Prediction of failures in steam boiler using quantification of residual stresses

• Published in: Engineering failure analysis Vol. 118; p. 104808
• Main Authors: Pástor, Miroslav, Lengvarský, Pavol, Trebuňa, František, Čarák, Peter
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-12-2020
• Subjects: FEM; Residual stresses; Steam boiler; Stress analysis; Stress analysis; Residual stresses; Steam boiler; FEM
• ISSN: 1350-6307; 1873-1961
• DOI: 10.1016/j.engfailanal.2020.104808

•• Residual stress measured in failure part of pipe system is analyzed.•• Safe operation of the piping system taking account of residual stresses is assessment.•• Effect of sudden temperature change on the failure of steam boiler by FEM is analyzed.
The paper presents an analysis of the causes of an accident that occurred in the steam boiler during operation as aresult of the failure of the control system and subsequent uncontrolled operation of the steam boiler for several hours. After shutdown of the boiler, cracks were identified in many places of the piping system of the boiler and in one place the pipeline was completely destroyed. Analysis of the chemical composition and mechanical properties of the material and quantification of residual stresses by the hole drilling method were performed to assess possible causes of the failure of the steam boiler piping system. The effect of sudden temperature change on the failure of a piping system was performed by the finite element method. Based on the obtained results, it can be concluded that the temperature change in the piping system cannot be considered the main cause of the pipe system failure and that the accident did not occur only due to the failure of several protective mechanisms of the system. High levels of residual stress quantified at the site of the breach were found to be the most important cause of the failure.