Hangbo Alloy Group
Shanghai · Est. 2012
UNS N10276 in plate, sheet, seamless tube, bar, forgings and fittings — supplied to ASTM and ASME with full heat traceability and EN 10204 3.1 certification.
Hastelloy C276 (UNS N10276, W.Nr. 2.4819, DIN NiMo16Cr15W) is the reference grade of the nickel-chromium-molybdenum family, and the alloy most engineers specify when a vessel, column or scrubber has to survive hot contaminated mineral acids, wet chlorine or aggressive flue gas desulphurisation liquors. Shanghai Hangbo Alloy Group stocks and produces the grade in every wrought form: plate, sheet, coil strip, seamless pipe and tube, round bar, forgings, and butt-weld fittings.
What separates C276 from the earlier C grade it replaced is chemistry control. Carbon is capped at 0.010% and silicon at 0.08%, which suppresses the grain-boundary carbide and mu-phase precipitation that used to make welded C-grade fabrications susceptible to knife-line attack. In practice this means a correctly welded C276 shell can be placed into service without post-weld solution annealing — a saving that usually outweighs the alloy's higher price per kilogram. Around 15.5% chromium carries the resistance to oxidising media, while roughly 16% molybdenum and 3.0-4.5% tungsten carry it in reducing media and against pitting and crevice attack.
Our technical library covers the metallurgy behind those choices in more depth. The Hastelloy C276 chemical composition page sets out the full element-by-element limits and how they are verified, the article on sensitisation and intergranular corrosion in Hastelloy C276 explains the heat-affected zone behaviour, and the PREn comparison guide shows how the grade ranks against C22, C2000 and Inconel 625 for localised attack.
Every product form is supplied to the applicable ASTM specification and its ASME Section II Part B counterpart, so pressure-retaining components can be stamped without further justification. Typical supply ranges from our mills are:
Upset forgings, machined rings and bespoke transition pieces are quoted against your drawing; we tell you at quotation stage which portions of the order will be forged stock and which will be machined from plate, because that choice affects grain flow and, in sour service, the through-thickness properties.
Nominal C276 chemistry is nickel balance, chromium 14.5-16.5%, molybdenum 15.0-17.0%, tungsten 3.0-4.5%, iron 4.0-7.0%, with cobalt limited to 2.5% and vanadium to 0.35%. Melt route is normally vacuum induction melting followed by electroslag remelting or vacuum arc remelting; the VIM, ESR and VAR melting guide explains why we specify remelted material for heavy section and for any part going into sour or nuclear-adjacent service.
Solution annealing is performed at 1120-1175 °C followed by rapid quenching. Holding in the 550-1100 °C band should be avoided in service and during hot forming, since that is the window in which secondary phases precipitate. Hot working is done at 950-1200 °C; cold forming is routine, though the alloy work hardens fast and intermediate annealing is normally required above roughly 20% reduction.
Welding is with matching composition filler: AWS A5.14 ERNiCrMo-4 for GTAW and GMAW, AWS A5.11 ENiCrMo-4 for shielded metal arc. Heat input should be kept moderate and interpass temperature held below about 120 °C. Because the base metal is low carbon, the heat-affected zone generally stays resistant and post-weld annealing is not required for most chemical duties — but we always recommend confirming the actual service conditions rather than assuming it. The nickel alloy welding guide and the C276 versus C22 comparison are useful references when you are fixing the welding procedure and the grade at the same time. Machining requires rigid setups, positive rake tooling and low cutting speeds; see our machining guide for feeds and tool geometry.
Shanghai Hangbo Alloy Group manufactures and inspects under ISO 9001:2015, GJB 9001C and GOST R certified systems. Every heat is traceable from the melt certificate through to the finished piece, and heat numbers are stamped or etched on the material so that traceability survives cutting and fabrication — a common failure point covered in our article on heat number traceability.
Standard documentation is an EN 10204 3.1 mill test certificate showing heat analysis, mechanical properties, heat treatment record and dimensional results. EN 10204 3.2 certification, counter-signed by an independent inspector, is available on request. Positive material identification is carried out by handheld or benchtop XRF as a minimum, with optical emission verification for critical chemistries; the article on PMI for nickel alloys describes the method and its limits.
Non-destructive examination to the purchaser's specification includes ultrasonic testing of plate and bar to ASTM E2375 / SE-1017 (for pipe) or the applicable product standard, dye penetrant to ASTM E165, and radiography of welds where required. Hydrostatic and eddy current testing of tube is performed to ASTM B622. Intergranular corrosion testing to ASTM G28 Method A is offered for verification of annealing quality. Third-party inspection can be arranged with BV, SGS, TUV, DNV or Lloyd's Register, with witness hold points agreed in the inspection and test plan before production starts; see third-party inspection hold points and how to verify a mill test certificate.
Plate and sheet to ASTM B575 runs from 0.5 mm to 100 mm thick in widths to 2,000 mm and lengths to 6,000 mm. Seamless pipe and tube to ASTM B622 is offered from 6 mm to 219 mm outside diameter with wall thickness 0.5 mm to 20 mm. Bar to ASTM B574 covers 6 mm to 300 mm diameter. Larger dimensions, heavy tube sheets and non-standard wall combinations are quoted against drawing.
Yes. C276 in the solution annealed condition is listed in NACE MR0175 / ISO 15156 for sour oil and gas environments, and it is one of the few materials used for downhole and wellhead components in high-H2S, high-chloride conditions. Age-hardened or heavily cold-worked conditions are not covered, so we supply only annealed material for these duties and confirm hardness on the certificate. See our NACE MR0175 guide for the limits that apply to your partial pressures and temperature.
EN 10204 3.1 is standard and issued for every shipment. EN 10204 3.2, counter-signed by an independent inspector, can be arranged, and we regularly work with BV, SGS, TUV, DNV and Lloyd's Register. Inspection and test plans with agreed witness hold points are prepared before production so that the inspector is present at melting, heat treatment and final testing as required by your project specification.
Send us your grade, diameter, length, quantity, and any special requirements. Our team responds within 10 minutes during business hours.