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
  • C22C38/58—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
  • C21D6/00—Heat treatment of ferrous alloys
  • C21D6/004—Heat treatment of ferrous alloys containing Cr and Ni
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
• • 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
  • C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
  • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
  • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
• • 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
  • C22C38/48—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
  • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
• • 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 present invention concerns a heat-resistant austenitic stainless steel used preferably as materials of heat transfer tubes such as for boilers and it particularly relates to a heat-resistant austenitic stainless steel having excellent cyclic oxidation resistance.
• the oxidation resistance required for the materials of heat transfer tubes include cyclic oxidation resistance. Since boilers are started and stopped repeatedly, oxides formed on the surface of the steel tubes (heat transfer tubes) are exposed to cyclic oxidation circumstance undergoing high temperature circumstance and low temperature circumstance alternately. In such a circumstance, oxides are peeled due to the difference of thermal expansion coefficient to the matrix to result in a problem of insufficiency of strength caused by further development of oxidation and weight loss (thinning) due to peeling off scale. The property less causing such phenomenon (referred to as "cyclic oxidation resistance" in the invention) even under such circumstance is required.
• SUS321 system has been known as the composition similar to that of 18Cr-8Ni austenitic stainless steel and KA-SUS321J2HTB has been known as the stainless steel for boilers having a specification for thermal power station according to SUS321 system has been known.
• a technology for improving the oxidation resistance in a wide sense includes (1) surface treatment such as shot peening or mechanical polishing, (2) addition of Al, Si and REM (rare earth metal) including Ce and La which are alloying elements for improving the corrosion resistance, and (3) refining of crystal grains. Technologies relating to austenitic stainless steels using Ti compounds as precipitation hardening mechanism have been proposed, for example, in Patent Literatures 1 and 2.
• the Patent Literature 1 discloses improvement of the oxidation resistance by the addition of Al that contributes to the improvement of the corrosion resistance and by the promotion of the formation of a Cr 2 O 3 layer by surface polishing. Further, as a substitute for obtaining the same effect as the surface polishing treatment, the literature shows that the oxidation resistance can be improved also by increasing the total amount of Al and Si to 4% or more and, in addition, adding REM such as Ce, Y, and La, or Ca.
• Patent Literature 2 discloses addition of Ce, La, and Hf for improving the oxidation resistance, it is expected that the cyclic oxidation resistance is low in the same manner as the technologies described above and the technology is not based on the recognition of the improvement for the cyclic oxidation resistance.
• the present invention has been accomplished in view of such a situation and it intends to provide a heat-resistant austenitic stainless steel having excellent cyclic oxidation resistance, having a chemical composition comparable with that of 18Cr-8Ni austenitic stainless steels in view of Ni and Cr content, not depending on the addition of Al or Si and surface treatment, with less peeling off surface oxides in cyclic oxidation circumstance, and causing less weight loss.
• a heat-resistant austenitic stainless steel of the invention capable of solving the problem described above consisting of C: 0.05 to 0.2% (means mass% for chemical composition here and hereinafter), Si: 0.1 to 1%, Mn: 0.1 to 2.5%, Cu: 1 to 4%, Ni: 7 to 12%, Cr: 16 to 20%, Nb: 0.1 to 0.6%, Zr: 0.05 to 0.4%, Ce: 0.005 to 0.1%, Ti: 0.1 to 0.6%, B: 0.0005 to 0.005%, N: 0.001 to 0.15%, S: 0.005% or less (not including 0%) and P: 0.05% or less (not including 0%) respectively, optionally, Mo: 3% or less (not including 0%) and/or W: 5% or less (not including 0%), Ca: 0.005% or less (not including 0%) and/or Mg: 0.005% or less (not including 0%), with the balance of iron and unavoidable impurities.
• the yield of Ce can be improved and the toughness can be improved .
• the high temperature strength is further improved by containing such elements.
• the heat-resistant austenitic stainless steel improved the cyclic oxidation resistance can be obtained by controlling the chemical composition as described above. Further, higher cyclic oxidation resistance can be obtained and, in addition, the property can be provided stably by refining the crystal grain size of a metal structure to 6 or more and less than 12 in terms of the ASTM grain size number.
• the power generation efficiency due to increase in the steam temperature can be improved by using the material as the heat transfer tube for coal-fired power plants and the service life of the heat transfer tube can be made longer compared with conventional materials, to reduce the maintenance cost. Further, when the material is used as the heat transfer tube, since less scale is peeled off, scattering of the scale in the inside can be suppressed to decrease damages of the turbine.
• the present inventors have made studies from various approaches in order to realize an austenitic stainless steel improved for cyclic oxidation resistance while maintaining necessary high temperature strength. As a result, it has been found that an outstandingly excellent cyclic oxidation resistance can be provided by containing of a predetermined amount of Zr and Ce to stainless steel having a chemical composition comparable with that of 18Cr-8Ni austenitic stainless steel, in view of the content of Ni and Cr to accomplish the present invention.
• the heat-resistant austenitic stainless steel of the invention has a feature of containing a predetermined amount of Zr and Ce to the chemical composition comparable with that of the 18Cr-8Ni austenitic stainless steel in view of the content of Ni and Cr, and the reason for defining the range of the content of Zr and Ce is as described below.
• Zr and Ce exhibit an effect of suppressing peeling off oxides due to a synergistic effect of them.
• 0.05% or more of Zr has to be contained.
• Ce has to be contained 0.005% or more for providing the effect. If the Ce content is excessive to exceed 0.1%, this increases cost from an economical point of view.
• a preferred lower limit of the Zr content is 0.10% or more (more preferably, 0.15% or more) and a preferred upper limit is 0.3% or less (more preferably, 0.25% or less).
• a preferred lower limit of the Ce content is 0.01% or more (more preferably, 0.015% or more) and a preferred upper limit is 0.05% or less (more preferably 0.03% or less).
• Ce-containing master alloy or a Ce-containing misch metal prepared. If La, Nd, Pr, etc. to be contained in the misch metal are contained in the steel at a concentration lower than that of Ce in the steel, they cause no problem, and handling during melting operation can be simplified by using the master alloy or misch metal compared with easily oxidizable pure Ce.
• Patent Literatures 1, 3, and 5 disclose that adhesion of the oxides is improved by the addition of REM including Y, La, and Ce but each of such disclosures is based on the assumption of sole addition of REM and they do not disclose at all the synergistic effect obtained by addition of Ce together with Zr.
• Patent Literature 2 also discloses that Zr and Ce can be contained in combination.
• each of them is not an essential alloy component in this technology and added optionally also including the case with no addition.
• Zr is contained by a content less than the range defined in the invention while intending to strengthen the grain boundary and improve the creep ductility.
• the heat-resistant austenitic stainless steel of the invention has a chemical composition comparable with that of 18Cr-8Ni austenitic stainless steel in view of the content of Ni and Cr.
• the chemical composition for each of the elements other than Zr and Ce should also be controlled appropriately. The effect and the reason for defining the range of such elements are as described below.
• C is an element of forming carbides in a high temperature service circumstance and having an effect of improving high temperature strength and creep strength necessary for the heat transfer tube, and it should be contained 0.05% or more in order to ensure the amount of carbide precipitates that works as hardening particles.
• a preferred lower limit of the C content is 0.07% or more (more preferably, 0.09% or more) and a preferred upper limit is 0.18% or less (more preferably, 0.15% or less).
• Si is an element having a deoxidation effect in molten steels. Further, it acts effectively for the improvement of the oxidation resistance if it is contained even in a small amount. For providing such effects, it is necessary that the Si content is 0.1% or more. However, if Si is added excessively and its content is more than 1%, this results in formation of ⁇ phase to embrittle the steel ( ⁇ embrittlement).
• a preferred lower limit of the Si content is 0.2% or more (more preferably, 0.3% or more) and a preferred upper limit is 0.9% or less (more preferably, 0.8% or less).
• Mn is an element having a deoxidation effect in molten steels in the same manner as Si. Further, it has an effect of stabilizing austenite. For providing such effects, it is necessary that the Mn content is 0.1% or more. However, if Mn is added excessively and its content is more than 2.5%, this deteriorates hot workability.
• a preferred lower limit of the Mn content is 0.2% or more (more preferably, 0.3% or more) and a preferred upper limit is 2.0% or less (more preferably, 1.8% or less).
• Cu is an element of forming coherent precipitates (precipitates in which the atomic arrangement is continuous with that of matrix) in steels and remarkably improving high temperature creep strength which is one of principal hardening mechanisms in stainless steels.
• it is necessary that Cu content is 1% or more. However, if Cu is added excessively and its content is more than 4%, the effect is saturated.
• a preferred lower limit of the Cu content is 2.0% or more (more preferably, 2.5% or more) and a preferred upper limit is 3.7% or less (more preferably, 3.5% or less).
• Ni has an effect of stabilizing austenite and it is necessary to be contained 7% or more in order to maintain an austenitic phase. However, if Ni is added excessively and its content is more than 12%, this increases the cost.
• a preferred lower limit of the Ni content is 7.5% or more (more preferably, 8.0% or more) and a preferred upper limit is 11.5% or less (more preferably, 11.0% or less).
• Cr is an essential element for providing corrosion resistance as a stainless steel. For providing such an effect, it is necessary that Cr is contained 16% or more. However, if Cr is added excessively and its content is more than 20%, a ferrite phase which lowers the high temperature strength increases.
• a preferred lower limit of the Cr content is 16.5% or more (more preferably, 17.0% or more) and a preferred upper limit is 19.5% or less (more preferably, 19.0% or less).
• Nb is an effective element to the improvement of the high temperature strength by precipitation of carbonitrides (carbides, nitrides, or carbonitrides) and, further, provides an effect of improving the corrosion resistance as a subsidiary effect by suppressing growing of the crystal grains and promoting diffusion of Cr by means of precipitates.
• Nb is contained 0.1% or more.
• a preferred limit of the Nb content is 0.12% or more (more preferably, 0.15% or more) and a preferred upper limit is 0.5% or less (more preferably, 0.3% or less).
• Ti also provides the same effect as Nb and, when it is added with Nb and Zr, precipitates are further stabilized, which is also effective for maintaining high temperature strength for a long time.
• the Ti content is 0.1% or more.
• the Ti content becomes excessive, precipitates become coarser to lower the toughness in the same manner as Nb, so that the Ti content should be 0.6% or less.
• a preferred lower limit of the Ti content is 0.12% or more (more preferably, 0.15% or more) and a preferred upper limit is 0.5% or less (more preferably, 0.3% or less).
• B has an effect of promoting formation of M 23 C 6 type carbides (M is carbide-forming elements) as one of principal hardening mechanisms by being solved into steel.
• M is carbide-forming elements
• the B content is 0.0005% or more.
• a preferred lower limit of the B content is 0.001% or more (more preferably, 0.0012% or more) and a preferred upper limit is 0.004% or less (more preferably, 0.003% or less).
• N is an element having an effect of improving the high temperature strength through solid-solution hardening by being solved into steel, which is also effective for the improvement of the high temperature strength by forming nitrides with Cr or Nb under load at high temperature for a long time.
• the N content is 0.001% or more.
• a preferred lower limit of the N content is 0.002% or more (more preferably, 0.003% or more) and a preferred upper limit is 0.10% or less (more preferably, 0.08% or less, and, further preferably, 0.02% or less).
• S is an unavoidable impurity and, since hot workability is deteriorated as the content increases, it is necessary that the content is 0.005% or less. Further, since S fixes Ce as sulfides to decrease the effect obtained by the addition of Ce, it is preferably restricted to 0.002% or less (more preferably, 0.001% or less).
• P is an unavoidable impurity and, since the weldability is deteriorated as the content increases, it should be 0.05% or less. Preferably, it is restricted to 0.04% or less (more preferably, 0.03% or less)
• the contained elements defined in the invention are described above and the balance is iron and unavoidable impurities.
• impurity elements having low melting point such as Sn, Pb, Sb, As, and Zn derived from scrap materials lower the grain boundary strength during hot working and use at high temperature circumstance, it is preferred that they are kept to a low concentration in order to improve the hot workability and embrittlement cracks in long time use.
• Mo, W, Ca, and Mg, etc. may also be optionally contained and the properties of the steel are further improved in accordance with the kind of the elements to be contained.
• Mo and W have an effect of improving the high temperature strength by solid solution hardening and can further increase the high temperature strength by optionally adding them.
• the hot workability is deteriorated when the Mo content is excessive, it is preferably 3% or less. More preferably, it is 2.5% or less (further preferably, 2.0% or less).
• excessive W content forms coarse intermetallic compounds to lower the high temperature ductility, it is preferably less than 5% or less. More preferably, it is 4.5% or less (further preferably, 4.0% or less).
• a preferred lower limit for providing the effect efficiently described above is 0.1% or more (more preferably, 0.5% or more) for Mo and 0.1% or more (more preferably, 1.0% or more) for W.
• the effect as described above can be provided by addition of such elements, since this increases the cost on the other hand, the content may be determined in accordance with the necessary hardening amount and an allowable cost.
• Ca and Mg act as desulfurizing and deoxidizing elements, they can suppress formation of Ce sulfides and Ce oxides to improve the yield of Ce and suppress lowering of the toughness due to formation of inclusions.
• a preferred lower limit for providing such effect effectively is 0.0002% or more and, more preferably, 0.0005% or more for each of them.
• each of the upper limits is defined to 0.005% or less. More preferably, the content of each of them is 0.002% or less.
• the crystal grain size of the microstructure of the heat-resistant austenitic stainless steel is preferably defined as a fine structure of 6 or more and less than 12 in terms of the ASTM (American Society for Testing and Materials) grain size number.
• the grain size number (crystal grain size number) is defined by ASTM and means a grain size number calculated by a counting method (Planimetric method).
• the crystal grain size of the microstructure is less than 6 in terms of the ASTM grain size number, while the effect of improving the cyclic oxidation resistance per se by the addition of Zr and Ce can be obtained, the improving effect cannot be increased sufficiently.
• the grain size number is preferably 7 or more and, more preferably, 9 or more.
• an upper limit of the crystal grain size is preferably less than 12. In view of the manufacturing cost and the productivity, the upper limit is more preferably 10 or less.
• the range of the crystal grain size as described above can be obtained by controlling the addition amount of the elements contributing to the pinning at the crystal grain boundary, conditions for hot and cold working such as drawing and extrusion in the tube production process, and heat treatment.
• the optimal condition for each of them changes depending on the three factors and, in order to refine the crystal grain size, it is necessary to increase the addition amount of the precipitating elements, make the degree of strain higher, and lower the heat treatment temperature.
• Cold and hot working are applied for controlling the tube thickness and introducing strains and conditioning the crystal grain structure by heat treatment after working and usually performed at a reduction ratio of 30% or more. Further, the heat treatment is applied for removing strains and performed in a temperature range generally at 1,000°C or higher and lower than 1,300°C.
• the defined range of the grain size can be obtained by setting the heat treatment temperature to 1,250°C or lower and, preferably, 1,225°C or lower and, particularly preferably, 1,150°C or lower, but the condition is not restricted depending on the balance for precipitating elements, working, and heat treatment.
• specimens Nos. 1 to 10 are steels that satisfy the requirements defined in the invention (steel of the invention), and specimens Nos. 11 to 16 are steels out of the requirements defined in the invention (comparative steels), in which the specimens Nos. 14, 15, and 16 are "steels corresponding to KA-SUS304J1HTB", “steels corresponding to SUS304L”, and “steels corresponding to SUS310S” which are conventional steels respectively.
• the specimens Nos. 7 and 8 are steels with addition of Ce by using a misch metal and contain La, Pr, Nd, etc. as impurities.
• the specimens Nos. 9 and 10 are steels with addition of Mg and Ca respectively.
• Step corresponding to KA-SUS304J1HTB belongs to 18Cr-8Ni austenitic stainless steel which is steel species used successfully as heat transfer tubes of boilers (for example, in “ MATERIA", vol. 46, No. 2, 2007, pp. 99-101 ). Further, steel corresponding to SUS310S (specimen No. 16) belongs to 25Cr-20Ni austenitic stainless steel. While this is expensive since it contains more Ni than 18Cr-8Ni austenitic stainless steel, this is steel species more excellent in the corrosion resistance than 18Cr-8Ni austenitic stainless steel essentially in view of the chemical composition. [Table 1] Specimen No.
• the weight loss is decreased in the steels that satisfy the chemical composition defined in the invention (steel of invention: specimens Nos. 1 to 10) compared with conventional steels (specimens Nos. 14, 15) and comparative steels that are out of the chemical compositions defined in the invention (specimen Nos. 11 to 13), and it can be seen that less scales are peeled and the weight loss can be suppressed by compound addition of Zr and Ce.
• the steel of the invention provides properties comparable with those of steels corresponding to conventional steels SUS310S of 25Cr-20Ni which contain higher Ni content and are considered to be excellent in the corrosion resistance (specimen No. 16), and the cyclic oxidation resistance can be improved to a level comparable with that of 25Cr-20Ni austenitic stainless steel although this is a 18Cr-8Ni austenitic stainless steel and inexpensive.
• the heat treatment temperature was changed in temperature range of 1125 to 1275°C after cold working at 35% reduction ratio to prepare specimens of the respective steels with crystal grain size numbers of 4.5 to 10.0.
• specimens were carried into and out of a furnace at 1100°C in air at a temperature cycle including furnace heating for 25 min and cooling for 5 min in air, and weight loss (reduction in thickness: mg ⁇ cm -2 ) was determined by comparing the mass of the specimen after 40 cycles with the mass of the specimen in the initial state.
• Specimens with a crystal grain size number of 6 or more are examples of the invention that satisfy the definition in the invention for the crystal grain size in addition to the chemical composition and specimens with the number of less than 6 are examples of the invention that satisfy the chemical composition but do not satisfy the crystal grain size (grain size numbers are underlined).
• the result of the comparative steel of the specimen No. 14 it can be seen that in the steel out of the chemical composition of the invention, weight loss does not change substantially even when the crystal grain size changes but, in the steel of the invention of specimens Nos. 1 to 6, the weight loss tends to be decreased as the crystal grain size number is larger.
• any of the steels of the invention of different crystal grain size can decrease the weight loss more than the conventional steel of specimen No. 14, it can be seen that the cyclic oxidation resistance is improved by the addition of Zr and Ce per se and that the property is further improved as the crystal grain size is smaller even when the chemical composition is within a range defined by the invention.
• the cyclic oxidation resistance is higher when the crystal grain size number is 6 or more compared with the cases of less than 6 in any of the steel species and a remarkable improving effect is obtained, particularly, in the case of the grain size number of 7 or more and, further, 9 or more. That is, the cyclic oxidation resistance can be improved in the steels that satisfy the range of composition of the invention, and the effect can be increased further by controlling the crystal grain size, and excellent cyclic oxidation resistance can be obtained stably.
• Japanese Patent Application No. 2011-106588 Japanese patent application filed on September 16, 2011
• Japanese Patent Application No. 2011-203604 Japanese patent application filed on March 5, 2012
• Japanese Patent Application No. 2012-048357 Japanese patent application filed on March 5, 2012
• the heat-resistant austenitic stainless steel of the invention can be used suitably as the material for heat transfer tubes of boilers, etc.

Landscapes

• 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)

Applications Claiming Priority (4)

Publications (3)

Family

ID=47139289

Family Applications (1)

Country Status (7)

Families Citing this family (11)

Family Cites Families (12)

• 2012
  • 2012-03-05 JP JP2012048357A patent/JP5143960B1/ja not_active Expired - Fee Related
  • 2012-05-10 CN CN201280022304.7A patent/CN103517998B/zh not_active Expired - Fee Related
  • 2012-05-10 WO PCT/JP2012/062039 patent/WO2012153814A1/ja active Application Filing
  • 2012-05-10 KR KR1020137029415A patent/KR20130137705A/ko not_active Application Discontinuation
  • 2012-05-10 ES ES12782655.0T patent/ES2590465T3/es active Active
  • 2012-05-10 EP EP12782655.0A patent/EP2708611B1/en not_active Not-in-force
  • 2012-05-10 US US14/115,570 patent/US20140154128A1/en not_active Abandoned

Also Published As

Similar Documents

Legal Events