MAN900X

MAN900X was developed primarily for applications up to 1000°C that are subjected to high stresses, thermal fatigue or even thermal shock. For many years, MAN900X has been widely used for outlet headers or “manifolds” in reformer furnaces, and for collectors and transfer lines in pyrolysis plants such as ethylene furnaces. The low carbon content helps maintain tensile ductility after service ageing, and careful composition control provides the high creep ductility to assist relaxation of weld-zone residual stresses in thick sections. MAN900X is also recommended for heat treatment furnace fixtures or any equipment that is subjected to rapid thermal cycling.

MAN900X is a low carbon, weldable chromium nickel, niobium-bearing heat and corrosion resistant steel, which is a cast alternative to wrought 20/32 Cr/Ni grades and equivalent of CT15C / ASTM A351. Niobium is a major strengthening addition and the composition is carefully ‘balanced’ to ensure that the alloy offers an excellent combination of creep and thermal fatigue strength, ductility, weldability and corrosion resistance. MAN900X is readily welded by metal arc (SMAW) or inert gas shielded arc (GTAW, GMAW) welding process using matching filler material.