Safety evaluating method of pressure equipment containing crack defects

Abstract

The invention discloses a safety evaluating method of pressure equipment containing crack defects, which comprises the following steps: 1, carrying out nondestructive testing and a standard stretching experiment; 2, obtaining a fully plastic solution factor h1 corresponding to the hardenability value n of different materials, and computing 1n(h1/h1(n=1)), wherein h1(n=1) is the value of h1 when nis equal to 1; 3, drawing a relationship curve between (h1/h1(n=1)) and n, fitting the relation curve into a linear relationship, recording the slope rate as B, and computing a defect size influence factor phi according to the formula phi=exp(-B), wherein exp presents an exponential function using a natural logarithm e as a base index; 4, establishing a failure evaluating curve and computing the positions of discontinuities; and 5, determining the plastic damage extent L'r and the fracture failure extent K'r of the pressure equipment, and judging the safety state of the pressure equipment containing the crack defects. In the method of the invention, the influence of the defect size factor phi to the safety is considered so that the evaluation is more accurate; phi is not limited by the material parameter n so that the invention can be simply and easily used for computing any materials.

Description

technical field [0001] The invention relates to a safety assessment method, in particular to a safety assessment method for pressure-bearing equipment containing crack defects, such as pressure vessels and pressure pipelines. Background technique [0002] Pressure equipment is a general term for equipment with fluid pressure as the basic load, such as pressure vessels, pressure pipes, pressure accessories, and pressure boilers. Widely used in petroleum, chemical, food, pharmaceutical, aerospace, energy and other fields. Because the service conditions of these pressure equipment vary widely, there are high temperature, low temperature, cryogenic; there are ultra-high pressure, high pressure, medium pressure, low pressure and vacuum; Equipment in production inevitably has defects of varying degrees. Therefore, once the equipment leaks or explodes, serious damage will occur, which will not only cause economic losses, but also cause serious environmental pollution. Among the ...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to overcome the problems that selection 1 and selection 2 FAD technology ignores the influence of defect size, the evaluation

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