ELECTROSEAMED STEEL PIPE FOR OIL WELL AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide an electroseamed steel pipe for oil well having high strength and excellent in sour resistance and a manufacturing method therefor.SOLUTION: A component of a base material part of an electroseamed steel pipe for oil well has ESSP(=[Ca](1-124[O])/1.25[S]) of 1.5 to 3.0, CE(=[C]+[Mn]/6+([Cu]+[Ni])/15+([Cr]+[Mo]+[V])/5) of 0.26 to 0.44, where each element symbol in formula 1 and formula 2 represents contents of the element by mass%, a metallographic structure of the base material part consists of one or both of acicular ferrite and bainite, a metallographic structure of an electroseamed steel pipe weld part for oil well has limitation of pearlite at 10% or less by area percentage and the balance consists of one or both of tempered bainite or tempered martensite.SELECTED DRAWING: None