{"title":"Fatigue Failure of a Carbon Steel Water-Wall Tube Because of an Undercut at a Welded Joint","authors":"","doi":"10.31399/asm.fach.power.c0048356","DOIUrl":null,"url":null,"abstract":"\n Welded to the top of a dust bin for rigid support, a furnace water-wall tube in a new stationary boiler broke at the welded joint shortly after start-up. The tubes measured 64 mm (2.5 in.) OD by 3.2 mm (0.125 in.) wall thickness and were made of carbon steel to ASME SA-226 specifications. Investigation supported the conclusion that a crevice-like undercut was likely the primary cause of the fracture and that the source of the necessary fluctuating stress was tube vibration inherent in boiler operation. Recommendations included magnetic-particle inspection of the remaining water-wall tubes in the row, replacing the broken tube, and repairing cracks in other tubes by welding.","PeriodicalId":107406,"journal":{"name":"ASM Failure Analysis Case Histories: Power Generating Equipment","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ASM Failure Analysis Case Histories: Power Generating Equipment","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.31399/asm.fach.power.c0048356","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Welded to the top of a dust bin for rigid support, a furnace water-wall tube in a new stationary boiler broke at the welded joint shortly after start-up. The tubes measured 64 mm (2.5 in.) OD by 3.2 mm (0.125 in.) wall thickness and were made of carbon steel to ASME SA-226 specifications. Investigation supported the conclusion that a crevice-like undercut was likely the primary cause of the fracture and that the source of the necessary fluctuating stress was tube vibration inherent in boiler operation. Recommendations included magnetic-particle inspection of the remaining water-wall tubes in the row, replacing the broken tube, and repairing cracks in other tubes by welding.