Method for evaluating the fatigue strength of welded joints

摘要

Method for evaluating the fatigue strength of welded joints produced by melting an alloy using a specified welding technique, which method comprises the following steps:a statistically significant number N of specimens are produced with a welded joint using said welding technique;each of the specimens is subjected to cyclic fatigue tests, with an alternating stress a, until failure;the size of the relevant defect appearing in the fracture plane of the specimens is measured by fractography;a range of defect dimensions for which the probability of measuring by fractography a defect outside the range is less than a predetermined level of probability t is determined from the measured sizes; andthe lowest stress σ_min liable to cause the specimen to fail with a level of probability t is determined from this range.