| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a martensitic stainless steel pipe superior in corrosion resistance, crushing resistance and toughness, and to provide a method for manufacturing the above steel pipe without heat-treating it. <P>SOLUTION: (1) The martensitic stainless steel pipe comprises 0.01-0.10% C, 9.0-15.0% Cr, 0.1-7.0% Ni, 0.005-0.1% N, 0.05-1.0% Si, 0.05-1.5% Mn, 0.1-5.0% Cu, 0.1-3.0% Mo, 0.01-0.20% V, 0.0005% or more but less than 0.05% Al and the balance Fe with impurities, while having P and S in the impurities respectively controlled to 0.03% or less and 0.01% or less; and has 0.3 to 1.3% of a share of austenite in a structure; and has an absolute value of compressive residual stress in a circumferential direction of 1.0 MPa or less. (2) The manufacturing method comprises finish-working a steel material having a temperature of Ac<SB>3</SB>or higher with a cross-sectional working ratio of 5 to 65%, finishing it at 750°C or higher, then cooling it to room temperature at a cooling rate of 0.5 to 10°C per second, and cold-straightening it at a working ratio of 1 to 5%. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
