Double walled steel pipe and manufacturing procedure of a double walled steel pipe

摘要

A double wall steel tube includes an inner tube wall and an outer tube wall. The inner and outer tube walls are formed from a tubing material including an inner layer of iron steel, first and second outer layers of an alloy of aluminum and silicon, a first intermediate layer disposed between the inner layer and the first outer layer, and a second intermediate layer disposed between the inner layer and the second outer layer. The first and second intermediate layers include aluminum, silicon and iron. The inner and outer tube walls are brazed together.