HIGH-STRENGTH STEEL SHEET FOR CAN MANUFACTURING AND PROCESS FOR MANUFATURING THE SHEET

摘要

The invention provides a high-strength steel sheet for can manufacturing which is improved in both strength and ductility while clearing the ASTM regulations and is thus excellent in workability. A high-strength steel sheet of 0.1 to 0.5 mm in product sheet thickness (t) for can manufacturing which has a composition containing by mass C: 0.04 to 0.13%, Si: more than 0.01% to 0.03%, Mn: 0.1 to 0.6%, P: 0.02% or below, S: 0.03% or below, Al: 0.01 to 0.2%, and N: 0.001 to 0.02% with the balance consisting of Fe and unavoidable impurities and a ferrite-base ferrite-martensite composite structure, characterized by having a martensite fraction of 5 to less than 30%, satisfying the relationship wherein d is martensite grain diameter (µm) and t is product sheet thickness (mm), and exhibiting a 30T hardness of 60 or above. 1.0 < (1 - EXP(-t x 3.0)) x 4/d... <A>