Document Type and Number:
Japanese Patent JPH035918
Kind Code:
B2
Abstract:
Tensile residual stress in an annular welded joint part (2) joining the ends of unit pipes (1) is mechanically removed by applying repeated hammering strokes against the inner surface of the pipes over the entire joint part thereby to cause this part to undergo locally plastic deformation. The repeated hammering strokes, which have a peening effect, are applied by several automatically operating hammering devices (21) mounted radially on a rotary head (18) secured to and unitarily moving with a shaft (6) which is driveable in rotation about its axis and in translation in its axial direction.
Inventors:
YOSHIDA TOSHIO
ATSUTA TOSHIO
ATSUTA TOSHIO
Application Number:
JP20508881A
Publication Date:
January 28, 1991
Filing Date:
December 21, 1981
Export Citation:
Assignee:
KAWASAKI HEAVY IND LTD
International Classes:
B23K31/00; B23K31/02; B23P9/04; B24B39/02; C21D7/04
Next Patent: MAGNETIC DISK MEDIUM FOR TESTING