CR39W

Because of the attractive combination of creep strength, carburisation resistance and ductility, CR39W is widely used in many applications in high temperature pyrolysis plants including ethylene furnaces up to 1050°C. The alloy is used for cast fittings including “wyes”, “elbow bends”, “return bends” and “tees”. CR39W centrifugal cast tubes are also an excellent choice for pyrolysis coils and transfer lines subjected to thermal stresses. Some coil designs may also require tubes to be supplied and formed into “swept bends” or “cranked” tube sections for specific furnace designs. CR39W is also recommended for heat treatment furnace fixtures or any equipment subjected to temperature cycling.

CR39W is a low carbon, weldable chromium nickel, niobium-bearing heat resisting steel developed from H39W (25/35-Cr/Ni + Nb: 0.4% C). The high chromium and nickel content means that CR39W combines the superior strength and carburisation resistance with the added attraction of increased ductility due to the low carbon content. This imported ductility minimises the effects of high temperature carburisation and thermal stresses. The alloy is readily welded by metal arc (SMAW) or inert gas shielded arc (GTAW, GMAW) welding processes using matching filler material.