War Office Overstrain of Metals: and its Application to the Auto-Frettage Process of Cylinder and Gun Construction

Abstract

BETWEEN 1840 and 1850, Rodman, in the United States, investigated a new method of casting thick iron cylinders. He cooled the bore so that the inside hardened first. The outside, cooling afterwards, contracted and thereby placed the cylinder wall in a state of stress, compressive on the inside, tensile on the outside. Further work was done forty years later by Kalakoutsky in Russia, by Prof. Perry at the beginning of the present century, and by M. Malaval during and since the War; the modern method of achieving the same result being to expand a forged steel cylinder hydraulically into the yield range, so that on release of pressure the permanent set of the interior places the exterior in elastic stress. Major Macrae now gives us a very complete record of the work done at Woolwich on this subject. Written mainly for gun-makers, this book should be of interest and value also to engineers in general, who will find therein a vast fund of experimental data on the testing of metals under both tensile and compressive loads up to and exceeding the elastic limit, and on the most suitable heat treatment to restore elasticity that has been lost by over strain.

War Office. Overstrain of Metals: and its Application to the Auto-Frettage Process of Cylinder and Gun Construction.

By Major A. E. Macrae. Pp. ix + 378. (London: H.M. Stationery Office, 1930.) 21s. net.