Patent ID: 11958095
Assignee: INDUSTRY-ACADEMIC COOPERATION FOUNDATION, DANKOOK UNIVERSITY
Field: Machine tools (Mechanical engineering)
Classification: CPC B  C  Y | IPC B  C

Claim 8:
9. A peening method for generating a compressive residual stress on the a pipe member having a hollow inside formed therein, using the peening apparatus of claim 1, the method comprising:
(a) injecting the first fluid in a liquid phase and the second fluid in a gas phase into the hollow inside formed in the pipe member;
(b) forming a cavity by applying a wave to the first fluid injected into the hollow inside of the pipe member;
(c) generating a compressive residual stress on the inner surface of the pipe member (P) by the formed cavity being exploded; and
(d) controlling the position of a pressure antinode formed by the wave.