Hot-stretch-reduced electric resistance welded pipe

A hot-stretch-reduced electric resistance welded pipe comprising:

• a base metal portion and a weld portion,
• a chemical composition of the base metal portion including, in mass %,
• C:
• 0.210 to 0.400%,
• Si:
• 0.05 to 0.50%,
• Mn:
• 0.50 to 1.70%,
• P:
• 0.100% or less,
• S:
• 0.010% or less,
• N:
• 0.0100% or less,
• Al:
• 0.010 to 0.100%,
• Ti:
• 0.010 to 0.060%,
• B:
• 0.0005 to 0.0050%,
• Cr:
• 0 to 0.500%,
• Mo:
• 0 to 0.500%,
• Cu:
• 0 to 1.000%,
• Ni:
• 0 to 1.000%,
• Nb:
• 0 to 0.050%,
• W:
• 0 to 0.050%,
• V:
• 0 to 0.500%,
• Ca:
• 0 to 0.0050%, and
• REM:
• 0 to 0.0050%,
• wherein a remaining being Fe and impurities,
• a Ti/N value obtained by dividing Ti content by N content is 3.0 or more,
• in a microstructure of the weld portion,
• an average grain diameter is 9.4 μm or less,
• an area ratio of ferrite is 20% or more, and a remaining structure includes at least one selected from the group consisting of pearlite, bainite, and martensite, and
• in a texture of the weld portion, an accumulation intensity of a {001} plane is 6.0 or less,
• a critical cooling rate Vc90 of the base metal portion is 5° C./s to 90° C./s, and
• the critical cooling rate Vc90 is expressed as the following equation (1), providing that a C content (mass %) is [C], a Si content (mass %) is [Si], a Mn content (mass %) is [Mn], a Cr content (mass %) is [Cr], a Mo content (mass %) is [Mo], and a Ni content (mass %) is [Ni],
• log10 Vc90=2.94−0.75×β (1)
• β=2.7×[C]+0.4×[Si]+[Mn]+0.8×[Cr]+2[Mo]+0.45×[Ni] (2).