| 摘要 |
PURPOSE:To improve reflectivity and press formability of the titled steel plate obtd. by regulating the surface waviness of the steel sheet rolled by the prescribed rolling roll to less than the specific value. CONSTITUTION:The steel sheet is rolled under light rolling reduction by the rolling roll forming ruggedness on the roll surface by dull electric discharge machining, and the steel sheet having high reflectivity, which the surface waviness has <=0.7mum under expression of center line waviness WCA in filtering wave (cut-off vale 0.8mm at low pass filter) and has random ruggedness surface, is obtd. Then, the surface roughness in this steel sheet is desirable to be in the range of about 0.6mum-about 3.0mum under expression of center line average roughness Ra. Further, this titled steel sheet is desirable to be rolled by the rolling roll forming the ruggedness corresponding to the above surface waviness on the roll surface. As this steel sheet has small surface waviness, the high reflectivity is found, and also by adjusting the surface roughness to the fixed range good press formability can be obtd. Therefore, this steel sheet is suitable for outer plate for car, etc., and facing material for building, etc. |
