[Object] To provide a steel sheet for carburizing that demonstrates improved ductility, and a method for manufacturing the same. [Solution] A steel sheet consisting of, in mass %, C: more than or equal to 0.02%, and less than 0.30%, Si: more than or equal to 0.005%, and less than 0.5%, Mn: more than or equal to 0.01%, and less than 3.0%, P: less than or equal to 0.1%, S: less than or equal to 0.1%, sol. Al: more than or equal to 0.0002%, and less than or equal to 3.0%, N: less than or equal to 0.2%, Ti: more than or equal to 0.010%, and less than or equal to 0.150%, and the balance: Fe and impurities, in which the number of carbides per 1000 μm.sup.2 is 100 or less, percentage of number of carbides with an aspect ratio of 2.0 or smaller is 10% or larger relative to the total carbides, average equivalent circle diameter of carbide is 5.0 μm or smaller, and average crystal grain size of ferrite is 10 μm or smaller.

The steel pipe according to the present disclosure contains a chemical composition consisting of, in mass %, C: more than 0.50 to 0.65%, Si: 0.05 to 0.50%, Mn: 0.05 to 1.00%, P: 0.025% or less, S: 0.0050% or less, Al: 0.005 to 0.100%, Cr: 0.30 to 1.50%, Mo: 0.25 to 3.00%, Ti: 0.002 to 0.050%, N: 0.0010 to 0.0100% and O: 0.0030% or less, with the balance being Fe and impurities. The steel pipe contains an amount of dissolved C within a range of 0.010 to 0.060 mass %. The tensile yield strength in the axial direction and the circumferential direction is 862 to 1069 MPa, and the yield ratio in the axial direction is 90% or more. The tensile yield strength in the circumferential direction is 30 to 80 MPa higher than the compressive yield strength in the circumferential direction.

The steel pipe according to the present disclosure contains a chemical composition consisting of, in mass %, C: more than 0.50 to 0.65%, Si: 0.05 to 0.50%, Mn: 0.05 to 1.00%, P: 0.025% or less, S: 0.0050% or less, Al: 0.005 to 0.100%, Cr: 0.30 to 1.50%, Mo: 0.25 to 3.00%, Ti: 0.002 to 0.050%, N: 0.0010 to 0.0100% and O: 0.0030% or less, with the balance being Fe and impurities. The steel pipe contains an amount of dissolved C within a range of 0.010 to 0.060 mass %. The tensile yield strength in the axial direction and the circumferential direction is 862 to 1069 MPa, and the yield ratio in the axial direction is 90% or more. The tensile yield strength in the circumferential direction is 30 to 80 MPa higher than the compressive yield strength in the circumferential direction.

Proposed is a Fe-based alloy and a filler metal including the same. The Fe-based alloy contains 15% to 25% by weight of nickel (Ni), 0.5% to 3% by weight of manganese (Mn), 2% to 8% by weight of cobalt (Co), 0.1% to 0.5% by weight of carbon (C), and the balance iron (Fe) and unavoidable impurities.

Provided herein is a stainless steel seamless pipe having a composition that contains, in mass %, C: 0.06% or less, Si: 1.0% or less, Mn: 0.01% or more and 1.0% or less, P: 0.05% or less, S: 0.005% or less, Cr: 15.2% or more and 18.5% or less, Mo: 1.5% or more and 4.3% or less, Cu: 1.1% or more and 3.5% or less, Ni: 3.0% or more and 6.5% or less, Al: 0.10% or less, N: 0.10% or less, O: 0.010% or less, and Sn: 0.001% or more and 1.000% or less, and in which C, Si, Mn, Cr, Ni, Mo, Cu, and N satisfy the predetermined formula, and the balance is Fe and incidental impurities, the stainless steel seamless pipe having a microstructure containing 30% or more martensitic phase, 65% or less ferrite phase, and 40% or less retained austenite phase by volume.

Provided is an austenitic stainless steel weld joint that is excellent in polythionic acid SCC resistance and naphthenic acid corrosion resistance, and is also excellent in creep ductility. An austenitic stainless steel weld joint includes a base material and a weld metal. The weld metal has a chemical composition at its width-center position and at its thickness-center position consisting of, in mass %, C: 0.050% or less, Si: 0.01 to 1.00%, Mn: 0.01 to 3.00%, P: 0.030% or less, S: 0.015% or less, Cr: 15.0 to 25.0%, Ni: 20.0 to 70.0%, Mo: 1.30 to 10.00%, Nb: 0.05 to 3.00%, N: 0.150% or less, and B: 0.0050% or less, with the balance: Fe and impurities.

Provided is an austenitic stainless steel weld joint that is excellent in polythionic acid SCC resistance and naphthenic acid corrosion resistance, and is also excellent in creep ductility. An austenitic stainless steel weld joint includes a base material and a weld metal. The weld metal has a chemical composition at its width-center position and at its thickness-center position consisting of, in mass %, C: 0.050% or less, Si: 0.01 to 1.00%, Mn: 0.01 to 3.00%, P: 0.030% or less, S: 0.015% or less, Cr: 15.0 to 25.0%, Ni: 20.0 to 70.0%, Mo: 1.30 to 10.00%, Nb: 0.05 to 3.00%, N: 0.150% or less, and B: 0.0050% or less, with the balance: Fe and impurities.

There is provided an austenitic heat resistant steel including a chemical composition that consists of, in mass %, C: 0.04 to 0.12%, Si: 0.01 to 0.30%, Mn: 0.50 to 1.50%, P: 0.001 to 0.040%, S: less than 0.0050%, Cu: 2.2 to 3.8%, Ni: 8.0 to 11.0%, Cr: 17.7 to 19.3%, Mo: 0.01 to 0.55%, Nb: 0.400 to 0.650%, B: 0.0010 to 0.0060%, N: 0.050 to 0.160%, Al: 0.025% or less, and O: 0.020% or less, with the balance: Fe and impurities and that satisfies [0.170≤Nb−Nb.sub.ER≤0.480].

There is provided an austenitic heat resistant steel including a chemical composition that consists of, in mass %, C: 0.04 to 0.12%, Si: 0.01 to 0.30%, Mn: 0.50 to 1.50%, P: 0.001 to 0.040%, S: less than 0.0050%, Cu: 2.2 to 3.8%, Ni: 8.0 to 11.0%, Cr: 17.7 to 19.3%, Mo: 0.01 to 0.55%, Nb: 0.400 to 0.650%, B: 0.0010 to 0.0060%, N: 0.050 to 0.160%, Al: 0.025% or less, and O: 0.020% or less, with the balance: Fe and impurities and that satisfies [0.170≤Nb−Nb.sub.ER≤0.480].

Provided is an abrasion-resistant steel plate excellent in both abrasion resistance and wide bending workability. An abrasion-resistant steel plate comprises a specific chemical composition, wherein a volume fraction of martensite at a depth of 1 mm from a surface of the abrasion-resistant steel plate is 90 % or more, hardness at a depth of 1 mm from the surface is 500 HBW 10/3000 to 650 HBW 10/3000 in Brinell hardness, and a transverse direction hardness difference is 30Hv10 or less in Vickers hardness, the transverse direction hardness difference being defined as a difference in the hardness at a depth of 1 mm from the surface between two points adjacent at intervals of 10 mm in a transverse direction of the abrasion-resistant steel plate.