A CHEMICAL COMPOSITION OF HIGH STRENGTH HOT ROLLED STEEL ALLOY WITH LOW DUCTILE BRITTLE TRANSITION TEMPERATURE

摘要

The present invention relates to a high strength hot rolled steel with low Ductile brittle transition temperature (DBTT), comprises (by weight %): 0 C≤ 0.1; 0 Mn ≤ 1.2; 0 S≤ 0.02; 0 P≤ 0.025; 0.25≤ Si≤ 0.035; 0.02≤ A1 ≤ 0.05; and 0.35≤ Nb≤ 0.45. In a preferred embodiment, a high strength hot rolled steel with low ductile brittle transition temperature (DBTT), comprises (by weight %): 0.04≤ C≤ 0.1; 0.5≤ Mn ≤ 1.2; 0 S≤0.02; 0.01≤P≤0.025; 0.25≤ Si ≤0.35; 0.02 ≤ Al≤0.05; and 0.035≤ Nb ≤0.045. A method for producing high strength hot rolled steel with low Ductile brittle transition temperature (DBTT), comprises heating a chemical composition of alloyed steel, processing of the composition of alloyed steel, casting the alloyed steel in slab means, processing the slab means into plurality of hot rolled coil means in a hot strip mill, processing the slab means at finishing temperature of around 860±10C, and processing the slab means at coiling temperature of around 630±10C. [IN-KOL-2010-01363A]