Showing papers on "Peening published in 1969"

Warpage minimizing process for machining metal castings

Abstract: A process of machining metal castings to minimize warping, especially useful in manufacturing propellers. When the casting is mounted for machining its shallow parts are restrained from warping out of alignment. After machining and while still so restrained, the more critical portions, for example, those near the roots of propeller blades, are machined to contour, then shot peened. The peening hardens the machined surface, increasing its bending resistance, to minimize warping when the casting is released from restraint.

Study of residual stresses in linearly varying biaxial-stress fields

Abstract: A theory has been developed for the calculation of relaxation strains effected by drilling a hole in a plate with a linearly varying stress field. With this theory, a technique was developed for the measurement of residual stress at the toe of tee-fillet welds. The above technique was employed for the measurement of residual stresses at the toe of tee-fillet welds in 11/2-in. HY-80 steel with the fillet in the as-welded, ground, shot peened, ground and shot peened, and mechanically peened condition. It was found that experimental data conform to the assumed theory, and that residual stresses in aswelded tee-fillet welds in both the transverse and longitudinal directions approach the yield strength of the steel. It was also found that residual stresses are reduced approximately 25 percent by grinding, 50 percent by shot peening and 50 percent by grinding and shot peening. Mechanical peening drastically affected residual stresses by converting high tension at the toe of the fillet weld to high compression of approximately the same magnitude.

Centrifugal blast wheel

Abstract: A centrifugal blast wheel for projecting peening balls comprises a runnerhead having a plurality of radial vanes mounted thereon and an impeller mounted in an impeller case in the central area of the runnerhead. Means are provided to prevent the peening balls from being trapped between the impeller blades and the slot in the impeller cage.

Internal peening tool

Abstract: An impact tool for peening the interior wall of a bore, wherein a sleeve has rows of axially staggered holes through which peening arms project, the arms being carried by a central rod reciprocable in the sleeve and spring biased in a direction to retract the arms, impact being applied to the rod and acting to project the arms through the holes into engagement with a bore wall. The sleeve has a collar for limiting the extent of insertion of the tool into a bore, and a handle is provided to enable rotation of the tool in the bore. The rod engages an adjustable anvil to limit the extension of the peening arms from the sleeve.