High-strength high-toughness low temperature steel for ship and manufacture method thereof

• Main Authors: YE QIBIN, YANG YU, HAO SEN, YAN LING, ZHANG CHAOFENG, ZHOU CHENG
• Format: Patent
• Language: Chinese; English
• Published: 02.01.2013
• Subjects: ALLOYS; CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION ORPROCESSING OF GOODS; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; PERFORMING OPERATIONS; PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OFWROUGHT-IRON OR STEEL; PUNCHING METAL; ROLLING OF METAL; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TRANSPORTING; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The invention discloses high-strength high-toughness low temperature steel for ship and manufacture method thereof. The steel is composed of (by wt%) C 0.04-0.12, Si 0.20-0.55, Mn 0.8-1.4, P 0.005-0.015, S less than or equal to 0.005, Als 0.02-0.07, N less than or equal to 0.005, Cu 0.05-0.40, Ni 0.05-0.50, and Fe and unavoidable impurity in balance, with Ni/Cu of 1.2-1.5; and one or more than two of Nb 0.005-0.03, Ti 0.005-0.02, Ca 0.001-0.006, and Mg 0.0005-0.002. The steel has advantages of low compression ratio, high strength, good low temperature impact energy, good texture uniformity, and good elongation, to ensure low hardenability and cold crack resistance of repair welding heat-affected zone even if under polar climate condition.