HIGH-STRENGTH STEEL PLATE HAVING EXCELLENT FORMABILITY, AND PRODUCTION METHOD FOR SAME

摘要

Disclosed is a high-strength steel plate wherein the Al content (%) and the Si content (%) conform to the relationship delimited by formula (A), and the average value (Yave) as defined by formula (B), which relates to the hardness as measured at 100 or more locations by means of a nanoindenter is 40 or higher. Formula (A): 0.3 = 0.7 x [Si] + [Al] = 1.5 Formula (B): Yave = S(180 x (Xi - 3)-2/n) (Therein, [Al] represents the Al content (%), [Si] represents the Si content (%), n represents the total number of hardness measurement locations, and Xi represents the hardness (GPa) at the i-th measurement location (with i being an integer not greater than n))