Screening of critical dangerous parts of Pi-shaped pipe in the corrosive environment

Abstract

In order to accurately predict the key dangerous parts of the polygonal pressure pipeline in a corrosive environment, based on the stress fatigue theory, a stainless steel pipeline damage calculation model coupled with the coupling of fatigue and corrosion is established, and the cold and operating conditions are carried out for the polygonal pressure pipeline. The analysis of stress and damage fields shows that the fatigue life of the square-shaped pipeline is reduced from 9225 to 42 years after the influence of the stress concentration factor of pitting corrosion. Based on the results of the damage analysis, by defining the dangerous concentration parameters, it is predicted that the key dangerous parts of the zigzag pressure pipeline are mainly the elbow and the long side abdomen. The greater the dangerous concentration parameter is, the more concentrated the dangerous parts are. When the dangerous concentration parameter is greater than 0.5, the elbow of the pipe shoulder and the long side joint are not critical dangerous parts anymore.