Residual stress improvement manner and residual stress improvement device and nozzle null for water jet peening

摘要

PURPOSE: To shorten the interval between a nozzle and the surface of metal and to improve residual stress while securing the ratio of the distance between the nozzle and the surface of metal and the hole diameter of the orifice of the nozzle by tilting both the center axis of a conduit part for supplying high- pressure liquid in the upstream side of the nozzle and the center axis of the spouting hole of liquid. ;CONSTITUTION: A water-jet peening nozzle 1 is provided with the spouting hole of liquid which consists of an orifice part 3 for increasing the flow velocity of liquid and the following horn part 4 for a conduit part 2 for supplying high- pressure liquid on the upstream side. The horn part 4 sectorially tapers while keeping the center axis 6 of this orifice 3 as a center axis on the downstream side of the orifice 3. Moreover both the center axis 5 of the conduit part 2 and the center axis 6 of the spouting hole have the specified oblique angle θ. Therefore, the distance between the nozzle and the surface of metal is made small in the spouting direction even in a narrow part and residual stress is improved.;COPYRIGHT: (C)1993,JPO&Japio