HARD-FACED SHAFT

摘要

1464846 Making shafts; rolling; welding by fusion HITACHI SHIPBUILDING & ENG CO Ltd 3 Feb 1975 4550/75 Headings B3A B3M and B3R [Also in Divisions F2 and H5] A steel shaft 19 has all or part of its peripheral surface coated with a weld metal overlay 30 of stainless steel or aluminium bronze which is rolled or shot peened to increase the fatigue strength of the shaft. A helical weld overlay 30 is formed on a shaft 19, e.g. a machine shaft, a ship's steering shaft, a propeller shaft, a sluicegate shaft by a submerged arc welding machine 22 using a band electrode 23 made of stainless steel or aluminium bronze. The welding machine 22 is connected to a screw 21 on the shaft 19 by a wire 26 so that when the shaft 19 is rotated by rollers 20, the machine 22 is advanced along rails 25. One side (31a) (Fig. 11, not shown) of each weld bead convolution is formed with a bevel, which the succeeding bead overlaps, by passing the band electrode 23 through a member 35, Fig. 12, which is connected via a coil 36 to an electrical supply (32) (Fig. 13, not shown) which is connected to the shaft 19. More than one weld layer 30 may be applied to the shaft 19. The weld overlay 30 on the shaft 19 is then rolled by rollers 40a, 40b, Fig. 15, which exert, by means of pistons 44a, 44b, a predetermined pressure set by a relief valve 51. In an alternative embodiment (Fig. 26, not shown) a keyway (64), which receives a key (63) for interconnecting a propeller, has its weld overlay shot peened.