MnV series non-quenched and tempered cold heading steel wire rod for 9.8-grade fastener and production method of MnV series non-quenched and tempered cold heading steel wire rod

• Main Authors: HUANG BOWEN, LI CHAO, QU XIAOBO, ZHANG LINXIANG, RUAN SHIPENG, WANG LUYI
• Format: Patent
• Language: Chinese; English
• Published: 01.11.2022
• Subjects: ALLOYS; CASTING; CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; METALLURGY; METALLURGY OF IRON; PERFORMING OPERATIONS; POWDER METALLURGY; PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OFWROUGHT-IRON OR STEEL; PUNCHING METAL; ROLLING OF METAL; TRANSPORTING; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The invention provides a MnV series non-quenched and tempered cold heading steel wire rod for a 9.8-grade fastener and a production method of the MnV series non-quenched and tempered cold heading steel wire rod. In the converter smelting process, the scrap steel ratio is smaller than or equal to 20%, the tapping temperature is larger than or equal to 1600 DEG C, the tapping carbon content is controlled to range from 0.12% to 0.20%, and the phosphorus content P is controlled to be smaller than or equal to 0.015%. In the bloom continuous casting process, low superheat degree control is adopted, the superheat degree range is 20-35 DEG C, and the continuous casting temperature is 20-30 DEG C; a crystallizer electric stirring and tail end electric stirring combined mode is adopted for stirring; in the rolling process, the initial rolling temperature is 1050-1120 DEG C, the finish rolling temperature is 840-860 DEG C, the reducing sizing temperature is 810-830 DEG C, the spinning temperature is 780-800 DEG C, and t