A steel sheet for cans has a chemical composition containing, in mass percent, C: 0.085% to 0.130%, Si: 0.04% or less, Mn: 0.10% to 0.60%, P: 0.02% or less, S: more than 0.010% to 0.020%, Al: 0.02% to 0.10%, N: 0.0005% to 0.0040%, Nb: 0.007% to 0.030%, and B: 0.0010% to 0.0050%, B/N that is the ratio of the content (mass percent) of B to the content (mass percent) of N being 0.80 or more, the remainder being Fe and inevitable impurities, and a ferrite microstructure containing 1.0% or more pearlite in terms of area fraction. The steel sheet for cans has a yield stress of 500 MPa or more, a tensile strength of 550 MPa or more, a uniform elongation of 10% or more, and a yield elongation of 5.0% or less.

A hot stamped article excellent in strength having a predetermined composition, having an average crystal grain size of prior austenite of 3 μm or less, containing at least one of lower bainite, martensite, and tempered martensite in an area rate 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 the grain boundaries)/(mass % of one or more of Nb and Mo at time of dissolution) of 0.3 or more.

A cold rolled annealed steel sheet having a chemical composition including, in weight %: 0.30%≤C≤0.50%, 1.00%≤Mn≤2.50%, 1.00%≤Si≤2.00%, Al≤2.00%, Cr≤0.100%, 0.100%≤Mo≤0. 500%, 0.020%≤Nb≤0.200%, B≤0.0005%, P≤0.02%, S≤0.005%, N≤0.01%, the remainder being Fe and unavoidable impurities, with the percentages in carbon, manganese, chromium, molybdenum and boron are such that the alloy satisfies the following condition:

250% C+120% Mn−200% Cr+200% Mo−10000% B≥320,

and wherein the microstructure comprises in surface fraction, 35% to 45% of islands of martensite and retained austenite (M-A), the total retained austenite is higher than or equal to 24%, the remainder consisting of bainitic ferrite.

Disclosed is a 980 MPa grade cold-roll steel sheets with high hole expansion rate and higher percentage elongation, and manufacturing method thereof. The mass percents of chemical components in the steel sheet are: C: 0.08%-0.12%, Si: 0.1%-1.0%, Mn: 1.9%-2.6%, Al: 0.01%-0.05%, Cr: 0.1-0.55%, Mo: 0.1-0.5%, Ti: 0.01-0.1%, the rest being Fe and other inevitable impurities. The steel plate has a yield strength >600 MPa, a tensile strength >980 MPa, a percentage elongation >11%, a hole expansion rate ≥45%, and a tensile strength up to 980 MPa grade; the microscopic structure is ferrite plus bainite plus martensite, with the volume fraction content of ferrite >10%, the volume fraction content of bainite >30%, and the volume fraction content of martensite >15%; the microscopic structure further comprises nanoscale precipitates in uniform dispersion distribution, the average size of precipitates being less than 20 nm.

Provided is a high-strength hot-rolled coated steel sheet having a TS of 980 MPa or more, excellent bulging formability and stretch flange formability, and excellent coatability. The high-strength hot-rolled coated steel sheet includes a steel sheet having a chemical composition containing, by mass %, C: 0.03% to 0.09%, Si: 0.01% to 1.60%, Mn: 2.20% to 3.60%, P: 0.100% or less, S: 0.0100% or less, Ti: 0.05% to 0.18%, B: 0.0005% to 0.0050%, Al: 0.005% to 0.40%, N: 0.010% or less, and a balance of Fe and inevitable impurities, in which a CSM value expressed by the equation 33.8[% C][% Mn]+12.4[% Si]/[% Mn] is 3.3 to 12.0, and a steel microstructure containing bainite in an amount of 85% or more in terms of area fraction and martensite in an amount of 2.0% or more and 15.0% or less in terms of area fraction and includes a coating layer or an alloyed coating layer on a surface of the steel sheet.

Hot rolling stock (1) made of metal which is rolled in at least one roll stand (2) and then cooled in a cooling section (5) arranged downstream of the at least one roll stand (2). Sound generated by means of a sound generator arrangement (8) is coupled into the rolling stock (1) by a coupling device (1) so that a standing sound wave is formed at least in the region of the rolling stock (1) which is located in the vicinity of the coupling device (10).

A high-strength steel sheet excellent in formability, toughness and weldability has a chemical composition including: by mass %, C: 0.05 to 0.30%, Si: 2.50% or less, Mn: 0.50 to 3.50%, P: 0.100% or less, S: 0.0100% or less, Al: 0.001 to 2.500%, N: 0.0150% or less, O: 0.0050% or less, and the balance consisting of Fe and inevitable impurities. The high-strength steel sheet has a microstructure in a region from ⅛t (t: sheet thickness) to ⅜t (t: sheet thickness) from a steel sheet surface, the microstructure including: by volume %, acicular ferrite (3): 20% or more, and martensite (4):10% or more, aggregated ferrite: 20% or less, residual austenite: 2.0% or less, and the martensite satisfies a formula (A),

[00001]$\begin{array}{cc}\underset{i=1}{\overset{5}{.Math.}}\frac{d_i}{{a_i}^{1.5}}\le 10.0& \left(A\right)\end{array}$

The present invention relates to a method for producing a steel component comprising a substrate and a coating, to a corresponding sleet component and to the use thereof in the automotive sector.

A cold rolled and annealed steel sheet, made of a steel having a composition including, by weight percent: C: 0.03-0.18%, Mn: 6.0-11.0%, Al: 0.2-3%, Mo: 0.05-0.5%, B: 0.0005-0.005%, S≤0.010%, P≤0.020%, N≤0.008%, and including optionally one or more of the following elements, in weight percentage: Si≤1.20%, Ti≤0.050%, Nb≤0.050%, Cr≤0.5%, V≤0.2%, the remainder of the composition being iron and unavoidable impurities resulting from the smelting, the steel sheet having a microstructure including, in surface fraction, from 25% to 55% of retained austenite, from 5% to 50% of ferrite, from 5 to 70% of partitioned martensite less than 5% of fresh martensite, a carbon [C].sub.A and manganese [Mn].sub.A content in austenite, expressed in weight percent, such that the ratio ([C].sub.A.sup.2×[Mn].sub.A)/(C %.sup.2×Mn %) is from 3.0 to 8.0, C % and Mn % being the nominal values in carbon and manganese in weight % and an inhomogeneous repartition of manganese characterized by a manganese distribution with a slope above or equal to −40.

A cold rolled, annealed and partitioned steel sheet, made of a steel having a composition including, by weight percent: C: 0.05 - 0.18%, Mn: 6.0 - 11.0%, Mo: 0.05 - 0.5%, B: 0.0005 - 0.005%, S ≤ 0.010%, P ≤ 0.020%, N ≤ 0.008%, and including optionally one or more of the following elements, in weight percentage: Al < 3%, Si ≤ 1.20%, Ti ≤ 0.050%, Nb ≤ 0.050%, Cr ≤ 0.5%, V ≤ 0.2%, the remainder of the composition being iron and unavoidable impurities resulting from the smelting, said steel sheet having a microstructure including, in surface fraction, from 0% to 30% of ferrite, such ferrite, when present, having a grain size below 1.0 .Math.m, from 8% to 40% of retained austenite, the fraction of austenite islands with a size above 0.5 .Math.m being below or equal to 5% from 30 to 92% of partitioned martensite less than 3% of fresh martensite, a carbon [C].sub.A and manganese [Mn].sub.A content in austenite, expressed in weight percent, such that the ratio ([C].sub.A.sup.2 x [Mn].sub.A) / (C%.sup.2 x Mn%) is below 18.0, C% and Mn% being the nominal values in carbon and manganese in weight %.