In the brittle stainless steel layer the crack is caused by the thermal stress. The stainless steel pipe mainly composed of austenite phase which grows in columnar grain in the radial direction of a carbon steel pipe and a thin ferrite layer was distributed between the austenite phases. The intermetallic compound AlNi precipitates in the ferrite phase and sigma-phase precipitates at the phase boundarie between the austenite and ferrite.