PRODUCTION OF HOT ROLLED STEEL PLATE EXCELLENT IN DEEP DRAWABILITY

• Main Authors: MATSUDA MICHIO, SATO SUSUMU, KATO TOSHIYUKI, MATSUOKA SAIJI
• Format: Patent
• Language: English
• Published: 31.07.1992
• 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; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; PERFORMING OPERATIONS; PUNCHING METAL; ROLLING OF METAL; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PURPOSE:To produce a hot rolled steel plate having deep drawability equal to that of a conventional cold rolled steel sheet by connecting rolling stocks of steel having specific composition so that specific hot finish rolling conditions are reached, exerting continuous rolling, and then applying recrystallization treatment to the resulting hot rolled steel plate. CONSTITUTION:A steel having a composition consisting of, by weight, <=0.05% C, <=1.0% Si, <=1.0% Mn, <=0.15% P, <=0.05% S, 0.01-0.15% Al, <=0.05% N, one or more kinds among 0.001-0.10% Ti, 0.001-0.10% Nb, and 0.0001-0.005% B, and the balance Fe with inevitable impurities is prepared. This steel is formed into a rolling stock by means of connection so that finish rolling mill outlet side tension becomes >=1kgf/mm (the upper limit is about 10kgf/mm ) at a temp. in the region between a temp. below the Ar3 transformation point and 500 deg.C, and this rolling stock is continuously rolled and then subjected to recrystallizatioh treatment in a coiling stage or in an annealing stage. By this method, the hot rolled steel plate usable for automobile steel sheet, etc., and excellent in deep drawability can be obtained.