The invention relates to a steel material which allows for components to be formed with low residual stress via additive manufacturing without pre- or post-heating. The steel material consists of a steel with the following composition, in wt. %: C: 0.28-0.65%, Co: <10.0, Cr: 3.5-12.5%, optionally Mo: 0.5-12.5%, wherein the sum of the content of Cr and Mo is 4-16%, the Ni equivalent Ni_eq calculated according to the formula Ni_eq [%]=30% C+% Ni+0.5% Mn from the C-content % C, the Ni-content % Ni, the Mn-content % Mn fulfills the condition (1) 10%≤Ni eq≤20%, and alongside C, optionally respectively up to 9% Mn and up to 4.5% Ni are provided to fulfill condition (1), wherein the Cr equivalent Cr_eq calculated according to the formula Cr_eq [mass]=% Cr+% Mo+1.5% S+0.5% Nb+2% XX from the CR-content Cr %, the Mo-content Mo %, the Si-content Si %, the Nb-content % Nb and the sum % XX of the contents of at least one element of the group “Sc, Y, Ti, Zr, Hf, V, Ta” fulfills the condition (2) 4% Cr_eq 16%, and optionally respectively up to 2% Si, up to 2% Nb or at least one element from the group “Sc, Y, Ti, Zr, Hf, V, Ta” are provided to fulfill condition (2), wherein the total proportion of elements of this group is at most equal to the mass fraction of 2%, which Ti must not exceed if Ti is the only element selected from the group consisting of “Sc, Y, Ti, Zr, Hf, V, Ta”, and wherein the rest of the steel consists of Fe and <0.5% impurities, including 0.025% P and 50.025% S. The steel material is suited, in particular as a powder, for LPBF or LMD methods and as wire for the WAAM method.

This application provides Fe—Mn—Al—C lightweight steel, including: Fe, wherein a weight percentage of the Fe is greater than or equal to 50.4 wt %; Mn, wherein a weight percentage of the Mn is 25-35 wt %; Al, wherein a weight percentage of the Al is 6-12 wt %; C, wherein a weight percentage of the C is 0.8-2.0 wt %; and O, wherein a weight percentage of the O is 0.005-0.6 wt %. This application further provides a terminal to which the Fe—Mn—Al—C lightweight steel is applied, a production method for the Fe—Mn—Al—C lightweight steel, a steel mechanical part, and an electronic device. The lightweight steel in this application has low density, high strength, and high elongation.

This application provides Fe—Mn—Al—C lightweight steel, including: Fe, wherein a weight percentage of the Fe is greater than or equal to 50.4 wt %; Mn, wherein a weight percentage of the Mn is 25-35 wt %; Al, wherein a weight percentage of the Al is 6-12 wt %; C, wherein a weight percentage of the C is 0.8-2.0 wt %; and O, wherein a weight percentage of the O is 0.005-0.6 wt %. This application further provides a terminal to which the Fe—Mn—Al—C lightweight steel is applied, a production method for the Fe—Mn—Al—C lightweight steel, a steel mechanical part, and an electronic device. The lightweight steel in this application has low density, high strength, and high elongation.

This Zn-plated hot stamped product includes a steel, a Zn-based plating layer, and an oxide layer, in which an upper layer which is a region on a surface side of the Zn-based plating layer has a two-phase structure of a Γ phase and an Fe—Zn solid solution, and a lower layer which is a region of the Zn-based plating layer excluding the upper layer has a single-phase structure of an Fe—Zn solid solution, an upper layer thickness and a lower layer thickness satisfy the following expression, a Mn content ratio of Max. Mn/Min. Mn, which is a ratio of a maximum value Max. Mn to a minimum value Min. Mn of an Mn content on a surface of the Zn-plated hot stamped product, is 10.0 or less, and an average value Ave. Mn is 0.5 to 7.5% by mass %.

0.20≤upper layer thickness/(upper layer thickness+lower layer thickness)≤0.80

The present invention relates to an additive manufacturing wire, containing, in terms of % by mass, 0%<Si≤2.0%, 0%<Mn≤6.0%, 3.0%≤Ni≤15.0%, 20.0%≤Cr≤30.0%, 1.0%≤Mo≤5.0%, 0%<N≤0.50%, with a balance being Fe and unavoidable impurities, in which C≤0.10% is satisfied, and 27<A<67 is satisfied, when Cr.sub.eq is defined as Cr+Mo+1.5Si+0.5(Nb+W)+2(Ti+Al), Ni.sub.eq is defined as Ni+30C+20N+0.5(Mn+Cu+Co), and A is defined as −16.2+6.3Cr.sub.eq−9.3Ni.sub.eq, here, in the definition of Cr.sub.eq and Ni.sub.eq, each element symbol indicates a content of the each element in units of % by mass.

The present invention relates to an additive manufacturing wire, containing, in terms of % by mass, 0%<Si≤2.0%, 0%<Mn≤6.0%, 3.0%≤Ni≤15.0%, 20.0%≤Cr≤30.0%, 1.0%≤Mo≤5.0%, 0%<N≤0.50%, with a balance being Fe and unavoidable impurities, in which C≤0.10% is satisfied, and 27<A<67 is satisfied, when Cr.sub.eq is defined as Cr+Mo+1.5Si+0.5(Nb+W)+2(Ti+Al), Ni.sub.eq is defined as Ni+30C+20N+0.5(Mn+Cu+Co), and A is defined as −16.2+6.3Cr.sub.eq−9.3Ni.sub.eq, here, in the definition of Cr.sub.eq and Ni.sub.eq, each element symbol indicates a content of the each element in units of % by mass.

An embodiment of the present invention provides a steel material, for a pressure vessel, comprising, in weight %, 0.06-0.25% of carbon (C), 0.05-0.50% of silicon (Si), 1.0-2.0% of manganese (Mn), 0.005-0.40% of aluminum (Al), 0.010% or less of phosphorus (P), 0.0010% or less of sulfur (S), 0.001-0.03% of niobium (Nb), 0.001-0.03% of vanadium (V), 0.001-0.03% of titanium (Ti), 0.01-0.20% of chromium (Cr), 0.05-0.15% of molybdenum (Mo), 0.01-0.50% of copper (Cu), 0.05-0.50% of nickel (Ni), 0.0005-0.0050% of magnesium (Mg), 0.0005-0.0050% of calcium (Ca), 0.0020% or less of oxygen (O), and the remainder being Fe and other unavoidable impurities. A microstructure comprises in terms of area fraction 30% or less of pearlite and the remainder being ferrite. A non-metallic inclusion contains Mg—Al—Ca—O composite oxide.

An embodiment of the present invention provides a steel material, for a pressure vessel, comprising, in weight %, 0.06-0.25% of carbon (C), 0.05-0.50% of silicon (Si), 1.0-2.0% of manganese (Mn), 0.005-0.40% of aluminum (Al), 0.010% or less of phosphorus (P), 0.0010% or less of sulfur (S), 0.001-0.03% of niobium (Nb), 0.001-0.03% of vanadium (V), 0.001-0.03% of titanium (Ti), 0.01-0.20% of chromium (Cr), 0.05-0.15% of molybdenum (Mo), 0.01-0.50% of copper (Cu), 0.05-0.50% of nickel (Ni), 0.0005-0.0050% of magnesium (Mg), 0.0005-0.0050% of calcium (Ca), 0.0020% or less of oxygen (O), and the remainder being Fe and other unavoidable impurities. A microstructure comprises in terms of area fraction 30% or less of pearlite and the remainder being ferrite. A non-metallic inclusion contains Mg—Al—Ca—O composite oxide.

The duplex stainless steel seamless pipe according to the present disclosure has the chemical composition described in the description and a microstructure consisting of 30 to 55% of ferrite, and austenite. In a square observation field of view region with sides of 250 μm including a center portion of the wall thickness and including a T direction and a C direction, a number of intersections NT which is a number of intersections between the line segment T1 to T4 described in the description and ferrite interfaces is 65 or more. A number of intersections NC which is a number of intersections between the line segments C1 to C4 described in the description and ferrite interfaces is 50 or more.

The duplex stainless steel seamless pipe according to the present disclosure has the chemical composition described in the description and a microstructure consisting of 30 to 55% of ferrite, and austenite. In a square observation field of view region with sides of 250 μm including a center portion of the wall thickness and including a T direction and a C direction, a number of intersections NT which is a number of intersections between the line segment T1 to T4 described in the description and ferrite interfaces is 65 or more. A number of intersections NC which is a number of intersections between the line segments C1 to C4 described in the description and ferrite interfaces is 50 or more.