Patent ID: 11535294

Abstract:
Carbon steel for a rack bar contains 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% by weight of manganese (Mn), 0.025% by weight or less of phosphorus (P), 0.025% by weight or less of sulfur (S), 0.65 to 0.85% by weight of chrome (Cr), 0.20% by weight or less of molybdenum (Mo), 0.001 to 0.02% by weight of aluminum (Al), 5 to 50 ppm of boron (B), and iron (Fe) as a remainder and unavoidable impurities. A method for manufacturing the rack bar includes quenching, tempering, and drawing the carbon steel and warm forging the drawn carbon steel.