| 摘要 |
After a starting material of steel comprising C: 0.001- 0.20 wt%, Si: 0.01-0.50 wt%, Mn: 0.05-2.0 wt%, P: not more than 0.05 wt%, S: not more than 0.05 wt%, sol.Al: 0.01-0.10 wt%, N: not more than 0.020 wt% and.the balance being Fe and inevitable impurities is heated above Ac3 point, rough rolling is completed within a temperature range of (Ar3 point + 100.degree.C) - (Ar3 point + 50.degree.C), and super-high pressure descaling is carried out under conditions satisfying a jetting pressure of not less than 25 kgf/cm2 and a liquid quantity density of not less than 0.002 liter/cm2, and subsequently finish rolling at a rolling reduction of not less than 80% above Ar3 point of a rolling completion temperature is started in 5 seconds and coiling is carried out below 700.degree.C, whereby hot rolled steel sheets having a surface roughness Ra of not more than 0.8 .mu.m and an average scale thickness of not more than 4 .mu.m is produced and the adhesion property in case of subjecting to shaping at a mill scale state and the pickling efficiency in case of applying to pickling are improved.
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