轴流水轮机的重要零件转轮室(如图1所示),在加工中,内成型表面粗糙度达不到设计要求。该转轮室内成型表面是由4部份组成:上部为φ6026mm的内圆柱面,中部为φ6026mm的内球面,下部为喉管状的旋转面及锥面。形状复杂,表面粗糙度值要求Ra5～10μm。转轮室内表面是由15块OCr18Ni9Ti不锈钢板焊接成,经退火后在立车加工成形。该转轮室是直径大、高度高的薄壁零 The important parts of the axial turbine runner room (shown in Figure 1), in the processing, forming the surface roughness less than the design requirements. The rotor indoor molding surface is composed of 4 parts: the upper part is φ6026mm inner cylindrical surface, the middle is φ6026mm inner spherical surface, the lower part is a throat-shaped rotating surface and a conical surface. Complex shape, the surface roughness requires Ra5 ~ 10μm. The inner surface of the runner is welded by 15 pieces of OCr18Ni9Ti stainless steel plate, which is formed by vertical lathe after annealing. The rotor chamber is large diameter, high-height thin-walled zero