Study on Surface Strengthening Technology for Blades Based on AHP and Pugh Matrix Method

Abstract

 In order to evaluate the applicability of various surface strengthening technology for steam turbine blades, the evaluation system of steam turbine blade surface strengthening technology was established by analytic hierarchy process (AHP) method, taking surface quality, surface performance and economic applicability as criteria layers, and 14 important evaluation indexes as index layers, and then assigning the weight to the parameters of criterion layer and index layer in turn. Based on the thermal spraying process, a variety of surface strengthening processes were compared horizontally with the traditional blade anti - water erosion technology through Pugh matrix method. The optimal technology of the contrasted results was used as the benchmark again, and then the second comparison was made to obtain the accurate comparison results. Results showed that the optimal process of the first comparison was pure water jet. After secondary comparison, it was found that compared with the traditional blade waterproofing technologies, new strengthening technologies such as abrasive water jet, double glow plasma metal penetration and electric spark deposition all had extensive advantages, the weight difference between advantages and disadvantages of which were 0.073 6, -0.050 2 and 0.155 3, respectively. In conclusion, pure water jet, abrasive water jet, double glow plasma metal penetration, electrospark deposition all had the possibility to be applied in the blade anti - water erosion technology.

Keywords

• analytic hierarchy process|pugh matrix|surface strengthening|steam turbine blades|evaluation system