Determination of Specific Failure Work on Compact Steel Samples

For critical structures in the oil and gas refining, petrochemical and chemical industries, it is necessary to determine the value of mechanical characteristics. In the present paper we consider issues related to the determination of the mechanical characteristics of structural materials using compact samples. Basically, current values ​​of the mechanical properties of materials are determined by measuring hardness using existing empirical dependences that combine hardness values ​​with yield limit and tensile strength values. But such dependencies are not universal and require experimental verification. The need for compact samples application occurs during determination of the reasons of equipment failure, when the size of a fragment of broken down equipment does not allow producing standard samples for traditional testing performance. The application of empirical dependencies for determination of hardness mechanical characteristics is complicated by the fact that it is necessary to take into account the degree of the material degradation. This, in its turn, requires additional studies. The key issue in determining the accuracy of measurements on compact samples is the role of the surface in the formation of fracture focal points. The experiments were carried out on thin steel samples and the mechanical characteristics were determined on Instron 8801 dynamometer unit. It was shown that in case of increase of thickness of the samples that underwent tension testing, the fracture work varies according to the power law.