EP2692887B1 - Cast austenitic stainless steel - Google Patents
Cast austenitic stainless steel Download PDFInfo
- Publication number
- EP2692887B1 EP2692887B1 EP12765111.5A EP12765111A EP2692887B1 EP 2692887 B1 EP2692887 B1 EP 2692887B1 EP 12765111 A EP12765111 A EP 12765111A EP 2692887 B1 EP2692887 B1 EP 2692887B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- percent
- mass
- austenitic stainless
- cast steel
- stainless cast
- 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.)
- Not-in-force
Links
Images
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
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
- B22D27/20—Measures not previously mentioned for influencing the grain structure or texture; Selection of compositions therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D30/00—Cooling castings, not restricted to casting processes covered by a single main group
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/004—Heat treatment of ferrous alloys containing Cr and Ni
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/02—Hardening by precipitation
-
- 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
- C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
-
- 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
- C22C38/18—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
- C22C38/48—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
- 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
-
- 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
- C21D2211/001—Austenite
-
- 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
- C21D2211/005—Ferrite
Definitions
- the present invention relates to an austenitic stainless cast steel.
- An austenitic stainless cast steel exhibits excellent properties especially in corrosion resistance, strength, weldability and the like, and has been widely used for piping, valves and the like in chemical plants and power plants.
- the austenitic stainless cast steel is formed of, for example from metallurgical viewpoint, two phases including approximately 10 - 20% of an alpha phase and approximately 90 - 80% of a gamma phase (austenitic phase).
- CF8C As for steel castings of the austenitic stainless steel, CF8C has been known.
- a CF8C austenitic stainless steel casting includes: up to 0.08 percent by mass of C (carbon); up to 2.0 percent by mass of Si (silicon); up to 1.5 percent by mass of Mn (manganese); 18.0 - 21.0 percent by mass of Cr (chromium); 9.0 - 12.0 percent by mass of Ni (nickel); and up to 1.0 percent by mass of Nb (niobium).
- CF8C includes approximately 12.0% of a ferrite phase.
- the ferrite phase can be, for example, measured as ferrite content in the austenitic stainless steel with a known ferrite scope, or calculated using a Schaeffler diagram based on component elements, and is indicated with volume fraction (percent (%)).
- the ferrite phase is considered effective for preventing weld cracking and reducing stress corrosion cracking.
- a ferrite phase content is large, for example, exposure of CF8C to high temperature for a long period of time may transform the ferrite phase into a sigma phase ( ⁇ phase), which is a compound of iron and chromium. This may lead to embrittlement of the steel casting.
- Patent Document 1 discloses CF8C-Plus, which is an alloy modified from CF8C, and describes that CF8C-Plus does not contain ferrite phase. Patent Document 1 also describes that CF8C-Plus includes: 0.05 - 0.15 percent by mass of C; 0.2 - 1.0 percent by mass of Si; 0.5 - 10.0 percent by mass of Mn; 18.0 - 25.0 percent by mass of Cr; 10.0 - 15.0 percent by mass of Ni; 0.1 - 1.5 percent by mass of Nb; and 0.05 - 0.5 percent by mass of N.
- Patent Document 1 an absence of the ferrite phase from CF8C-Plus is considered important for retaining the properties imparted at casting of materials during a life of the component part produced from the materials.
- the Japanese patent application JP H02-97648 A discloses an austenitic stainless steel having a composition consisting of, by weight, ⁇ 0.03 % C, ⁇ 2 % Si, ⁇ 10% Mn, 6 to 20 % Ni, 16 to 30 % Cr, 0.1 to 0.3 % N, 0.02 to 0.25 % Nb, and the balance Fe is refined.
- This steel is rough rolled at 1000 to 1200 °C and ⁇ 50 % draft. After the above roughing, the steel is cooled for 10 sec to 5 minutes subsequently, the steel is rolled at 800 to 1000 °C finish rolling temperature and ⁇ 30% draft and then cooled at ⁇ 4 °C/min cooling rate, by which the structure of the steel is formed into recrystallization working duplex structure.
- Shim J. H. et al. refers to numerical simulations of long-term precipitate evolution in austenitic heat-resistant steels being published in Calphad Computer Coupling of Phase Diagrams and Thermochemistry, New York, vol. 34, no. 1, March 1, 2010 pages 105 to 112, ISSN 0364-5916 .
- the Japanese patent application JP H02-97647 A discloses a steel constituted of, by weight, ⁇ 0.03 % C, ⁇ 20 % Si, ⁇ 10 % Mn, 6 to 20 % Ni, 16 to 30 % Cr, 0.1 to 0.3 % N, 0.02 to 0.25 % Nb and the balance Fe is melted.
- the steel is rolled at 1000 to 1200 °C rough rolling temperature at ⁇ 50% working ratio and it is thereafter cooled for 16 sec to 5 minutes.
- the steel is then rolled at 800 to 1000 °C finish rolling temperature at ⁇ 30 % working ratio and is thereafter cooled at ⁇ 4 °C/min cooling speed to form its structure into the recrystallization treated double constitutional one.
- the Japanese patent application JP S63-169362 A discloses a nonmagnetic steel consisting of, by weight, ⁇ 0.15 % C, ⁇ 1.0 % Si, ⁇ 5.0 % Mn, ⁇ 0.030 % S and the balance Fe with inevitable impurities.
- It contains 7.0 to 15.0 % Ni, 16.0 to 22.0 % Cr, ⁇ 0.5 % Nb and 0.1 to 0.4 % N and it further contains ⁇ 7.5 % in total of one or more among ⁇ 4.0 % Mo, ⁇ 3.0 % Cu and ⁇ 0.5 % V and/or ⁇ 0.31 % in total of one or more among ⁇ 0.20 % rare earth element, ⁇ 0.10 % Ca, ⁇ 0.10 % Mg and ⁇ 0.01 %.
- the Japanese patent application JP S63-53244 A discloses a stainless steel consisting of, by weight, ⁇ 0.03 % C, ⁇ 2 % Si, ⁇ 5 % Mn, 6 to 13 % Ni, 16 to 21 % Cr, 0.1 to 0.3 % N, 0.02 to 0.25 % Nb, and the balance Fe is refined.
- This steel is rolled at 1,000 to 1,200 °C at ⁇ 50% draft and cooled for 10sec to 5min, which is subjected to finish rolling at 800 to 1,000 °C at ⁇ 30 % draft and then to cooling at a cooling rate of ⁇ 4 °C/min.
- the Japanese patent application JP S60-121098 A discloses a build-up weld layer of an austenitic stainless steel having a composition containing ⁇ 0.1 % C, ⁇ 1.0 % Si, ⁇ 3.0 % Mn, 17.0 t 23.0 % Cr, 7.0 to 15.0 % Ni, ⁇ 0.4 % Mo and ⁇ 1.0 % Nb and consisting of 0.08 to 0.20 % N.
- the calculated value of the delta ferrite by the prescribed formula is kept within a -2.0 to 20.0 % range.
- the German patent application DE 26 34 403 A1 discloses a stainless cast alloy steel suitable for ground joint portions, airtight portions, sliding portions, etc., used at low temperatures.
- This steel comprises from about 0.03 to about 0.15 % by weight of C; up to about 2 % by weight of Si; up to about 2 % by weight of Mn; from about 18 to about 26 % by weight of Cr; from about 5 to about 13 % by weight of Ni, the remainder being Fe and unavoidable trace impurities; wherein a ferrite phase is present in an amount of from about 10 to about 40 % by volume, based on the volume of the stainless cast alloy steel.
- Patent Document 1 Japanese translation of a PCT application Kohyo No. 2009-545675
- the austenitic stainless cast steel of the present invention is excellent in, for example, aging ductility, tensile strength and oxidation resistance, as will be described in Examples. Especially, the aging ductility in Examples of the present invention was approximately 2.4 times as high as that in Comparative Examples. Likewise, oxidation resistance in Examples of the present invention was approximately 9.5 times as high as that in Comparative Examples.
- the reason that the austenitic stainless cast steel exhibits such excellent properties seems to be that the volume fraction of the ferrite phase is 0.1 - 5.0 %, and the contents of the components C, Si, Mn, Cr, Ni, Nb and N seem to play important roles. Hereinbelow, each component will be described in detail.
- the volume fraction of the ferrite phase By setting the volume fraction of the ferrite phase to 0.1 - 5.0 %, even when the cast steel is exposed to high temperature for a long period of time, a precipitation amount of the sigma phase can be suppressed low. Since the precipitation amount of the sigma phase is low, the austenitic stainless cast steel is unlikely to be embrittled, and exhibits excellent aging ductility.
- an additive amount of C in the present invention is set to 0.01 - 0.10 percent by mass.
- Si serves as deoxidizing agent for molten metal, and is effective for improving fluidity, oxidation resistance, and weldability.
- an excessive addition will make the austenitic structure unstable, leading to deterioration of castability, hinder workability and weldability, and promotion of weld cracking. Therefore, an additive amount of Si in the present invention is set to 0.6 - 1.0 percent by mass.
- Mn is effective as deoxidizing agent for molten metal, and enhances fluidity during the casting to thereby improve productivity. In addition, it is also effective for reducing weld cracking. Since an excessive addition will deteriorate oxidation resistance, an additive amount of Mn in the present invention is set to 2.0 - 2.8 percent by mass. When Mn is in this range, the austenitic stainless cast steel exhibiting excellent oxidation resistance can be obtained, as will be described in Examples.
- N improves high-temperature strength and thermal fatigue resistance, and is a strong austenite forming element which stabilizes an austenitic matrix.
- N is an element effective for grain refining. With this grain refining, ductility of the material which is important as structure can be secured, and in addition, a drawback of poor machinability, which is specific in the austenitic stainless cast steel, can be improved. Especially, N renders excellent perforation machinability to a member to be perforated for connecting parts.
- an additive amount ofN in the present invention is set to 0.1 - 0.4 percent by mass.
- the amount of Cr is set to 18.0 percent by mass or more.
- the upper limit of the Cr amount is set to 24.0 percent by mass.
- Ni facilitates the formation of the stable austenitic matrix, stabilizes the austenitic phase, and enhances high-temperature strength and oxidation resistance of the steel. Taking excellent castability, corrosion resistance and weldability into consideration, an additive amount of Ni in the present invention is set to 8.0 - 15.0 percent by mass.
- Nb binds with C to form fine carbide, and improves high-temperature strength.
- the formation of Cr carbide is suppressed, and thus oxidation resistance can be improved.
- the content of 0.2 % or more is required.
- an additive amount of Nb in the present invention is set to 0.2 - 0.7 percent by mass.
- the austenitic stainless cast steel of the present invention can be produced by performing cooling from a temperature range of 1,150 - 1,350°C to a temperature range of 600 - 800°C at a cooling rate of 30°C/min or more.
- excellent strength property can be obtained, and thus solution heat treatment can be omitted.
- the produced austenitic stainless cast steel is used as, for example, materials for piping, valves and the like in chemical plants and power plants.
- Fig. 1 is a graph showing results of oxidation resistance (mm/year) examined with respect to the austenitic stainless cast steel.
- the austenitic stainless cast steel of the present invention is formed in such a manner that the volume fraction of the ferrite phase becomes 0.1 - 5.0%, preferably 0.5 - 3.0%.
- the austenitic stainless cast steel of the present invention includes C, Si, Mn, Cr, Ni, Nb, N and the like as components thereof.
- the austenitic stainless cast steel of the present invention by setting the volume fraction of the ferrite phase to 0.1 - 5.0 %, even when the cast steel is exposed to high temperature for a long period of time, the precipitation amount of the sigma phase can be suppressed low. Therefore, the austenitic stainless cast steel of the present invention is unlikely to be embrittled, and exhibits excellent aging ductility.
- the austenitic stainless cast steel of the present invention has a higher Mn content and a lower C content than those of CF8C. With this configuration, the strength and oxidation resistance at high temperature can be improved.
- the austenitic stainless cast steel of the present invention can be produced by melting the above-described metal components in a melting furnace and performing cooling from a temperature range of 1,150 - 1,350 °C to a temperature range of 600 - 800 °C at a cooling rate of 30 °C/min or more.
- the produced austenitic stainless cast steel is used, for example, for piping, valves and the like in chemical plants and power plants.
- Example 1-1 Aging ductility (%) Tensile strength (Mpa) 0.2% proof stress (Mpa) Oxidation resistance (mm/year) High-temperature low-cycle fatigue test (times)
- Example 1-1 24.4 120 90 0.300 - Example 1-2 28.8 125 87 0.370 6200
- Example 1-5 20.4 131 91 0.489 - Example 1-6 22.1 129 88 0.394 - Comparative Example 1-1 17.2 93 70 1.278 2388 Comparative Example 1-2 6.8 101 75 3.494 - Comparative Example 1-3 8.6 127 84 1.854 - Comparative Example 1-4 11.2 98 73 4.101 - Comparative 8.2 104 77 3.124 - Example 1-5
- Examples exhibited 113 - 134 Mpa, while Comparative Examples exhibited 93 - 127 Mpa.
- Example exhibited excellent result in aging ductility, tensile strength and oxidation resistance.
- an average value of the aging ductility in Examples was 24.8%, while an average value in Comparative Examples was 10.4%, and thus the value in Example was approximately 2.4 times as high as that in Comparative Example.
- an average value of oxidation resistance in Examples was 0.290mm/year, while an average value in Comparative Examples was 2.770 mm/year, and thus the value in Example was improved approximately 9.5 times as much as that in Comparative Example.
- Example 1 the volume fraction of the ferrite phase of the austenitic stainless cast steel of the present invention was 0.2% (Examples 1-1 - 1-6).
- Examples 1-1 - 1-6 the volume fraction of the ferrite phase is 1 - 3%
- aging ductility, tensile strength, 0.2% proof stress and oxidation resistance were examined (Examples 2-1 - 2-4) under the same condition for Example 1.
- the components of Examples 2-1 - 2-4 are shown in Table 5, and the results are shown in Table 6.
- oxidation resistance can be reduced to 1 mm/year or less.
- the present invention is applicable to the production of the austenitic stainless cast steel.
Description
- The present invention relates to an austenitic stainless cast steel.
- An austenitic stainless cast steel exhibits excellent properties especially in corrosion resistance, strength, weldability and the like, and has been widely used for piping, valves and the like in chemical plants and power plants. The austenitic stainless cast steel is formed of, for example from metallurgical viewpoint, two phases including approximately 10 - 20% of an alpha phase and approximately 90 - 80% of a gamma phase (austenitic phase).
- As for steel castings of the austenitic stainless steel, CF8C has been known. For example, a CF8C austenitic stainless steel casting includes: up to 0.08 percent by mass of C (carbon); up to 2.0 percent by mass of Si (silicon); up to 1.5 percent by mass of Mn (manganese); 18.0 - 21.0 percent by mass of Cr (chromium); 9.0 - 12.0 percent by mass of Ni (nickel); and up to 1.0 percent by mass of Nb (niobium).
- CF8C includes approximately 12.0% of a ferrite phase. The ferrite phase can be, for example, measured as ferrite content in the austenitic stainless steel with a known ferrite scope, or calculated using a Schaeffler diagram based on component elements, and is indicated with volume fraction (percent (%)).
- The ferrite phase is considered effective for preventing weld cracking and reducing stress corrosion cracking. However, if a ferrite phase content is large, for example, exposure of CF8C to high temperature for a long period of time may transform the ferrite phase into a sigma phase (σ phase), which is a compound of iron and chromium. This may lead to embrittlement of the steel casting.
-
Patent Document 1 discloses CF8C-Plus, which is an alloy modified from CF8C, and describes that CF8C-Plus does not contain ferrite phase.Patent Document 1 also describes that CF8C-Plus includes: 0.05 - 0.15 percent by mass of C; 0.2 - 1.0 percent by mass of Si; 0.5 - 10.0 percent by mass of Mn; 18.0 - 25.0 percent by mass of Cr; 10.0 - 15.0 percent by mass of Ni; 0.1 - 1.5 percent by mass of Nb; and 0.05 - 0.5 percent by mass of N. - In
Patent Document 1, an absence of the ferrite phase from CF8C-Plus is considered important for retaining the properties imparted at casting of materials during a life of the component part produced from the materials. - When CF8C is exposed to high temperature for a long period of time under usage environment, the sigma phase is precipitated to cause aging embrittlement, and thus aging ductility may become poor. Also in the case of CF8C-Plus described in
Patent Document 1, further improvement has been demanded in oxidation resistance. - Therefore, it has been desired to provide an austenitic stainless cast steel exhibiting excellent aging ductility and oxidation resistance.
- The Japanese patent application
JP H02-97648 A - Shim J. H. et al. refers to numerical simulations of long-term precipitate evolution in austenitic heat-resistant steels being published in Calphad Computer Coupling of Phase Diagrams and Thermochemistry, New York, vol. 34, no. 1, March 1, 2010 pages 105 to 112, ISSN 0364-5916.
- The Japanese patent application
JP H02-97647 A - The Japanese patent application
JP S63-169362 A - The Japanese patent application
JP S63-53244 A - The Japanese patent application
JP S60-121098 A - The German patent application
DE 26 34 403 A1 discloses a stainless cast alloy steel suitable for ground joint portions, airtight portions, sliding portions, etc., used at low temperatures. This steel comprises from about 0.03 to about 0.15 % by weight of C; up to about 2 % by weight of Si; up to about 2 % by weight of Mn; from about 18 to about 26 % by weight of Cr; from about 5 to about 13 % by weight of Ni, the remainder being Fe and unavoidable trace impurities; wherein a ferrite phase is present in an amount of from about 10 to about 40 % by volume, based on the volume of the stainless cast alloy steel. - Patent Document 1: Japanese translation of a
PCT application Kohyo No. 2009-545675 - In order to provide such an austenitic stainless cast steel, the inventions of the following items (1) - (5) are provided.
- (1) An austenitic stainless cast steel, wherein a volume fraction of the ferrite phase is 0.1 - 5.0 %, and the cast steel consists of: 0.01 - 0.10 percent by mass of C; 0.6 - 1.0 percent by mass of Si; 2.0 - 2.8 percent by mass of Mn; 0.1 - 0.4 percent by mass of N; 18.0 - 24.0 percent by mass of Cr; 8.0 - 15.0 percent by mass of Ni; 0.2 - 0.7 percent by mass of Nb; and the balance is Fe and inevitable impurities.
- (2) The austenitic stainless cast steel according to item (1), wherein the volume fraction of the ferrite phase is 0.5 - 3.0.
- (3) The austenitic stainless cast steel according to item (1) or (2), wherein Mn is 2.07 - 2.8 percent by mass and Nb is 0.26 - 0.7 percent by mass.
- (4) A method of producing the austenitic stainless cast steel according to any one of items (1) - (3), the method comprising: a melting of metal components in a melting furnace, and a cooling of the molten metal componensts from a temperature range of 1,150 - 1,350 °C to a temperature range of 600 - 800 °C at a cooling rate of 30 °C/min or more.
- (5) A valve formed of austenitic stainless cast steel according to any one of items (1) - (3).
- The austenitic stainless cast steel of the present invention is excellent in, for example, aging ductility, tensile strength and oxidation resistance, as will be described in Examples. Especially, the aging ductility in Examples of the present invention was approximately 2.4 times as high as that in Comparative Examples. Likewise, oxidation resistance in Examples of the present invention was approximately 9.5 times as high as that in Comparative Examples.
- The reason that the austenitic stainless cast steel exhibits such excellent properties seems to be that the volume fraction of the ferrite phase is 0.1 - 5.0 %, and the contents of the components C, Si, Mn, Cr, Ni, Nb and N seem to play important roles. Hereinbelow, each component will be described in detail.
- By setting the volume fraction of the ferrite phase to 0.1 - 5.0 %, even when the cast steel is exposed to high temperature for a long period of time, a precipitation amount of the sigma phase can be suppressed low. Since the precipitation amount of the sigma phase is low, the austenitic stainless cast steel is unlikely to be embrittled, and exhibits excellent aging ductility.
- C has an effect of lowering a melting point and improving fluidity, i.e. castability of molten metal. In addition, it is preferable that the amount of C is low from the viewpoint of corrosion resistance, and if a large amount is added, the corrosion resistance of the base metal is reduced. In view of these, in order to improve high-temperature ductility, an additive amount of C in the present invention is set to 0.01 - 0.10 percent by mass.
- Si serves as deoxidizing agent for molten metal, and is effective for improving fluidity, oxidation resistance, and weldability. However, an excessive addition will make the austenitic structure unstable, leading to deterioration of castability, hinder workability and weldability, and promotion of weld cracking. Therefore, an additive amount of Si in the present invention is set to 0.6 - 1.0 percent by mass.
- Mn is effective as deoxidizing agent for molten metal, and enhances fluidity during the casting to thereby improve productivity. In addition, it is also effective for reducing weld cracking. Since an excessive addition will deteriorate oxidation resistance, an additive amount of Mn in the present invention is set to 2.0 - 2.8 percent by mass. When Mn is in this range, the austenitic stainless cast steel exhibiting excellent oxidation resistance can be obtained, as will be described in Examples.
- N improves high-temperature strength and thermal fatigue resistance, and is a strong austenite forming element which stabilizes an austenitic matrix. In addition, N is an element effective for grain refining. With this grain refining, ductility of the material which is important as structure can be secured, and in addition, a drawback of poor machinability, which is specific in the austenitic stainless cast steel, can be improved. Especially, N renders excellent perforation machinability to a member to be perforated for connecting parts. When N is added in a large amount, embrittlement is promoted, while an effective Cr amount is reduced and thus oxidation resistance is deteriorated. Therefore, an additive amount ofN in the present invention is set to 0.1 - 0.4 percent by mass.
- Cr improves oxidation resistance and stabilizes the ferrite structure. In order to reliably attain this effect, the amount of Cr is set to 18.0 percent by mass or more. On the other hand, an excessive addition will lower the aging ductility of the steel due to excessive precipitation of Cr carbide when the cast steel is used at high temperature, and thus the upper limit of the Cr amount is set to 24.0 percent by mass.
- Ni facilitates the formation of the stable austenitic matrix, stabilizes the austenitic phase, and enhances high-temperature strength and oxidation resistance of the steel. Taking excellent castability, corrosion resistance and weldability into consideration, an additive amount of Ni in the present invention is set to 8.0 - 15.0 percent by mass.
- Nb binds with C to form fine carbide, and improves high-temperature strength. In addition, the formation of Cr carbide is suppressed, and thus oxidation resistance can be improved. In order to effectively exert these effects, the content of 0.2 % or more is required. However, when Nb is added in an excessive amount, heat cracking susceptibility is notably enhanced, and inner quality will be deteriorated. Therefore, an additive amount of Nb in the present invention is set to 0.2 - 0.7 percent by mass.
- In addition, the austenitic stainless cast steel of the present invention can be produced by performing cooling from a temperature range of 1,150 - 1,350°C to a temperature range of 600 - 800°C at a cooling rate of 30°C/min or more. By producing the austenitic stainless cast steel of the present invention under the above-described conditions, excellent strength property can be obtained, and thus solution heat treatment can be omitted.
- The produced austenitic stainless cast steel is used as, for example, materials for piping, valves and the like in chemical plants and power plants.
-
Fig. 1 is a graph showing results of oxidation resistance (mm/year) examined with respect to the austenitic stainless cast steel. - Hereinbelow, embodiments of the present invention will be described with reference to the drawings.
- The austenitic stainless cast steel of the present invention is formed in such a manner that the volume fraction of the ferrite phase becomes 0.1 - 5.0%, preferably 0.5 - 3.0%. The austenitic stainless cast steel of the present invention includes C, Si, Mn, Cr, Ni, Nb, N and the like as components thereof.
- The contents are as follows:
- C: 0.01 - 0.10 percent by mass, preferably 0.02 - 0.04 percent by mass;
- Si: 0.6 - 1.0 percent by mass, preferably 0.7 - 0.9 percent by mass;
- Mn: 2.0 - 2.8 percent by mass, preferably 2.2 - 2.4 percent by mass;
- N: 0.1 - 0.4 percent by mass, preferably 0.15 - 0.25 percent by mass;
- Cr: 18.0 - 24.0 percent by mass, preferably 19.5 - 21.5 percent by mass;
- Ni: 8.0 - 15.0 percent by mass, preferably 10.5 - 12.5 percent by mass; and
- Nb: 0.2 - 0.7 percent by mass, preferably 0.2 - 0.4 percent by mass.
- The compositions (percent by mass) of the austenitic stainless cast steel of the present invention, and of CF8C and CF8C-Plus for comparison, are shown in Table 1.
[Table 1] Austenitic stainless cast steel of the present invention CF8C CF8C-Plus Ferrite (volume fraction (%)) 0.1 - 5.0 12.0 - C (percent by mass) 0.01 - 0.10 Up to 0.08 0.05 - 0.15 Si (percent by mass) 0.6 - 1.0 Up to 2.0 0.2 - 1.0 Mn (percent by mass) 2.0 - 2.8 Up to 1.5 0.5 - 10.0 Cr (percent by mass) 18.0 - 24.0 18.0 - 21.0 18.0 - 25.0 Ni (percent by mass) 8.0 - 15.0 9.0 - 12.0 10.0 - 15.0 Nb (percent by mass) 0.2 - 0.7 Up to 1.0 0.1 - 1.5 N (percent by mass) 0.1 - 0.4 - 0.05 - 0.5 - In the austenitic stainless cast steel of the present invention, by setting the volume fraction of the ferrite phase to 0.1 - 5.0 %, even when the cast steel is exposed to high temperature for a long period of time, the precipitation amount of the sigma phase can be suppressed low. Therefore, the austenitic stainless cast steel of the present invention is unlikely to be embrittled, and exhibits excellent aging ductility.
- In addition, the austenitic stainless cast steel of the present invention has a higher Mn content and a lower C content than those of CF8C. With this configuration, the strength and oxidation resistance at high temperature can be improved.
- The austenitic stainless cast steel of the present invention can be produced by melting the above-described metal components in a melting furnace and performing cooling from a temperature range of 1,150 - 1,350 °C to a temperature range of 600 - 800 °C at a cooling rate of 30 °C/min or more. By producing the austenitic stainless cast steel of the present invention under the above-described conditions, even when the cast steel is left as-cast, excellent strength property can be obtained, and thus solution heat treatment can be omitted.
- The produced austenitic stainless cast steel is used, for example, for piping, valves and the like in chemical plants and power plants.
- Example of the present invention will be described.
- The main components (percent by mass) of the austenitic stainless cast steel of the present invention (Examples 1-1 - 1-6) and CF8C (Comparative Examples 1-1 - 1-5) are shown in Tables 2 and 3, respectively.
[Table 2] Example 1-1 1-2 1-3 1-4 1-5 1-6 Ferrite (volume fraction (%)) 0.2 0.2 0.2 0.2 0.2 0.2 C (percent by mass) 0.04 0.03 0.04 0.03 0.08 0.06 Si (percent by mass) 0.76 0.86 0.76 0.86 0.89 0.86 Mn (percent by mass) 2.07 2.15 2.07 2.15 2.07 2.12 Cr (percent by mass) 20.55 19.90 20.55 19.90 22.35 22.10 Ni (percent by mass) 11.38 11.12 11.38 11.12 10.50 10.34 Nb (percent by mass) 0.27 0.26 0.27 0.26 0.29 0.32 N (percent by mass) 0.21 0.20 0.21 0.20 0.19 0.21 [Table 3] Comparative Example 1-1 1-2 1-3 1-4 1-5 Ferrite (volume fraction (%)) 12.0 9.0 0 0 0 C (percent by mass) 0.03 0.03 0.017 0.08 0.06 Si (percent by mass) 0.47 0.63 0.37 0.48 0.57 Mn (percent by mass) 1.04 4.48 1.83 1.02 2.02 Cr (percent by mass) 19.98 19.93 19.93 19.35 19.60 Ni (percent by mass) 9.92 9.45 11.63 11.49 11.55 Nb (percent by mass) 0.59 0.42 0.43 0.69 0.71 N (percent by mass) 0.03 0.10 0.24 0.25 0.24 - In these Examples and Comparative Examples, aging ductility (700°C - 620 hours), tensile strength (900°C), 0.2% proof stress (900°C) and oxidation resistance (1,000°C) were examined, and further a high-temperature low-cycle fatigue test (alternate triangular waves, strain rate of 0.1%/sec, 700°C, total strain of 0.5%) was performed.
- It should be noted that both in Examples and Comparative Examples, casting was performed using normal static casting method. In Examples 1 and 2, the cast steel was left as-cast, while in the other Examples and Comparative Examples, the cast steel was subjected to SHT (solution heat treatment). Aging ductility, tensile strength, 0.2% proof stress, and oxidation resistance were examined and the results are shown in Table 4.
[Table 4] Aging ductility (%) Tensile strength (Mpa) 0.2% proof stress (Mpa) Oxidation resistance (mm/year) High-temperature low-cycle fatigue test (times) Example 1-1 24.4 120 90 0.300 - Example 1-2 28.8 125 87 0.370 6200 Example 1-3 24.0 113 91 0.066 3400 Example 1-4 29.2 134 89 0.122 2420 Example 1-5 20.4 131 91 0.489 - Example 1-6 22.1 129 88 0.394 - Comparative Example 1-1 17.2 93 70 1.278 2388 Comparative Example 1-2 6.8 101 75 3.494 - Comparative Example 1-3 8.6 127 84 1.854 - Comparative Example 1-4 11.2 98 73 4.101 - Comparative 8.2 104 77 3.124 - Example 1-5 - As a result, regarding aging ductility, Examples exhibited 20.4% or more, while Comparative Examples exhibited 17.2% or less.
- Regarding tensile strength, Examples exhibited 113 - 134 Mpa, while Comparative Examples exhibited 93 - 127 Mpa.
- Regarding 0.2% proof stress, Examples exhibited 87 - 91 Mpa, while Comparative Examples exhibited 70 - 84 Mpa.
- Regarding oxidation resistance, Examples exhibited 0.489 mm/year or less, while Comparative Examples exhibited 1.278 mm/year or more.
- To sum up, though Examples and Comparative Examples were not notably distinguishable in the 0.2% proof stress, it was found that Example exhibited excellent result in aging ductility, tensile strength and oxidation resistance. Especially, an average value of the aging ductility in Examples was 24.8%, while an average value in Comparative Examples was 10.4%, and thus the value in Example was approximately 2.4 times as high as that in Comparative Example. Likewise, an average value of oxidation resistance in Examples was 0.290mm/year, while an average value in Comparative Examples was 2.770 mm/year, and thus the value in Example was improved approximately 9.5 times as much as that in Comparative Example.
- The above-described results shows the case where the volume fraction of the ferrite phase of the austenitic stainless cast steel of the present invention was 0.2%, and it is considered that similar results will be obtained when a lower limit of the volume fraction of the ferrite phase is set to 0.1%.
- In Example 1, the volume fraction of the ferrite phase of the austenitic stainless cast steel of the present invention was 0.2% (Examples 1-1 - 1-6). In addition, also for a case in which the volume fraction of the ferrite phase is 1 - 3%, aging ductility, tensile strength, 0.2% proof stress and oxidation resistance were examined (Examples 2-1 - 2-4) under the same condition for Example 1. The components of Examples 2-1 - 2-4 are shown in Table 5, and the results are shown in Table 6.
[Table 5] Example 2-1 2-2 2-3 2-4 Ferrite (volume fraction (%)) 2 1 3 1 C (percent by mass) 0.014 0.013 0.020 0.013 Si (percent by mass) 0.67 0.72 0.62 0.72 Mn (percent by mass) 2.26 2.37 2.00 2.22 Cr (percent by mass) 21.10 21.10 21.70 22.22 Ni (percent by mass) 11.29 11.38 12.09 11.54 Nb (percent by mass) 0.29 0.29 0.27 0.27 N (percent by mass) 0.22 0.23 0.16 0.23 [Table 6] Aging ductility (%) Tensile strength (Mpa) 0.2% proof stress (Mpa) Oxidation resistance (mm/year) Example 2-1 27.0 128 89 0.006 Example 2-2 24.0 123 88 0.058 Example 2-3 27.0 95 63 0.558 Example 2-4 20.4 137 88 0.015 - As a result, an average value of aging ductility in Examples 2-1 - 2-4 was 24.6%, and an average value of oxidation resistance was 0.159 mm/year. Like in Example 1, these values are recognized as being excellent over the values in Comparative Example. It is considered that similar results will be obtained when an upper limit of the volume fraction of the ferrite phase of the austenitic stainless cast steel of the present invention is set to 5%.
- With respect to the austenitic stainless cast steel whose Mn content was approximately 1.0 - 4.5 percent by mass, oxidation resistance (mm/year) was examined. As the austenitic stainless cast steel of the present invention, those with the Mn content of 2.26 percent by mass (Example 3-1) and 2.33 percent by mass (Example 3-2) were used. As the austenitic stainless cast steel of Comparative Example, those with the Mn content of 1.04 percent by mass (Comparative Example 3-1), 1.17 percent by mass (Comparative Example 3-2), 1.81 percent by mass (Comparative Example 3-3), 4.37 percent by mass (Comparative Example 3-4), and 4.48 percent by mass (Comparative Example 3-5) were used. The components for these Examples and Comparative Examples are shown in Table 7. The results are shown in Table 8 and
Fig. 1 .[Table 7] Example Comparative Example 3-1 3-2 3-1 3-2 3-3 3-4 3-5 Ferrite (volume fraction (%)) 2 3 12 8 0.2 10 9 C (percent by mass) 0.03 0.03 0.03 0.03 0.017 0.03 0.03 Si (percent by mass) 0.65 0.64 0.47 0.61 0.36 0.62 0.63 Mn (percent by mass) 2.26 2.33 1.04 1.17 1.81 4.37 4.48 Cr (percent by mass) 20.45 20.47 19.98 20.09 19.87 19.87 19.93 Ni (percent by mass) 11.35 11.33 9.92 9.92 12.49 9.35 9.45 Nb (percent by mass) 0.65 0.62 0.59 0.62 0.29 0.66 0.42 N (percent by mass) 0.14 0.12 0.03 0.12 0.20 0.10 0.10 [Table 8] Oxidation resistance (mm/year) Example 3-1 0.5062 Example 3-2 0.4521 Comparative Example 3-1 1.2782 Comparative Example 3-2 2.6405 Comparative Example 3-3 1.7060 Comparative Example 3-4 3.6345 Comparative Example 3-5 3.4943 - As can be seen in
Fig. 1 , in the austenitic stainless cast steel of the present invention where the Mn content is 2.0 - 2.8 percent by mass, oxidation resistance can be reduced to 1 mm/year or less. - The present invention is applicable to the production of the austenitic stainless cast steel.
Claims (5)
- An austenitic stainless cast steel, whereina volume fraction of a ferrite phase is 0.1 - 5.0 %, andthe cast steel consists of: 0.01 - 0.10 percent by mass of C; 0.6 - 1.0 percent by mass of Si; 2.0 - 2.8 percent by mass of Mn; 0.1 - 0.4 percent by mass of N; 18.0 - 24.0 percent by mass of Cr; 8.0 - 15.0 percent by mass of Ni; 0.2 - 0.7 percent by mass of Nb; and the balance is Fe and inevitable impurities.
- The austenitic stainless cast steel according to claim 1, wherein the volume fraction of the ferrite phase is 0.5 - 3.0 %.
- The austenitic stainless cast steel according to claim 1 or 2, wherein Mn is 2.07 - 2.8 percent by mass and Nb is 0.26 - 0.7 percent by mass.
- A method of producing the austenitic stainless cast steel according to any one of claims 1 to 3, the method comprising:a melting of metal components in a melting furnace, anda cooling of the molten metal components from a temperature range of 1,150 - 1,350 °C to a temperature range of 600 - 800 °C at a cooling rate of 30 °C/min or more.
- A valve formed of the austenitic stainless cast steel according to any one of claims 1 to 3.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2011079965 | 2011-03-31 | ||
PCT/JP2012/054523 WO2012132679A1 (en) | 2011-03-31 | 2012-02-24 | Cast austenitic stainless steel |
Publications (3)
Publication Number | Publication Date |
---|---|
EP2692887A1 EP2692887A1 (en) | 2014-02-05 |
EP2692887A4 EP2692887A4 (en) | 2015-01-21 |
EP2692887B1 true EP2692887B1 (en) | 2017-07-19 |
Family
ID=46930439
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP12765111.5A Not-in-force EP2692887B1 (en) | 2011-03-31 | 2012-02-24 | Cast austenitic stainless steel |
Country Status (7)
Country | Link |
---|---|
US (1) | US20140056751A1 (en) |
EP (1) | EP2692887B1 (en) |
JP (1) | JP5863770B2 (en) |
KR (1) | KR20140044318A (en) |
CN (1) | CN103429778B (en) |
CA (1) | CA2830586A1 (en) |
WO (1) | WO2012132679A1 (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108200771B (en) | 2016-03-28 | 2021-02-12 | Lg电子株式会社 | Stainless steel and pipe made of the same |
KR102030162B1 (en) | 2016-12-23 | 2019-11-08 | 주식회사 포스코 | Austenitic stainless steel having excellent formability and surface properties and manufacturing method of the same |
WO2018117683A1 (en) * | 2016-12-23 | 2018-06-28 | 주식회사 포스코 | Austenitic stainless steel having excellent processability and surface characteristics, and manufacturing method therefor |
CN109454220A (en) * | 2018-11-24 | 2019-03-12 | 共享铸钢有限公司 | A kind of production method of austenitic stainless steel material steel-casting |
CN110093561B (en) * | 2019-05-13 | 2021-06-18 | 襄阳市立强机械有限公司 | As-cast nonmagnetic austenitic stainless steel and preparation method thereof |
JP6793866B1 (en) * | 2020-06-17 | 2020-12-02 | 株式会社クボタ | Gas valve and propane gas flow control method |
CN113699453B (en) * | 2021-08-30 | 2023-03-10 | 上海海塔机械制造有限公司 | Heat-resistant high-nitrogen steel and production method thereof |
Family Cites Families (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5218418A (en) * | 1975-08-02 | 1977-02-12 | Jgc Corp | Stainless cast steel for low temperature use |
JPS5487627A (en) * | 1977-12-23 | 1979-07-12 | Kubota Ltd | Stainless steel for extreme low temperature excellent in weld ability |
JPS5547370A (en) * | 1978-09-30 | 1980-04-03 | Kubota Ltd | Stainless cast steel for cryogenic temperature use |
JPS60121098A (en) * | 1983-12-05 | 1985-06-28 | Kawasaki Steel Corp | Prevention of hydrogen peeling crack in build-up welding of austenitic stainless steel |
JPS6353244A (en) * | 1986-08-25 | 1988-03-07 | Aichi Steel Works Ltd | Stainless steel excellent in strength and corrosion resistance and having small anisotropy and its production |
JPS63169362A (en) * | 1986-12-29 | 1988-07-13 | Aichi Steel Works Ltd | Nonmagnetic tool steel |
JPH0297648A (en) * | 1988-09-30 | 1990-04-10 | Aichi Steel Works Ltd | Austenitic stainless steel excellent in creep rupture strength and its production |
JPH0297647A (en) * | 1988-09-30 | 1990-04-10 | Aichi Steel Works Ltd | Steel for valve stem having excellent torsional strength and its manufacture |
JP2574917B2 (en) * | 1990-03-14 | 1997-01-22 | 株式会社日立製作所 | Austenitic steel excellent in stress corrosion cracking resistance and its use |
JP2915691B2 (en) * | 1992-05-08 | 1999-07-05 | 日本冶金工業株式会社 | High ductility austenitic-ferrite dual phase heat resistant steel and method for producing the same |
JPH0830248B2 (en) * | 1993-05-27 | 1996-03-27 | 工業技術院長 | Stainless cast steel for seawater pumps at nuclear power plants |
JP3336820B2 (en) * | 1995-07-25 | 2002-10-21 | 株式会社日立製作所 | Seawater corrosion resistant austenitic cast stainless steel and seawater pump |
US20060266439A1 (en) | 2002-07-15 | 2006-11-30 | Maziasz Philip J | Heat and corrosion resistant cast austenitic stainless steel alloy with improved high temperature strength |
JP3954954B2 (en) * | 2002-10-25 | 2007-08-08 | 新日本製鐵株式会社 | Manufacturing method of austenitic stainless steel and strip slab |
KR100689783B1 (en) * | 2003-06-10 | 2007-03-08 | 수미도모 메탈 인더스트리즈, 리미티드 | Austenitic stainless steel for hydrogen gas and method for production thereof |
DE602005021286D1 (en) * | 2004-09-15 | 2010-07-01 | Sumitomo Metal Ind | Steel pipe with excellent resistance to flaking on the inner surface |
BRPI0820586B1 (en) * | 2007-12-20 | 2018-03-20 | Ati Properties Llc | AUSTENIC STAINLESS STEEL AND MANUFACTURING ARTICLE INCLUDING AUSTENIC STAINLESS STEEL |
CN101845605B (en) * | 2009-03-24 | 2013-01-02 | 宝山钢铁股份有限公司 | Austenitic stainless steel plate with excellent strength at medium and low temperature and manufacturing method thereof |
-
2012
- 2012-02-24 CN CN201280013824.1A patent/CN103429778B/en not_active Expired - Fee Related
- 2012-02-24 CA CA2830586A patent/CA2830586A1/en not_active Abandoned
- 2012-02-24 KR KR1020137028616A patent/KR20140044318A/en not_active Application Discontinuation
- 2012-02-24 EP EP12765111.5A patent/EP2692887B1/en not_active Not-in-force
- 2012-02-24 WO PCT/JP2012/054523 patent/WO2012132679A1/en active Application Filing
- 2012-02-24 JP JP2013507281A patent/JP5863770B2/en active Active
- 2012-02-24 US US14/007,578 patent/US20140056751A1/en not_active Abandoned
Non-Patent Citations (1)
Title |
---|
None * |
Also Published As
Publication number | Publication date |
---|---|
JP5863770B2 (en) | 2016-02-17 |
JPWO2012132679A1 (en) | 2014-07-24 |
WO2012132679A1 (en) | 2012-10-04 |
CN103429778B (en) | 2016-01-06 |
EP2692887A4 (en) | 2015-01-21 |
US20140056751A1 (en) | 2014-02-27 |
CA2830586A1 (en) | 2012-10-04 |
CN103429778A (en) | 2013-12-04 |
EP2692887A1 (en) | 2014-02-05 |
KR20140044318A (en) | 2014-04-14 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2692887B1 (en) | Cast austenitic stainless steel | |
AU2015281542B2 (en) | Carburized alloy steel, method for preparing same, and use thereof | |
US11085093B2 (en) | Ultra-high strength maraging stainless steel with salt-water corrosion resistance | |
EP3279359B1 (en) | Exhaust system part having stainless steel sheet having excellent intermittent oxidation characteristics | |
JPWO2012036313A1 (en) | Heat-resistant ferritic stainless steel sheet with excellent oxidation resistance | |
JPWO2007138815A1 (en) | Austenitic stainless steel | |
JP2019052349A (en) | Nickel-based alloy | |
JP2017002352A (en) | Duplex stainless steel material and duplex stainless steel pipe | |
EP3722448A1 (en) | High-mn steel and method for manufacturing same | |
JP2021505771A (en) | Ferritic stainless steel with excellent high-temperature oxidation resistance and its manufacturing method | |
JP2018031028A (en) | Fe-Ni-Cr-Mo ALLOY AND METHOD FOR PRODUCING THE SAME | |
KR101089718B1 (en) | C+N austenitic stainless steel with high strength and corrosion resistance having tungsten and molybdenum, and fabrication method thereof | |
US9816163B2 (en) | Cost-effective ferritic stainless steel | |
KR20150074697A (en) | Low-nickel containing stainless steels | |
JP3483493B2 (en) | Cast steel for pressure vessel and method of manufacturing pressure vessel using the same | |
KR101089714B1 (en) | C+N austenitic stainless steel with high strength and corrosion resistance having tungsten and fabrication method thereof | |
JPS5940901B2 (en) | Corrosion-resistant austenitic stainless steel | |
KR20180074322A (en) | Austenite stainless steel excellent in corrosion resistance and hot workability | |
JP6337514B2 (en) | Precipitation hardening type Fe-Ni alloy and manufacturing method thereof | |
JP6201731B2 (en) | Austenitic heat-resistant casting alloy | |
TWI454583B (en) | Zinc-modified ferritic stainless steels and manufacturing method thereof | |
TW201816124A (en) | Martensitic stainless steel and method for the manufacture | |
KR101650258B1 (en) | Austenitic stainless and manufacturing method thereof | |
CN112030041B (en) | MonelK500A alloy with corrosion resistance in oxygen-containing hydrofluoric acid | |
JP2017145437A (en) | Ferritic stainless steel |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 20130925 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
DAX | Request for extension of the european patent (deleted) | ||
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R079 Ref document number: 602012034743 Country of ref document: DE Free format text: PREVIOUS MAIN CLASS: C22C0038000000 Ipc: B22D0027200000 |
|
A4 | Supplementary search report drawn up and despatched |
Effective date: 20150105 |
|
RIC1 | Information provided on ipc code assigned before grant |
Ipc: C22C 38/58 20060101ALI20141218BHEP Ipc: C21D 6/00 20060101ALI20141218BHEP Ipc: C22C 38/00 20060101ALI20141218BHEP Ipc: B22D 30/00 20060101ALI20141218BHEP Ipc: C21D 6/02 20060101ALI20141218BHEP Ipc: C22C 38/02 20060101ALI20141218BHEP Ipc: C22C 38/48 20060101ALI20141218BHEP Ipc: B22D 27/20 20060101AFI20141218BHEP Ipc: C21D 6/04 20060101ALI20141218BHEP |
|
17Q | First examination report despatched |
Effective date: 20161110 |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
INTG | Intention to grant announced |
Effective date: 20170413 |
|
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: SAKAMOTO NOBUYUKI Inventor name: HINENO MAKOTO |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: REF Ref document number: 909894 Country of ref document: AT Kind code of ref document: T Effective date: 20170815 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R096 Ref document number: 602012034743 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: MP Effective date: 20170719 |
|
REG | Reference to a national code |
Ref country code: LT Ref legal event code: MG4D |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: MK05 Ref document number: 909894 Country of ref document: AT Kind code of ref document: T Effective date: 20170719 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: HR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: SE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: LT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: NL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: FI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: AT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: NO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171019 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: PLFP Year of fee payment: 7 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: RS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: LV Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: BG Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171019 Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171119 Ref country code: PL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20171020 Ref country code: ES Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R097 Ref document number: 602012034743 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CZ Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: RO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: SM Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: EE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 |
|
26N | No opposition filed |
Effective date: 20180420 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MC Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20180224 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: MM4A |
|
REG | Reference to a national code |
Ref country code: BE Ref legal event code: MM Effective date: 20180228 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20180228 Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20180228 Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20180224 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20180224 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20180224 Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20180228 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20180224 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: TR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20200211 Year of fee payment: 9 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 Ref country code: HU Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO Effective date: 20120224 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MK Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20170719 Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20200113 Year of fee payment: 9 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170719 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R119 Ref document number: 602012034743 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210901 Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210228 |