| 摘要 |
<p>The present invention provides a martensitic stainless steel seamless pipe, having no inner surface defect and suppressing a delayed fracture generation in the impact-worked portions, and a method for manufacturing such a seamless steel pipe. A martensitic stainless steel seamless pipe, characterized by consisting of C: 0.15 to 0.22%, Si: 0.1 to 1.0%, Mn: 0.10 to 1.00%, Cr: 12.00 to 14.00%, P: 0.020% or less, S: 0.010% or less, N: 0.05% or less, O(Oxygen): 0.0060% or less, at least one alloying element selected from V, Nb and Ti of 0.005 to 0.200 % and B of 0.0005 to 0.0100 %, and the balance Fe and impurities, satisfying either the following inequalities (1), (2), (4) and (5) or the following inequalities (1), (3), (4) and (5): C* + 10N* <= 0.45, (1) H1 <= -0.003(C* + 10N*) + 0.0016, (2) H2 <= -0.0018(C* + 10N*) + 0.00096, (3) Cr* <= 9.0, (4) S <= 0.088N* + 0.00056, (5).</p> |
