Abstract: A method of manufacturing a ferritic stainless steel sheet having good workability with less anisotropy. The steps include providing a ferritic stainless steel comprising C up to about 0.03 mass %, N up to about 0.03 mass %, Si up to about 2.0 mass %, Mn up to about 2.0 mass %, Ni up to about 0.6 mass %, Cr about 9–35 mass %, Nb about 0.15–0.80 mass % and the balance being Fe except inevitable impurities; precipitation-heating said stainless steel at a temperature in a range of 700–850° C. for a time period not longer than 25 hours; and finish-annealing said stainless steel at a temperature in a range of 900–1100° C. for a time period not longer than 1 minute.

Abstract: An iron based, fine-grained, martensitic stainless steel essentially free of delta ferrite has a nominal composition of (wt. %): 0.05<C<0.15; 7.5<Cr<15; 2<Ni<5; Co<4; Cu<1.2; Mn<5; Si<1; (Mo+W)<4; 0.01<Ti<0.75; 0.135<(1.17Ti+0.6Zr+0.31Ta+0.31Hf)<1; V<2; Nb<1; N<0.02; Al<0.2; Al and Si both present such that (Al+Si)>0.01; B<0.1; P<0.1; S<0.03; and the balance essentially iron and impurities. This steel is different from other martensitic stainless steels because thermal mechanical treatment is used to refine the grains and precipitate a relatively uniform dispersion of fine, coarsening-resistant, MX-type particles. The steel combines high strength and impact toughness with good corrosion resistance.

Abstract: Martensitic stainless steel whose steel composition is restricted within a specific range for each element is provided. The scale layer formed on the surface of the base material consists of an inner layer scale mainly including FeCr2O4 and an outer layer scale having a thickness of not more than 20 ?m, which outer layer is deposited on the inner layer scale at a surface coverage of not less than 1% and not more than 15%. The application of rust preventive oil onto the surface of the steel ensures an excellent weather resistance during a long term, and therefore a martensitic stainless steel forming no rust either in the outdoor depository or in the indoor depository can be provided. The steel can be used to manufacture, not only steel pipes, but also steel plates, steel rods and others in a wide application field.

Abstract: An iron based, fine-grained, alloy.

Abstract: High pressure cylinders comprising backing steel cylinders and tool steel liners are disclosed. An annealed tool steel liner is inserted into the backing steel cylinder, followed by heat treating to harden the tool steel liner. The tool steel liner may be provided as a single continuous tube, thereby avoiding problems associated with segmented liners. The high-pressure cylinders are suitable for use as plastic and rubber extruders injection molding cylinders and the like.

Abstract: Ferritic stainless steel, comprising the following Chemical elements expressed in percentage by weight: —Cr 14.0-20.0 —Al 0.50-1.50 —Zr 0.10-0.50 —Si 0.30-1.50 —Ti 0.10-0.35 —Nb 0.25-0.55 —C<0.035 —N<0.035 provided that the content of Ti, Nb, C and N satisfy the following relation: %Ti+%Nb/1.94>9 (%C+%N) and substantially iron q. s. to 100. This steel may also comprise Yttrium and/or rare earth elements in a percentage by weight comprised in the range 0.10-0.30. The invention also encompasses products manufacturable with the steel of the invention, in particular vehicle exhaust manifold systems. Figure (I) shows a cyclic oxidation test carried out at 1000° C. on samples having the composition of an embodiment of the steel according to the invention.

Abstract: A steel composition contains: 0.05% or less of C; 0.5% or less of Si; 0.20% to 1.80% of Mn; 0.03% or less of P; 0.005% or less of S; 14.0% to 18.0% of Cr; 5.0% to 8.0% of Ni; 1.5% to 3.5% of Mo; 0.5% to 3.5% of Cu; 0.05% or less of Al; 0.20% or less of V; 0.01% to 0.15% of N; and 0.006% or less of O on a mass basis, and satisfies the following expressions: Cr+0.65Ni+0.6Mo+0.55Cu−20C≧18.5 and Cr+Mo+0.3Si−43.5C−0.4Mn−Ni−0.3Cu−9N≦11 (where Cr, Ni, Mo, Cu, C, Si, Mn, and N represent their respective contents (mass %)). After such a steel pipe material is formed into a steel pipe, the steel pipe is quenched by cooling after heating to a temperature of the AC3 transformation point or more and tempered at a temperature of the AC1 transformation point or less. The composition may further contain at least one element of Nb and Ti; at least one element selected from the group consisting of Zr, B, and W; or Ca, singly or in combination.

Abstract: A metallurgical process for producing a metallic implantable medical device, such as a stent, in a condition wherein the metallic alloy of the device has improved mechanical properties. The starting material is formed into an oversized tube which is drawn to finished outer diameter. The drawing process cold works the tube to produce a material having a high dislocation density and a yield strength that is above approximately 125 ksi. Next, the drawn tube is heat treated at a temperature of approximately one-half the absolute melting temperature of the alloy. The heat treatment causes dislocations to rearrange, forming sub-grains and re-crystallization of the grain structure. Upon cooling, a material is obtained having a yield strength between approximately 45-70 ksi and an elongation exceeding 40 percent. The material also has good resistance to fatigue fracture due to the fine grains and sub-grains that are established during the heat treatment.

Abstract: A method for manufacturing a high Cr system seamless steel pipe having a high inside surface quality with a high efficiency and at a reduced production cost is provided. An initial material including Cr at a content of 10 to 20%, and impurities S and P at respective contents of not more than 0.050% is used to form a finished pipe, and when using parameters, the total soaking period &Sgr;t1 (hours) for soaking the initial material to form a primary pipe material as a billet or bloom and the total soaking period &Sgr;t2 (hours) for soaking the primary pipe material, a finished pipe is formed at a heating temperature of 1,200° C. under the condition that the following equation (b) is satisfied: F = f + 0.

Abstract: The present invention provides an austenitic stainless steel tube with a uniform fine grained structure of regular grains, which is not changed to a coarse structure and the steam oxidation resistance is maintained even if the tube is subjected to a high temperature reheating during welding and high temperature bending working. The austenitic stainless steel tube consists of, by mass %, C: 0.03-0.12%, Si: 0.1-0.9%, Mn: 0.1-2%, Cr: 15-22%, Ni: 8-15%, Ti: 0.002-0.05%, Nb: 0.3-1.5%, sol. Al: 0.0005-0.03%, N: 0.005-0.2% and O (oxygen): 0.001-0.008%, and the balance Fe and impurities, the austenitic stainless steel tube having austenitic grain size number of 7 or more and a mixed grain ratio of preferably 10% or less.

Abstract: A surface treatment process for enhancing the resistance to intergranular corrosion and intergranular cracking of components fabricated from austenitic Ni—Fe—Cr based alloys comprising the application of surface deformation to the component, to a depth in the range of 0.01 mm to 0.5 mm, for example by high intensity shot peening below the recrystallization temperature, followed by recrystallization heat treatment, preferably at solutionizing temperatures. The surface deformation and annealing process can be repeated to further optimize the microstructure of the near-surface region. Following the final heat treatment, the process optionally comprises the application of further surface deformation (work) of reduced intensity, yielding a worked depth of between 0.005 mm to 0.01 mm, to impart residual compression in the near surface region to further enhance cracking resistance.

Abstract: A method for manufacturing a high Cr system seamless steel pipe having a high inside surface quality with a high efficiency and at a reduced production cost is provided. An initial material including Cr at a content of 10 to 20%, and impurities S and P at respective contents of not more than 0.050% is used to form a finished pipe, and when using parameters, the total soaking period &Sgr;t1 (hours) for soaking the initial material to form a primary pipe material as a billet or bloom and the total soaking period &Sgr;t2 (hours) for soaking the primary pipe material, a finished pipe is formed at a heating temperature of 1,200° C. under the condition that the following equation (b) is satisfied: 1 F = f + 0.6 × ( 1 - 1 e ∑   ⁢ t1 ) + 0.8 × ( 1 - 1 e ∑ t2 ) > - 9.

Abstract: An improved silicon steel sheet has two lateral ends each having a side edge narrower than the width of the silicon sheet. The side edge has two end points linking respectively to two lateral sides of the silicon steel sheet to form two symmetrical slant edges for reducing tension area of the silicon steel sheet at the side edge. The slant edges and the side edges form two solder zones to anchor the silicon steel sheet for soldering at the initial winding stage and after the winding is completed.

Abstract: A composition and method for the manufacture of products of a precipitation hardenable martensitic stainless steel, the composition of which comprises at least 0.5% by weight of Cr and at least 0.5% by weight of Mo wherein the sum of Cr, Ni and Fe exceeds 50%. The method steps include smelting the material into a casting, hot extrusion followed by a number of cold deforming steps so as to obtain at least 50% martensite and finally an ageing treatment at 425-525° C. to obtain precipitation of quasicrystalline particles. Such material can be used in vehicle components where demands for corrosion resistance, high strength and good toughness are to be satisfied.

Abstract: Heat resistant stainless steel may be treated in a low oxidizing atmosphere in a heat/soak-heat/soak sequence to deplete its surface of Ni and Cr which tend to catalyze coking of hydrocarbons in contact with the surface of the stainless steel, and enrich it with elements which are inert to coke formation. Parts made of stainless steel, such as furnace tubes or coils, treated in accordance with the present invention when used have a significantly reduced rate of catalytic coking.

Abstract: A surface treatment process for enhancing the intergranular corrosion and intergranular cracking resistance of components fabricated from austenitic Ni—Fe—Cr based alloys comprised of the application of surface cold work to a depth in the range of 0.01 mm to 0.5 mm, for example by high intensity shot peening, followed by recrystallization heat treatment preferably at solutionizing temperatures (>900 C.). The surface cold work and annealing process can be repeated to further optimize the microstructure of the near-surface region. Following the final heat treatment, the process can optionally comprise the application of surface cold work of reduced intensity, yielding a cold worked depth of 0.005 mm to 0.01 mm, in order further enhance resistance to cracking by rendering the near surface in residual compression.

Abstract: A compound tube including a layer of a Fe—Cr alloy and a layer of load-carrying component, with the optional addition of further layers. The Fe—Cr alloy preferably has a composition including, in weight-%: less than 0.3% carbon, 15-60% chromium, less than 10% nickel, less than 5% molybdenum, less than 5% silicon, less than 0.3% nitrogen, less than 5% manganese, and the remainder iron with naturally occurring impurities. The compound tubes are very resistant to carbonization and metal dusting, and are suited for use as bayonet tubing, superheater tubing, and reforming tubing in steam formation environments.

Abstract: An austenitic rounding fixture is inserted into the horizontal joint of a turbine casing. The casing is then assembled and stress relief cycle is carried out, resulting in rerounding of the casing and relief of residual stresses. Since an austenitic material has a higher thermal expansion coefficient than the metallic materials of conventional turbine casings, the rounding fixtures expand more than the casing during a stress relief cycle. The length of the fixtures are designed in such a way that at stress relief temperature the casing is slightly over-rounded. After the stress relief, the casing is rerounded and the austenitic rounding Fixtures is disengaged. The rounding fixture is installed in a cold condition (or with minimal heat for heavily collapsed casings). The removal of the rounding fixtures is easy since a clearance exists between the casing and the fixtures; the spring back of the casing is far less then the contraction of the fixtures.

Abstract: A method of oxidation treatment of the inner surface of a ferritic stainless steel pipe comprising feeding an oxidizing gas into steel pipe from one end thereof while moving the steel pipe in a pipe-length direction, and heating the pipe in a heating furnace in a non-oxidizing atmosphere at a specific temperature of T° C. which falls within the range of 700-1100° C. The method is capable of efficiently forming Cr oxide film having a uniform Cr content and film thickness over the entire length of the inner surface of the steel pipe used as a piping member or piping for supplying a high-purity fluid, such as high-purity gas or water used in a semiconductor manufacturing process.

Abstract: A martensitic stainless steel pipe comprises, on the weight basis, C: 0.005 to 0.2%, Si: 1% or below, Mn: 0.1 to 5%, Cr: 7 to 15%, and Ni: 0 to 8%, wherein a wall thickness t (mm) and contents of C and Cr satisfy the relationship represented by the following equation (1).t(mm).ltoreq.exp{5.21-18.1C(%)-0.0407Cr(%)} (1)The steel pipe can be made by employing water quenching as a quenching method.

Abstract: A high-Cr martensite steel pipe having excellent pitting resistance and method for manufacturing the same, which involves forming a pipe of steel including C: about 0.03 wt % or less, Si: about 0.5 wt % or less, Mn: about 0.5-3.0 wt %, Cr: about 10.0-14.0 wt %, Ni: about 0.2-2.0 wt %, Cu: about 0.2-1.0 wt % and N: about 0.03 wt % or less with the balance being Fe and incidental impurities, and having a value X shown as defined in the following formula (1) of about 12.2 or more. The pipe is quenched after austenitizing it at a temperature substantially equal to an A.sub.C3 point or higher, and the pipe is annealed in a temperature range from about 550.degree. C. or higher to a temperature lower than an A.sub.C1 point.

Abstract: A process for forming a cylindrical pipe from a welded metal pipe stock by roll extruding and annealing whereby the weldment microstructure forming the seam is essentially reformed to provide a recrystallized grain structure which is substantially homogeneous with the parent material of the pipe stock.

Abstract: A method of cooling a martensitic steel pipe by cooling the inner and outer surface substantially equally while rotating the pipe around the axis, wherein the cooling rate is 8.degree. C./s or higher. The inner surface is preferably cooled by passing water without completely filling the inside of pipe. The maximum cooling rate at the both surfaces is 35.degree. C./s or lower for a martensitic stainless steel pipe. The 2-step cooling method of a martensitic stainless steel pipe, comprising the 1st air cooling where the pipe is cooled from 30.degree. C. lower than Ms(martensitic transformation start temp.) to the average of Ms and Mf(martensitic transformation finish temp.) and 2nd intensive water cooling where the the pipe is cooled down below Mf. The 3-step cooling method comprising 1st intensive cooling where the pipe is cooled from Ms+400.degree. C. to Ms, 2nd mild cooling where the pipe is cooled from Ms to the average of Ms and Mf, and 3rd intensive cooling to the Mf.

Abstract: The present invention provides a highly corrosion-resistant alloy used as a boiler tube in equipment the energy source of which is obtained by burning fossil fuel or waste, a steel tube for which the alloy is used, and a process for producing the steel tube. The alloy comprises up to 0.05% of C, 1.0 to 2.6% of Si, 0.02 to 1.0% of Mn, 20.0 to 28.0% of Cr, 18.0 to 30.0% of Ni, up to 4.0% of Mo, up to 0.05% of Al, 0.05 to 0.30% of N and the balance Fe and unavoidable impurities. Furthermore, the present invention also provides a multilayer steel tube having the alloy as a liner material and a standardized boiler tube as a base layer material, and a process for producing the multilayer steel tube.

Abstract: A steel material and a steel pipe each exhibiting an excellent corrosion resistance in an environment containing a wet carbon dioxide and a small amount of hydrogen sulfide are produced at low cost and with high productivity, a steel slab which contains, in wt %, 0.01 to 0.6% of Si, 0.02 to 1.8% of Mn, 7.5 to 14.0% of Cr, 1.5 to 4.0% of Cu and 0.005 to 0.1% of Al, which reduces C to not more than 0.02%, N to not more than 0.02%, P to not more than 0.025% and S to not more than 0.01%, and whose balance consists of Fe and unavoidable impurities, is heated to a temperature of 1,100.degree. to 1,300.degree. C., hot rolling is finished at a rolling finish temperature of not less than 800.degree. C. and a cumulative rolling reduction quantity at a temperature not more than 1,050.degree. C. is at least 65%, and cooling is carried out at a cooling rate of less than 0.02.degree. C./sec to at least 500.degree. C. so as to substantially convert the metallic structure to ferrite.

Abstract: In the fabrication of components from a face centered cubic alloy, wherein the alloy is cold worked and annealed, the cold working is carried out in a number of separate steps, each step being followed by an annealing step. The resultant product has a grain size not exceeding 30 microns, a "special" grain boundary fraction not less than 60%, and major crystallographic texture intensities all being less than twice that of random values. The product has a greatly enhanced resistance to intergranular degradation and stress corrosion cracking, and possesses highly isotropic bulk properties.

Abstract: A method for heat-treating steel, primarily strip-like or rod-like steel material, such as steel strip, steel sheet, steel rod or steel wire which have been rolled and heated in an oven or furnace to a surface temperature above about 900 degrees C. and thereafter cooled and optionally treated in an electrolyte bath and/or acid bath. The oven burners are fired with a liquid or a gaseous fuel which is burned with the aid of a gas that contains at least 85 percent by volume oxygen and at most 10 percent by volume nitrogen.

Abstract: In the fabrication of components from a face centred cubic alloy, wherein the alloy is cold worked and annealed, the cold working is carried out in a number of separate steps, each step being followed by an annealing step. The resultant product has a grain size not exceeding 30 microns, a "special" grain boundary fraction not less than 60%, and major crystallographic texture intensities all being less than twice that of random values. The product has a greatly enhanced resistance to intergranular degradation and stress corrosion cracking, and possesses highly isotropic bulk properties.

Abstract: Martensitic steel components of apparatus for magnetic conditioning of liquids which are subjected to cathodic reaction and degradation are treated prior to use to form a barrier of iron-chromium oxide and a uniform level of hardness throughout by heating the steel to a temperature near the grain boundary temperature of the steel, maintaining that temperature for a specified period and then rapidly quenching the steel.

Abstract: Disclosed is a process for producing seamless steel pipes or flat products (strip or sheet) for pipes or vessels which are intended for the conveyance, transport or processing of gaseous or liquid hydrocarbons containing CO.sub.2 and water and possibly small proportions of H.sub.2 S and are resistant to stress crack corrosion and have good welding properties at the same time and a 0.2-percent elongation limit of at least 450 N/mm.sup.2. The process uses a nickel-containing steel of the following composition (percent by weight): min. 0.015% C, 0.15-0.50% Si, max. 2.00% Mn, max. 0.020% P, max. 0.003% S, 12.0-13.8% Cr, 0.002-0.02% N, 0.01-0.05% Nb, remainder iron and usual impurities. It is presently suggested that the nickel content is limited to a maximum of 0.25%, the manganese content amounts to at least 1.0%, the carbon content is limited to 0.035%, and 0.01 to 1.2% molybdenum is contained as additional alloying component.

Abstract: A properly balanced chemical composition and the choice of a heat treatment (annealing and quenching) under controlled conditions allow to obtain uperduplex stainless steel manufactures which, in the hot-worked form, are excellent in resistance to corrosion and have unit tensile yield strength at room temperature of 90 ksi min.