Fatigue of Thick Cylinders: Further Practical Information

Work on the fatigue strength of thick cylinders subjected to repeated internal pressure described in earlier papers has been continued. Topics investigated include size effect, the effect of radial and tangential cross-bores, the improvement obtainable by autofrettaging such cylinders and the effect of the surface finish of the bores of the cylinders. The additional materials tested include 13 per cent chromium steel (En 56), 18 per cent nickel-cobalt-molybdenum maraging steel, 1 per cent chromium ball race steel, fully hardened (En 31), beryllium copper and tungsten carbide. Not all these materials could be obtained in a size large enough to make the previously used 1 in bore cylinders and a new head for the fatigue machine was designed to accommodate a variety of cylinder sizes and industrial high pressure components.