Hangbo Alloy Group
Shanghai · Est. 2012
Solid oxide fuel cells expose nickel alloys to 700-1000 C oxidation, creep, and chromium volatilization. Compare the grades and how Hangbo supplies them.
Solid oxide fuel cells (SOFCs) convert fuel directly into electricity at 600-1000 C with very high efficiency and low emissions, but that operating window is brutal on metal. Every metallic part that touches the hot zone - interconnects, balance-of-plant tubing, pre-reformers, and heat exchangers - must resist oxidation, creep, carburization, and chromium volatilization for tens of thousands of hours. Nickel-based and iron-nickel-chromium alloys are the default choice for these components, and selecting the right family is the difference between a stack that runs for a decade and one that fails in its first season.
The electrochemical core of an SOFC is ceramic, but the surrounding system is overwhelmingly metallic. Interconnect plates carry current between cells while separating fuel and air; they sit at 700-900 C for the full service life. Balance-of-plant parts - recuperators, steam reformers, and fuel-mixing manifolds - see similar temperatures with reactive gases (steam, hydrogen, trace sulfur, and light hydrocarbons).
Ordinary stainless steels form porous, chromium-rich scale and chalk up poorly on all four counts, which is why SOFC engineers reach for nickel alloys instead. See our guide to creep and stress-rupture behavior in nickel superalloys for the underlying mechanism.
High-temperature nickel alloys for fuel cells split into two camps by the protective scale they grow. Chromia-forming grades (Ni-Cr-Fe with ~20-30% Cr) are workhorses for interconnects and BOP tubing: they are formable, weldable, and relatively cheap, but they do lose some chromium to vaporization at the top of the SOFC window. Alumina-forming grades - strengthened with aluminum plus refractory elements - form a denser Al2O3 scale that virtually eliminates volatilization and extends life above 900 C, at the cost of tougher fabrication.
For the very hottest, most stressed parts, ultra-high-temperature nickel grades such as those covered in our Alloy 602CA ultra-high-temperature guide are specified where a chromia former would simply not survive. The trade is machinability and price, so most commercial stacks reserve them for liners and the most exposed hardware.
A realistic SOFC bill of materials looks like this:
The grade list overlaps heavily with other high-temperature electrolysis work - our article on nickel alloys for hydrogen electrolysis covers the same alloy families from the electrolyzer angle.
SOFC programs live or die on consistency. A single off-spec heat with stray sigma phase or a bad surface finish can seed a crack that takes out a whole stack, so material is bought against tight chemistry ranges, controlled grain size, and full mill traceability. Buyers should expect EN 10204 3.1 certification, verified high-temperature oxidation data, and surface condition suitable for coating or brazing.
Because fuel-cell volumes are still ramping, working with a manufacturer that can hold narrow tolerances across bar, sheet, and tube - and that documents every heat - de-risks scale-up far more than chasing the lowest price per kilogram.
For most commercial stacks, a chromia-forming nickel-chromium grade in the 20-30% Cr range is the default for interconnects because it balances oxidation resistance, formability, and cost. Above about 900 C or where chromium volatilization must be minimized, an alumina-forming grade is preferred. Ultra-high-temperature alloys such as Alloy 602CA are reserved for the most exposed liners.
Some nickel superalloys perform well in the hot, reactive BOP environment, especially on the fuel side where carburization resistance matters, but many are selected more for strength and corrosion margin than for lowest chromium loss. The final choice depends on operating temperature, gas chemistry, and whether the part is structural or current-carrying; our creep and stress-rupture guide helps frame that trade.
Hangbo supplies the nickel alloy families used in SOFC interconnects, reformers, and heat exchangers as bar, sheet, and tube with full ASTM/ASME documentation and EN 10204 3.1 certification per heat. Every lot is traceable and can be supplied against controlled chemistry and surface-finish requirements suited to coating or brazing.
As a dedicated nickel alloy manufacturer serving power generation sectors, Hangbo Alloy Group supplies the grades discussed here across all standard product forms with full ASTM/ASME documentation and EN 10204 3.1 certification. Our material is specified for applications where corrosion resistance, high-temperature strength, and traceable quality are non-negotiable. See our production & testing facilities for more on how every heat is verified.