CarTech®
SCF19 Max Alloy
Non-Mag
NON-MAG SCF-19
GENERAL SCOPE
CarTech SCF 19 Max alloy is an austenitic, nitrogen-strengthened stainless steel containing 5% Mo for improved stress-corrosion-cracking resistance. The alloy can be warm worked to achieve a minimum yield strength of 140 ksi. Because of its combination of stress-corrosion-cracking resistance, chloride pitting resistance, high strength, and low magnetic permeability it has been used as a nonmagnetic drill collar and MWD/LWD housing alloy in some of the harshest drilling environments. Laboratory and field evaluations have shown its superiority over the conventional chromium-manganese stainlesses commonly used for such applications.
CarTech SCF 19 Max has been used for the following oil and gas well drilling components:
– Drill collars
– MWD/LWD housings
CHEMICAL COMPOSITION
| Carbon (Maximum) | 0.04% | Manganese | 4.00 to 7.00% |
| Phosphorus (Maximum) | 0.030% | Sulfur (Maximum) | 0.003% |
| Silicon (Maximum) | 0.60% | Chromium | 18.00 to 23.00% |
| Nickel | 16.00 to 20.00% | Molybdenum | 4.00 to 6.00% |
| Nitrogen | 0.35% | Iron | Balance |
MECHANICAL PROPERTIES
Typical Room Temperature Mechanical Properties – SCF 19® Max Alloy
| Condition | 0.2% Yield Strength (ksi / MPa) | Ultimate Tensile Strength (ksi / MPa) | % Elongation in 4D | % Reduction of Area | Charpy V-Notch Impact (Ft-lbs / J) |
|---|---|---|---|---|---|
| Bar – 7.50" Warm-Worked (191 mm) Round |
144 / 994 | 159 / 1097 | 25 | 74 | 187 / 253 |
| Bar – 5.50" Warm-Worked (140 mm) Round |
145 / 1000 | 163 / 1124 | 25 | 69 | 220 / 298 |
Heat Treatment
Annealing
SCF 19 Max alloy is generally used in the as-forged, warm-worked condition. However, if annealing is desired, heat to 2150°F (1177°C), hold for one hour per inch of thickness, and water quench. The strength of annealed SCF 19 Max will be greatly reduced since high strength is imparted through warm working.