LEAF SPRING STEEL SHEET HAVING EXCELLENT FATIGUE LIFE, AND MANUFACTURING METHOD THEREFOR

摘要

A leaf spring steel sheet according to one aspect of the present invention comprises, by wt%, 0.7-1.0% of carbon (C), 0.1-0.4% of silicon (Si), 0.2-1.0% of manganese (Mn), 0.05-2.0% of chromium (Cr), 0.07-0.2% of vanadium (V), 0.03% or less of phosphorus (P), 0.03% or less of sulfur (S) and the balance of Fe and inevitable impurities, wherein the steel sheet comprises, as a microstructure, 99 area% or more of pearlite and 1 area% or less (excluding 0%) of vanadium carbide (VC), and the average particle size of prior austenite can be 28 μm or less.