The backing material null which was treated by silicate scaling prevention manner and the said

摘要

PURPOSE: To prevent the formation of the silicate scale on a base material and the deterioration of function by constituting the surface of the base material allowing to contact with steam of the specified ceramic containing the oxide such as of Nb and the oxide of W. ;CONSTITUTION: At least the surface of the base material such as a turbine blade allowing to contact with steam is composed of the ceramic expressed by the formula aM_cO_d.bW_xO_y (wherein M is Nb, Zr, Ni, Co, Cu, Fe, Mg and Mn, a/b is 0-1, (c), (d), (x) and (y) are the integer values decided in reference to the charge value of M and W). The ceramic is obtained by oxidation and changing into the ceramic after being formed to a structure by a powder metallurgical processing and being applied or deposited with a metallic coating film, and the thickness of the ceramic coating film is about ≥10μm but about ≥100μm is preferable. In this way, the formation of the silicate scale on the base material is prevented, and the scale is eliminated easily by a mechanical means even in the case the scale is caused, and the deterioration of function and the damage of the turbine blade, etc., are canceled.;COPYRIGHT: (C)1994,JPO&Japio