NON-QUENCHED AND TEMPERED STEEL FOR PARTS OF AN AUTOMOBILE AND METHOD FOR MANUFACTURING SPINDLE KNUCKLE USING IT

摘要

PURPOSE: Non-quenched and tempered steel for parts of a vehicle and a manufacturing method for a spindle knuckle using the same are provided to satisfy intensity and toughness and to increase machinability. CONSTITUTION: Non-quenched and tempered steel is made of C(Carbon) 0.38~0.42wt.%, Si(Silicon) 0.15~0.50wt.%, Mn(Manganese) 1.40~1.60wt.%, S(Sulfur) 0.10~0.24wt.%, Cu(Copper) 0.5~3.0wt.%, Cr(Chromium) 0.16~0.38wt.%, Mo(Molybdenum) 0.10~0.20wt.%, Bi(Bismuth) 0.15~0.65wt.%, residual Fe(Iron) and inevitable impurities.