WIRE ROD HAVING SUPERIOR HYDROGEN DELAYED FRACTURE RESISTANCE, METHOD FOR MANUFACTURING SAME, HIGH STRENGTH BOLT USING SAME AND METHOD FOR MANUFACTURING BOLT

摘要

The present invention relates to a wire rod used in bolts for automobile engines, for example, and more specifically to a wire rod having an improved resistance to hydrogen delayed fracture, to a manufacturing method for same, to a bolt using same and a method for manufacturing the bolt. Provided are a high strength wire rod having a superior resistance to hydrogen delayed fracture and a method for manufacturing same, a high strength bolt using the wire rod and a method for manufacturing same, wherein the wire rod comprises, 0.3-0.7 wt% C, 0.05-2.0 wt% Si, 0.7-1.5 wt% Mn, 0.01-0.1 wt% Ni, and 30-70 ppm La, and the remainder thereof is comprised by Fe and inevitable impurities.