347/347H – 1.4550

Due to the stabilization with niobium, this grade has the corrosion resistance at high temperatures as its main characteristic. When submitted to temperatures ranging from 450-900 ºC, some grades tend to form chromium carbide precipitate in the grain boundary region, and the material becomes susceptible to intergranular corrosion. The stabilization with niobium inhibits the formation of chromium carbide, and consequently increases the resistance to this type of corrosion. Grade AISI 347 has excellent weldability, a characteristic common to austenitic steels, as well as high mechanical properties, which guarantees good ductability, and it s recommended for some cold forming processes.

Equipment for the aeronautical industry, such as turbine collector rings and exhaust systems, expansion joints and also for high temperature chemical process equipment. It also finds application in the oil industry, especially during refining, in the form of tubes, connections or flat plates.