CARBONE STEEL FOR RACK-BAR AND MANUFACTURING METHOD THEREOF

摘要

The present invention provides 0.50 to 0.55% by weight of carbon (C); 0.15 to 0.35% by weight of silicon (Si); 0.75 to 0.95 wt % of manganese (Mn); 0.025% by weight or less of phosphorus (P); 0.025 wt% or less of sulfur (S); 0.65 to 0.85% by weight of chromium (Cr); 0.20 wt% or less of molybdenum (Mo); 0.001 to 0.02% by weight of aluminum (Al); 5 to 50 ppm boron (B); and iron (Fe) and unavoidable impurities of the remainder; to a carbon steel for a rack bar, and a method for manufacturing the rack bar.