| 摘要 |
PROBLEM TO BE SOLVED: To produce a high lubricity rust-proof treated steel sheet having high lubricity, excellent in press workability and furthermore good in rust preventing properties by application by an operating method similar to the conventional one without giving troubles to the efficiency and operability in pickling. SOLUTION: The surface of a pickled steel sheet having 0.5 to 2.5μm surface roughness Ra is coated with a high lubricity rust preventing oil composed by adding base oil with (a) a rust inhibitor by 1 to 20 wt.%, (b) excessbasic calcium sulfonate by >=0.5 wt.% as the content of calcium, (c) sulfurized oil or sulfurized ester by 0.25 wt.% as the content of sulfur and (d) potassium borate by >=0.15 wt.% as the content of borom and having <=30 mm<2> /s viscosity at 40 deg.C. |
