| 摘要 |
<p>PROBLEM TO BE SOLVED: To make a deformed amount of a metallic conduit accurately and easily measured in hydraulic bulging of the metallic conduit. SOLUTION: Plural circular patterns for measuring the amount of plastic deformation are drawn on a surface of the metallic conduit, and curves constituting the circular patterns comprises an oxide of a scale, in this scribed metallic conduit. A device for manufacturing the conduit is also provided in the present invention.</p> |
