Alloy compositions for 3D metal printing procedures which provide metallic parts with high hardness, tensile strengths, yield strengths, and elongation. The alloys include Fe, Cr and Mo and at least three or more elements selected from C, Ni, Cu, Nb, Si and N. As built parts indicate a tensile strength of at least 1000 MPa, yield strength of at least 640 MPa, elongation of at least 3.0% and hardness (HV) of at least 375.

Alloy compositions for 3D metal printing procedures which provide metallic parts with high hardness, tensile strengths, yield strengths, and elongation. The alloys include Fe, Cr and Mo and at least three or more elements selected from C, Ni, Cu, Nb, Si and N. As built parts indicate a tensile strength of at least 1000 MPa, yield strength of at least 640 MPa, elongation of at least 3.0% and hardness (HV) of at least 375.

A cold rolled and coated steel sheet having a composition including of the following elements, 0.12%≤Carbon≤0.2%, 1.7%≤Manganese≤2.10%, 0.1%≤Silicon≤0.5%, 0.1%≤Aluminum≤0.8%, 0.1%≤Chromium≤0.5%, 0%≤Phosphorus≤0.09%, 0%≤Sulfur≤0.09%, 0%≤Nitrogen≤0.09%, Nickel≤3%, Niobium≤0.1%, Titanium≤0.1%, Calcium≤0.005%, Copper≤2%, Molybdenum≤0.5%, Vanadium≤0.1%, Boron≤0.003%, Cerium≤0.1%, Magnesium≤0.010%, Zirconium≤0.010% the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel sheet including in area fraction, 10 to 60% Bainite, 25 to 55% Ferrite, 5% to 15% Residual Austenite wherein carbon content in residual austenite is between 0.7% and 1% and 5% to 18% Martensite, wherein the cumulated amount of Bainite and Ferrite is at least 70%.

A copper-coated steel wire includes a core wire made of a steel and a coating layer that covers the outer peripheral surface of the core wire and is made of copper or a copper alloy. In a cross section perpendicular to the longitudinal direction of the core wire, the ten-point average roughness Rzjis of the outer peripheral surface of the core wire is 50% or more and 250% or less of the thickness of the coating layer.

A copper-coated steel wire includes a core wire made of a steel and a coating layer that covers the outer peripheral surface of the core wire and is made of copper or a copper alloy. In a cross section perpendicular to the longitudinal direction of the core wire, the ten-point average roughness Rzjis of the outer peripheral surface of the core wire is 50% or more and 250% or less of the thickness of the coating layer.

The steel material according to the present disclosure has a chemical composition consisting of, in mass %, C: more than 0.20 to 0.35%, Si: 0.05 to 1.00%, Mn: 0.02 to 1.00%, P: 0.025% or less, S: 0.0100% or less, Al: 0.005 to 0.100%, Cr: 0.40 to 1.50%, Mo: 0.30 to 1.50%, Ti: 0.002 to 0.050%, B: 0.0001 to 0.0050%, N: 0.0100% or less and O: 0.0100% or less, with the balance being Fe and impurities, and satisfies Formula (1) and Formula (2) described in the description. The yield strength is 862 MPa or more. A numerical proportion of precipitates having an equivalent circular diameter within a range of 20 to 300 nm among precipitates having an equivalent circular diameter of 20 nm or more in the steel material is 0.85 or more.

This steel sheet has a predetermined chemical composition, and, on a surface parallel to a surface at a ¼ position of a sheet thickness in a sheet thickness direction from the surface, with respect to a total area of three types of oxides of MnO, Cr.sub.2O.sub.3 and Al.sub.2O.sub.3 having a major axis of more than 1.0 μm, a total area ratio of the MnO and the Cr.sub.2O.sub.3 is 98.0% or more, and an area ratio of the Al.sub.2O.sub.3 is 2.0% or less.

This steel sheet has a predetermined chemical composition, and, on a surface parallel to a surface at a ¼ position of a sheet thickness in a sheet thickness direction from the surface, with respect to a total area of three types of oxides of MnO, Cr.sub.2O.sub.3 and Al.sub.2O.sub.3 having a major axis of more than 1.0 μm, a total area ratio of the MnO and the Cr.sub.2O.sub.3 is 98.0% or more, and an area ratio of the Al.sub.2O.sub.3 is 2.0% or less.

A seal member includes a γ′ precipitation-hardening alloy, in which the γ′ precipitation-hardening alloy has a component composition of, in mass %: Ni: from 40 to 62%; Cr: from 13 to 20%; Ti: from 1.5 to 2.8%; Al: from 1.0 to 2.0% (provided that Ti/Al: 2.0 or less); Nb: 2.0% or less; Ta: 2.0% or less (provided that Nb+Ta: from 0.2 to 2.0%); B: from 0.001 to 0.010%; W: 3.0% or less; and Mo: 2.0% or less (provided that Mo+(1/2)W: from 1.0 to 2.5%), and optionally, C: 0.08% or less; Si: 1.0% or less; Mn: 1.0% or less; P: 0.02% or less; and S: 0.01% or less, with the balance being Fe and inevitable impurities, and in which the seal member has a hardness of 250 Hv or more, and includes a cold-rolled microstructure obtained by a cold rolling.

There is provided a precipitation hardening steel with the composition: C: 0.05-0.30 wt %, Ni: 3-9 wt %, Mo: 0.5-1.5 wt %, Al: 1-3 wt %, Cr: 2-14 wt %, V: 0.25-1.5 wt %, Co: 0-0.03 wt %, Mn: 0-0.5 wt %, Si: 0-0.3 wt %, and remaining part up to 100 wt % is Fe and impurity elements, with the additional proviso that the amounts of Al and Ni also fulfil Al=Ni/3±0.5 in wt %. There is the possibility to have very low amounts of cobalt, well below 0.01 wt %. The precipitation hardening steel displays, low segregation, high yield strength at elevated temperatures, high resistance against corrosion, and can also suitably be nitrided. The precipitation hardening steel is more economical to manufacture compared to steel according to the state of the art with the same strength at elevated temperatures.