| 摘要 |
PURPOSE:To inexpensively produce a hot rolled steel plate excellent in magnetic shielding property by applying hot rolling to a dead-soft carbon Si-killed steel slab under specific temp. conditions and subjecting the resulting hot rolled plate to temper rolling and heat treatment. CONSTITUTION:A slab of a dead-soft carbon Si-killed steel having a composition containing, by weight, <0.005% C, 0.05-0.20% Si, 0.05-0.40% Mn, and <0.0050% H is hot rolled at a finishing temp. not lower than the Ar3 transformation point and the resulting hot rolled steel plate is coiled at >=600 deg.C, by which the structure is formed into a state of coarse uniform crystalline grains. This hot rolled steel plate is subjected to temper rolling at 5-18% elongation percentage and then to heat treatment at 660-780 deg.C so as to be formed into a structure consisting of uniform ultra-coarse crystalline grains, by which the hot rolled steel plate having high magnetic transmission and excellent in magnetic shielding property even if thickness is reduced can be produced. |
