manufacturing process of a steel strip and a steel laminations in place of cold, and improved possibilities for cold forming

摘要

1453460 Making steel sheet; altering molecular structure NIPPON STEEL CORP 28 Dec 1973 [28 Dec 1972] 60033/73 Heading B3V [Also in Division C7] Killed steel containing by wt. with the Mn : S ratio lying within the range 7 : 1 to 30 : 1, the contents of Mn, C and S lying within one of the four areas shown in Fig. 1, and the content of Al, or equivalent amounts of other alloying elements, satisfying the relationship (O and N being essential constituents of the steel) is cast, hot rolled, cooled at a temperature within either of the regions I or II of Fig. 3, cold rolled and annealed. Preferably hot rolling is carried out above 900‹ C. and cooling above 735‹ C., while cold rolling may involve a reduction of at least 75% and may be followed by annealing at 800-880‹ C., possibly with subsequent overageing at 350-600‹ C. In a particular embodiment the composition satisfies the relationship