Abstract: A substrate steel of the comprising from 0.01 to 0.60 wt. % of La, from 0.0 to 0.65 wt. % of Ce; from 0.06 to 1.8 wt. % of Nb up to 2.5 wt. % of one or more trace elements and carbon and silicon may be treated in an oxidizing atmosphere to product a coke resistant surface coating of MnCr2O4 having a thickness up to 5 microns.

Abstract: The present invention provides a cast product that can further enhance the stability of a barrier layer and can exhibit further superior oxidation resistance, carburization resistance, nitriding resistance, and corrosion resistance, when used under a high-temperature atmosphere, the cast product having a surface with a barrier layer comprising an Al-containing metal oxide expressed in (Al(1-x)M(x))2O3, where M is at least one of Cr, Ni, Si, and Fe, wherein the Al-containing metal oxide includes a solid solution of at least one of Cr, Ni, Si, and Fe with Al, in a relationship of Al/(Cr+Ni+Si+Fe)?2.

Abstract: The present invention provides an alloy for overlay welding with which an alumina barrier layer containing an Al oxide can be formed on a projection that is overlay welded on an inner surface of a reaction tube, and a reaction tube having a projection that is overlay welded on the inner surface as a stirring member. An alloy for overlay welding according to the present invention is an alloy for overlay welding that is to be used in overlay welding, and the alloy contains C in an amount of 0.2 mass % to 0.6 mass %, Si in an amount of more than 0 mass % to 1.0 mass %, Mn in an amount of more than 0 mass % to 0.6 mass % or less, Cr in an amount of 25 mass % to 35 mass %, Ni in an amount of 35 mass % to 50 mass %, Nb in an amount of 0.5 mass % to 2.0 mass %, Al in an amount of 3.0 mass % to 6.0 mass %, Y in an amount of 0.005 mass % to 0.05 mass %, wherein Y/Al is 0.002 or more to 0.015 or less; and the balance being Fe and inevitable impurities.

Abstract: The present invention provides a thermal cracking tube having the effect of agitating a fluid in the tube and capable of preventing overheating due to the generation of laminar flow, wherein the thermal cracking tube 10 has an agitating element 20 formed on and projecting inwardly from an inner surface of the tube, wherein the fluid agitating element comprises a fin 21 extending along the inner surface of the tube and bumps 24 provided on a region near the fin and projecting inwardly from the inner surface of the tube, wherein the region near the fin includes an upstream side and/or a downstream side of the fin in the direction of the fluid flowing through the tube.

Abstract: The present invention provides a Ni-based alloy, a heat-resistant and corrosion-resistant component, and a heat treatment furnace component, all of which have excellent corrosion resistance and mechanical strength at high temperatures. The Ni-based alloy of the present invention consists of, by mass %, Al: more than 5.0% and up to 26.0%, and Zr: more than 0% and up to 5.0%, the balance being Ni and unavoidable impurities. The Ni-based alloy preferably contains more than 0% and up to 5.0% of B, by mass %, in a combined amount with Zr. Moreover, it is preferable that the Ni-based alloy has P value and Q value and satisfies a relationship of Q value ? 0.89 × P value - 0.53, when the P value is obtained from a formula -18.95 + 0.1956 × Ni% + 0.1977 × Al% + 0.2886 × Zr% + 12.4 × B%, and the Q value is obtained by dividing an area percentage of Ni3Al precipitated on the surface of the alloy by 100.

Abstract: The present invention provides a thermal cracking tube formed with an agitating element that has a good agitation effect and improves heat transfer efficiency while minimizing an increase in the pressure loss of the fluid flowing through the cracking tube. A thermal cracking tube 10 with an agitating element of the present invention is a thermal cracking tube having a tube axis with one end and the other end, wherein a fluid inlet is on the one end and a fluid outlet is on the other end, the tube being provided on an inner surface thereof with one or more fluid agitating elements 20 extending from the inner surface of the tube and having an inwardly facing top portion, wherein the agitating element is helically inclined to or is orthogonal to a longitudinal direction of the tube axis, and the top portion deviates to the fluid inlet side 11 or the fluid outlet side 12, relative to a center 0 of a width direction of the agitation element.

Abstract: The present invention provides a pyrolysis tube for manufacturing olefin which tube can improve a yield of olefin in a pyrolysis reaction of a hydrocarbon raw material. The pyrolysis tube (1A) for manufacturing olefin includes a tubular base material (2) made of a heat resistant metal material and a dehydrogenating catalyst (4A) which is supported on an inner surface of the tubular base material (2).

Abstract: The present invention provides a cast product that can further enhance the stability of a barrier layer and can exhibit further superior oxidation resistance, carburization resistance, nitriding resistance, and corrosion resistance, when used under a high-temperature atmosphere, the cast product having a surface with a barrier layer comprising an Al-containing metal oxide expressed in (Al(1-x)M(x))2O3, where M is at least one of Cr, Ni, Si, and Fe, wherein the Al-containing metal oxide includes a solid solution of at least one of Cr, Ni, Si, and Fe with Al, in a relationship of Al/(Cr+Ni+Si+Fe)?2.

Abstract: Provided is a dehydrogenating catalyst that is capable of preventing or reducing coking and improving the yield of an olefin in a pyrolysis reaction of a hydrocarbon raw material. A dehydrogenating catalyst (4A) for production of an olefin contains, as a catalyst component, at least one of La and Ce, wherein, when the dehydrogenating catalyst (4A) does not contain Ce, the dehydrogenating catalyst (4A) contains at least one element selected from the group consisting of Ba, Fe, and Mn, or wherein, when the dehydrogenating catalyst (4A) contains Ce, the dehydrogenating catalyst (4A) contains at least one of Fe and Mn.

Abstract: The present invention provides a tube body that is to be used in a high-temperature atmosphere and a method for stably forming a metal oxide layer on an inner surface of the tube body at a high area percentage wherein the tube body is constituted by a heat-resistant alloy containing Cr in an amount of 15 mass % or more and Ni in an amount of 18 mass % or more, so that the inner surface has an arithmetic average roughness (Sa) of three-dimensional surface roughness that satisfies 1.5 ?m?Sa?5.0 ?m and a skewness (Ssk) of a surface height distribution that satisfies |Ssk|?0.30, wherein the heat-resistant alloy may contain Al in an amount of 2.0 mass % or more and the inner surface may have a kurtosis (Sku) of a surface height distribution of the three-dimensional surface roughness that satisfies Sku?2.5.

Abstract: The present invention provides a steel product that has excellent oxidation resistance on a surface thereof that is to come into contact with a steel material and that also has excellent weldability. The steel product for use in contact with a steel material according to the present invention is a steel product for use in contact with a steel material, the steel product including a centrifugally-cast portion formed on a surface of the steel product that is to come into contact with the steel material, the centrifugally-cast portion being made through centrifugal casting, and a statically-cast portion to which the centrifugally-cast portion is welded, the statically-cast portion being formed through static casting, the centrifugally-cast portion containing, in terms of mass %, C: 0.2% to 0.7%; Si: more than 0% and 2.0% or less; Mn: more than 0% and 3.0% or less; Cr: 15.0% to 40.0%; Ni: 18.0% to 55.0%; Al: 1.0% to 5.5%; and at least one type selected from the group consisting of Ti: 0.01% to 0.6% and/or Nb: 0.

Abstract: The present invention provides a heat-resistant alloy and a reaction tube having excellent oxidation resistance, excellent mechanical properties such as tensile ductility, and weldability. A heat-resistant alloy of the present invention comprises, in terms of % by mass, C: 0.35% to 0.7%, Si: more than 0% and 1.5% or less, Mn: more than 0% and 2.0% or less, Cr: 22.0% to 40.0%, Ni: 25.0% to 48.3%, Al: 1.5% to 4.5%, Ti: 0.01% to 0.6%, and the balance being Fe and inevitable impurities, wherein when Pa=?11.1+28.1×C+29.2×Si?0.25×Ni?45.6×Ti, and Ya=?13.75×Al+63.75, Pa<Ya.

Abstract: To provide a cast product having an alumina barrier layer and method for producing the same. A cast product having an alumina barrier layer of the present invention is a cast product in which an alumina barrier layer containing Al2O3 is formed on the surface of a cast body, and the cast body contains C: 0.3 mass % to 0.7 mass %, Si: 0.1 mass % to 1.5 mass %, Mn: 0.1 mass % to 3 mass %, Cr: 15 mass % to 40 mass %, Ni: 20 mass % to 55 mass %, Al: 2 mass % to 4 mass %, rare earth element: 0.005 mass % to 0.4 mass %, W: 0.5 mass % to 5 mass % and/or Mo: 0.1 mass % to 3 mass %, and 25 mass % or more of Fe in the remainder and an inevitable impurity, and 80 mass % or more of the rare earth element is La.

Abstract: A substrate steel of the comprising from 0.01 to 0.60 wt. % of La, from 0.0 to 0.65 wt. % of Ce; from 0.06 to 1.8 wt. % of Nb up to 2.5 wt. % of one or more trace elements and carbon and silicon may be treated in an oxidizing atmosphere to product a coke resistant surface coating of MnCr2O4 having a thickness up to 5 microns.

Abstract: The present invention provides an alloy for overlay welding with which an alumina barrier layer containing an Al oxide can be formed on a projection that is overlay welded on an inner surface of a reaction tube, and a reaction tube having a projection that is overlay welded on the inner surface as a stirring member. An alloy for overlay welding according to the present invention is an alloy for overlay welding that is to be used in overlay welding, and the alloy contains C in an amount of 0.2 mass % to 0.6 mass %, Si in an amount of more than 0 mass % to 1.0 mass %, Mn in an amount of more than 0 mass % to 0.6 mass % or less, Cr in an amount of 25 mass % to 35 mass %, Ni in an amount of 35 mass % to 50 mass %, Nb in an amount of 0.5 mass % to 2.0 mass %, Al in an amount of 3.0 mass % to 6.0 mass %, Y in an amount of 0.005 mass % to 0.05 mass %, and Fe and inevitable impurities as a remaining portion.

Abstract: A substrate steel of the comprising from 0.01 to 0.60 wt. % of La, from 0.0 to 0.65 wt. % of Ce; from 0.06 to 1.8 wt. % of Nb up to 2.5 wt. % of one or more trace elements and carbon and silicon may be treated in an oxidizing atmosphere to product a coke resistant surface coating of MnCr2O4 having a thickness up to 5 microns.

Abstract: The present invention provides an alloy for overlay welding with which an alumina barrier layer containing an Al oxide can be formed on a projection that is overlay welded on an inner surface of a reaction tube, and a reaction tube having a projection that is overlay welded on the inner surface as a stirring member. An alloy for overlay welding according to the present invention is an alloy for overlay welding that is to be used in overlay welding, and the alloy contains C in an amount of 0.2 mass % to 0.6 mass %, Si in an amount of more than 0 mass % to 1.0 mass %, Mn in an amount of more than 0 mass % to 0.6 mass % or less, Cr in an amount of 25 mass % to 35 mass %, Ni in an amount of 35 mass % to 50 mass %, Nb in an amount of 0.5 mass % to 2.0 mass %, Al in an amount of 3.0 mass % to 6.0 mass %, Yin an amount of 0.005 mass % to 0.05 mass %, wherein Y/Al is 0.002 or more to 0.015 or less; and the balance being Fe and inevitable impurities.

Abstract: The present invention provides a heat-resistant alloy and a reaction tube having excellent oxidation resistance, excellent mechanical properties such as tensile ductility, and weldability. A heat-resistant alloy of the present invention comprises, in terms of % by mass, C: 0.35% to 0.7%, Si: more than 0% and 1.5% or less, Mn: more than 0% and 2.0% or less, Cr: 22.0% to 40.0%, Ni: 25.0% to 48.3%, Al: 1.5% to 4.5%, Ti: 0.01% to 0.6%, and the balance being Fe and inevitable impurities, wherein when Pa=?11.1+28.1×C+29.2×Si?0.25×Ni?45.6×Ti, and Ya=?13.75×Al+63.75, Pa<Ya.

Abstract: The present invention provides a pyrolysis tube for manufacturing olefin which tube can improve a yield of olefin in a pyrolysis reaction of a hydrocarbon raw material. The pyrolysis tube (1A) for manufacturing olefin includes a tubular base material (2) made of a heat resistant metal material and a dehydrogenating catalyst (4A) which is supported on an inner surface of the tubular base material (2).

Abstract: The present invention provides an alloy for overlay welding with which an alumina barrier layer containing an Al oxide can be formed on a projection that is overlay welded on an inner surface of a reaction tube, and a reaction tube having a projection that is overlay welded on the inner surface as a stirring member. An alloy for overlay welding according to the present invention is an alloy for overlay welding that is to be used in overlay welding, and the alloy contains C in an amount of 0.2 mass % to 0.6 mass %, Si in an amount of more than 0 mass % to 1.0 mass %, Mn in an amount of more than 0 mass % to 0.6 mass % or less, Cr in an amount of 25 mass % to 35 mass %, Ni in an amount of 35 mass % to 50 mass %, Nb in an amount of 0.5 mass % to 2.0 mass %, Al in an amount of 3.0 mass % to 6.0 mass %, Y in an amount of 0.005 mass % to 0.05 mass %, and Fe and inevitable impurities as a remaining portion.