IMPELLER FOR HYDRAULIC MACHINERY AND HYDRAULIC MACHINERY

摘要

PROBLEM TO BE SOLVED: To provide an impeller for a hydraulic machinery, which is formed by welding steel materials of different kinds which can keep an anti-corrosion effect over a long period of time. SOLUTION: A stainless steel welding material is built up substantially like a flat plate on a support member 5 made of carbon cast steel to form at least one coating layer 13, a blade 3 made of stainless steel is welded to the coating layer 13, and welding material made of carbon steel is built up at least on the surface of the support member 5 coming into contact with the coating layer 13 to form a sacrifice anode 19. Thus, wear resistance to the cavitation action is provided so that anti-corrosion of an impeller can be kept over a long period of time by the sacrifice anode 19 having a low speed of consumption due to abrasion.