METAL PIPE FOR MECHANICAL PIPE-EXPANDING WORK

摘要

PROBLEM TO BE SOLVED: To provide a metal pipe for mechanical pipe-expanding work with excellent workability, which can be easily formed even if a pipe-expanding rate is large. SOLUTION: The metal pipe for the mechanical pipe-expanding work is expanded to a prescribed outer diameter by a segment pipe-expanding tool 2 arranged in a pipe 1. The pipe is made of a material having an r value of≥2.0 in the pipe circumferential direction. It has a surface irregularities composed of 5-100 stripes per 100μm of the length in the pipe circumferential direction at least on the pipe inner face at a portion to be expanded. The surface roughness Ra on the inner face is 0.10-1.0μm. COPYRIGHT: (C)2005,JPO&NCIPI