| 摘要 |
PROBLEM TO BE SOLVED: To provide a martensitic stainless steel oil well pipe exhibiting high strength and excellent delayed fracture characteristics and usable in the severe oil well environment. SOLUTION: This high strength martensitic stainless steel has a steel composition containing, by mass, <=0.1% C, <=2.0% Si, <=3.0% Mn, <=0.03% P, <=0.01% S, 9.0 to 15.0% Cr, 0.1 to 7.0% Mo and 0.1 to 8.0% Ni and also satisfies the following inequality (a), and this high strength martensitic stainless steel oil well pipe is produced with the same steel as the stock: H<=9-YS/125... (a); wherein H: the content (ppm) of hydrogen in the steel, and YS: the yield strength (MPa) of the steel.
|
