HIGH STRENGTH COLD ROLLED STEEL SHEET FOR DEEP DRAWING, EXCELLENT IN STABILITY OF MATERIAL QUALITY AS WELL AS SURFACE CHARACTERISTICS AFTER PRESS FORMING, AND ITS PRODUCTION

• Main Authors: TSUKATANI ICHIRO, MIURA MASAAKI
• Format: Patent
• Language: English
• Published: 07.12.1999
• Edition: 6
• 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

PROBLEM TO BE SOLVED: To provide a high strength cold rolled steel sheet for deep drawing, excellent in stability of material quality as well as surface characteristics after press forming in spite of containing P of certain quantity, and its production. SOLUTION: This steel sheet has a composition consisting of, by mass, <=0.0040% C, <=1.0% Si, 0.5-2.0% Mn, 0.03-0.12% P, <=0.02% S, 0.01-0.10% Al, <=0.0040% N, 0.02-0.07% Ti, 0.01-0.07% Nb, 0.0003-0.0020% B, elements which satisfy inequalities 0.8<= 100P/(10Si+2.5Mn)}<=3.0 and 10<= Ti-(48/14)N+(48/92) Nb}/C, respectively, and the balance Fe with inevitable impurities.