| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a seamless steel tube manufacturing method capable of effectively controlling uneven thickness likely occurring in a thin-wall seamless steel pipe. <P>SOLUTION: A billet soaked for a predetermined time at a predetermined temperature in a heating furnace is subjected to piercing rolling and draw rolling to produce a material pipe which is then soaked for a predetermined time at a predetermined temperature in a reheating furnace and subjected to fixed diameter rolling to produce a seamless steel pipe having a wall thickness of 4 mm or less. The wall thickness of the steel pipe subjected to fixed diameter rolling is set at≤4 mm, the soaking time at a predetermined temperature in the heating furnace is set at the billet diameter (mm)×0.14-0.35 min, and the soaking time at a predetermined temperature in the reheating furnace is set at the bare pipe wall thickness (mm)×3.0-10.0 min. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
