The problem of fatigue crack growth retardation is a very urgent problem of reliability of pipeline transportation. However, due to the specific structure of the pipeline (being underground for a long time) is almost impossible. Characteristics of low-cycle fracture strength determined by testing specimens with an edge crack under cyclic stretching of soft pulsating cycle. For small-diameter pipes can define test parameters semicircular specimens with edge cracks. In this case the stress intensity factor calculated by the formula for determining the stress intensity factor in bending of flat samples. Processing of low-cycle test results of samples is given basic information about the properties of the metal on the sample under test conditions and characteristics of the test set, the amount of crack and plastic zone before and during testing. We evaluated the parameters of the kinetic equation low-cycle fracture.
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