BÖHLER L718 API (UNS N07718) is a high-strength, corrosion-resistant nickel chromium iron molybdenum material that offers high strength and excellent corrosion resistance, particularly in H2S and CO2 environments. It is a precipitation hardenable alloy, the precipitation hardening effect is mainly achieved by additions of Niobium, Titanium and Aluminium. The ease and economy with which BÖHLER L718 API can be fabricated, combined with good tensile, fatigue, creep, and rupture strength, have resulted in its use in a wide range of applications. It have been widely recognised by the oil industry and it is now widely used in this field. BÖHLER L718 API offers outstanding weldability with resistance to post-weld cracking. It can be used in high temperatures as it maintains strength at elevated temperatures. Several conditions of BÖHLER L718 API are available and it is offered to the NACE/API 6A CRA versions at 120 /140 ksi min yield as well as the 150 ksi high strength version. All tempers are suitable for sour service and can be used for pressure containing and pressure controlling equipment in corrosive environments. Typical applications include packers, pumps, connectors, and fasteners as well as gate valves, choke stems, tubing hangers and fire safe valves but also multiple downhole drilling & completions, nuclear and surface applications.
L718 API can be ordered in two different strength levels. The variant L718 API Designation 120K has a minimum yield strength of 827 MPa (120 ksi) with very good cold toughness values and a maximum hardness of 39 HRC. For applications where higher strength or reduced wall thickness is required, the L718 API Designation 150K is the perfect choice. An optimized heat treatment developed by BÖHLER Edelstahl enables a minimum yield strength of 1034 MPa (150 ksi) with the same toughness, and a maximum hardness of 45 HRC.
Market grade | UNS |
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Alloy 718API | N07718 |
Others | Others | Others |
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API 6A CRA | NACE MR0103 / ISO 17945 | NACE MR0175 / ISO 15156 |
C | Si | Mn | P | S | Cr | Mo | Ni | Cu | Co | Ti | Al | B | Fe | Pb | Bi | Ca | Mg | Se | |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
max. 0.045 | max. 0.35 | max. 0.35 | max. 0.010 | max. 0.010 | 17.0 to 21.0 | 2.80 to 3.30 | 50.0 to 55.0 | max. 0.23 | max. 1.00 | 0.80 to 1.15 | 0.40 to 0.60 | max. 0.0060 | REM | max. 0.0010 | max. 0.00005 | max. 0.0030 | max. 0.0060 | max. 0.0005 |