Cu添加極低炭素冷延鋼板のr値に及ぼす熱延板中のCuの存在状態の影響
1995 年 81 巻 7 号 p. 739-744
詳細
1995 年 81 巻 7 号 p. 739-744
The effect of morphorogy of Cu phase before cold rolling on r-value of Cu-added extra low carbon Ti-added steel sheets was studied.
The morphorogy of Cu phase can be affected by the hot-band heat treatment temperature and the cooling rate after the heat treatment. When hot-bands are heat treated at 550°C or at 800°C and slowly cooled, fine Cu-rich cluster which strengthens the steel is formed. When heat treated at 700°C, ε-Cu is formed but Cu-rich cluster is not formed at the cooling rate range examined. When hot-bands are heat treated at 450°C or 800°C and rapidly cooled, Cu is in solid solution.
The r-value of annealed steel sheets is affected by the structure of Cu precipitates before the cold rolling. When Curich cluster is formed, the r-value is low according to the decreasing of the intensity of {554} <225> in recrystallization texture. When Cu is in solid solution or ε-Cu is formed before cold rolling, the pole figures of annealed sheets are {554} <225> type and r-value is kept high.
