| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a duplex stainless steel material and a duplex stainless steel tube exhibiting good corrosion resistance and hot workability in an environment containing corrosive substances such as chloride, hydrogen sulfide and carbon dioxide gas.SOLUTION: The duplex stainless steel material containing a ferrite phase and an austenite phase and has a constitution composition containing, C:0.10 mass% or less, Si:0.1 to 2.0 mass%, Mn:0.1 to 2.0 mass%, P:0.05 mass% or less, S:0.01 mass% or less, Al:0.001 to 0.050 mass%, Ni:1.0 to 10.0 mass%, Cr:22.0 to 28.0 mass%, Mo:2.0 to 6.0 mass%, N:0.2 to 0.5 mass%, Ta:0.01 to 0.50 mass% and O:0.030 mass% or less and the balance Fe with inevitable impurities and a ratio of Ta/O of 2.5 or more by mass%.</p> |
