Abstract
A transition piece used for super-heater tubes of power plants was made by friction weld holding an Inconel tube between an austenitic stainless steel tube and a 2.25 Ci-1Mo steel tube, them mechanical properties at room temperature of the tubular transition piece were examined and thermal cycle and creep rupture tests were carried out for practical use. The test results are as follows:
1. Welded joints (730°C S.R) made by friction weld showed satisfactory tensile and bending properties.
2. Under thermal stress by 230-650°C thermal cyclic heating and internal pressure, the tubular transition piece was ruptured within the 2.25 Cr-1Mo steel tube in every case.
3. In the creep rupture test at 650°C, the tubular transition piece was ruptured within the 2.25 Cr-1Mo steel tube.
