Kubota Corporation

Nova Chemicals (international) S.a.

Nova Chemicals Inc.

Kunihide Hashimoto

Motoyuki Matsubara

Hiroshi Yamaguchi

Masayuki Tomita

Vasily Simanzhenkov

Makoto Takahashi

Leslie Wilfred Benum

Hany Farag

Makoto Hineno

Shinichi Uramaru

Billy Santos

Nobuyuki Sakamoto

Michael Gyorffy

Kathleen Donnelly

Kenji Otsubo

Yasushi Sekine

Youhei Enjo

Yohei Enjo

Toru Sukawa

Shigeki Nakamura

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 tubehas an agitating element 20 formed on and projecting inwardly from an inner surface of the tube, wherein the fluid agitating element comprises a finextending along the inner surface of the tube and bumpsprovided 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.

Thermal cracking tube with fluid agitating element

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 tubewith 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 elementsextending 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 sideor the fluid outlet side, relative to a centerof a width direction of the agitation element.

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 MnCrOhaving a thickness up to 5 microns.

Protective surface on stainless steel

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 (AlM)O, 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)&#x2265;2.0 in an atomic % ratio, the barrier layer being composed of two layers consisting of a first Al-containing metal oxide layer and a second Al-containing metal oxide layer formed between the surface of the cast product and the first Al-containing metal oxide layer, and the second Al-containing metal oxide layer being greater than the first Al-containing metal oxide layer with respect to the atomic % ratio of Al/(Cr+Ni+Si+Fe), and having a thickness that is at least one fifth of a thickness of the barrier layer.

Cast product having alumina barrier layer

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.

Alloy for overlay welding and reaction tube

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 (A) for manufacturing olefin includes a tubular base material () made of a heat resistant metal material and a dehydrogenating catalyst (A) which is supported on an inner surface of the tubular base material ().

Pyrolysis tube for manufacturing olefin and method for manufacturing dehydrogenating catalyst

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 &#x3bc;m&#x2264;Sa&#x2264;5.0 &#x3bc;m and a skewness (Ssk) of a surface height distribution that satisfies |Ssk|&#x2264;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&#x2265;2.5.

Tube body that is to be used in high-temperature atmosphere and method for forming metal oxide layer on inner surface of tube body

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=&#x2212;11.1+28.1&#xd7;C+29.2&#xd7;Si&#x2212;0.25&#xd7;Ni&#x2212;45.6&#xd7;Ti, and Ya=&#x2212;13.75&#xd7;Al+63.75, Pa&#x3c;Ya.

Heat-resistant alloy, and reaction tube

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 AlOis 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.

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.

A thermal cracking tube is adapted to suppress pressure losses while maintaining heat transfer promoting effect on the fluid inside the tube. The tube has a plurality of projections rows extending circumferentially along inner surface of the tube orthogonal to or as inclined with respect to the axis of tube, each of the projection rows including a plurality of projections provided on the tube inner surface. The tube is defined by S/10&#x3c0;D=0.2&#x2212;0.7, h/D=0.02&#x2212;0.05 and L/&#x3c0;D=0.04&#x2212;0.5. D is inner diameter of the tube, h is height of projection A arbitrarily chosen in a projection row &#x3b1;, L is length of circular arc of projection A in a direction orthogonal to tube axis, and S is area of a region R surrounded by projection A, phantom lines L1 and L2 (extending respectively from circumferentially opposite ends of projection A in parallel to tube axis) and projection row &#x3b2; downstream from projection row &#x3b1;.

Thermal cracking tube

A heat resistant alloy comprising, in % by weight, over 0.6% to not more than 0.9% of C, up to 2.5% of Si, up to 3.0% of Mn, 20 to 28% of Cr, 8 to 55% of Ni, 0.01 to 0.8% of Ti and 0.05 to 1.5% of Nb, the balance being Fe and inevitable impurities, the value of (Ti+Nb)/C being 0.12 to 0.29 in atomic % ratio. When the alloy further contains up to 0.5% of Zr, the value of (Ti+Nb+Zr)/C is 0.12 to 0.29 in atomic % ratio. When the alloy is heated at a temperature of at least about 800 degrees C., a fine Ti&#x2014;Nb&#x2014;Cr carbide or Ti&#x2014;Nb&#x2014;Zr&#x2014;Cr carbide precipitates within grains to thereby retard creep deformation and give an improved creep rupture strength. The alloy is therefore suitable as a material for hydrogen production reforming tubes.

Heat resistant alloy adapted to precipitate fine Ti-Nb-Cr carbide or Ti-Nb-Zr-Cr carbide

A heat-resistant cast steel excellent in high-temperature strength, aged ductility and creep rupture strength for use as a material for steam reforming reaction tubes in fuel cell hydrogen generation systems and the like. The cast steel has a chemical composition comprising, in mass %, 0.1 to 0.5% of C, up to 2.5% of Si, up to 2.5% of Mn, 15 to 26% of Cr, 8 to 23% of Ni, 0.1 to 1.2% of Nb, 0.01 to 1.0% of Ti, 0.001 to 0.15% of Ce, up to 0.06% of N and the balance substantially Fe, the cast steel being 20 to 45 in the parameter value P calculated from the expression:When desired, the steel contains at least one of 0.001 to 0.05% of B, 0.01 to 0.5% of Zr and 0.001 to 0.15% of La, and/or 0.01 to 0.3% of Al. Further when desired, the C, Cr and Ni contents are limited to 0.1 to 0.3% of C, 15 to 20% of Cr and 8 to 18% of Ni.

Growing community of inventors

Hirakata, Japan

Kunihide Hashimoto