Oil & Gas
RAS Alloy provides NACE MR0175 compliant nickel alloys for sour service wellheads, downhole completion tools, subsea manifolds and offshore platform piping.
Typical Alloy Grades
625 / 825 / K-500 / C-276 / 718
Subsea wellhead connectors and Christmas trees — Inconel 718, Inconel 625
Downhole completion tools and packer components — Incoloy 925, Inconel 718
Sour gas production tubing hangers — Hastelloy C-276, Inconel 625
High-pressure gate valve stems and seats — Incoloy 925, Monel K-500
Offshore platform seawater piping — Monel 400, Inconel 625
Applicable Standards
A North Sea operator experienced catastrophic Monel K-500 completion tool failur...
A North Sea operator experienced catastrophic Monel K-500 completion tool failure after 18 months in sour gas service.
Residual tensile stress exceeding 400 MPa at the thread root, combined with hydrogen charging from H2S, caused intergranular cracking. Hardness was 38 HRC — above NACE limit of 35 HRC.
RAS Alloy now supplies K-500 in solution-treated condition (max 35 HRC) with post-machining stress relief at 530°C for 4 hours.