Steel strip composite and a method for making the same

A three-layer steel strip composite consisting of steel strip having a first microstructure disposed between two steel strips having a second microstructure,

• (i) wherein the steel strip having the first microstructure is selected from the group consisting of:
• (a) a TRIP steel containing in weight %
• 0.10-0.30% C,
• 1.0-3.5% Mn,
• 0.2-0.8% Si and
• 0.5-2.0% Al,
• (b) a TWIP steel containing in weight % between 10 and 40% manganese and up to 10% aluminium,
• (c) a quenched and partitioned steel containing in weight %
• 0.15-0.4% C,
• 1.0-3.0% Mn,
• 1.0-2.5% Si,
• 0-0.5% Mo and
• 0-1.0% Cr, and
• (d) a low density steel containing in weight %
• 0-0.2% C,
• 0-2.0% Si,
• 0-5% Mn,
• 2-17% Al,
• 0-3% Cr,
• 0-0.2% Ti and
• 0-0.2% Ce,
• (ii) wherein the steel strip having the second microstructure is selected from the group consisting of an interstitial-free, extra low carbon, ultra low carbon or low carbon steel containing in weight %
• 0-0.1% C,
• 0-1.0% Mn,
• 0-0.1% Si,
• 0-0.1% Al and
• 0-0.1% Cr, and
• (iii) wherein a metal or metal alloy coating comprising zinc, aluminium or an alloy thereof is present on each steel strip having the second microstructure on a surface opposite to the surface contacting the steel strip having the first microstructure.