| 摘要 |
PROBLEM TO BE SOLVED: To provide an outer surface lubricating oil for a pipe with an inner surface groove, smoking less, similar to or better than the conventional outer surface lubricating oil in lubricity (friction coefficient, seizure pressure), and capable of suppressing temperature rise in the process thanks to well-sustained lubricity; and to provide a grooving process for the inner surface of a pipe by using the oil. SOLUTION: The lubricating oil is applied to the outer surface of a copper pipe or a copper alloy pipe in the process of manufacturing, by rolling or by reduction, a copper pipe or a copper alloy pipe having grooves in its inner surface. The oily agent of the lubricating oil comprises a fatty acid ester accounting for not more than 40% and the balance of a mineral oil accounting. The fatty acid ester exhibits a kinematic viscosity of not less than 8 mm<SP>2</SP>/s at 40°C, and the mineral oil exhibits a kinetic viscosity of not less than 60 mm<SP>2</SP>/s at 40°C. COPYRIGHT: (C)2004,JPO |
