| 摘要 |
<p>A method of production of electric resistance welded steel pipe which is low in yield ratio and is excellent in aging resistance characteristics, characterized by hot rolling a steel slab which contains C: 0.03 to 0.12%, Si: 0.03 to 0.5%, Mn: 0.5 to 2.0%, P: 0.03% or less, S: 0.003% or less, Al: 0.10% or less, Nb: 0.003% to less than 0.02%, Ti: 0.005 to 0.03%, and N: 0.006% or less, which satisfies Ti>3.4N and weld cracking parameter Pcm (%)‰¤0.21, and which has a balance of Fe and unavoidable impurities, coiling the hot rolled steel plate at 600°C or less, then working this hot rolled steel plate to a pipe shape and welding the abutting faces by electric resistance welding to thereby obtain electric resistance welded steel pipe, and
heating this electric resistance welded steel pipe at a heating temperature of 400 to 720°C in range.</p> |
