Abstract: 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 (Rm) is 980-1500 MPa.

Abstract: A cold rolled steel strip or sheet has a composition consisting of (in wt. %): C 0.15-0.25; Si 0.5-1.6; Mn 2.2-3.2; Cr?0.8; Mo?0.2; Al 0.03-1.0; Nb?0.04; V?0.04; Ti 0.01-0.04; B 0.001-0.010; TUB 5-30; Cu?0.15; Ni?0.15; Ca?0.01; balance Fe apart from impurities, where the cold rolled steel has a multiphase microstructure comprising a matrix mainly composed of tempered martensite and has a tensile strength (Rm) of at least 1380 MPa.

Abstract: 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?0.2, Nb<0.05, Mo<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 ?10, polygonal ferrite ?10, balance bainite+tempered martensite 50-90, c) a tensile strength (Rm) 1180-1300 MPa, a yield strength (Rp0.2) 800-970 MPa, an elongation (A50) ?8%, or an elongation (A80) ?6%, and d) a bendability value Ri/t of ?4 for a sample having the size of 35 mm×100 mm, wherein Ri is the bending radius in mm and t is the thickness in mm of the steel sheet.

Abstract: 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 ?m.

Abstract: A high strength cold rolled steel sheet has a composition consisting of the following elements (in wt. %): C 0.07-0.15, Mn 2.3-3.2, Si 0.6-1.2, Cr 0.05-0.5, Al?0.2 Nb?0.1, balance Fe apart from impurities, a multiphase microstructure comprising a matrix of bainitic ferrite, and a tensile strength (Rm) of 980-1100 MPa.

Abstract: A high strength galvannealed steel sheet having, a) a composition consisting of the following elements (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?0.2 Nb<0.05 Mo<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?10 polygonal ferrite?10 balance bainite+tempered martensite 50-90, c) at least one of the following mechanical properties a tensile strength (Rm) 1180-1300 MPa a yield strength (Rp0.2) 800-970 MPa an elongation (A50)?8% an elongation (A80)?6%, and d) a bendability according to a 90° V Bend test value Ri/t of ?4 for a sample having the size of 35 mm×100 mm, wherein Ri is the bending radius in mm and t is the thickness in mm of the steel sheet.