Abstract: A water turbine runner has a plurality of vanes, each made of a rolled steel plates which contains, by weight, 0.01 to 0.10% of C, 0.10 to 1.0% of Si, 0.10 to 2% of Mn, 2 to 7% of Ni, 10 to 15% of Cr and 0.10 to 4% of Mo, 71.9 to 87.7% of Fe, and which has a metallic structure mixture containing, by volume, martensite and 10 to 35% of residual austenite. Each of the vanes is made of a plurality of plate pieces, cut out from the rolled steel plate, press-formed in a shape of a part of the vane and joined by welding into the complete vane.

Abstract: A water intake portion of a hydraulic machine consists of a casing and a speed ring positioned between the casing and guide vanes for guiding water from the casing to the guide vanes. The speed ring consists of a pair of upper and lower flat members of a ring form, a plurality of stay vanes positioned between the aforesaid pair of members for interconnecting same rigidly, and a reinforcing member of a cylindrical form, which is welded to the top surface of the upper flat member between the inner and outer circumferential edges of the upper flat member. Edges defining therebetween an opening of this casing are welded to the top surface of the upper flat member of a ring form, of the speed ring in the position between the aforesaid reinforcing member and the outer circumferential edge of the upper flat member, as well as to the undersurface of the lower flat member of a ring form, respectively.