| 摘要 |
<p>PURPOSE:To improve the deep drawability and adhesion of a galvanized film in a steel sheet by subjecting a steel in which the relationship between effective Ti content and the content of Nb and C is specified to rolling, acid pickling and carburization annealing under specified conditions and thereafter subjecting this steel to hot-dip galvanizing. CONSTITUTION:A steel constituted of, by weight, <=0.01% C, <=0.2% Si, 0.05 to 1.0% Mn, <=0.1% P, <=0.02% S, 0.005 to 0.08% solAl, <=0.006% N and the balance Fe with inevitable impurities and, in which the relationship between the effective Ti content expressed by a formula I and the content of Nb and C satisfies an inequality II, is subjected to rough rolling. This steel is subjected to finish rolling at (Ar3 - 50) to (Ar3 + 100) deg.C and is coiled. The steel is subjected to acid-pickling and cold rolling, and is thereafter annealed in a carbu rizing atmosphere at the recrystallization temp. or above to regulate the amt. of carbon entering into solid soln. from the surface of the steel sheet to 100mum in the thickness direction to 10 to 100ppm. The steel is successively subjected to continuous hot-dip galvanizing.</p> |
