US3754899A - Austenitic alloy containing boron and processes for manufacturing thesame - Google Patents
Austenitic alloy containing boron and processes for manufacturing thesame Download PDFInfo
- Publication number
- US3754899A US3754899A US00098101A US3754899DA US3754899A US 3754899 A US3754899 A US 3754899A US 00098101 A US00098101 A US 00098101A US 3754899D A US3754899D A US 3754899DA US 3754899 A US3754899 A US 3754899A
- Authority
- US
- United States
- Prior art keywords
- boron
- percent
- alloy
- carbon
- max
- 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.)
- Expired - Lifetime
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
- C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
Definitions
- the austenite is an ironchromium-nickel alloy containing from 0.01 to 0.2 percent boron, less than 0.009 percent carbon, and substantially free from nitrogen and oxygen.
- the boron is a solute in the austenite.
- the process of manufacture is to form a melt of iron, chromium, nickel and other additives, and then add a ferro-boron alloy having a melting point well below that of the base alloy. The process is carried out in a vacuum furnace in order to substantially eliminate carbon, nitrogen, and oxygen from the alloy.
- the invention relates to improvements in austenitic iron base alloys for use at elevated temperatures, and to processes for manufacturing the same, and more particularly to austenitic alloys containing boron that demonstrate improved high temperature stability.
- Austenitic iron base alloys have found many uses. They are used in articles in which strength, toughness, and resistance to corrosion are required. At elevated temperatures, however, for example. at-temperatures above about 1000F, austenitic stainless steels loose their stability, become sensitized, and are made susceptible to corrosion, cracking, and general deterioration.
- the austenitic alloys should not be exposed to temperatures above about l,000"F in fabrication or service for substantial periods of time withoutadverse deterioration and sensitization.
- the temperature of 1,05 F is regarded as the austenite barrier.
- Sensitization of the alloy as used herein refers to the phenomena that occurs when the alloy is heated to elevated temperatures for a period of time. Sensitization causes adverse effects: cracking, corrosion, and general deterioration of the metal. Sensitization is a time-temperature eifect, and use of the austenitic alloy in service for extended periods of time at about 1,000F or at higher temperatures for shorter periods of time results in corrosion and cracking.
- Another object of the invention is to provide austenitic alloys characterized by improved resistance to corrosion and cracking.
- Still another object of the invention is to provide an austenitic iron base alloy having improved stability at elevated temperatures.
- Yet another object of the invention is to provide an austenitic iron base alloy which has improved resistance to corrosion in the manufacture of parts for gas and steam generators, nuclear reactor systems, turbines, jet engines for aircraft, piping systems, and the like, which operate at temperatures above 1000F.
- Still yet another object of the invention is to provide a ferrous base austenitic alloy containing boron in which the precipitation of boron is avoided or substantially reduced.
- an austenitic alloy having high temperature stability can be produced by substantially eliminating the interstitial elements, carbon, nitrogen, and oxygen, and by incorporating boron in lieu thereof.
- the austenitic alloys of the invention are iron-chromium-nickel alloys which contain from about 0.01 percent by weight to about 0.2 percent by weight boron, and which are substantially free from carbon, nitrogen and oxygen.
- the carbon is eliminated as much as practicable, and ordinarily will be less than 0.009 percent by weight.
- the boron is a solid solute in the austenite.
- the austenitic alloys of the invention possessing the improved properties at elevated temperatures, comprise broadly from about 12 percent to about 30 percent by weight chromium, from about 8 percent to about 20 percent by weight nickel, from about 0.01 percent to about 0.2 percent by weight boron, 0 percent to about 2.5 percent by weight manganese, 0 percent to about 1.5 percent silicon, less than 0.009 percent by weight carbon, and the balance iron with incidental impurities.
- Such alloys are substantially free from carbon, nitrogen and oxygen, and from the precipitated forms of boron.
- An austenitic alloy of the invention having particular utility has a composition within the range between 18 percent to 20 percent chromium, 8 percent to 12 percent nickel, 0.03 percent to 0.15 percent boron, 0 percent to 2 percent manganese, 0 percent to 1 percent silicon, less than 0.009 percent carbon, the balance iron with incidental impurities, and substantially free from nitrogen and oxygen.
- the austenitic alloy of the invention depends upon the boron element locked within the lattice structure. Precipitation of the boron or migration of the boron through the alloy at high temperatures is to be avoided, and for this reason elements that react with the boron at elevated temperatures, particularly carbon and nitrogen, and also oxygen, or any other elements that might interfer with the solution of boron, are eliminated as far as practicable.
- the boron remains soluble in the alloy, EXAMPLE VII and during preparation and use efforts are made to Boron 003F059, maintain the boron as a solute 1n the austenite.
- the boron content usually is within the range from nickel g 0.01 percent to 0.2 percent, and preferably in the range 5 ggz 1% from 0.03 percent to 0.15 percent by weight, in the ab- Phosphorus 0.045 max sence of nitrides, carbides, or oxides thereof. remand
- the boron employed in the alloy may be the naturally EXAMPLE vm occuring element (B) having an atomic weight of 10.82. For some applications, however, it may be adgzg' i 'g vantageous to employ the isotope of boron (18 having Nickel 342% an atomic weight of about 1 l.
- the isotope B provides ggfiggg f max several advantages. It has less tendancy to migrate in on remainder the alloy than the naturally occuring element. Also, in
- the isotope may be more desirable since it has a lower nuclear capture Boron I 0 012% cross-section than natural boron.
- ghrpn uum I Chromium is the predominant element for providing 'g g 2% max COI'IOSIOI] resistance and oxidation resistance to the Silicon 1% rnax alloy at elevated temperatures. Chromium also enters 20 remand the solid solution and materially contributes to the EXAMPLE X strength of the matrix when it is present within the broad range. Chromium usually is in amounts less than gf zg' l I gig 58 22 percent by weight.
- Manganese if present, functions not only as a scav enger, but may increase the rupture ductility of the alloy, and may confer hot workability to the alloy.
- Silicon if present, functions not only as a scavenger, but may confer strength to the alloy, and also may contrib-
- the alloys are P'Qp y double vacuum meltingute to oxidation resistance Vacuum 1s first applied to the components before melt- While other additives may be beneficial, the alloy is i to remove oxygen and gf and also to the mellsubstantially free of elements, or impurities, that intermg procedures- T vacuum be Pressures fer with the solubility of boron in the austenite. For exbelow atmosphenc, and ordmanly at Pressures,
- the alloys 1 to Xl above are substantially free from carbon, nitrogen, and oxygen, and preferably the total amount of said elements is as low as practically possible, and most desirably, the combined total of all of said elements does not exceed 0.02percent by weight.
- tures of melting may be in the range from 2,500F to
- the presence of nitrogen and/or carbon in the alloy 3,0000 ⁇ :- has been discovered to interfer with the solubility of the
- the alloy of the present invention is prepared in a boron in the austenite therby reducing the stability of vacuum induction furnace.
- the vacuum furnace is necthe alloy at elevated temperatures.
- the alloy of the inessary for the out gassing of the elements carbon, nitrovention, therefore, is substantially free from the presgen, and oxygen from the melt, and to eliminate these ence of elements nitrogen and carbon.
- a total content particular elements as far as practicable.
- nents for example, manganese and/or silicon.
- electroaustenitic alloys embodying the invention magnetic coils to assure uniform combination of all the components of the melt. Shortly before the melt is to be poured, the desired amount of ferro-boron alloy is added. The chromium and silicon additions precede the boron addition in order to eliminate any nuclei that might cause precipitation of the boron. Due to its high melting point, boron is added as a ferro-boron alloy having a melting point substantially below the melting point of the base alloy to avoid nucleation of refractory chromium borides. The ferro-boron alloys containing less than percent by weight of boron are satisfactory for this purpose. The melt is stirred, and then may be teemed into ingots.
- the ingots may be forged or wrought after heating them to temperatures between l,500F and 2,200F. Heating at these elevated temperatures should be performed under a protective atmosphere of inert gases, such as helium, argon, and neon, or mixtures thereof, in order to prevent oxygen and nitrogen from entering the alloy and reacting with the boron.
- the articles may be cast, for instance, by precision casting, or shell molding, procedures from the melt without forging or working to the desired shape.
- the cast members may be ground or machined to the desired dimensions and configurations.
- novel austenitic alloys may be used for many purposes, but it has particular use under service conditions employing high temperatures.
- a protective atmosphere of inert gases such as helium, argon, neon, or mixtures thereof, may be used in order to prevent deterioration.
- inert gases such as helium, argon, neon, or mixtures thereof.
- Other inert gases may be employed which will not diffuse into the alloy and react with the boron element.
- the austenitic stainless steel alloys which are currently the subject of much investigation because of the sensitization problem is an acute form of the phenomena to which all iron based alloys are more or less susceptible upon being heated to elevated temperatures.
- Sensitization is a phase change occasioned by the diffusion or migration of the interstitial elements in the alloy, unlocking the phase transformation from austenite to ferrite.
- it is well known as to the 300 series austenitic stainless steels, that in order to put them in thebest condition to resist corrosion and cracking, they should be heated to 2,100F to solutionize the interstitial elements, and then rapidly cooled.
- the element boron serves as an interstitial alloying element. It readily enters into the solution of the alloy and is locked within the lattice of the alloy. It is less susceptible to migration or diffusion than the other commonly employed interstitial elements, such as carbon and nitrogen.
- addition of boron to a nitrogen containing alloy would nucleate a compound with a melting point around 5,400F, and boron nitride thus formed cannot be solutionized in the alloy by the customary heat treatment which comprises heating to 2,100F and then quenching.
- reaction of carbon with boron'to form boron carbide nucleates a compound having a melting point at about loys of the present invention are not to be confused with stainless steel, since steel by definition is a form of iron containing carbon.
- the alloys of the present invention eliminate carbon as far as practicable.
- a process for preparing ferrous base alloys characterized by stability at elevated temperatures comprising, preparing a melt having a composition within the range between about 12 percent to about 30 percent chromium, about 8 percent to about 20 percent nickel, 0 percent to about 2.5 percent manganese, 0 percent to 1.5 percent silicon, less than 0.009 percent carbon, and the balance iron with incidental impurities, maintaining said melt under vacuum pressures, adding to said melt sufficient ferro-boron alloy to introduce 0.01 percent to 0.2 percent by weight boron, said ferro-boron alloy having a melting point substantially below the melt temperature and containing less than 10 percent by weight boron, and teeming said melt into a mold.
- a ferrous base alloy characterized by high temperature stability and by being substantially completely austenitic, consisting essentially of from about 12 per- 5 cent to about 30 percent by weight chromium, from about 8 percent to about 20 percent by weight nickel, from about 0.01 percent to about 0.2 percent boron, 0 percent to about 2.5 percent by weight manganese, 0 percent to about 1.5 percent by weight silicon, less than 0.009 percent by weight carbon, and in which the total amount of carbon and nitrogen is less than 0.01 percent by weight, and the balance iron with incidental impurities that do not interfere with the solubility of boron, said boron in the form of a solid solute in the austenite, said alloy substantially free from carbon, nitrogen, and oxygen in total amounts that will react with the boron and adversely affect the alloy, and said alloy substantially free from the precipitated forms of boron.
- iron with incidental impurities that do not interfere with thesolubility of boron said alloy substantially free from carbon, nitrogen, and oxygen, in total amounts that will react with the boron and adversely affect the alloy.
- An austenitic-ferrous base alloy characterized by high temperature stability having essentially the following composition: I
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
Description
Claims (7)
- 2. A ferrous base alloy characterized by high temperature stability and by being substantially completely austenitic, consisting essentially of from about 12 percent to about 30 percent by weight cHromium, from about 8 percent to about 20 percent by weight nickel, from about 0.01 percent to about 0.2 percent boron, 0 percent to about 2.5 percent by weight manganese, 0 percent to about 1.5 percent by weight silicon, less than 0.009 percent by weight carbon, and in which the total amount of carbon and nitrogen is less than 0.01 percent by weight, and the balance iron with incidental impurities that do not interfere with the solubility of boron, said boron in the form of a solid solute in the austenite, said alloy substantially free from carbon, nitrogen, and oxygen in total amounts that will react with the boron and adversely affect the alloy, and said alloy substantially free from the precipitated forms of boron.
- 3. An austenitic iron-base alloy having a composition within the range between from about 12 percent to about 30 percent chromium, from about 8 percent to about 20 percent nickel, from about 0.03 percent to about 0.15 percent boron, from 0 percent to about 2.5 percent manganese, from 0 percent to about 1.5 percent silicon, less than 0.009 percent by weight carbon, and in which the total amount of carbon and nitrogen is less than 0.01 percent by weight, said boron in the form of a solid solute in the austenite, and the balance iron with incidental impurities that do not interfere with the solubility of boron, said alloy substantially free from carbon, nitrogen, and oxygen, in total amounts that will react with the boron and adversely affect the alloy.
- 4. An austenitic ferrous base alloy characterized by high temperature stability having essentially the following composition: Boron 0.03-0.15% Chromium 17-19% Nickel 8-10% Manganese 2% max Silicon 1% max Phosphorus 0.045% max Carbon 0.009% max Iron remainder said boron in the form of a solid solute in the austenite, and said alloy substantially free from carbon, nitrogen and oxygen in total amounts that will react with the boron and adversely affect the alloy.
- 5. An austenitic ferrous base alloy characterized by high temperature stability having essentially the following composition: Boron 0.02-0.08% Chromium 18-20% Nickel 8-12% Manganese 2% max Silicon 1% max Carbon 0.009% max Iron remainder said boron in the form of a solid solute in the austenite, and said alloy substantially free from carbon, nitrogen and oxygen, in total amounts that will react with the boron and adversely affect the alloy.
- 6. An austenitic ferrous base alloy characterized by high temperature stability having essentially the following composition: Boron 0.012% Chromium 17-19% Nickel 10-13% Manganese 2% max Silicon 1% max Carbon 0.009% max Iron remainder said boron in the form of a solid solute in the austenite, and said alloy substantially free from carbon, nitrogen and oxygen in total amounts that will react with the boron and adversely affect the alloy.
- 7. An austenitic ferrous base alloy characterized by high temperature stability having essentially the following composition: Boron 0.01-0.08% Chromium 22-24% Nickel 19-22% Manganese 2% max Silicon 1% max Carbon 0.009% max Iron remainder said boron in the form of a solid solute in the austenite, and said alloy substantially free from carbon, nitrogen and oxygen, in total amounts that will react with the boron and adversely affect the alloy.
- 8. An austenitic ferrous base alloy characterized by high temperature stability having essentially the following composition: Boron 0.01-0.08% Chromium 24-26% Nickel 19-22% Manganese 2% max Silicon 1.5% max Carbon 0.009% max Iron remainder said boron in the form of a solid solute in the austenite, and said alloy substantially free from carbon, nitrogen and oxygen in total amounts that will react with the boron and adversely affect the alloy.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US9810170A | 1970-12-14 | 1970-12-14 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3754899A true US3754899A (en) | 1973-08-28 |
Family
ID=22267087
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US00098101A Expired - Lifetime US3754899A (en) | 1970-12-14 | 1970-12-14 | Austenitic alloy containing boron and processes for manufacturing thesame |
Country Status (1)
Country | Link |
---|---|
US (1) | US3754899A (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3899321A (en) * | 1974-05-28 | 1975-08-12 | Bethlehem Steel Corp | Method of producing a vaccum treated effervescing boron steel |
US3900316A (en) * | 1972-08-01 | 1975-08-19 | Int Nickel Co | Castable nickel-chromium stainless steel |
US3955972A (en) * | 1966-07-20 | 1976-05-11 | Atlantic Richfield Company | Method of producing sheets and article to practice such method |
US4536215A (en) * | 1984-12-10 | 1985-08-20 | Gte Products Corporation | Boron addition to alloys |
US20040038104A1 (en) * | 2001-04-06 | 2004-02-26 | Qinbai Fan | Low cost metal bipolar plates and current collectors for polymer electrolyte membrane fuel cells |
US20050063827A1 (en) * | 2002-10-09 | 2005-03-24 | Ishikawajima-Harima Heavy Industries Co., Ltd. | Rotating member and method for coating the same |
US20060035068A1 (en) * | 2002-09-24 | 2006-02-16 | Ishikawajima-Harima Heavy Industries Co., Ltd. | Method for coating sliding surface of high-temperature member, high-temperature member and electrode for electro-discharge surface treatment |
US20100086398A1 (en) * | 2002-09-24 | 2010-04-08 | Ihi Corporation | Method for coating sliding surface of high-temperature member, high-temperature member and electrode for electro-discharge surface treatment |
US20130087254A1 (en) * | 2010-06-25 | 2013-04-11 | Jfe Steel Corporation | High strength hot-rolled steel sheet having excellent stretch-flange formability and method for manufacturing the same |
-
1970
- 1970-12-14 US US00098101A patent/US3754899A/en not_active Expired - Lifetime
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3955972A (en) * | 1966-07-20 | 1976-05-11 | Atlantic Richfield Company | Method of producing sheets and article to practice such method |
US3900316A (en) * | 1972-08-01 | 1975-08-19 | Int Nickel Co | Castable nickel-chromium stainless steel |
US3899321A (en) * | 1974-05-28 | 1975-08-12 | Bethlehem Steel Corp | Method of producing a vaccum treated effervescing boron steel |
US4536215A (en) * | 1984-12-10 | 1985-08-20 | Gte Products Corporation | Boron addition to alloys |
US20040038104A1 (en) * | 2001-04-06 | 2004-02-26 | Qinbai Fan | Low cost metal bipolar plates and current collectors for polymer electrolyte membrane fuel cells |
US20060035068A1 (en) * | 2002-09-24 | 2006-02-16 | Ishikawajima-Harima Heavy Industries Co., Ltd. | Method for coating sliding surface of high-temperature member, high-temperature member and electrode for electro-discharge surface treatment |
US20100086398A1 (en) * | 2002-09-24 | 2010-04-08 | Ihi Corporation | Method for coating sliding surface of high-temperature member, high-temperature member and electrode for electro-discharge surface treatment |
US9187831B2 (en) | 2002-09-24 | 2015-11-17 | Ishikawajima-Harima Heavy Industries Co., Ltd. | Method for coating sliding surface of high-temperature member, high-temperature member and electrode for electro-discharge surface treatment |
US9284647B2 (en) | 2002-09-24 | 2016-03-15 | Mitsubishi Denki Kabushiki Kaisha | Method for coating sliding surface of high-temperature member, high-temperature member and electrode for electro-discharge surface treatment |
US20050063827A1 (en) * | 2002-10-09 | 2005-03-24 | Ishikawajima-Harima Heavy Industries Co., Ltd. | Rotating member and method for coating the same |
US7537809B2 (en) * | 2002-10-09 | 2009-05-26 | Ihi Corporation | Rotating member and method for coating the same |
US20090200748A1 (en) * | 2002-10-09 | 2009-08-13 | Ihi Corporation | Rotating member and method for coating the same |
US20100124490A1 (en) * | 2002-10-09 | 2010-05-20 | Ihi Corporation | Rotating member and method for coating the same |
US7918460B2 (en) | 2002-10-09 | 2011-04-05 | Ihi Corporation | Rotating member and method for coating the same |
US20130087254A1 (en) * | 2010-06-25 | 2013-04-11 | Jfe Steel Corporation | High strength hot-rolled steel sheet having excellent stretch-flange formability and method for manufacturing the same |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0016225B2 (en) | Use of an austenitic steel in oxidizing conditions at high temperature | |
CN101906595B (en) | Austenite heat-resistance stainless steel forming Al2O3 protective layer spontaneously | |
US4437913A (en) | Cobalt base alloy | |
US3754899A (en) | Austenitic alloy containing boron and processes for manufacturing thesame | |
CN109652628B (en) | FeCrAl alloy for nuclear fuel cladding and preparation and grain size control method thereof | |
US4818485A (en) | Radiation resistant austenitic stainless steel alloys | |
US5283032A (en) | Controlled thermal expansion alloy and article made therefrom | |
CN112501510A (en) | High-aluminum ferrite heat-resistant steel and preparation method thereof | |
US2542220A (en) | Ferritic alloy | |
US3318690A (en) | Age hardening manganese-containing maraging steel | |
JP2000273570A (en) | Cast steel for pressure vessel and production of pressure vessel using the same | |
JP2021095625A (en) | Ferritic alloy and method of manufacturing nuclear fuel cladding tube using the same | |
US3940295A (en) | Low expansion alloys | |
CN115976426A (en) | High-strength and high-toughness martensite heat-resistant steel | |
JPS5980757A (en) | High strength austenitic steel | |
US3902899A (en) | Austenitic castable high temperature alloy | |
US3202506A (en) | High-temperature oxidation-resistant cobalt base alloys | |
US3954509A (en) | Method of producing low expansion alloys | |
US3740212A (en) | Oxidation resistant austenitic ductile nickel chromium iron | |
JPH0248613B2 (en) | ||
US4481033A (en) | High Mn-Cr non-magnetic steel | |
CN111304555A (en) | In-situ endogenously precipitated ceramic particle reinforced Cr-Mn-Ni-C-N austenitic heat-resistant steel and preparation method and application thereof | |
JPS59193242A (en) | High silicon spheroidal graphite cast iron | |
US3719475A (en) | Low carbon ferrous alloy containing chromium | |
JPH0380865B2 (en) |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: KANTER, MICHAEL E. TRUSTEE TRUST B JEROME KANTER D Free format text: COURT APPOINTMENT;ASSIGNOR:KANTER, JEROME J. DEC D.;REEL/FRAME:004324/0543 Effective date: 19840824 Owner name: HILL, JUDITH K. TRUSTEE TRUST B JEROME KANTER DEC Free format text: COURT APPOINTMENT;ASSIGNOR:KANTER, JEROME J. DEC D.;REEL/FRAME:004324/0543 Effective date: 19840824 Owner name: KANTER, HARRIET F. TRUSTEE TRUST B JEROME KANTER, Free format text: COURT APPOINTMENT;ASSIGNOR:KANTER, JEROME J. DEC D.;REEL/FRAME:004324/0543 Effective date: 19840824 |