WO2016159011A1 - 断続酸化特性に優れた排気系部品用ステンレス鋼板及び排気系部品 - Google Patents
断続酸化特性に優れた排気系部品用ステンレス鋼板及び排気系部品 Download PDFInfo
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- WO2016159011A1 WO2016159011A1 PCT/JP2016/060249 JP2016060249W WO2016159011A1 WO 2016159011 A1 WO2016159011 A1 WO 2016159011A1 JP 2016060249 W JP2016060249 W JP 2016060249W WO 2016159011 A1 WO2016159011 A1 WO 2016159011A1
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- 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
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- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
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- C21D6/004—Heat treatment of ferrous alloys containing Cr and Ni
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- C21D6/00—Heat treatment of ferrous alloys
- C21D6/005—Heat treatment of ferrous alloys containing Mn
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- C21D6/00—Heat treatment of ferrous alloys
- C21D6/008—Heat treatment of ferrous alloys containing Si
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- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
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- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
- C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
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- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
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- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
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- 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
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- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of silicon
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
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- C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
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- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
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- 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
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- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/16—Selection of particular materials
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/105—General auxiliary catalysts, e.g. upstream or downstream of the main catalyst
- F01N3/106—Auxiliary oxidation catalysts
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/24—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
- F01N3/28—Construction of catalytic reactors
- F01N3/2803—Construction of catalytic reactors characterised by structure, by material or by manufacturing of catalyst support
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2330/00—Structure of catalyst support or particle filter
- F01N2330/30—Honeycomb supports characterised by their structural details
- F01N2330/40—Honeycomb supports characterised by their structural details made of a single sheet, foil or plate
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2370/00—Selection of materials for exhaust purification
- F01N2370/02—Selection of materials for exhaust purification used in catalytic reactors
Definitions
- the present invention relates to a heat-resistant stainless steel plate excellent in intermittent oxidation characteristics, and an exhaust system component.
- the exhaust system component of the present invention is particularly suitable as a component that is used in an environment where it is repeatedly heated to a high temperature of 1000 ° C. or higher, such as an exhaust manifold or turbocharger component of an automobile engine.
- austenitic stainless steel SUS310S 25Cr-20Ni-0.5Si
- SUS302B 18Cr-8Ni-2Si
- XM15J1 (20Cr-12Ni-3Si)
- DIN1.4828 (19Cr-11Ni-2Si)
- ferritic stainless steel It is more expensive than ferritic stainless steel, and the steel type is selected from environmental factors such as availability and molding technology in each region.
- ferritic stainless steel has insufficient strength
- austenitic stainless steel has problems such as thermal fatigue and scale peeling, which cannot be used.
- Patent Document 1 heat-resistant cast steel and stainless steel cast as shown in Patent Document 1 are also used for exhaust manifolds and turbocharger parts, but there is a great need for weight reduction of automobile parts, and efforts to replace cast parts with plate-formed press-formed parts Has been done.
- Patent Document 2 discloses a material that ensures heat resistance at 950 ° C. by adding Mo, Nb, Cu, W, or the like to SUS444, which is a ferritic stainless steel, to increase the high-temperature strength.
- SUS444 which is a ferritic stainless steel
- Patent Document 3 in a repetitive heating and cooling environment of 900 ° C. or more, the Mo content is reduced as much as possible, a trace amount of V is added, and the crystal grain size and surface roughness of the hot-rolled sheet are controlled, thereby improving the heat resistance. It is disclosed that a hot-rolled steel sheet having excellent properties is obtained. However, it is difficult to produce the plate thickness required for automobile exhaust system parts by hot rolling, and the required plate thickness accuracy cannot be obtained.
- exhaust manifolds and turbocharger parts are also made into double pipe structures. Specifically, by using austenitic stainless steel on the inner side and ferritic stainless steel on the outer side, the restraint of the inner austenitic stainless steel member is relaxed and thermal strain is reduced. This makes it possible to lower the temperature by not letting the outer ferritic stainless steel directly touch the high-temperature exhaust gas.
- Such a double structure part is expensive, but is often used for an exhaust manifold having an exhaust gas temperature of 1000 ° C. or less. Even when the exhaust gas temperature is 900 ° C. or lower, it may be used to suppress the oxidation of the outer surface of the exhaust manifold and improve the design.
- the present invention can be suitably used as an automobile exhaust system part such as a double pipe inner pipe of an exhaust manifold or a turbocharger part (including a case of a double pipe structure), has no surface flaws, and has high high temperature strength and corrosion resistance.
- Another object of the present invention is to provide a stainless steel plate that does not cause embrittlement at high temperatures and exhibits high oxidation resistance. It is another object of the present invention to provide an automobile exhaust system component that uses the stainless steel plate and has excellent base material and welded portion oxidation resistance.
- the present inventors first reviewed the component composition.
- austenitic stainless steel having good oxidation resistance stainless steel with increased Si and stainless steel with REM added, such as SUS302B, XM15J1, and DIN1.4828, are generally used.
- the inventors conducted an intermittent oxidation test in an atmosphere gas simulating an automobile exhaust gas environment. The weight loss due to oxidation was noticeable, and it was judged that there was no oxidation resistance at 1050 ° C.
- the present inventors have made various studies in order to clarify the material composition that can withstand an environment of 1050 ° C.
- a stainless steel sheet having oxidation resistance capable of withstanding 1050 ° C. can be obtained by a method for forming a highly protective scale even in an intermittent oxidation environment by ensuring the amount of the product and controlling the precipitation form. I found out.
- an oxide scale mainly composed of Cr 2 O 3 that hardly causes diffusion of oxygen ions and metal atoms in the scale is formed.
- An internal oxide layer is formed so that the scale does not peel due to thermal expansion and contraction of the base material during heating and cooling.
- An internal oxide layer refers to Si oxide formed in an austenite grain boundary. If a scale mainly composed of Cr 2 O 3 having a high protective property is not formed on the surface, this grain boundary oxidation becomes shallow, and it is difficult to prevent scale peeling. In addition, when austenite grains grow, grain boundary oxidation is suppressed by the movement of grain boundaries, and thus oxidation resistance is impaired. Therefore, precipitates are dispersed in order to suppress grain growth.
- FIG. 1 shows the results of examining the influence of Cr, Mo and Si, C, N on the oxidation resistance in intermittent oxidation.
- the test method is as follows.
- Austenitic stainless steels of various compositions are melted in the laboratory, heated to 1250 ° C for 1 hour, hot-rolled to a plate thickness of 3 mm, hot-rolled sheet annealed at 1100 ° C for 20 seconds, immediately water-cooled, shot After blasting, the scale was removed with sulfuric acid and nitric hydrofluoric acid.
- FIG. 2 shows the cross-sectional shape of the sample welded by lap fillet and the reduction of the plate thickness after the oxidation test.
- the oxidation became prominent in the heat affected zone, and as a result of the increase in plate thickness reduction, the sample was sometimes separated (upper left of the lower photograph in FIG. 2). ). Therefore, it was found that the weld heat affected zone dominates the life of the exhaust system parts.
- the scale mainly composed of Cr 2 O 3 was not uniformly formed on the surface, and it was found that the grain boundary oxidation did not occur much. I understood.
- the “gradient of plate thickness change (toe angle)” means the angle at which the surface of the base material and the surface tangent of the weld bead (welded metal) intersect in the cross-sectional observation of the side surface of the weld. When expressed in degrees, it refers to an angle of (180-X). The toe angle is usually displayed in the range of 0 to 90 degrees.
- the toe angle in the present invention is defined as the largest angle in the cross-sectional view.
- a large toe angle means that the gradient at which the plate thickness changes due to the swelling (swelling) of the surface of the weld bead is steep.
- 24Cr-12Ni-0.1C-0.02N-2.0Si-1Mn-0.5Mo-0.05Al-0.05V steel was melted in the laboratory, heated to 1250 ° C for 1 hour, After rolling to a sheet thickness of 3 mm, hot-rolled sheet annealing was performed at 1100 ° C. for 20 seconds, immediately cooled with water, shot blasted, and the scale was removed with sulfuric acid and nitrohydrofluoric acid. Subsequently, it was cold-rolled to a thickness of 1.2 mm.
- an intermittent oxidation test was performed in 2000 cycles of heating and cooling between 200 ° C. and 1050 ° C. in an automobile exhaust gas environment.
- the thickness reduction of the weld heat affected zone was measured, and the thickness reduction of 0.4 mm or less was accepted.
- the scale peeling of the weld heat affected zone can be reduced by setting the gradient of the plate thickness change to 15 degrees or less. It was.
- the effect of butt welding was also investigated.
- the oxidation of the weld heat affected zone is further reduced by reducing the gradient of the plate thickness change, and when the gradient of the plate thickness change is eliminated, it has the same oxidation resistance as the base material, but at over 15 degrees. It was found that the effect of improving oxidation resistance was small.
- the type of welding method is not limited, but good results can be obtained particularly in the case of arc welding. Even in other welding methods, the same effect can be obtained based on the technical mechanism disclosed in the present invention.
- the durability as an exhaust system component can be made durable at 1050 ° C. by optimizing the component design of the base metal and controlling the shape of the weld metal.
- the present invention has been made on the basis of the above findings, and the gist thereof is as follows.
- W 0.01 to 3.00%
- Zr 0.05 to 0.30%
- Sn 0.01 to 0.10%
- Co 0.01 to 0.30 %
- Mg 0.0002% to 0.010% of one or more kinds
- the present invention it is possible to improve the oxidation resistance of the stainless steel plate for exhaust system parts and the exhaust system parts, and since surface flaws are less likely to occur in the steel sheet, the surface grinding process ( CG) can be omitted or simplified.
- the surface grinding process CG
- FIG. 1 is a graph showing the influence of components on the resistance to intermittent oxidation at 1050 ° C. of a thin plate.
- FIG. 2 shows the thickness change shape in the cross section of the weld metal welded by lap fillet. The upper row shows the case where the gradient of the plate thickness change at the welded portion is 11 degrees, and the lower row shows the case where the gradient is 25 degrees.
- FIG. 3 is a graph showing the influence of the gradient of the plate thickness change on the oxidation resistance (plate thickness reduction) at 1050 ° C.
- C 0.05 to 0.15% C is effective for increasing the stability of the austenite structure and the high temperature strength. In addition, it forms carbides with Cr and suppresses the growth of austenite grains, moderately grows grain boundary oxidation, and improves the scale peeling resistance. Since this effect appears at 0.05% or more of C, the lower limit is made 0.05%. In order to suppress grain growth stably, it is desirable to make it 0.10% or more. If it exceeds 0.15%, the amount of Cr carbide increases, and the chromium-deficient layer at the grain boundary increases. Even in high Cr austenitic stainless steel such as this steel, exhaust manifold parts and turbocharger parts for automobiles However, the required corrosion resistance cannot be maintained, so the upper limit is made 0.15% or less. From the viewpoint of corrosion resistance, it is desirable to make it 0.12% or less.
- Si 1.0% to 4.0% Si is effective in oxidation resistance, and is particularly effective in preventing scale peeling during intermittent oxidation. In order to form grain boundary oxidation in an environment exceeding 1000 ° C. and suppress scale peeling on the surface, 1.0% or more of Si is required. In order to improve oxidation resistance, it is desirable to make it 2.0% or more. Si is a ferrite stabilizing element and increases the amount of ⁇ -ferrite in the solidified structure, so that the hot workability is deteriorated in hot rolling. In addition, since Si promotes the formation of a sigma layer and there is a risk of embrittlement when used at a high temperature for a long time, it is preferably 3.5% or less.
- Mn 0.5 to 3.5%
- Mn is an element added as a deoxidizer, and contributes to the stabilization of the structure by expanding the austenite single phase region. The effect appears clearly at 0.5% or more, so 0.5% or more.
- it since it has the effect of improving hot workability by forming sulfides and reducing the amount of solute S in the steel, it is desirable to set it to 1.0% or more.
- excessive addition reduces the corrosion resistance, so it is made 3.5% or less.
- an oxide mainly composed of Cr 2 O 3 is desirable, and an oxide of Mn is not preferable.
- P 0.010 to 0.040%
- P is an element contained as an impurity in the main raw material such as hot metal or ferrochrome. Since it is an element harmful to hot workability, it is set to 0.040% or less. In addition, Preferably it is 0.030% or less. Excessive reduction leads to an increase in cost, such as making it necessary to use a high-purity raw material, so 0.010% or more. Economically preferably 0.020% or more is desirable.
- the upper limit of the content is preferably as small as 0.010%. Further, the smaller the S content, the better the corrosion resistance. However, since the desulfurization load increases and the production cost increases for lowering the S content, the lower limit is preferably made 0.0001%. Preferably, the content is 0.001 to 0.008%.
- Cr 20-30%
- Cr is an essential element for ensuring oxidation resistance and corrosion resistance. If it is less than 20%, these effects are not exhibited. On the other hand, if it exceeds 30%, the austenite single phase region is reduced and the hot workability at the time of production is impaired, so 20-30%. From the viewpoint of oxidation resistance, it is desirable to make it 24% or more. Further, if the amount of Cr is increased, embrittlement occurs due to the formation of a sigma phase.
- Ni 8-25%
- Ni is an element that stabilizes the austenite phase, and unlike Mn, is an element that is effective in oxidation resistance. Since these effects are obtained at 8% or more, the lower limit is made 8% or more. Since it also has an effect of suppressing the formation of sigma phase, it is desirable to make it 10% or more. On the other hand, excessive addition increases the susceptibility to solidification cracking and lowers the hot workability, so the content is made 25% or less. Furthermore, in order to suppress scale peeling in intermittent oxidation, it is desirable to make it 15% or less.
- Mo 0.01 to 1.5% Mo, together with Si and Cr, is effective for forming a protective scale on the surface, and the effect is obtained at 0.01%, so the lower limit is made 0.01% or more. Further, since it is an element effective for improving corrosion resistance, it is desirable to add 0.3% or more. On the other hand, it is also a ferrite stabilizing element, and as the amount of Mo added increases, it is necessary to increase the amount of Ni added. Further, since the formation of the sigma phase is promoted to cause embrittlement, the content is made 1.5% or less. Since the effect of improving corrosion resistance and oxidation resistance is almost saturated at 0.8% or more, it is desirable to make it 0.8% or less.
- Al 0.001 to 0.10%
- Al is an element that improves oxidation resistance. Since the effect is obtained at 0.001% or more, the lower limit is made 0.001% or more. In order to improve deoxidation efficiency, it is desirable to make it 0.003% or more.
- excessive addition forms a nitride to reduce the amount of dissolved N and lowers the high temperature strength, so the upper limit is made 0.10% or less. Considering the weldability, it is desirable to make it 0.05% or less.
- N 0.13-0.50% N is one of the very important elements in the present invention.
- increasing Ni austenite stability also makes it possible to reduce Ni.
- a larger amount than C can be added.
- the content is made 0.13% or more.
- the reduction effect of Ni it is desirable to make it 0.25% or more.
- the upper limit is made 0.50% or less.
- the strength at normal temperature is too high, the load during cold rolling becomes high and the productivity is impaired, so it is desirable to make it 0.30% or less.
- the stainless steel plate of the present invention includes Cu: 0.1 to 3.0%, V: 0.03 to 0.5%, Ti: 0.001 to 0.3%, Nb One or two or more of: 0.001 to 0.3%, B: 0.0001 to 0.0050%, and Ca: 0.001 to 0.010% may be optionally added.
- Cu 0.1 to 3.0%
- Cu is a relatively inexpensive element that substitutes for Ni as an austenite stabilizing element. Furthermore, it is effective in suppressing the progress of crevice corrosion and pitting corrosion. To that end, it is desirable to add 0.1% or more.
- Cu is often mixed from raw materials such as scrap and is inevitably contained in an amount of about 0.2% as an impurity. However, if it exceeds 3.0%, the hot workability is lowered, so the content is made 3.0% or less.
- V 0.03-0.5%
- V is generally contained in a range of 0.01 to 0.10% because it is mixed as an inevitable impurity in the alloy raw material of stainless steel and is difficult to remove in the refining process. Moreover, since it forms fine carbonitride and has the effect of suppressing grain growth, it is an element that is intentionally added as necessary. The effect is stably manifested when 0.03% or more is added, so the lower limit is made 0.03%. Since it is not preferable that the crystal grain size changes due to the variation of V, 0.08% or more is desirable in order to make the crystal grain size within a certain range. On the other hand, if added excessively, the precipitates may be coarsened. As a result, the toughness after quenching decreases, so the upper limit is made 0.5%. In view of manufacturing cost and manufacturability, it is desirable to set it to 0.2% or less.
- Ti 0.001 to 0.3%
- Ti is an element that suppresses deterioration of sensitization and corrosion resistance due to precipitation of chromium carbonitride in stainless steel by forming carbonitride similarly to Nb.
- the upper limit is made 0.3% or less.
- Ti may not be contained.
- Nb 0.001 to 0.3%
- Nb is an element that suppresses deterioration of sensitization and corrosion resistance due to precipitation of chromium carbonitride in stainless steel by forming carbonitride.
- the upper limit is made 0.3%.
- Nb may not be contained.
- B 0.0001 to 0.0050% B is an element effective for improving the hot workability. Since the effect is manifested at 0.0001% or more, 0.0001% or more may be added. In order to improve the hot workability in a wider temperature range, the content is preferably 0.0005% or more. On the other hand, excessive addition causes surface flaws due to a decrease in hot workability, so 0.0050% is made the upper limit. In consideration of corrosion resistance, 0.0025% or less is desirable.
- Ca 0.001 to 0.010%
- Ca is added as a desulfurization element, and has the effect of reducing S in steel and improving hot workability.
- CaO is added to slag during melting and refining, and a part of this is dissolved as Ca in steel.
- a composite oxide such as CaO—SiO 2 —Al 2 O 3 —MgO is also contained in the steel. Since the effect of improving hot workability is obtained from 0.001%, it is desirable to make it 0.001% or more.
- a relatively coarse water-soluble inclusion CaS is precipitated, so that the content is preferably 0.010% or less in order to reduce the corrosion resistance.
- W 0.01 to 3.00%
- Zr 0.05 to 0.30%
- Sn 0.01 to 0.10%
- Co 0.01 to 0.30 %
- Mg 0.0002 to 0.010%, or two or more of them may be optionally added.
- W 0.01-3.0% W is an element that improves the corrosion resistance like Cr and Mo. There is also an effect of increasing the high temperature strength by solid solution strengthening. In order to exhibit these effects, it is desirable to add 0.01% or more. On the other hand, it is an element that promotes precipitation of the sigma phase, and in order to cause a reduction in the strength of the material due to aging embrittlement, it is desirable to make it 3.0% or less. Moreover, since it is an expensive element like Mo and Nb, it is more preferable to make it 1.5% or less.
- Zr 0.05-0.30%
- Zr is an element that suppresses sensitization and deterioration of corrosion resistance due to precipitation of chromium carbonitride in stainless steel by forming carbonitrides similarly to Ti and Nb.
- the upper limit is made 0.30% or less. Considering the improvement in high temperature strength by securing the amount of dissolved C and N, it is desirable to make it 0.1% or less. Zr may not be contained.
- Sn 0.01-0.10% Sn is an element effective for improving the corrosion resistance after quenching, and it is preferable to add 0.02% or more as necessary. However, excessive addition promotes ear cracking during hot rolling, so it is preferable to make it 0.10% or less.
- Co 0.01 to 0.30%
- Co is an element that is easily mixed as an inevitable impurity from alloy raw materials in austenitic stainless steel. Moreover, since it is an element effective in improving high temperature strength, it is desirable to add 0.01% or more. However, excessive addition causes surface flaws due to a decrease in hot workability, so it is desirable to make it 0.30% or less.
- Mg 0.0002 to 0.010%
- Mg is added as a desulfurization element in the same manner as Ca, and in general, a parallel amount is dissolved in the molten steel from the slag and may be contained as MgO in the composite oxide.
- MgO in the refractory may be dissolved into the molten steel. Since the desulfurization effect appears at 0.0002% or more, it is desirable to set the lower limit to 0.0002%. On the other hand, excessive addition causes the water-soluble inclusion MgS to precipitate coarsely and lowers the corrosion resistance, so it is desirable to make it 0.010% or less.
- the balance of the component composition is Fe and inevitable impurities.
- the inevitable impurities are not intentionally included from the raw materials and production environment, etc., but are inevitably mixed when the stainless steel plate having the component composition defined in the present invention is industrially produced. Say.
- the above-described optional added element may be mixed as an unavoidable impurity even if it is not intended to be contained, but there is no particular problem as long as it is below the upper limit of the content described above. Moreover, elements other than those described above can also be contained within a range not impairing the effects of the present invention.
- a stainless steel plate exhibiting high oxidation resistance can be obtained by having the above-described component composition. Furthermore, by having the above-described welded shape, an exhaust system component that is excellent in both oxidation resistance of the base material and the welded portion can be obtained.
- steel having the composition shown in Table 1 was melted and cast into a 200 mm thick slab. This slab is heated to 1200 ° C, then hot-rolled steel plate with a thickness of 4 mm after rough hot rolling and finish hot rolling, and inserted into an 800 ° C heat treatment furnace to simulate winding in the temperature range of 800 ° C. After holding for 1 hour, it was air cooled. Subsequently, hot-rolled sheet annealing was performed at 1100 ° C. for 20 seconds, followed by water cooling. Then, it was shot blasted and pickled to remove scale. The presence or absence of surface wrinkles was evaluated by observing with the naked eye and a magnifier with a magnification of 10 times. Those in which surface wrinkles could be confirmed by either naked eye observation or loupe observation were rejected.
- the high temperature strength of the cold-rolled sheet was measured at 1000 ° C., and the one with 0.2% proof stress of 30 MPa or more was regarded as acceptable. Moreover, after oxidizing at 700 degreeC for 300 hours, the thin plate which grind
- this thin plate was subjected to a JIS salt spray test, and a product in which rust occurred was regarded as a corrosion resistance failure.
- the oxidation resistance was evaluated using a test piece in which a flat plate as pickled and a flat plate were stacked and welded on the fillet.
- the atmosphere for the oxidation test was an atmosphere in which H 2 O was 5 to 10%, O 2 was 0.2 to 1.0%, and the balance was nitrogen.
- the atmospheric gas composition was changed periodically by simulating automobile exhaust gas.
- the test piece was heated and held at 1050 ° C., cooled to 200 ° C. as one cycle, tested up to 2500 cycles, the appearance was recorded, and the weight change was measured. The location where oxidation was most advanced was recorded and the thickness of the portion was evaluated, and 0.8 mm or more was regarded as having good oxidation resistance (O).
- the base material has good oxidation resistance, and surface defects, high-temperature strength and high-temperature embrittlement are acceptable. There was also good corrosion resistance. In particular, NO. 1 to NO. As a result of controlling the shape of the weld bead within the range of the present invention, not only the base material but also the oxidation resistance of the welded portion was satisfactory. On the other hand, in the component composition that departs from the present invention, the oxidation resistance is poor, and it is difficult to achieve both surface flaws, high temperature strength, high temperature embrittlement, corrosion resistance and oxidation resistance, Any property was rejected. Thereby, it turns out that a comparative example is inferior to the example of this invention in a characteristic.
- test NO. 31 is low in C, so NO. No. 33 is low in Si, so NO. No. 36 has a high Mn, so NO. 43 is low in Mo, so NO. 45 has a high V, so NO. Since Nos. 49 and 53 had low Cr + 20Mo or low Si + 20C + 15N, both the base metal and the welded portion had poor oxidation resistance. NO. No. 32 had poor corrosion resistance due to high C.
- NO. 34 is high in Si, so NO. 35 has a low Mn, so NO. 37 has a high P, so NO. 42 is high in Ni, so NO. No. 48 was defective because surface defects occurred because N was high.
- NO. No. 38 had high S and low Al, so the surface flaws were poor and the corrosion resistance was also poor.
- NO. No. 39 had a low Cr and a low Cr + 20Mo, so the surface defects were poor and the oxidation resistance of the base metal and the welded part was also poor.
- NO. 40 is high in Cr, NO. No. 41 has low Ni and NO. Since No. 44 had high Mo, high temperature embrittlement was bad.
- NO. 46 is high in Al, NO. No. 47 had a poor high temperature strength because N was low.
- NO. No. 49 does not contain Mo, and because of this, Cr + 20Mo is low, so that the oxidation resistance of the base metal and the welded part was both poor.
- NO. Nos. 50 to 52 used A23 satisfying the provisions of the present invention as the test steel. Therefore, NO. For 50 to 52, only the oxidation resistance of the welded part is poor, but other properties and performance including the base metal oxidation resistance were satisfactory, so it is applicable to parts that do not require welding. Is possible.
- test steel used was B20, and the value of Cr + 20C + 15N was 5.60, which was lower than the lower limit defined in the present invention, so that the oxidation resistance of the base metal and the welded part was poor. .
- the stainless steel plate for exhaust system parts and the exhaust system parts with excellent intermittent oxidation characteristics of the present invention can improve the oxidation resistance of the heat affected zone by controlling the shape of the welded part as well as the component design that improves the oxidation resistance. is there. Moreover, since there are few surface wrinkles, the surface grinding process (CG) at the time of thin plate manufacture can be omitted or simplified. Furthermore, by improving the oxidation resistance, it is possible to reduce the thickness of the exhaust system parts, and by reducing the weight of the parts, the effect of improving the fuel efficiency of the automobile can also be obtained. The industrial applicability of the invention is great.
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Abstract
Description
Cは、オーステナイト組織の安定と高温強度を高めるために有効である。また、Crと炭化物を形成しオーステナイト粒の成長を抑制して粒界酸化を適度に成長させ、耐スケール剥離特性を向上させる。この効果は0.05%以上のCで発現することから、下限を0.05%とする。粒成長を安定的に抑制するためには0.10%以上にすることが望ましい。0.15%超では、Cr炭化物の量が増えて、粒界のクロム欠乏層が増加し、本鋼の様な高Crオーステナイト系ステンレス鋼であっても、自動車のエキゾーストマニホールド部材やターボチャージャー部品としても必要とされる耐食性が維持できなくなるため、上限を0.15%以下とする。耐食性の観点からは0.12%以下にすることが望ましい。
Siは耐酸化性に効果があり、とくに断続酸化におけるスケール剥離の防止に効果がある。1000℃を超える環境で粒界酸化を形成し、表面のスケール剥離を抑制するためには1.0%以上のSiが必要である。耐酸化性を高めるためには2.0%以上にすることが望ましい。またSiはフェライト安定化元素であり、凝固組織におけるδフェライト量を増加させ、熱間圧延において熱間加工性の低下が問題になるため、4.0%以下にする。そのほか、Siはシグマ層の生成も促進し高温長時間使用時の脆化も危惧されるため3.5%以下にすることが望ましい。
Mnは、脱酸剤として添加される元素であるとともに、オーステナイト単相域を拡大し組織の安定化に寄与する。その効果は0.5%以上で明確に現れるため0.5%以上とする。また硫化物を形成し、鋼中の固溶S量を低減することで熱間加工性を向上させる効果もあることから、1.0%以上とすることが望ましい。一方、過度の添加は耐食性を低下させることから3.5%以下とする。また耐酸化性の点ではCr2O3主体の酸化物が望ましく、Mnの酸化物は好ましくないため、2.0%以下にすることが望ましい。
Pは、原料である溶銑やフェロクロム等の主原料中に不純物として含まれる元素である。熱間加工性に対しては有害な元素であるため、0.040%以下とする。なお、好ましくは0.030%以下である。過度な低減は高純度原料の使用を必須にするなど、コストの増加に繋がるため、0.010%以上とする。経済的に好ましくは、0.020%以上にすることが望ましい。
Sは、硫化物系介在物を形成し、鋼材の一般的な耐食性(全面腐食や孔食)を劣化させるため、その含有量の上限は少ないほうが好ましく、0.010%とする。また、Sの含有量は少ないほど耐食性は良好となるが、低S化には脱硫負荷が増大し、製造コストが増大するので、その下限を0.0001%とするのが好ましい。なお、好ましくは0.001~0.008%である。
Crは、本発明において、耐酸化性や耐食性確保のために必須な元素である。20%未満では、これらの効果は発現せず、一方で、30%超ではオーステナイト単相域が縮小し、製造時の熱間加工性を損ねるため、20~30%とする。なお、耐酸化性の観点からは24%以上にすることが望ましい。また、Cr量を高くするとシグマ相の形成により脆化するため、27%以下にすることが望ましい。
Niは、オーステナイト相を安定化させる元素であり、Mnと異なって耐酸化性に有効な元素である。これらの効果は8%以上で得られるため、下限を8%以上とする。シグマ相の生成を抑制する効果もあるので10%以上にすることが望ましい。一方、過度な添加は凝固割れ感受性を高めると共に、熱間加工性も低下させるために、25%以下とする。更に、断続酸化におけるスケール剥離を抑制するためには、15%以下にすることが望ましい。
MoもSiやCrと共に、表面の保護性スケール形成に有効であり、その効果は0.01%で得られることから、その下限を0.01%以上とする。また耐食性の向上にも有効な元素であることから、0.3%以上添加することが望ましい。一方、フェライト安定化元素でもあり、Mo添加量が増えるとNiの添加も増やす必要が生じるため、過度な添加は好ましくない。また、シグマ相の形成を促進して脆化を生じることがあるため、1.5%以下とする。耐食性や耐酸化性の向上効果は0.8%以上でほぼ飽和するために、0.8%以下にすることが望ましい。
Alは、脱酸元素として添加される他、耐酸化性を向上させる元素である。その効果は0.001%以上で得られるため、下限を0.001%以上にする。脱酸効率を高めるためには0.003%以上にすることが望ましい。一方、過度な添加は窒化物を形成して固溶N量を低下させ、高温強度が低下するために、上限を0.10%以下とする。溶接性も考慮すると0.05%以下とすることが望ましい。
Nは、本発明において非常に重要な元素のひとつである。Cと同様に高温強度を上げるほか、オーステナイト安定度を上げることで、Niの低減も可能になる。またCよりも鋭敏化による耐食性低下影響が小さいため、Cよりも多量の添加が可能である。高温環境に耐える高温強度を得るために、0.13%以上とする。Niの低減効果も考慮すると、0.25%以上にすることが望ましい。一方多量に添加すると、製鋼工程で凝固時に気泡系欠陥が生じるために、上限を0.50%以下とする。その他にも、常温における強度が高すぎて冷間圧延時の負荷が高くなり、生産性を損なうため、0.30%以下にすることが望ましい。
1050℃で耐酸化性を発揮するためには、表面に保護性の高い酸化スケールを形成するとともに、断続酸化時のスケール剥離を抑制するために、スケール下のオーステナイト相に於いて、Si酸化物による粒界酸化を形成させることが必要である。そのためには、各元素を先の条件範囲にするだけでは不十分であり、保護性の高いスケールを形成させるために、Cr及びMoの含有量をCr+20Moを24%以上とし、オーステナイトの粒成長を抑制し、かつ粒界酸化を形成させるためにはSi、C、及びNの含有量を、Si+20C+15Nを5.8%以上とすることが必要である。Cr+20Moは27.0%以上がより好ましく、30.0%以上がさらに好ましい。Si+20C+15Nは7.0%以上がより好ましく、8.5%以上がさらに好ましい。
自動車のエキゾーストマニホールドやターボチャージャーなどの排気系部品の多くが溶接構造を有している。母材と溶接金属の板厚差が大きいと、加熱冷却時の温度差により熱歪を生じ、高温時に表面に生成したスケールが剥離しやすくなり、繰り返し加熱時に表面が保護されず酸化による板厚減少が進行する。母材と溶接金属との板厚変化の勾配が小さいほど熱歪が緩和するが、板厚変化の勾配が15度以下になると、耐酸化性の改善効果が大きくなるため、15度以下とした。耐酸化性をより高めるためには、板厚変化の勾配を10度以下に低減することが望ましい。
Cuは、オーステナイト安定化元素としてNiを代替する、相対的に安価な元素である。さらに、隙間腐食や孔食の進展抑制に効果があり、そのためには0.1%以上添加することが望ましい。ただし、オーステナイト系ステンレス鋼の製造において、Cuはスクラップ等の原料から混入することが多く、不可避的に不純物として0.2%程度含まれることが多い。ただし、3.0%を超えると熱間加工性を低下させるため3.0%以下とする。
Vは、ステンレス鋼の合金原料に不可避的不純物として混入し、精錬工程における除去が困難であるため、一般的に0.01~0.10%の範囲で含有される。また、微細な炭窒化物を形成し、粒成長抑制効果を有するため、必要に応じて、意図的な添加も行われる元素である。その効果は0.03%以上の添加で安定して発現するため、下限を0.03%とする。Vの変動により、結晶粒径が変化することは好ましくないので、結晶粒径の一定範囲に造りこむためには、0.08%以上にすることが望ましい。一方、過剰に添加すると、析出物の粗大化を招くおそれがあり、その結果、焼入れ後の靭性が低下してしまうため、上限を0.5%とする。なお、製造コストや製造性を考慮すると、0.2%以下にとすることが望ましい。
Tiは、Nbと同様に炭窒化物を形成することで、ステンレス鋼におけるクロム炭窒化物の析出による鋭敏化や耐食性の低下を抑制する元素である。しかしながら、大型の製鋼介在物を形成することで、表面疵の原因になりやすいため、その上限は0.3%以下とする。固溶C、N量の確保による高温強度向上を考慮すると、0.01%以下にすることが望ましい。Tiは含有していなくても良い。
Nbは、炭窒化物を形成することで、ステンレス鋼におけるクロム炭窒化物の析出による鋭敏化や耐食性の低下を抑制する元素である。しかしながら、大型の製鋼介在物を形成することで、表面疵の原因になりやすいため、その上限は0.3%とする。固溶C、N量の確保による高温強度向上を考慮すると、0.01%以下にすることが望ましい。Nbは含有していなくても良い。
Bは、熱間加工性の向上に有効な元素であり、その効果は0.0001%以上で発現するため、0.0001%以上添加してもよい。より広い温度域における熱間加工性を向上させるためには、0.0005%以上とすることが望ましい。一方、過度な添加は熱間加工性の低下により、表面疵の原因となるため、0.0050%を上限とする。耐食性も考慮すると0.0025%以下が望ましい。
Caは、脱硫元素として添加され、鋼中のSを低減して熱間加工性を向上させる効果がある。一般には、溶解精錬時のスラグ中にCaOとして添加させ、この一部が鋼中にCaとして溶解する。また、CaO-SiO2-Al2O3-MgOなどの複合酸化物としても鋼中に含有される。熱間加工性の改善効果は0.001%から得られるために、0.001%以上にすることが望ましい。一方、多量に含有すると比較的粗大な水溶性介在物CaSが析出し、耐食性を低下させるために0.010%以下にすることが望ましい。
Wは、CrやMoと同様に耐食性を向上させる元素である。また固溶強化により高温強度を高める効果もある。これらの効果を発現するためには、0.01%以上添加することが望ましい。一方、シグマ相の析出を促進する元素であり、時効脆化による材料の強度低下を生じるために、3.0%以下にすることが望ましい。また、Mo、Nbと同様に高価な元素であるため、1.5%以下にすることがより好ましい。
Zrは、Ti、Nbと同様に炭窒化物を形成することで、ステンレス鋼におけるクロム炭窒化物の析出による鋭敏化や耐食性の低下を抑制する元素である。しかしながら、大型の製鋼介在物を形成することで、表面疵の原因になりやすいため、その上限は0.30%以下とする。固溶C、N量の確保による高温強度向上を考慮すると、0.1%以下にすることが望ましい。Zrは含有していなくても良い。
Snは、焼入れ後の耐食性向上に有効な元素であり、必要に応じて0.02%以上添加する事が好ましい。ただし、過度な添加は熱延時の耳割れを促進するため、0.10%以下にすることが好ましい。
Coは、オーステナイト系ステンレス鋼においては、合金原料から不可避的不純物として混入しやすい元素である。また高温強度の向上に有効な元素であるために、0.01%以上添加することが望ましい。ただし、過度な添加は熱間加工性の低下による表面疵の原因となるために、0.30%以下にすることが望ましい。
Mgは、Caと同様に脱硫元素として添加され、一般にはスラグ中から溶鋼中に平行量が固溶するほか、複合酸化物中にMgOとして含有される場合もある。また耐火物中のMgOが溶鋼中に溶け出す場合もある。脱硫効果は0.0002%以上で現われるため、下限を0.0002%とすることが望ましい。一方、過度な添加は、水溶性介在物MgSが粗大析出し、耐食性を低下させるため、0.010%以下にすることが望ましい。
NO.50~52、54、55は溶接部における板厚変化の勾配が大きかったために、溶接部の耐酸化性が不良であった。
Claims (4)
- 質量%で、
C :0.05~0.15%、
Si:1.0%~4.0%、
Mn:0.5~3.5%、
P :0.010~0.040%、
S :0.0001~0.010%、
Cr:20~30%、
Ni:8~25%、
Mo:0.01~1.5%、
Al:0.001~0.10%、及び
N:0.13~0.50%
を含有し、残部がFe及び不可避的不純物であり、
Cr、Mo、Si、C、及びNの含有量が
Cr+20Mo≧24.0%、及び
Si+20C+15N≧5.8%
を満たすことを特徴とする断続酸化特性に優れた排気系部品用ステンレス鋼板。 - さらに、質量%で、
Cu:0.1~3.0%、
V :0.03~0.5%、
Ti:0.001~0.3%、
Nb:0.001~0.3%、
B:0.0001~0.0050%、及び
Ca:0.001~0.010%
の1種又は2種以上を含有することを特徴とする請求項1に記載の断続酸化特性に優れた排気系部品用ステンレス鋼板。 - さらに、質量%で
W :0.01~3.00%、
Zr:0.05~0.30%、
Sn:0.01~0.10%、
Co:0.01~0.30%、及び
Mg:0.0002%~0.010%
の1種又は2種以上を含有することを特徴とする請求項1又は2に記載の断続酸化特性に優れた排気系部品用ステンレス鋼板。 - 請求項1~3のいずれか一項に記載のステンレス鋼板を母材として用いた溶接構造を有し、溶接部における板厚変化の勾配が15度以下であることを特徴とする排気系部品。
Priority Applications (7)
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PL16772892T PL3279359T3 (pl) | 2015-03-31 | 2016-03-29 | Element układu wydechowego zawierający blachę cienką ze stali nierdzewnej o doskonałych właściwościach w przypadku okresowego utleniania |
JP2017510057A JP6239192B2 (ja) | 2015-03-31 | 2016-03-29 | 排気系部品 |
ES16772892T ES2890333T3 (es) | 2015-03-31 | 2016-03-29 | Chapa de acero inoxidable para su uso en una pieza de sistema de escape con excelentes características de oxidación intermitente y una pieza de sistema de escape |
US15/563,159 US20180080106A1 (en) | 2015-03-31 | 2016-03-29 | Stainless steel sheet for exhaust system part use excellent in intermittent oxidation characteristic and exhaust system part |
KR1020177026809A KR101988150B1 (ko) | 2015-03-31 | 2016-03-29 | 배기계 부품 |
CN201680018828.7A CN107429358B (zh) | 2015-03-31 | 2016-03-29 | 断续氧化特性优异的排气***部件用不锈钢板和排气***部件 |
EP16772892.2A EP3279359B1 (en) | 2015-03-31 | 2016-03-29 | Exhaust system part having stainless steel sheet having excellent intermittent oxidation characteristics |
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US (1) | US20180080106A1 (ja) |
EP (1) | EP3279359B1 (ja) |
JP (1) | JP6239192B2 (ja) |
KR (1) | KR101988150B1 (ja) |
CN (1) | CN107429358B (ja) |
ES (1) | ES2890333T3 (ja) |
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JP6429957B1 (ja) * | 2017-08-08 | 2018-11-28 | 新日鐵住金ステンレス株式会社 | オーステナイト系ステンレス鋼およびその製造方法、ならびに燃料改質器および燃焼器の部材 |
ES2717692A1 (es) * | 2017-12-22 | 2019-06-24 | Univ Madrid Politecnica | Acero refractario resistente al desgaste endurecible por formacion termica y/o mecanica de fase sigma |
JP2019101002A (ja) * | 2017-12-08 | 2019-06-24 | 日本製鉄株式会社 | 金属化合物粒子の抽出用電解液、およびそれを用いた電解抽出方法 |
JP2019218588A (ja) * | 2018-06-18 | 2019-12-26 | 日鉄ステンレス株式会社 | オーステナイト系ステンレス鋼板およびその製造方法 |
WO2020090936A1 (ja) * | 2018-10-30 | 2020-05-07 | 日鉄ステンレス株式会社 | オーステナイト系ステンレス鋼板 |
JP2020147770A (ja) * | 2019-03-11 | 2020-09-17 | 日鉄ステンレス株式会社 | 高温高サイクル疲労特性に優れたオーステナイト系ステンレス鋼板およびその製造方法ならびに排気部品 |
JP2020164949A (ja) * | 2019-03-29 | 2020-10-08 | 日鉄ステンレス株式会社 | 高温高サイクル疲労特性に優れたオーステナイト系ステンレス鋼板およびその製造方法ならびに排気部品 |
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JP2020147770A (ja) * | 2019-03-11 | 2020-09-17 | 日鉄ステンレス株式会社 | 高温高サイクル疲労特性に優れたオーステナイト系ステンレス鋼板およびその製造方法ならびに排気部品 |
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JP2020164949A (ja) * | 2019-03-29 | 2020-10-08 | 日鉄ステンレス株式会社 | 高温高サイクル疲労特性に優れたオーステナイト系ステンレス鋼板およびその製造方法ならびに排気部品 |
JP7270445B2 (ja) | 2019-03-29 | 2023-05-10 | 日鉄ステンレス株式会社 | 高温高サイクル疲労特性に優れたオーステナイト系ステンレス鋼板およびその製造方法ならびに排気部品 |
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Publication number | Publication date |
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EP3279359A4 (en) | 2018-08-22 |
US20180080106A1 (en) | 2018-03-22 |
KR20170123647A (ko) | 2017-11-08 |
EP3279359A1 (en) | 2018-02-07 |
CN107429358B (zh) | 2019-12-13 |
JP6239192B2 (ja) | 2017-11-29 |
ES2890333T3 (es) | 2022-01-18 |
KR101988150B1 (ko) | 2019-06-11 |
PL3279359T3 (pl) | 2021-12-27 |
JPWO2016159011A1 (ja) | 2017-08-31 |
CN107429358A (zh) | 2017-12-01 |
EP3279359B1 (en) | 2021-07-21 |
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