| 摘要 |
A process for manufacturing high strength deep well casing, tubing, and drill pipes, which have improved resistance to stress corrosion cracking is disclosed. The process comprises the steps of preparing an alloy composition which is: -C</=0.05% Si</=1.0% -Mn </=2.0% P </=0.030% -S </=0.005% N 0-0.30% -Ni 25-60% Cr 15-35% -Mo 0-12% W 0-24% -Cr (%) + 10Mo (%) + 5W (%) >/= 50% -1.5% </= Mo (%) + 1/2W (%) </= 12% -Cu 0-2.0% Co 0-2.0% -Rare Earths 0-0.10% Y 0-0.20% -Mg0-0.10%Ti0-0.5%Ca0-0.10% -and incidental impuritiesbalance; - applying, after hot working, the solid solution treatment to the alloy at a temperature of from the lower limit temperature ( DEG C.) defined by the following empirical formula: 260 log C(%)+1300 to the upper limit temperature ( DEG C. ) defined by the following empirical formula: 16Mo(%)+10W(%)+10Cr(%)+777 for a period of time of not longer than 2 hours; and applying cold working to the resulting alloy with a reduction in thickness of 10-60%. The hot working may be carried out with a reduction in thickness of 10% or more for the temperature range of not higher than the recrystallizing temperature thereof. |
