Based on the mechanism of water erosion damage occurred on the final-stage blades in steam turbines

the damaged blades have been repaired by using gas tungesten arc welding(GTAW)

and the microstructure performance of welded joints being tested.Results show that the hardness of weld joints satisfies the requirements in application

the mechanical properties of weld joints is good

the high-cycle fatigue resistant behavior of the weld joints can meet the requirement of blades in service.In order to enhance the water erosion resisting performance of said blades to lengthen their service life

the microstructure

the mechanical properties

the thermal shocking behavior

the abrasive wear and erosion damage properties of two different coatings NiCr and WC-Co ceramet sprayyed using high speed oxygen fuel have been compared and analysed.Compared with WC-Co coatings

the NiCrceramet coating has excellent resistance to abrasion and erosion

it can be used on final-stage blades in steam turbines as water-resistant coatings.