Provided is a steel sheet and a method for manufacturing same, the steel sheet which can be used for automobile parts and the like, having excellent bending workability, and excellent balance of strength and ductility and of strength and hole expansibility.

A steel material for a vacuum tube according to an aspect of the present disclosure may include C: 0.1˜0.2%, Si: 0.05∞0.5%, Mn: 1.0∞1.6%, Ni: 0.5∞1.0%, Cr: 1.5∞4.0%, and the balance of Fe and unavoidable impurities in percentage by weight, and may have a complex structure of ferrite and pearlite as a microstructure.

This disclosure is related to high yield strength steel where mechanical properties, such as elongation, ultimate tensile strength and yield strength in a sheet are maintained or enhanced via thermal treatment optionally provided during a galvanization coating operation.

This disclosure is related to high yield strength steel where mechanical properties, such as elongation, ultimate tensile strength and yield strength in a sheet are maintained or enhanced via thermal treatment optionally provided during a galvanization coating operation.

A hot stamped article having excellent shock absorption having a predetermined chemical composition, having a microstructure containing prior austenite having an average grain size of 3 μm or less and further containing at least one of lower bainite, martensite, and tempered martensite in an area ratio of 90% or more, and having a grain boundary solid solution ratio Z defined by Z=(mass % of one or both of Nb and Mo at grain boundaries)/(mass % of one or both of Nb and Mo at time of melting) of 0.3 or more.

A hot stamped article having excellent shock absorption having a predetermined chemical composition, having a microstructure containing prior austenite having an average grain size of 3 μm or less and further containing at least one of lower bainite, martensite, and tempered martensite in an area ratio of 90% or more, and having a grain boundary solid solution ratio Z defined by Z=(mass % of one or both of Nb and Mo at grain boundaries)/(mass % of one or both of Nb and Mo at time of melting) of 0.3 or more.

Method for producing a precoated steel blank including the successive steps of: —providing a precoated steel strip including a steel substrate having, on at least one of its main faces, a precoating, the precoating including an intermetallic alloy layer and a metallic layer extending atop said intermetallic alloy layer, the metallic layer being a layer of aluminum, a layer of aluminum alloy or a layer of aluminum-based alloy, —laser cutting the precoated steel strip in order to obtain at least one precoated steel blank, the precoated steel blank including a laser cut edge surface resulting from the laser cutting operation, the laser cut edge surface including a substrate portion and a precoating portion, wherein the laser cutting is carried out in such a way that the substrate portion of the laser cut edge directly resulting from the cutting operation has an oxygen content greater than or equal to 15% in weight.

The present invention relates to a zinc plated steel sheet having excellent surface quality and spot weldability, and a manufacturing method therefore. A zinc plated steel sheet according to one aspect of the present invention comprises a base steel sheet and a zinc-based plating layer formed on the surface of the base steel sheet, wherein the GDOES profile of oxygen, which is measured in the depth direction from the surface of the base steel sheet, has a form in which a local minimum point and a local maximum point alternately appear in the depth direction from the surface, and the difference (a local maximum value—a local minimum value) between the oxygen concentration (a local minimum value) at the local minimum point and the oxygen concentration (a local maximum value) at the local maximum point can be 0.1 wt % or more.

The present invention relates to a zinc plated steel sheet having excellent surface quality and spot weldability, and a manufacturing method therefore. A zinc plated steel sheet according to one aspect of the present invention comprises a base steel sheet and a zinc-based plating layer formed on the surface of the base steel sheet, wherein the GDOES profile of oxygen, which is measured in the depth direction from the surface of the base steel sheet, has a form in which a local minimum point and a local maximum point alternately appear in the depth direction from the surface, and the difference (a local maximum value—a local minimum value) between the oxygen concentration (a local minimum value) at the local minimum point and the oxygen concentration (a local maximum value) at the local maximum point can be 0.1 wt % or more.

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.