A method for the manufacture of a cold-rolled steel sheet of thickness e.sub.f between 0.5 mm and 3 mm is provided. At least two hot-rolled sheets of thickness e.sub.i are supplied and butt welded, so as to create a welded joint (S1) with a direction perpendicular to the direction of hot rolling. The at least two hot-rolled sheets are pickled by continuous passage through a bath, then the assembly is cold rolled, in a step (L1), to an intermediate thickness e.sub.int, the direction of cold rolling (DL.sub.1) coinciding with the direction of hot rolling. The cold rolling is carried out with a reduction ratio ${\mathrm{.Math.}}_1=\mathrm{Ln}\left(\frac{e_i}{e_{\mathrm{int}}}\right)$
such that: $0.35\le \frac{\mathrm{Ln}\left(\frac{\mathrm{ei}}{e\mathrm{int}}\right)}{\mathrm{Ln}\left(\frac{ei}{ef}\right)}\le 0.65,$
then the welded joint (S1) is removed so as to obtain at least two intermediate cold-rolled sheets. Then the two intermediate cold-rolled sheets are butt welded, so as to create a welded joint (S2), the dire

Intended is to improve the corrosion resistance of an overlay used in a nuclear power plant, and to reduce dissolution of cobalt from an overlay. The corrosion and wear resistant overlay 7 is formed along a surface of a base 2 by laser lamination modeling, and is configured from a plurality of metal layers 1a, 1b, 1c, and 1d of a Co-base alloy. The thickness of carbide eutectics that precipitate in the metal layers 1a, 1b, 1c, and 1d is the largest in the metal layer 1a closest to the base 2, and is gradually smaller in the metal layers 1b, 1c, and 1d farther away from the base 2. The intensity of the laser beam applied to form layers by laser lamination modeling is adjusted so that the carbide eutectics that precipitate in at least the outermost metal layer 1d have a controlled size of 10 μm or less.

A differential hypoid gear, a pinion gear, and paired hypoid gears formed by a combination thereof are provided. The differential hypoid gear includes a ring-shaped main body and a tooth-forming surface, and has a chemical component composition including C: 0.15-0.30 mass %, Si: 0.55-1.00 mass %, Mn: 0.50-1.20 mass %, Cr: 0.50-1.50 mass %, Al: 0.020-0.080 mass %, B: 0.0005-0.0050 mass %, Ti: 0.01-0.08 mass %, N: 0.0020-0.0100 mass %, Mo: 0.25 mass % or less, and Nb: less than 0.10 mass %, the remainder being Fe and unavoidable impurities. The chemical component composition satisfies Formulae 1 and 2. The differential hypoid gear has a metallographic structure including mainly tempered martensite. A martensite ratio at an inside of a dedendum differs between an end portion of a tooth and a central portion of the tooth within a range of 15% or less. A core hardness of the dedendum at the central portion falls within 350-500 HV.

Alloy compositions, structures, and production methods for an appropriate slit cut surface shape improve productivity by increasing welding speed and stabilizing quality during high speed welding in Ti-containing Fe—Ni—Cr alloy production. The Ti-containing Fe—Ni—Cr alloy contains, hereinafter in weight %, C: 0.001 to 0.03%, Si: 0.05 to 1.25%, Mn: 0.10 to 2.00%, P: 0.001 to 0.030%, S: 0.0001 to 0.0030%, Ni: 15 to 50%, Cr: 17 to 25%, Al: 0.10 to 0.80%, Ti: 0.10 to 1.5%, N: 0.003 to 0.025%, 0: 0.0002 to 0.007%, Fe as a remainder, and inevitable impurities, and when the number and size of titanium nitrides contained in material are evaluated in a freely selected field of view of 5 mm2, the titanium nitrides having sizes of not more than 15 μm are not less than 99.3% of total of the titanium nitrides.

Disclosed is an electrochemical cell with ceramic components having a ceramic/metal gradient below a ceramic outer layer.

In certain embodiments described herein, a heated line forming system includes a heating coil system configured to produce a heated line on a surface of a metal part. The heated line forming system also includes an air knife cooling system configured to maintain a dry area for the heated line, and to direct a coolant (e.g., cooling water, liquified gases such as liquid argon, solidified gases such as carbon dioxide snow, and so forth) around the heated line via a spray mechanism such that the coolant does not flow or splash into the heated line on the metal part. In certain embodiments, the heated line forming system includes multiple induction coils arranged along a line and spaced a short distance apart, but which, when operated simultaneously together, form a heated line on a surface of a metal part.

The invention concerns a method for heat treatment of an austenitic steel of the High Nitrogen Steel or austenitic HNS type, or of an austenitic steel of the High Interstitial Steel or austenitic HIS type, said austenitic HNS or austenitic HIS containing precipitates of nitrides, carbides or carbonitrides of chromium and/or of molybdenum, this method comprising the step which consists, after machining the austenitic HNS or austenitic HIS containing the precipitates, in redissolving the precipitates by bringing the austenitic HNS or austenitic HIS to its austenitizing temperature, then cooling the austenitic HNS or austenitic HIS sufficiently rapidly to avoid the re-formation of precipitates. The invention also concerns different heat treatment methods allowing chromium and/or molybdenum nitride, carbide or carbonitride type precipitates to appear in an austenitic HNS or austenitic HIS. Indeed, the presence of these precipitates in the matrix of the austenitic HNS or austenitic HIS makes machining operations easier by promoting the formation and removal of chips during machining of the components.

A method for producing a high strength tube part is provided. The method includes the acts of: producing a sheet metal blank, producing a tube part by cold forming the sheet metal blank, and hardening the tube part at least in some sections to a high strength tube part.

Tubes for use in ultrahigh pressure devices, and associated systems and methods of manufacture are disclosed herein. In one embodiment, a metal tube includes an elongate bore having a circular transverse cross-sectional shape. The metal tube also includes an elongate wall extending around the bore and having an annular transverse cross-sectional shape with an inner surface closest to the bore, an outer surface furthest from the bore, and a wall thickness extending from the inner surface to the outer surface. An inner portion of the wall is under swage-autofrettage-induced overall compressive stress.

A shaft part excellent in static torsional strength and torsional fatigue strength containing, by mass %, essential elements of C: 0.35 to 0.70%, Si: 0.01 to 0.40%, Mn: 0.5 to 2.6%, P: 0.050% or less, S: 0.005 to 0.020%, Al: 0.010 to 0.050%, N: 0.005 to 0.025%, and O: 0.003% or less, further containing optional elements, having a balance of Fe and impurities, having a chemical composition satisfying formula (1), having at least one hole at an outer circumferential surface, having a volume ratio (R1) of 4 to 20% of retained austenite at a position of a 2 mm depth from the outer circumferential surface, having a volume ratio of retained austenite at a position of a 2 mm depth from the outer circumferential surface in an axial direction of the hole and at a position of a 20 μm depth from the surface of the hole as R2, and having a reduction rate Δγ of 40% or more of retained austenite found by the formula (A): Δγ=[(R1−R2)/R1]×100: Formula (1): 15.0≤25.9C+6.35Mn+2.88Cr+3.09Mo+2.73Ni≤27.2 (Notations of elements in formula are contents of the elements)