US3551142A - Austenitic stainless steels - Google Patents

Austenitic stainless steels Download PDF

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Publication number
US3551142A
US3551142A US609503A US3551142DA US3551142A US 3551142 A US3551142 A US 3551142A US 609503 A US609503 A US 609503A US 3551142D A US3551142D A US 3551142DA US 3551142 A US3551142 A US 3551142A
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United States
Prior art keywords
percent
steel
steels
nitrogen
vanadium
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Expired - Lifetime
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US609503A
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English (en)
Inventor
Jean H Decroix
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Ugine Kuhlmann SA
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Ugine Kuhlmann SA
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Priority claimed from FR45726A external-priority patent/FR1475735A/fr
Priority claimed from FR87383A external-priority patent/FR91296E/fr
Priority claimed from FR87502A external-priority patent/FR91370E/fr
Application filed by Ugine Kuhlmann SA filed Critical Ugine Kuhlmann SA
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Publication of US3551142A publication Critical patent/US3551142A/en
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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
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • 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
    • 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
    • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese

Definitions

  • the present invention relates to new austenitic stainless steels, having improved properties, especially improved creep strength characteristics at high temperatures, and to articles made from these new steels.
  • chrome-nickel steels improved by the addition of a variety of elements are frequently utilized. Some such additions, for example,
  • titanium and aluminum have the disadvantage that structural hardening must be made during heat treatment before the article is placed in service. Steels obtained in this manner are also costly and not readily Weldable.
  • Other additives such as nitrogen and vanadium, cause a hardening precipitation in the course of creepage. Still other additives, such as boron, molybdenum, tungsten, copper, manganese and columbium, render the austenitic matrix more rigid at high temperatures.
  • the present invention provides new austenitic stainless steels which have creep strength characteristics above 650 C. which are comparable to those of the special alloys referred to above.
  • this invention provides a special treatment for these new steels which gives additional improvement in the properties of the steels.
  • These new steels are particularly useful for superheater tubes, components of aircraft jet engines, blades for gas turbines,
  • Steels within the scope of this invention are stainless austenitic steels having a composition within the following limits stated as percent by weight:
  • the steels should contain at least one of the elements molybdenum and copper.
  • the steels preferably have a nitrogen content of at least 0.20 percent.
  • the improved properties of the steels of this invention result from a combination of novel features in the austenitic steels of this invention. These include the addition of either molybdenum or copper or both, in addition to tungsten in the specified limits, the addition of manganese in the specified limits, the particular nitrogen and vanadium contents and the relationship between them, and the addition of boron in the specified limits.
  • the relationship between the nitrogen and vanadium contents correspond to a balance between these two elements of addition, a balance that permits the precipitation of nitrides of vanadium N V which contributes to the hardness.
  • the boron content is kept sufliciently low to avoid manufacturing difliculties that a higher content would entail, whereby the steels of the invention can be produced without special precautions.
  • All of the steels of the present invention have an improved creep strength.
  • the stress levels, causing fracture at the end of 5,000 hours, are set forth in Table I.
  • Elongation at creep fracture is at least equal to 10 percent atthe end of 5,000 hours, and the elastic limit E is at least equal to 32 kg./mm.
  • the single of the drawing shows a plurality of stress curves in which the stress causing creep fracture in 10,000 hours is plotted as a function of temperatures.
  • curves 1 to 5 which are drawn in full lines represent known alloys. All of the alloys represented are intended for use in the manufacture of superheater tubes.
  • Curve 1 represents a steel having a composition of percent chromium, 15 percent nickel, molybdenum, tungsten, nitrogen and columbium.
  • Curve 2 represents a steel having a composition of 16 percent chromium, 10 percent nickel, 6 percent manganese, molybdenum, vanadium and columbium.
  • Curve 3 represents a steel having a composition of 17 percent chromium, 14 percent nickel, molybdenum, copper, columbium and titanium.
  • Curve 4 represents a super alloy having a composition of 20 percent chromium, 20 percent nickel, 20 percent cobalt, molybdenum, tungsten, nitrogen, and columbium.
  • curve 5 represents a Hastelloy having a composition of 20 percent chromium, 55 percent nickel, 9 percent molybdenum and 1 percent cobalt.
  • Curve 6 drawn in broken lines represents a steel of this invention intended for use in the manufacture of superheater tubes which will not be subject to corrosion when hot.
  • the steel had a composition within the limits set forth below in Example I.
  • the end use for which the steels of this invention are intended may dictate a specific composition within the scope of the general composition set forth above. Certain qualities in addition to improved creep strength may be useful, and therefore, in each instance the composition of steel will be selected that has the desired qualities in addition to the improved creep strength. Such qualities, for instance, may be stress-rupture elongation, resistance to corrosion caused by the ashes of impure fuels or by organic lead salts, and elastic limit.
  • the preferred composition of steels within the scope of this invention is as follows:
  • EXAMPLE 3 Steels well suited for the manufacture of exhaust valves for internal combustion engines require a high elastic limit and resistance to corrosion in the presence of the combustion products of organic lead salts.
  • the preferred composition of steels within the scope of this invention is as follows:
  • composition Percent by weight It is desirable that the composition contain both tungsten and copper, and possibly molybdenum.
  • EXAMPLE 4 Two steels intended for the manufacture of movable blades for gas turbines having the compositions set forth in percent by weight Table III.
  • Steel 7 is a steel Within the scope of the present invention While steel 8 is an austenitic steel having tungsten and titanium present.
  • a steel having a composition within the scope of this invention s rolled when hot. This is terminated by a pass of complete self-recrystallization into grains of controlled dimensions. This is then followed by cold rolling and, finally, a thermal annealing treatment at a temperature equal at the most to 1,050 C. and a stress-relaxation treatment that does no cause complete self-recrystallization of the metal.
  • a thermal annealing treatment at a temperature equal at the most to 1,050 C.
  • a stress-relaxation treatment that does no cause complete self-recrystallization of the metal.
  • the final hot rolling pass should eliminate the work hardening produced by the preceding passes and should produce in the steel the formation of grains in which dimensions are favorable for the continuation of the process. It is known that in order to obtain rather large grains, this latter pass must be carried out at a rather high temperature with a rather low rate of reduction. The cold rolling operation then causes a new work hardening of the metal. The latter stages are intended to relax the metal Without causing complete recrystallization.
  • the following example illustrates a steel within the scope of the present invention which may be rolled into sheets and compares the properties of the steel sheet when obtained according to the process described above and when obtained by conventional methods.
  • a steel within the scope of this invention suitable for making steel sheets for gas turbines and jet engines has a composition as follows:
  • steel 7 of this invention has an elastic limit in tensile test and a creep resistance at 700
  • One sheet (sheet 9) of this composition was obtained by the conventional method comprising successively a hot C. equal to those of a titanium-aluminum steel with strucrolling pass, an annealing treamtent at 1,100 'C., a cold pass, and an annealing treatment at 1,100 C.
  • a second sheet (sheet was obtained by the method of this invention which comprises a hot rolling pass terminated by a pass at a temperature above 1,000 C. with a reduction in thickness of from 5 to percent, a cold pass with a reduction in thickness of from to percent, and an annealing treatment from a temperature on the order of 970l000 C.
  • Table V shows the results of tests on sheets 9 and 10 giving the values for the elastic limits E (in kg. per mm?) measured at various temperatures, and the values of the elongation (in percent on an initial reference length equal to 5.65 /S, S being the section of the test piece) after deformation by creepage obtained by keeping it at 700 C. for 300 hours under a stress of 16 kg./mm.
  • the improvement in resistance to creep elongation was obtained without any appreciable change in the limit of creep fracture, and with a decrease in ductility at creep fracture of 40 to 20' percent on the average for a fracture caused at the end of approximately 800 hours.
  • the presentation of the steel of the invention in sheets obtained in according with the process imparts to it an elastic limit and resistance to creep elongation which are on the same order of magnitude as those of a conventional structurally hardened austenitic steel containing titanium and aluminum.
  • a stainless austenitic steel consisting essentially of up to 0.175 percent carbon, up to 1.0 percent silicon, 15 to 20 percent chromium, 4 to 16 percent nickel, 1 to 12 percent manganese, 0 to 4 percent molybdenum, 1 to 6 percent tungsten, 0 to 4 percent copper, at least 0.15 percent nitrogen, vanadium in an amount at least equal to 1.2 times the amount of nitrogen, the sum of vanadium and nitrogen not exceeding 0.65 percent, 0 to 1 percent columbium, 0.001 to 0.005 percent boron, and the balance iron and incidental impurities.
  • a stainless austenitic steel having improved creep strength above 650 C., ductility, and corrosion resistance when hot consisting essentially of up to 0.06 percent carbon, up to 1.0 percent silicon, 16 to 20 percent chromium, 6 to 10 percent nickel, 5 to 10 percent manganese, 0 to 2 percent molybdenum, 2 to 4 percent tungsten, 1 to 4 percent copper, at least 0.15 percent nitrogen, vanadium in an amount at least equal to 1.2 times the nitrogen content, the sum of the nitrogen and vanadium content not exceeding 0.65 percent, 0 to 1 percent columbium, 0.001 to 0.005 percent boron and the balance iron and incidental impurities.
  • a stainless austenitic steel having improved creep strength above 650 C., ductility, and corrosion resistance when hot consisting essentially of up to 0.060 percent carbon, up to 1 percent silicon, 15 to 19 percent chromiurn, 8 to 16 percent nickel, 1 to 3 percent manganese, 1 to 3 percent molybdenum, 2 to 4 percent tungsten, 0 to 3 percent copper, at least 0.15 percent nitrogen, vanadium in an amount at least equal to 1.2 times the nitrogen content, the sum of the nitrogen and vanadium content not exceeding 0.65 percent, 0 to 1 percent columbium, 0.001 to 0.005 percent boron and the balance iron and incidental impurities.
  • a stainless austenitic steel having high elastic limits consisting essentially of up to 0.13 percent carbon, up to 1.0 percent silicon, 15 to 20 percent chromium, 7 to 16 percent nickel, 1 to 5 percent manganese, 1 to 3 percent molybdenum, 2 to 4 percent tungsten, 0 to 3 percent copper, at least 0.15 percent nitrogen, vanadium in an amount at least equal to 1.2 times the nitrogen content, the sum of the nitrogen and vanadium content not exceeding 0.65 percent, 0.001 to 0.005 percent boron, and the balance iron and incidental impurities.
  • a stainless austenitic steel having high elastic limits and corrosion resistance in the presence of combustion products of organic lead salts consisting essentially of 0.10 to 0.15 percent carbon, up to 0.30 percent silicon,
  • a stainless austenitic steel containing about 0.05 percent carbon, about 0.60 percent silicon, about 18 percent chromium, about 14.5 percent nickel, about 1.75 percent manganese, about 2.53 percent molybdenum, about 3.42 percent tungsten, about 0.21 percent nitrogen, about 0.35 percent vanadium, and about 0.003 percent boron.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)
US609503A 1966-01-13 1967-01-16 Austenitic stainless steels Expired - Lifetime US3551142A (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
FR45726A FR1475735A (fr) 1966-01-13 1966-01-13 Aciers améliorés
FR87383A FR91296E (fr) 1966-01-13 1966-12-14 Aciers améliorés
FR87502A FR91370E (fr) 1966-01-13 1966-12-15 Aciers améliorés
FR87796A FR91375E (fr) 1966-01-13 1966-12-16 Aciers améliorés

Publications (1)

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US3551142A true US3551142A (en) 1970-12-29

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US609503A Expired - Lifetime US3551142A (en) 1966-01-13 1967-01-16 Austenitic stainless steels

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US (1) US3551142A (fr)
BE (1) BE692561A (fr)
CH (1) CH485859A (fr)
DE (1) DE1558668C3 (fr)
FR (1) FR91375E (fr)
GB (1) GB1169393A (fr)
LU (1) LU52803A1 (fr)
NL (1) NL154788B (fr)
SE (1) SE344080B (fr)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2421604A1 (de) * 1973-05-04 1974-11-14 Nippon Steel Corp Rostfreier stahl
US4102677A (en) * 1976-12-02 1978-07-25 Allegheny Ludlum Industries, Inc. Austenitic stainless steel
US4172716A (en) * 1973-05-04 1979-10-30 Nippon Steel Corporation Stainless steel having excellent pitting corrosion resistance and hot workabilities
US4218268A (en) * 1977-06-30 1980-08-19 Kubota Ltd. High corrosion resistant and high strength medium Cr and low Ni stainless cast steel
US4224061A (en) * 1977-06-30 1980-09-23 Kubota Ltd. High corrosion resistant and high strength medium Cr and low Ni stainless cast steel
US4246047A (en) * 1977-12-27 1981-01-20 Sumitomo Electric Industries, Ltd. Non-magnetic stainless steel
US4353755A (en) * 1980-10-29 1982-10-12 General Electric Company Method of making high strength duplex stainless steels
US4371394A (en) * 1980-11-21 1983-02-01 Carpenter Technology Corporation Corrosion resistant austenitic alloy
US4556423A (en) * 1982-01-08 1985-12-03 Nippon Kokan Kabushiki Kaisha Austenite stainless steels having excellent high temperature strength
US4742324A (en) * 1984-04-27 1988-05-03 Sumitomo Metal Industries Ltd. Sheath heater
US4897132A (en) * 1984-10-03 1990-01-30 Kabushiki Kaisha Tohsiba Turbine casing formed of a heat resistant austenitic cast steel
US20060141333A1 (en) * 2004-12-22 2006-06-29 Samsung Sdi Co., Ltd. Metallic separator for fuel cell and fuel cell including the same
US20070072039A1 (en) * 2005-09-26 2007-03-29 Samsung Sdi Co., Ltd. Metallic separator for fuel cell
US20100272595A1 (en) * 2006-04-21 2010-10-28 Shell Oil Company High strength alloys
US9803267B2 (en) 2011-05-26 2017-10-31 Upl, L.L.C. Austenitic stainless steel

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3407305A1 (de) * 1984-02-24 1985-08-29 Mannesmann AG, 4000 Düsseldorf Verwendung einer korrosionsbestaendigen austenitischen legierung fuer mechanisch hoch beanspruchte, schweissbare bauteile
DE3407307A1 (de) * 1984-02-24 1985-08-29 Mannesmann AG, 4000 Düsseldorf Verwendung einer korrosionsbestaendigen austenitischen eisen-chrom-nickel-stickstoff-legierung fuer mechanisch hoch beanspruchte bauteile
US4741080A (en) * 1987-02-20 1988-05-03 Eaton Corporation Process for providing valve members having varied microstructure
EP0613960B1 (fr) * 1993-02-03 1997-07-02 Hitachi Metals, Ltd. Acier de moulage réfractaire austénitique et composant de système d'échappement fabriqué avec cet acier

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB675809A (en) * 1949-04-22 1952-07-16 Electric Furnace Prod Co Improvements in iron base alloys for high-temperature service
AT175594B (de) * 1950-01-09 1953-07-25 Deutsche Edelstahlwerke Ag Stahl für Gegenstände, die eine hohe Dauerstandfestigkeit aufweisen müssen
FR1173755A (fr) * 1956-04-27 1959-03-02 Armco Int Corp Acier inoxydable et son procédé de fabrication
US3201233A (en) * 1962-06-13 1965-08-17 Westinghouse Electric Corp Crack resistant stainless steel alloys

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2421604A1 (de) * 1973-05-04 1974-11-14 Nippon Steel Corp Rostfreier stahl
US4172716A (en) * 1973-05-04 1979-10-30 Nippon Steel Corporation Stainless steel having excellent pitting corrosion resistance and hot workabilities
US4102677A (en) * 1976-12-02 1978-07-25 Allegheny Ludlum Industries, Inc. Austenitic stainless steel
US4218268A (en) * 1977-06-30 1980-08-19 Kubota Ltd. High corrosion resistant and high strength medium Cr and low Ni stainless cast steel
US4224061A (en) * 1977-06-30 1980-09-23 Kubota Ltd. High corrosion resistant and high strength medium Cr and low Ni stainless cast steel
US4246047A (en) * 1977-12-27 1981-01-20 Sumitomo Electric Industries, Ltd. Non-magnetic stainless steel
US4353755A (en) * 1980-10-29 1982-10-12 General Electric Company Method of making high strength duplex stainless steels
US4371394A (en) * 1980-11-21 1983-02-01 Carpenter Technology Corporation Corrosion resistant austenitic alloy
US4556423A (en) * 1982-01-08 1985-12-03 Nippon Kokan Kabushiki Kaisha Austenite stainless steels having excellent high temperature strength
US4742324A (en) * 1984-04-27 1988-05-03 Sumitomo Metal Industries Ltd. Sheath heater
US4897132A (en) * 1984-10-03 1990-01-30 Kabushiki Kaisha Tohsiba Turbine casing formed of a heat resistant austenitic cast steel
US20060141333A1 (en) * 2004-12-22 2006-06-29 Samsung Sdi Co., Ltd. Metallic separator for fuel cell and fuel cell including the same
US7947409B2 (en) * 2004-12-22 2011-05-24 Samsung Sdi Co., Ltd. Metallic separator for fuel cell and fuel cell including the same
US20070072039A1 (en) * 2005-09-26 2007-03-29 Samsung Sdi Co., Ltd. Metallic separator for fuel cell
US8148034B2 (en) * 2005-09-26 2012-04-03 Samsung Sdi Co., Ltd. Metallic separator for fuel cell
US20100272595A1 (en) * 2006-04-21 2010-10-28 Shell Oil Company High strength alloys
US8192682B2 (en) * 2006-04-21 2012-06-05 Shell Oil Company High strength alloys
US9803267B2 (en) 2011-05-26 2017-10-31 Upl, L.L.C. Austenitic stainless steel

Also Published As

Publication number Publication date
DE1558668C3 (de) 1982-11-18
BE692561A (fr) 1967-06-16
SE344080B (fr) 1972-03-27
GB1169393A (en) 1969-11-05
FR91375E (fr) 1968-05-31
CH485859A (fr) 1970-02-15
NL154788B (nl) 1977-10-17
DE1558668B2 (de) 1978-12-07
LU52803A1 (fr) 1967-03-13
NL6700566A (fr) 1967-07-14
DE1558668A1 (de) 1973-05-24

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