Niobium-lanthanum microalloyed Si-Mn thermoformed steel plate and heat threatment technique thereof

• Main Authors: LI PEIDE, SHI WENYI, GAO ZHIGUO, CHENG DEFU, LIU LI
• Format: Patent
• Language: Chinese; English
• Published: 28.11.2012
• 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; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The invention discloses a niobium-lanthanum microalloyed Si-Mn thermoformed steel plate and a heat treatment technique thereof, belonging to the technical field of metallurgy and relating to a forming technology. The invention is characterized in that the plate blank comprises the following chemical components in percentage by weight: 0.16-0.35% of C, 0.6-1.6% of Si, 1.5-2.0% of Mn, at most 0.015% of P, at most 0.005% of S, 0.01-0.06% of Nb, 0.001-0.3% of La, and the balance of Fe and inevitable impurities. The heat treatment technique comprises the following steps: after keeping the austenitizing temperature of 890-940 DEG C for 0.5-3 hours, quenching with water; and keeping the tempering temperature of 190-300 DEG C for 3-10 hours. The finished steel plate is 5-30mm, and has favorable mechanical properties: the tensile strength is up to 1450-1700 MPa, the yield strength is 1150-1300 MPa, and the elongation percentage is 8-15%.