«Equipment and technologies for oil and gas complex»

INFLUENCE OF INHOMOGENEITY OF THE MECHANICAL CHARACTERISTICS OF PIPES METAL ON THE CARRYING CAPACITY AND RESIDUAL LIFE OF GAS PIPELINES

UDC: 622.691.4.053
DOI: 10.33285/1999-6934-2021-1(121)-88-90

Authors:

¹ National University of Oil and Gas "Gubkin Uiversity", Moscow, Russian Federation

Keywords: main gas pipeline; technical diagnostics; stress-strain state; limit state criterion; fracture mechanics

Annotation:

The paper is devoted to the assessment of the technical state and residual resource of the linear part of the main pipelines and compressor stations technological pipeline. Approaches to assessing the hazard of fracture-like defects based on the criteria of linear fracture mechanics are considered. An approach to assessing the influence of elastic-plastic deformation along the crack front on the degree of defect hazard is formulated. It is shown that taking into account the inhomogeneity of pipelines mechanical characteristics of steels when assessing their technical state and residual operational life-time can be carried out by using Irwin's corrections, the formula of which is formulated taking into account the correlation between the steel yield strength and hardness values. The results of mechanical tests of a pipe segment made of steel of strength class K65 are presented. The results of the experiment, which showed the presence of a significant inhomogeneity of the mechanical characteristics along the pipe wall thickness, are analyzed.

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