Steel for automobile piston pin and manufacturing method thereof

• Main Authors: ZHANG XUECHENG, LU MINGXIA, CHEN BIN, WU XIAOLIN, BAO JIAN, CAO HONGFU, ZHANG YONGQI, BAI YUN, JI YUZHONG
• Format: Patent
• Language: Chinese; English
• Published: 29.07.2022
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OFWROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The invention relates to steel for an automobile piston pin and a manufacturing method thereof. The round steel comprises the following chemical components in percentage by mass: 0.23-0.27% of C, less than or equal to 0.06% of Si, 0.65-0.80% of Mn, 0.95-1.20% of Cr, less than or equal to 0.015% of P, less than or equal to 0.005% of S, 0.20-0.35% of Mo, 0.015-0.035% of Nb, 0.010-0.040% of Al, 0.008-0.023% of N, less than or equal to 15 ppm of O, less than or equal to 1.5 ppm of H, less than or equal to 0.06% of (Cu + Ni), greater than or equal to N/14 of (Nb/93 + Al/27-O * 3/32) and the balance of Fe and inevitable impurities. The diameter of the manufactured round steel is smaller than phi 55 mm through the technological steps of KR molten iron desulphurization pretreatment, converter primary smelting, refining furnace refining, RH furnace vacuum degassing treatment, small square billet continuous casting, continuous casting billet high-temperature diffusion, casting billet rolling, high-temperature rolled me