A method for producing a coated steel sheet having a tensile strength TS of at least 1450 MPa and a total elongation TE of at least 17% includes the successive steps of providing a cold rolled steel sheet made of a steel having a chemical composition comprising, in weight %: 0.34%C0.45%, 1.50%Mn2.30%, 1.50Si2.40%, 0%<Cr0.7%, 0%Mo0.3%, 0.10%Al0.7%, and optionally 0%Nb0.05%, the remainder being Fe and unavoidable impurities, annealing the cold-rolled steel sheet at an annealing temperature AT higher than the Ac3 transformation point of the steel, quenching the annealed steel sheet by cooling it down to a quenching temperature QT lower than the Ms transformation point of the steel and comprised between 150 C. and 250 C., and reheating the quenched steel sheet to a partitioning temperature PT between 350 C. and 450 C. and maintaining the steel sheet at the partitioning temperature PT for a partitioning time Pt of at least 80s, and coating the steel sheet by galvannealing, with an alloying temperature GAT comprised between 470 C. and 520 C.

One aspect of the disclosure provides an iron-based hardfacing layer which includes hard or wear resistant phases resulting at least in part from dissolution of silicon and/or boron carbide particles into a liquid iron-based metal during the fabrication process. In an embodiment, the hardfacing layer is formed by a fusion welding process in which carbide particles are added to the molten weld pool. In an example, the filler metal supplied to the welding process is a mild steel. In an embodiment, the hardness as measured at the surface of the hardfacing ranges from 40 to 65 HRC. In an example, the iron-based hardfacing layer also includes tungsten carbide particles.

A steel sheet includes a hot-dip galvanized layer or a galvannealed layer on a surface of the steel sheet, the steel sheet including: in mass %, C: 0.06% or more and 0.22% or less; Si: 0.50% or more and 2.00% or less; Mn: 1.50% or more and 2.80% or less; Al: 0.02% or more and 1.00% or less; P: 0.001% or more and 0.100% or less; S: 0.0005% or more and 0.0100% or less; N: 0.0005% or more and 0.0100% or less; and a balance: Fe and impurities.

A surface-treated steel sheet for a battery container, including a steel sheet, an iron-nickel diffusion layer formed on the steel sheet, and a nickel layer formed on the iron-nickel diffusion layer and constituting the outermost layer, wherein when the Fe intensity and the Ni intensity are continuously measured from the surface of the surface-treated steel sheet for a battery container along the depth direction with a high frequency glow discharge optical emission spectrometric analyzer, the thickness of the iron-nickel diffusion layer being the difference between the depth at which the Fe intensity exhibits a first predetermined value and the depth at which the Ni intensity exhibits a second predetermined value is 0.04 to 0.31 m; and the total amount of the nickel contained in the iron-nickel diffusion layer and the nickel contained in the nickel layer is 10.8 to 26.7 g/m.sup.2.

Provided is an automotive member, or particularly, a steel sheet having a tensile strength exceeding 900 MPa. The automotive member has a resistance weld for fixing two or more steel sheets containing a predetermined composition, in which a maximum hardness (HV.sub.BM) in a heat-affected zone of the resistance weld is at least 1.1 times hardness (HV.sub.W) of a nugget in the resistance weld formed in a softest steel sheet of a sheet set during resistance welding, and furthermore, an average grain size of a steel sheet structure of the heat-affected zone within 2 mm in a direction at a right angle to a sheet thickness from an end part of the nugget of the high-strength steel sheet is 3 m or less, and a minimum hardness (HV.sub.min) in the heat-affected zone is at least 90% of hardness (HV.sub.) of the high-strength steel sheet before the resistance welding.

A clad material includes a first layer made of stainless steel and a second layer made of Cu or a Cu alloy and roll-bonded to the first layer. In the clad material, a grain size of the second layer measured by a comparison method of JIS H 0501 is 0.150 mm or less.

Provided are a high-strength galvanized hot-rolled steel sheet and a method for manufacturing the steel sheet. A steel sheet has a chemical composition, and a galvanized layer is disposed on the steel sheet. The chemical composition includes, in mass %, C: 0.02% or greater and 0.30% or less, Si: 0.01% or greater and 2.5% or less, Mn: 0.3% or greater and 3.0% or less, P: 0.08% or less, S: 0.02% or less, and Al: 0.001% or greater and 0.20% or less. The galvanized layer has a coating weight per side of 20 to 120 g/m.sup.2. A surface of the steel sheet has a specific surface area ratio, r, of 2.5 or less, and an amount of Si present in the galvanized layer and an amount of Mn present in the galvanized layer respectively satisfy: amount of Sir0.06, and amount of Mnr0.10.

An aluminium-zinc-hot-dipped and colour-coated steel plate having a 600 MPa yield strength grade and a high elongation and a manufacturing method thereof, with the chemical components in mass percentage of a substrate of the steel plate being: 0.07-0.15% of C, 0.02-0.5% of Si, 1.3-1.8% of Mn, N0.004%, S0.01%, Ti0.20%, Nb0.060%, and the balance being Fe and other inevitable impurities, and meanwhile satisfying the conditions of: (C+Mn/6)0.3%; Mn/S150; Nb satisfying 0.01%(Nb0.22C1.1N)0.06% where no Ti is contained; Ti satisfying 0.5Ti/C1.5 where no Nb is contained; and 0.04%(Ti+Nb)0.26% where Ti and Nb are added in combination. The steel plate has a yield strength of 600 MPa, a tensile strength of 650 MPa, an elongation after fracture of 12%, a good strength and toughness and an excellent corrosion resistance.

A steel sheet for a drawn can has a predetermined chemical composition and has a ferrite single-phase structure with a crystal grain size number of 11.0 or more, the sheet thickness is 0.15 to 0.50 mm, in an L direction of the steel sheet after an ageing treatment at 100 C. for one hour, an yield strength YP is 220 to 290 MPa, a tensile strength TS is 330 to 390 MPa, a total elongation EL is 32% or more, an yield point elongation YP-EL is 0%, an average plastic strain ratio r.sub.m is more than 1.35, and an in-plane anisotropy r is 0.30 to +0.15.

The present invention provides a nickel-plated heat-treated steel sheet for a battery can (1), having a nickel layer with a nickel amount of 4.4 to 26.7 g/m.sup.2 on a steel sheet (11), wherein when the Fe intensity and the Ni intensity are continuously measured along the depth direction from the surface of the nickel-plated heat-treated steel sheet for a battery can, by using a high frequency glow discharge optical emission spectrometric analyzer, the difference (D2-D1) between the depth (D1) at which the Fe intensity exhibits a first predetermined value and the depth (D2) at which the Ni intensity exhibits a second predetermined value is less than 0.04 m.