Patent ID: 8257647
Filing Date: 2012-09-04
Classification: C21D,C22C,Y02P

Abstract:
1. A hot rolled, micro-alloyed low carbon steel strip with micro-alloying elements comprising V, Ti and Nb, the steel strip having a thickness≧0.7 mm, the steel strip having a fine ferritic grain microstructure, wherein at least 95% of the grains in a head region of the strip have fineness greater than grade 11 of the ASTM E112 standard and at least 80% of the grains in a middle region of the strip have fineness greater than grade 11 of the ASTM E112 standard, wherein a ratio σ wherein a ratio between the yield load and breaking load is ≧70%, such metallurgical and geometrical features substantially corresponding to those of a cold rolled strip upon pickling and skinpassing, and wherein the sum of elements V, Ti and Nb does not exceed 0.2% wt.