| 摘要 |
PROBLEM TO BE SOLVED: To manufacture water turbine parts capable of improving the duration of life by restraining water flowing surface members of a Francis turbine utilizing a river water containing sand from damages due to wear and corrosion caused by earth and sand. SOLUTION: The surface of members such as a runner, guide vane, a stay vane and a runner liner which, constitute the water flowing surface of the river water containing earth and sand, is subjected to peening. Then, a combined coating layer of plastics with, by vol.% <=90 ceramics is thermally sprayed on the obtained rugged surface with an ultrahigh speed thermal spraying to obtain the layer of 0.5-5mm in thickness. By this way, a thick wall layer is obtained by using the ceramic and cermet spraying material and the low cost coating layer is obtained, whereby the economical and high-reliable water turbine is manufactured. |
