| 摘要 |
<p>A Ni base alloy pipe stock having a chemical composition comprising, by mass %, C <= 0.04%, Si <= 0.50%, Mn: 0.01 to 6.0%, P <= 0.03%, S <= 0.01%, Cr: 15 to 30%, Ni: more than 45% to not more than 60%, Mo: 0 to 18%, W: 0 to 36%, with Mo(%) + 0.5W(%): more than 1.5% to not more than 18%, Cu: 0.01 to 1.5%, Al <= 0.01% and N: 0.0005 to 0.20%, and the balance substantially being Fe, with 1380 - 5000P - 100S - 4400C >= 1300, Ni + 10(Mo + 0.5W) + 100N <= 200, (Ni - 50) + 10(N - 0.1) - 2(Cr - 25) - 5(Mo + 0.5W - 6) + 12 >= 0, can be manufactured into a seamless pipe by use of a Mannesmann piercing and rolling mill because of its excellent inner surface properties. The resulting seamless pipe has excellent mechanical properties and moreover has excellent corrosion resistance in a sour gas environment, and thus, the Ni base alloy pipe stock can be used as a pipe stock for oil country tubular goods and line pipes and further as a pipe stock for various structural members of nuclear power plants and chemical industrial plants.</p> |
