It is known that the interdiffusion at the aluminide coating/matrix interface during the long time exposure at high temperature would change the microstructure of the matrix and deteriorate the mechanical properties of the matrix. To analyze the high temperature strength of aluminide coating on T92 steel for ultra-supercritical unit

aluminide coating is prepared on the inner wall of T92 steel boiler tube by low temperature powder embedding method

and the tensile test was carried out at room temperature to 625 ℃ and the durability test was carried out at 625 ℃ environment. The effect of aluminide coating on the tensile properties and durability life of T92 matrix are studied by combining scanning electron microscope(SEM)

optical microscope(OM) and X-ray diffraction analysis(XRD).The results show that the aluminide coating prepared on the inner wall of T92 boiler tube by low temperature powder embedding aluminizing

which is metallurgically combined with the matrix

has a double-layer structure

and each layer is continuous and uniform. The total thickness of the prepared aluminide coating is about 30.4 μm. The coating has columnar crystal structure and the surface is cracked in the room temperature is increased to 625 ℃. During the creep rupture process at 625 ℃ environment

FeAl coating have many cracks

but the crack depth is shallow and very few cracks extend to the matrix. The coating peels off locally large strains under the high stress state. It can be concluded that even deforms of the aluminide coating occurred during the long-time creep process

it can still has good metallurgical bonding with T92 matrix.