What is alloy 718 for oilfield applications?
Alloy 718 (UNS N07718) was developed for use in aircraft gas turbine engines, but its unique combination of room temperature strength and resistance to water corrosion makes it a candidate for use in oilfield fasteners, valves, drilling tools and completion equipment .
Part of its popularity stems from distributors offering rods in a variety of sizes. As the oil and gas well environment becomes more severe, production equipment is experiencing stress corrosion and hydrogen embrittlement failures. This has driven the development of chemistry Today's oilfield grade 718 has a different microstructure than aerospace grade. This paper reviews the development of this grade and its applications and describes some of its unique characteristics, testing and manufacturing methods. Oilfield 718 consumption has probably reached its peak. Offshore production from deep sour oil fields created a need for stronger, more corrosion-resistant alloys, leading to the development of new alloys that began to eat into 718's market share.
