High strength, high ductility hot rolled transformation organic plastic steel with excellent yield strength

摘要

Chemical composition 0.05% ≤ Nibium (Nb) in the basic composition of 0.15-0.30% carbon (C), 1.5-2.5% silicon (Si), 1.0-1.8% manganese (Mn), 0.02-0.10% aluminum (Al) + Nibium (Nb) may be added alone or in combination with titanium (Ti) in the range of titanium (Ti) ≤ 0.2%, and also calcium (Ca) may be added to the copper steel for the control of inclusions. The steel consisting of iron (Fe) and unavoidable impurity elements is finished rolling at a temperature range of 790-860 ° C. and water cooling is started at 690-750 ° C., and then at a temperature range of 420 ° C. ≤ water cooling stop temperature ≤ 540 ° C. The hot-rolled steel sheet is manufactured by slow cooling after stopping the water cooling, so that the tensile strength is over 80kg / mm ² and at the same time, it shows 25% high ductility and 60kg / mm ² high yield strength, which is suitable for structural use. The present invention discloses a method for producing an organoplastic steel sheet.