A cemented carbide comprising 55-90 parts by mass of WC particles and 10-45 parts by mass of a Fe-based binder phase; the binder phase having a composition comprising 0.5-10% by mass of Ni, 0.2-2% by mass of C, 0.5-5% by mass of Cr, 0.2-2.0% by mass of Si, and 0.1-5% by mass of W, the balance being Fe and inevitable impurities, and containing 0.05-2.0% by area of Fe—Si—O-based particles.

Provided is a clad welded pipe or tube that has improved pipe or tube mechanical properties by reducing the width of a weld without its function as a clad pipe or tube being impaired. A clad welded pipe or tube comprises: a first layer made of base metal; and a second layer placed on one surface of the first layer, and made of first cladding metal that is a material different from the base metal, wherein a pipe or tube circumferential length L1 of weld metal at a pipe or tube inner surface and a pipe or tube circumferential length L2 of the weld metal at a pipe or tube outer surface in a weld are each 0.0010 mm or more and 1.0 mm or less, and the base metal is not exposed at a first cladding metal-side surface of the clad welded pipe or tube in the weld.

Provided is a clad welded pipe or tube that has improved pipe or tube mechanical properties by reducing the width of a weld without its function as a clad pipe or tube being impaired. A clad welded pipe or tube comprises: a first layer made of base metal; and a second layer placed on one surface of the first layer, and made of first cladding metal that is a material different from the base metal, wherein a pipe or tube circumferential length L1 of weld metal at a pipe or tube inner surface and a pipe or tube circumferential length L2 of the weld metal at a pipe or tube outer surface in a weld are each 0.0010 mm or more and 1.0 mm or less, and the base metal is not exposed at a first cladding metal-side surface of the clad welded pipe or tube in the weld.

Provided is a high-strength steel sheet including: 0.12% to less than 0.17% of carbon (C), 0.3% to 0.8% of silicon (Si), 2.5% to 3.0% of manganese (Mn), 0.4% to 1.1% of chromium (Cr), 0.01% to 0.3% of aluminum (Al), 0.01% to 0.03% of niobium (Nb), 0.01% to 0.03% of titanium (Ti), 0.001% to 0.003% of boron (B), 0.04% or less of phosphorus (P), 0.01% or less of sulfur (S): 0.01% or less of nitrogen (N), and a balance of iron (Fe) and inevitable impurities. The contents of C, Si, and Al satisfy: [C]+[Si]+[Al])/5≤0.35 wt. A microstructure includes more than 1% to 4% or less of retained austenite, more than 10% to 20% or less of fresh martensite, 5% or less (excluding 0%) of ferrite, more than 50% to 70% or less of tempered martensite, and a balance of bainite.

Provided are: steel for knives, having a higher hardness and better corrosion resistance than conventional steel for knives; a knife; steel for martensitic knives; and a production method for same. The steel for knives comprises a component composition containing, in mass %, 0.45%-1.00% C, 0.1%-1.5% Si, 0.1%-1.5% Mn, 7.5%-11.0% Cr, and 0.5%-3.0% of either Mo or W or a complex of both (Mo+W/2), with the remainder being Fe and unavoidable impurities. Also provided are steel for martensitic knives and a knife. A production method for steel for martensitic knives is also provided that includes a quenching temperature at quenching of 1,050-1,250° C., a processing temperature for subzero processing of no more than −50° C., and a tempering temperature at tempering of 100-400° C., and obtains steel for martensitic knives that has a hardness of at least 700 HV.

A clad material (30) includes a first layer (31) made of stainless steel, a second layer (32) made of Cu or a Cu alloy and roll-bonded to the first layer, and a third layer (33) made of stainless steel and roll-bonded to a side of the second layer opposite to the first layer. The clad material has an overall thickness of 1 mm or less, and in a cross-sectional view along a stacking direction, a minimum thickness of the first layer in the stacking direction and a minimum thickness of the third layer in the stacking direction are 70% or more and less than 100% of an average thickness of the first layer in the stacking direction and an average thickness of the third layer in the stacking direction, respectively.

Method for welding two stainless steel sheets of thickness (e) 0.10 to 6.0 mm and having a particular composition having: a first welding step lasting a time (t) in ms: 0.10 to 0.50 mm, t=(40×e+36)±10%; 0.51 to 1.50 mm: t=(124×e 13)±10%; 1.51 to 6.0 mm: t=(12×e+47)±10%; with clamping force (F) in daN: 0.10 to 1.50 mm: F=(250×e+90)±10%; 1.51 mm to 6.0 mm: F=(180×e+150)±10%; appling a current between the welding electrodes, of intensity between 80 and 100% the maximum permissible intensity corresponding to expulsion of molten metal; a second step with an intensity between zero and 1 kA; and a third step with an intensity of 3.5 kA to 4.5 kA, for a time of at least 755 ms.

Method for welding two stainless steel sheets of thickness (e) 0.10 to 6.0 mm and having a particular composition having: a first welding step lasting a time (t) in ms: 0.10 to 0.50 mm, t=(40×e+36)±10%; 0.51 to 1.50 mm: t=(124×e 13)±10%; 1.51 to 6.0 mm: t=(12×e+47)±10%; with clamping force (F) in daN: 0.10 to 1.50 mm: F=(250×e+90)±10%; 1.51 mm to 6.0 mm: F=(180×e+150)±10%; appling a current between the welding electrodes, of intensity between 80 and 100% the maximum permissible intensity corresponding to expulsion of molten metal; a second step with an intensity between zero and 1 kA; and a third step with an intensity of 3.5 kA to 4.5 kA, for a time of at least 755 ms.

Embodiments of the disclosure relate to a ferritic alloy having excellent ability to withstand nuclear power plant accidents and a method of manufacturing a nuclear fuel cladding tube using the same. The alloy includes iron (Fe), aluminum (Al), chromium (Cr), and nickel (Ni). The nickel (Ni) may be included 0.5 to 10 wt % based on a total amount of the alloy. The chromium may be included 13 to 18 wt % based on the total amount of the alloy. The aluminum may be included 5 to 7 wt % based on the total amount of the alloy.

Embodiments of the disclosure relate to a ferritic alloy having excellent ability to withstand nuclear power plant accidents and a method of manufacturing a nuclear fuel cladding tube using the same. The alloy includes iron (Fe), aluminum (Al), chromium (Cr), and nickel (Ni). The nickel (Ni) may be included 0.5 to 10 wt % based on a total amount of the alloy. The chromium may be included 13 to 18 wt % based on the total amount of the alloy. The aluminum may be included 5 to 7 wt % based on the total amount of the alloy.