Low-carbon 420 MPa grade TMCP structural steel and production method thereof

• Main Authors: XIAO XIONG, HU ZENG, ZHANG CHENGYUAN, DU HAO, YANG YONG, WANG HEMU, YANG WENZHI, ZUO JIANLIN, TAN JUN
• Format: Patent
• Language: Chinese; English
• Published: 17.03.2023
• 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 discloses steel for a low-carbon 420 MPa grade TMCP structure. The steel comprises chemical components in percentage by mass as follows: 0.04%-0.06% of C, 0.15%-0.40% of Si, 1.20%-1.60% of Mn, smaller than or equal to 0.020% of P, smaller than or equal to 0.005% of S, 0.020%-0.050% of Alt, 0.030%-0.045% of Nb, 0.010%-0.020% of Ti, smaller than or equal to 0.80% of Ni, smaller than or equal to 0.025% of N, smaller than or equal to 0.20% of Mo, smaller than or equal to 0.30% of Cr, smaller than or equal to 0.40% of Cu and the balance of Fe and inevitable impurities. The carbon equivalent CE is less than or equal to 0.40%, and the Pcm is less than Comprising the following process steps of converter smelting, furnace rear slagging-off, LF refining, vacuum degassing treatment, continuous casting, slab heating and rolling. The structure of the obtained steel is ferrite and pearlite, and the grain size is more than 9 grade; the yield strength is larger than or equal to 420 MPa, and the tensile strength