| 摘要 |
A martensitic stainless steel pipe for an oil well, characterized in that it hasa chemical composition, in mass %, that C: 0.005 to 0.1 %, Si: 0.05 to 1 %, Mn: 1.5to 5 %, P: 0.05 % or less, S: 0.01 % or less, Cr: 9 to 13 %, Ni: 0.5 % or less, Mo: 2 % or less,Cu: 2 % or less, Al: 0.001 to 0.1 %, N: 0.001 to 0.1 % and the balance: Fe and impurities,and has a region being deficient in Cr under the surface thereof. The above martensiticstainless steel pipe for an oil well forms no passive coating film on the surfacethereof, and the whole surface thereof is corroded at a low rate. Further, thereduction of a Ni content prevents the generation of non-uniform corrosion.As a result of the above, it can inhibit the generation of SCC, though it has a regionbeing deficient in Cr. |
