Application Segments

Oil & Gas/CPI

Melting Route


Product Description

BÖHLER L725 (UNS N07725) is a nickel chromium-molybdenum-niobium alloy that is highly resistant to corrosion and is age hardenable for extremely high strength. It has essentially the same corrosion resistance as alloy 625, which is widely used in a broad range of severely corrosive environments in the oil & gas sector. The strength of age-hardened BÖHLER L725 is of the order of twice that of annealed Alloy 625 and comparable alloy 718.
High levels of nickel and chromium provide corrosion resistance in reducing and oxidizing environments. The substantial molybdenum content enhances resistance to reducing media and provides a high degree of resistance to pitting and crevice corrosion. Additionally, the combination of elements makes the alloy resistant to hydrogen embrittlement and stress corrosion cracking.
The properties of BÖHLER L725 are useful for a range of applications that require outstanding corrosion resistance along with high strength high ductility and toughness. Originally developed for Oil Patch applications such as well head and subsurface completions, it has been used as pressure containing, flow wetted components in subsurface safety valves and other down hole components. BÖHLER L725 is approved under NACE MR0175 for use in sour gas wells.
The alloy is used for hangers, landing nipples, side pocket mandrels and polished bore receptacles in sour gas service, where it resists the effects of hydrogen sulfide, chlorides and carbon dioxide. The alloy is also attractive for Pumps and propeller shafts and for high strength fasteners, Hydraulic couplings in marine applications, where it resists corrosion, pitting and crevice attack in sea water.

Technical Specifications

Material Numbers

Alloy 725 N07725


B637 B805 NACE MR0103 / ISO 17945 NACE MR0175 / ISO 15156 API 6A CRA

Chemical Composition

Chemical composition (average %)
max. 0.030 max. 0.20 max. 0.35 max. 0.015 max. 0.010 19.0 to 22.5 7.00 to 9.50 55.0 to 59.0 1.00 to 1.70 max. 0.35 2.75 to 4.00 REM


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