| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a stretch-reduction method of an extra thin-walled steel pipe by which the limit of thinning of the final product by a conventional method is broken down and a thinner-walled steel pipe can be manufactured. <P>SOLUTION: The stretch-reduction method of the extra thin-walled steel pipe is provided by which the steel pipe being a material is finished into the target extra thin thickness by passing the steel pipe through a stretch reducer in which (n+1) roll stands are arranged in series, wherein the rolling is performed under conditions where required elongation strainε<SB>i</SB>(i=1-(n+1)) in respective stands, each interstand tension T<SB>i</SB>(MPa) and the passing speed v<SB>i</SB>(m/s), (i=1-n) of a material satisfyΣ√(αT<SB>i</SB>/v<SB>i</SB>)≥Σε<SB>i</SB>, whereinα=tl/η(t is the starting temperature (K) of stretch reduction), l is the average interstand distance (m) andηis a constant. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
