Voestalpine Stahl Gmbh

Toyota Motor Europe Nv/sa

Toyota Jidosha Kabushiki Kaisha

Thomas Hebesberger

Florian Winkelhofer

Martin Gruber

Andreas Pichler

Daniel Krizan

Stefan Paul

Johannes Rehrl

Dieter Paesold

Markus Anzenberger

Edip Oze Arman

Markus Stögmüller

Michael Schwarzenbrunner

Edip Ozer Arman

A resistance spot welded joint of at least two steel sheets and a method of producing a resistance spot welded joint of at least two steel sheets, wherein at least one of the steel sheets is provided with a Zn containing layer, the steel sheet has a tensile strength of at least 980 MPa, a multiphase microstructure comprising bainite, bainitic ferrite and tempered martensite in a total amount of at least of 75 volume % and retained austenite in an amount of 3-20 volume % and wherein the steel sheet provided with the Zn containing layer has a composition consisting of (in wt. %): C 0.1-0.3; Si 0.2-3.0; Mn 1.0-3.0; Cr≤2.0; Mo≤0.5; Al≤2.0; Nb≤0.2; V≤0.2; Ti 0.01-0.15; B 0.0005-0.01; and balance Fe apart from impurities, wherein the heat affected zone in the spot welded joint is free from cracks having a length of more than 500 μm.

Resistance spot welded joint comprising a zinc coated AHSS steel sheet

The invention relates to a cold rolled steel sheet having a composition consisting of (in wt. %): C 0.15-0.25; Si 0.5-1.6; Mn 2.2-2.8; Cr≤0.8; Mo≤0.2; Al 0.03-1.0; Nb≤0.04; V≤0.04; Ti 0.02-0.04; B 0.001-0.005; balance Fe apart from impurities, wherein the impurity contents of Cu and Ni are limited to ≤0.15, the cold rolled steel has a multiphase microstructure comprising a matrix of bainitic ferrite and ≤10 vol. % polygonal ferrite and the tensile strength (R) is 980-1500 MPa.

Cold rolled steel sheet

High strength galvannealed steel sheet having, a) a composition consisting of (in wt. %): C 0.10-0.2, Mn 2.0-3.0, Si 0.2-0.5, Cr 0.1-0.7, Ti 0.01-0.07, Al&#x2264;0.2, Nb&#x3c;0.05, Mo&#x3c;0.1, optionally B 0.001-0.005, balance Fe apart from impurities, b) a multiphase microstructure comprising (in vol. %) retained austenite 4-20, martensite 5-25, bainitic ferrite &#x2264;10, polygonal ferrite &#x2264;10, balance bainite+tempered martensite 50-90, c) a tensile strength (Rm) 1180-1300 MPa, a yield strength (R) 800-970 MPa, an elongation (A50) &#x2265;8%, or an elongation (A80) &#x2265;6%, and d) a bendability value Ri/t of &#x2264;4 for a sample having the size of 35 mm&#xd7;100 mm, wherein Ri is the bending radius in mm and t is the thickness in mm of the steel sheet.

High strength galvannealed steel sheet and method of producing such steel sheet

The present invention relates to high strength cold rolled steel sheet suitable for applications in automobiles, construction materials and the like, specifically high strength steel excellent in formability. In particular, the invention relates to cold rolled steel sheets having a tensile strength of at least 780 MPa.

High strength cold rolled steel sheet

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Pasching, Austria

Thomas Hebesberger