| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high strength welded steel pipe excellent in HIC (Hydrogen Induced Cracking) resistance and SSC (Sulfide Stress corrosion Cracking) resistance, particularly, SSC resistance not only in steel pipe but also in circumferential welded part of steel pipes with each other. <P>SOLUTION: The high strength welded steel pipe excellent in sulfide stress corrosion cracking resistance and having a tensile strength of 600 MPa or more satisfies: a CP value, obtained from a specified formula which is a function of a chemical composition of a mother material, of ≤1.1; a Py value, obtained by another formula, of ≤0.175; and a Py value, calculated by a chemical composition of a welded metal, of ≤0.175, wherein the area of an inner surface welded metal portion is 2.5 times or more the area of an outer surface welded metal portion. <P>COPYRIGHT: (C)2013,JPO&INPIT |
