relates in general to method, particularly Fe-base, Fe-Ni base or the Ni-base alloy of alleviating stress corrosion crack in the austenite solid solution hardened stainless steel, those alloys that for example use in the high temperature and high pressure aqueous environments.More specifically, the present invention relates to prevent the austenite solid solution to strengthen the intergranular stress corrosion cracking (IGSCC) of 800 and 300 series alloys.Compared with prior art, the inventive method comprises the sensitization of alloy part, forms the chromium carbide precipitation at the crystal boundary place, prolongs heat treatment time then, and chromium is diffused in the poor chromium district that sensitization causes.In the object lesson of 800 series alloys, material can be stayed in the sensitization condition, and in austenitic stainless steel, needs to prolong thermal treatment and form with the chromium that recovers the crystal boundary place.Chromium carbide precipitation is in the nature spherical or lamelliform, combines with the diffusion of chromium in poor chromium district, has strengthened the resistivity to IGSCC.
[0016] in another embodiment, the alloy part after sensitization is handled can be exposed to heat treatment process, and chromium is diffused in the poor chromium district that sensitization causes.As mentioned above, the sensitization alloy comprises that partly near the rich chromium carbide the crystal boundary precipitates.So, alloy has partly experienced the self-healing process.
[0017] as used herein, the solution hardened stainless steel is the notion on its common meaning, typically refer to heat treatment process, its interalloy is heated to suitable temperature, keeps the sufficiently long time under this temperature, makes the secondary solid-state dissolving of experiencing mutually, and make these one or more components in mutually enter the matrix phase solid solution, cooling rapidly is enough to these compositions are stayed in the solution then, guarantees that perhaps secondary phase can not separate out again.Under this condition, the microtexture of formation generally includes the primary carbide that is dispersed in the single-phase matrix, has clean substantially crystal boundary.In addition, term " first ", " second " etc. are not meant any order or importance, but being used to distinguish a kind of element and another kind of element, term " described ", " one " and " a kind of " are not meant quantitative restriction, and are meant and exist at least a or a described project.With the modifier " approximately " of quantity coupling, comprise described numerical value and have the implication (for example, comprising and the relevant error degree of specific quantity measurement) of context indication.In addition, all scopes disclosed herein comprise endpoint value and can independently make up.
[0018] in one embodiment, described method comprises the sensitization of alloy part, heats described part then after the alloy material sensitization continuously.As discussed above, sensitization can cause chromium carbide to be separated out at the crystal boundary place.Separating out of these carbide exhausted to a certain degree the chromium in adjacent grain boundary zone, makes them no longer have erosion resistance.The formation of chromium carbide causes sensitization around the crystal boundary.The Fu Ge precipitation attracts the chromium in the adjacent substrate, and this causes the formation in poor chromium district.If the content of chromium is lower than the 11-12 atomic percent in the poor chromium district, think that then stainless steel is by sensitization.
[0019] as a result of, described part can be subject to intergranular stress corrosion cracking (IGSCC) influence usually.Yet, heating the part that the crystal boundary place has poor chromium district continuously, the chromium in the matrix effectively can be diffused in the poor chromium district.In one embodiment, the part with poor chromium district is heated for some time at about 450 to about 700 ℃, and the chromium in the matrix is spread along the chromium composition gradient due to the sensitization, and replenishes poor chromium district along the border, recovers the erosion resistance of metal.The present invention finds that the existence of the rich chromium carbide of crystal boundary place intergranular can strengthen the resistivity to IGSCC.The more important thing is that for some high chromium Fe-Ni base alloy, for example 800 families of super stainless steel are listed as, the existence of rich chromium carbide can strengthen the resistibility to the IGSCC development alone.Therefore, the present invention relates in general to heat treating method, is designed to make its self-healing produce the IGSCC resistivity again by first sensitization metal.The gained alloy material to promoting the environment of intergranular SCC, under static state or dynamic mechanically load, has the IGSCC resistivity.
[0020] in illustrative embodiment, alloy material is that the austenite solid solution is strengthened super stainless steel, is similar to the compositing range of 800 series alloys.The general feature of austenitic stainless steel is: high ductibility, low relatively yielding stress and ultimate tensile strength, (in annealing or solution annealing conditions), cold working (cold work) can significantly increase tensile property.Typical soft steel is wustite and iron carbide (Fe through cooling from austenitic transformation
3C) mixture.And austenitic stainless steel, high chromium and nickel content suppress this transformation, make material basic austenite that keeps under cooling.
[0021] austenitic steel is divided three classes, AISA200 series (alloy of iron-chromium-nickel-manganese), AISA300 series (alloy of iron-chromium-nickel) and nitrogen reinforced alloys.Carbon content is had nothing in common with each other (be generally 0.15% or still less carbon) with the difference of series, and in 300 series, carbon content depends on that whether alloy is that L level, low carbon concentration (0.03% or still less) or nominal are formed (0.08% or still less).The composition of these alloys has certain limit, but comprises minimum 16% chromium and enough nickel and manganese usually, to provide stable austenitic structure under the temperature that is lower than martensite initial (Ms) temperature.It is the alloy of chromium-manganese-nitrogen that nitrogen is strengthened austenitic stainless steel; Some rank also contains nickel.Austenitic stainless steel is generally used in corrodibility or the low temperature environment, and this moment, erosion resistance and toughness were primary requirements.Typical application comprises axle, pump, fastening piece and the pipeline in the seawater and processes the equipment of chemical, food and milk-product.Another kind of, more related with the present invention, be austenite " super stainless steel ", it is in the centre of austenitic stainless steel and Fe-Ni base superalloy.These materials, representative are alloy 800 series, it is characterized by: much higher nickel and chromium content, higher carbon content and a little amount of titanium and the aluminium of having a mind to adding.
[0022] in illustrative embodiment, the consisting of of alloy material: 18-30% chromium, 8-80% nickel and less alloy additive (carbon, nitrogen, molybdenum, niobium, titanium and manganese).
[0023] suitable austenitic alloy includes, but not limited to 800 series (19.0-23 weight %Cr, 30-35 weight %Ni, 0.15-0.6 weight %Al, 0.15-0.6 weight %Ti, with 10 weight %C maximum values) representative super stainless steel and 300 serial austenitic alloys, for example stainless grade of steel 304 (18-20%Cr and 8-12%Ni), 316 (16-18%Cr, 10-14%Ni, and 2-3%Mo), 316Ti (add titanium 316), 320 (same 316Ti), 321 (17-19%Cr, 9-12%Ni, and titanium), 347 (17-19%Cr, 9-13%Ni, and niobium), 308 (19-22%Cr, 9-11%Ni), 309 (22-24%Cr, 12-15%Ni), 310 (24-26%Cr, 19-22%Ni), 904L (20%Cr, 25%Ni, 4.5%Mo) or the like.Other alloying element can comprise vanadium (V), aluminium (Al), tungsten (W), cobalt (Co), copper (Cu), nitrogen (N), and carbon (C).Therefore as if, number of levels is unrestricted, manufacturer can add different substances according to concrete application in a large amount of standards is formed.For the purposes of the present invention; it is inapplicable that chromium concn is lower than the stainless steel rank of 16 weight %; because lower chromium concn can not be used for expection comprehensively erosion resistance is provided enough, this is because the character of the protectiveness Cr oxide skin that forms and owing to the minimizing that causes Cr in the alloy substrate of separating out of rich Cr intergranular carbide.
[0024] alloy production can be with various technology approach, for example casting, powder metallurgy or foundry goods/affinage metallurgy.Can use any conventional melting process to make alloying constituent fusing, for example air fusing, argon hydrogen reduction (AOD), ladle refining, vacuum induction melting (VIM), vacuum arc melt (VAR), electroslag again and melt (ESR) etc. again.
[0025] can make the alloy homogenizing then before hot-work, perhaps it can be heated and directly carry out hot-work.If the use homogenizing can be undertaken by adding thermalloy to metal temperature (about 1100 ℃ to about 1400 ℃ of scope) for some time (8 hours) at least,, also make even structureization to dissolve solvable element and carbide.Appropriate time in homogenizing metal temperature scope is 8 hours or longer.Usually, the soaking time under homogenization temperature needn't prolong above 72 hours.After the homogenizing, alloy carries out hot-work usually.Alloy hot-work can be passed through, but is not limited to, and hot rolling, forge hot, or hot extrusion or its arbitrary combination are to obtain required size and dimension.After this process is to give the human consumer with alloy product, carries out the last production of assembly and suitable thermal treatment and precision work (finishing).Usually the human consumer can make alloy required shape.Can heat-treat separately or with various combinations, temperature processing or cold working are to obtain required tensile property and fracture toughness.
[0026] Fig. 1 schematically sets forth the crystal boundary in the austenite super stainless steel under the solution annealing conditions.In step 10, before sensitization of the present invention and heat treatment process, the interface 12 of several crystal grain of polycrystalline alloy material shows clean substantially crystal boundary, and wherein the chromium carbide precipitation does not also occur.In step 20, the Steel Alloy material at first is exposed to sensitizing, and wherein the Steel Alloy material is heated under certain speed and condition and cools off, and chromium carbide precipitation 22 is formed at the grain boundary interfaces place.The sedimentary formation of chromium carbide causes poor chromium district 24 occurring near the chromium carbide precipitation.In illustrative embodiment, chromium carbide precipitation 22 is Cr
23C
6, and also can comprise Mo, V, W, Nb, Ta, B and combination thereof.According to the situation of alloy described in the step 30, Steel Alloy can be diffused in the poor chromium district 24 chromium further through heat treatment process.Heat treatment process can independently be carried out, perhaps can with the process that causes sensitization (that is, grain boundary interfaces place form chromium carbide) combination.Ensuing heat exposes; Described part is perhaps processed in thermal treatment, operation, can order about chromium and spread along the Cr composition gradient that chromium carbide precipitates and growth causes, and recover the anticorrosion properties of material.The existence of intergranular carbide 22 and the chromium that spreads at the interface can provide the resistibility to the intergranular stress corrosion cracking.
[0027] heating source can be any means that can replenish above-mentioned poor chromium district.In one embodiment, heating source can be steam stove or electric furnace, induction, infrared rays, fused salt or metal bath, or laser.In another embodiment, thermal source can use aforesaid method to be positioned to the specific region of part, perhaps can be used as production, welding or heat treated result and occurs, and perhaps occurs in the operating process to part under hot environment.
[0028] using time expand thermal treatment to obtain IGSCC resistivity crystal boundary chemistry (erosion resistance), is the approach of the economy of prevention IGSCC.Compare with specifying professional alloy or assembling postheat treatment, thermal treatment is relatively cheap a kind of method.The present invention will provide significant material and work cost savings, and the more long lifetime of gasification product is provided simultaneously.In addition, disclosed heat treating method is useful, for example be of value to need be used for gasifying, the austenitic alloy of the structure division of nuclear, water and oil and gas industry etc. has the IGSCC resistivity anything.
[0029] following examples are covered by within the scope of method of the more general description that proposes above, and are used for the method for the more general description that illustration proposes above.The proposition of embodiment is illustrative purpose only, has no intention to limit the scope of the invention.
Embodiment 1
[0030] in one embodiment, studied the sensitization of alloy 800H.The IGSCC test of sensitization sample has confirmed the IGSCC resistivity.Alloy 800H has been carried out repeated in experiments, comprised sensitization, carbide precipitation according to the inventive method, and thermal treatment subsequently.Use ASTM A262 Practice C boiling nitric acid (or " Huey ") test to detect sensitization, and by using transmission electron microscope (Transmission Electron Microscope) (TEM) to measure the chromium concn affirmation sensitization of crystal boundary adjacent domain.The evidence that effect of the present invention is more certain is to measure to separate out intergranular M through thermal treatment
23C
6The IGSCC rate of rise of the alloy 800H of carbide in high temperature (288 ℃) and high pressure (1500psig) aqueous environments.Test used mechanical testing condition, be designed to impel the austenitic metal of wide scope chemical constitution to produce IGSCC.The test-results of sensitization heat treatment material shows extremely low IGSCC rate of rise (1x10
-9Mm/s), this possibility that shows the SCC sustainable growth is extremely low.Typical sensitized material records under this and the simulated condition greater than 1x10
-7The IGSCC rate of rise of mm/s forms contrast.
[0031] this printed instructions uses embodiment disclose best mode, also makes any technician in this area can implement the present invention, comprises making and uses any device or system and carry out any method that the present invention comprises.Claim of the present invention is by the claim defined, and can comprise other embodiment that those skilled in the art can expect.These other embodiment are covered by within the scope of this claim, if their structural element is not different from the word language of claim, if perhaps they comprise that the word language with claim does not have the suitable structural element of essence difference.
Components list
10 steps 10
12 interfaces
20 steps 20
22 carbide precipitations
24 poor chromium districts
30 steps 30
The chromium of 34 diffusions
Claims (10)
1. method of resisting Fe-Ni-Cr alloy material intergranular stress corrosion cracking, described method comprises:
The Fe-Ni-Cr alloy material is carried out sensitization handle, locate to form carbide precipitation (22), and near carbide precipitation (22), form poor chromium district (24) in grain boundary interfaces (12); With
The Fe-Ni-Cr alloy material of sensitization is heated to certain temperature and time, chromium (34) is diffused in the poor chromium district (24).
2. the process of claim 1 wherein that the Fe-Ni-Cr alloy material comprises at least 16% chromium.
3. each method in the aforementioned claim, wherein carbide precipitation comprises chromium.
4. each method in the aforementioned claim, wherein carbide precipitation is formula Cr
23C
6, Cr
7C
3And combination.
5. each method in the aforementioned claim, wherein carbide precipitation also comprises Fe, Mo, V, W, Ti, Nb, Ta, Hf and combination thereof.
6. handle the method for the Fe-Ni-Cr alloy material of sensitization; the Fe-Ni-Cr alloy material of described sensitization has been located carbide precipitation and poor chromium district (24) has been arranged near carbide precipitation (22) in grain boundary interfaces (12); described method comprises: the Fe-Ni-Cr alloy material of sensitization is heated to certain temperature and time; chromium (34) is diffused into the poor chromium district (24) from the crystal grain matrix of Fe-Ni-Cr alloy material, and wherein the resistivity to the intergranular stress corrosion cracking increases to some extent with respect to the Fe-Ni-Cr that does not have the sensitization of heating.
7. the method for claim 6, wherein the Fe-Ni-Cr alloy material comprises at least 16% chromium.
8. each method in the aforementioned claim 6 and 7, wherein carbide precipitation comprises chromium.
9. each method in the aforementioned claim 6 to 8, wherein carbide precipitation is formula Cr
23C
6, Cr
7C
3And combination.
10. each method in the aforementioned claim 6 to 9, wherein carbide precipitation also comprises Fe, Ti, Mo, V, W, Nb, Ta, Hf and combination thereof.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US12/047471 | 2008-03-13 | ||
| US12/047,471 US20090229714A1 (en) | 2008-03-13 | 2008-03-13 | Method of mitigating stress corrosion cracking in austenitic solid solution strengthened stainless steels |
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|---|---|
| CN101532075A true CN101532075A (en) | 2009-09-16 |
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| CN200910127528A Pending CN101532075A (en) | 2008-03-13 | 2009-03-12 | Method of increasing resistance to stress corrosion cracking of austenitic stainless steels |
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| US (1) | US20090229714A1 (en) |
| EP (1) | EP2100977A1 (en) |
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| CN110195152A (en) * | 2019-06-11 | 2019-09-03 | 河南神州精工制造股份有限公司 | A method of improving austenitic stainless steel anti intercrystalline corrosion ability |
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| EP2760977B1 (en) * | 2011-09-30 | 2019-12-11 | Uop Llc | Process for treating hydrocarbon streams |
| US20180010222A1 (en) * | 2015-02-06 | 2018-01-11 | Atomic Energy Of Canada Limited / Énergie Atomique Du Cannada Limitée | Nickel-chromium-iron alloys with improved resistance to stress corrosion cracking in nuclear environments |
| DE102018113396A1 (en) * | 2018-06-06 | 2019-12-12 | Man Energy Solutions Se | Burst protection device for a turbomachine |
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| JPS5469516A (en) * | 1977-11-14 | 1979-06-04 | Hitachi Ltd | Heat treating method for austenitic stainless steel to prevent stress corrosion cracking |
| US4168994A (en) * | 1978-11-13 | 1979-09-25 | Combustion Engineering, Inc. | Thermal homogenization of steam generating tubing |
| US4239556A (en) * | 1978-12-22 | 1980-12-16 | General Electric Company | Sensitized stainless steel having integral normalized surface region |
| JPS60197816A (en) * | 1984-03-19 | 1985-10-07 | Mitsubishi Heavy Ind Ltd | Heat treatment of stainless cast steel |
| US5017249A (en) * | 1988-09-09 | 1991-05-21 | Inco Alloys International, Inc. | Nickel-base alloy |
| US4877461A (en) * | 1988-09-09 | 1989-10-31 | Inco Alloys International, Inc. | Nickel-base alloy |
| SE8904065L (en) * | 1988-12-07 | 1990-06-08 | Hitachi Ltd | METHOD OF IMPROVING THE PROPERTIES OF AUSTENITIC STAINLESS STEEL WELDERS |
| JP3218779B2 (en) * | 1993-03-18 | 2001-10-15 | 株式会社日立製作所 | Structural member excellent in neutron irradiation embrittlement resistance, austenitic steel used for it and its use |
| US5569896A (en) * | 1994-03-24 | 1996-10-29 | Marcelo; Ruben V. | Method and apparatus for determining the exponential powers of "i" |
| US6714618B1 (en) * | 1997-11-28 | 2004-03-30 | General Electric Company | Temperature-based method for controlling the amount of metal applied to metal oxide surfaces to reduce corrosion and stress corrosion cracking |
| US6391173B1 (en) * | 1999-10-25 | 2002-05-21 | General Electric Company | Electrochemical corrosion potential sensor |
| US6488782B2 (en) * | 2001-01-29 | 2002-12-03 | General Electric Company | Method of reducing corrosion potential and stress corrosion cracking susceptibility in nickel-based alloys |
| US6724854B1 (en) * | 2003-06-16 | 2004-04-20 | General Electric Company | Process to mitigate stress corrosion cracking of structural materials in high temperature water |
-
2008
- 2008-03-13 US US12/047,471 patent/US20090229714A1/en not_active Abandoned
-
2009
- 2009-03-11 EP EP09154817A patent/EP2100977A1/en not_active Withdrawn
- 2009-03-12 CN CN200910127528A patent/CN101532075A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110195152A (en) * | 2019-06-11 | 2019-09-03 | 河南神州精工制造股份有限公司 | A method of improving austenitic stainless steel anti intercrystalline corrosion ability |
Also Published As
| Publication number | Publication date |
|---|---|
| US20090229714A1 (en) | 2009-09-17 |
| EP2100977A1 (en) | 2009-09-16 |
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Application publication date: 20090916 |