High-strength stainless steel seamless pipe for oil country tubular goods and method for manufacturing same

A high-strength stainless steel seamless pipe for oil country tubular goods having a composition that comprises, in mass %,

• C:
• 0.012 to 0.05%,
• Si:
• 0.05 to 0.50%,
• Mn:
• 0.04 to 1.80%,
• P:
• 0.030% or less,
• S:
• 0.005% or less,
• Cr:
• 11.0 to 14.0%,
• Ni:
• 0.5 to 6.5%,
• Mo:
• 0.5 to 3.0%,
• Al:
• 0.005 to 0.10%,
• V:
• 0.005 to 0.20%,
• Co:
• 0.01 to 0.3%,
• N:
• 0.002 to 0.15%,
• O:
• 0.010% or less, and
• Ti:
• 0.001 to 0.20%, and
• that satisfies all of the following formula (1) to formula (3),
• and in which the balance is Fe and incidental impurities,
• the high-strength stainless steel seamless pipe having a steel microstructure with 6 to 20% retained austenite in terms of a volume percentage,
• the high-strength stainless steel seamless pipe having a yield strength of 758 MPa or more, the high-strength stainless steel seamless pipe having an absorption energy vE−60 at −60° C. of 70 J or more,
• Cr
• +
• 0.65
• ×
• Ni
• +
• 0.6
• ×
• Mo
• +
• 0.55
• ×
• Cu
• -
• 20
• ×
• C
• ≥
• 15.
• (
• 1
• )
• Cr
• +
• Mo
• +
• 0.3
• ×
• Si
• -
• 43.4
• ×
• C
• -
• 0.4
• ×
• Mn
• -
• Ni
• -
• 0.3
• ×
• Cu
• -
• 9
• ×
• N
• ≤
• 1
• ⁢
• 1
• .
• 0
• (
• 2
• )
• Ti
• ×
• N
• ≤
• 0.00016
• ,
• (
• 3
• )
• wherein Cr, Ni, Mo, Cu, C, Si, Mn, N, and Ti in the formula (1) to formula (3) represent the content of each element in mass %, and the content is zero for elements that are not contained.