Application Ion-Plated Cr-Tin Multilayer Coating To Steam Turbine Blades.
Abstract
In order to apply a recently developed ion-plated coatings to compressor driving steam turbine blades, cavitation erosion tests were conducted to select the effective multilayer coating to prevent drain erosion of the blading material. Among the tested ion plated materials such as Cr, TiN, Cr-CrN and Cr-TiN on 13 Cr stainless steel, Cr-TiN multilayer coating showed the most effective cavitation erosion resistibility. Physical properties of the coatings were evaluated by high resolution transmission electron microscopy, scanning electron microscopy, and X-ray diffraction studies. It was determined that the high drain erosion resistibility of the Cr-TiN coating could be enhanced by a strong adhesive force at the bonded layer, high compressive residual stress of the coating, fine columner structure, and orientation of the microstructure of the coated material. In order to apply this coating to steam turbine blades, mechanical tests such as fatigue and corrosion fatigue, thermal shock and oxidation in steam were conducted. It was also demonstrated that any influences of the coating were not detected on mechanical properties of the 13 Cr stainless steel. A couple of practical application of the ion-plated coating for compressor driving steam turbine blades are briefly introduced.
Description
LecturePg. 3-8
Subject
TurbomachinesCollections
Citation
Ebara, Ryuichio; Nakajima, Hiroshi; Odohira, Toshihiko; Wada, Tetsuyoshi; Hatano, Masaaki (1987). Application Ion-Plated Cr-Tin Multilayer Coating To Steam Turbine Blades.. Texas A&M University. Turbomachinery Laboratories. Available electronically from https : / /hdl .handle .net /1969 .1 /163615.