METHOD OF DETERMINATION OF MAXIMUM PERMITTED SIZE OF MICRODEFECTS IN METALS UNDER CYCLIC LOADING

摘要

The invention relates to the investigation of the mechanical properties of metals, in particular, to methods for determining the maximum size of the microdefect metals under cyclic loading. The purpose of the invention - an increase of the process productivity by reducing the duration of the test. Said object is achieved in that for experiments using only one sample, the surface is sequentially applied are increasing in size prints indentor hardness Vickers, and which after application of the next print is subjected to cyclic loading with amplitudes voltage equal to the limit of endurance for a number of cycles corresponding to the inflection fatigue curve. The size of the maximum permissible defects is determined by the formula: VpK Fp Ig Np / lgNn. where Fp - the projected area of ​​the defect, in which there usta- fragmentation of lines of disruption in the plane of action of the maximum stress, Np - number of cycles to failure, Nn - number of cycles to achieve the inflection metal fatigue without defect. EGR deVFC