ULTRA-HIGH STRENGTH HOT DIP GALVANIZED STEEL SHEET HAVING EXCELLENT DELAYED FRACTURE RESISTANCE AND A METHOD FOR MANUFACTURING THE SAME USING A CARBIDE FORMER TO FUNCTION AS A TRAP SITE OF DIFFUSIBLE HYDROGEN

摘要

PURPOSE: An ultra-high strength hot dip galvanized steel sheet having excellent delayed fracture resistance and a method for manufacturing the same are provided to secure the stability of the delayed fracture of a steel sheet by reducing the amount of diffusible hydrogen integrated in a stress concentrated part.;CONSTITUTION: An ultra-high strength hot dip galvanized steel sheet having excellent delayed fracture resistance comprises carbon 0.06~0.25 weight%, manganese 0.5~2.5 weight%, silicon 0.3~1.0 weight%, aluminum 0.5~1.5 weight%, phosphorus 0.1 weight% or less, sulfur 0.005 weight% or less, copper 0.5 weight% or less, nickel 0.5 weight% or less, nitrogen 0.02 weight% or less, and inevitable impurities.;COPYRIGHT KIPO 2011