Abstract
After 204,000 h of operation, some welds in the main steam line of a thermal generating station were examined ultrasonically. This examination found a major reflector close to a butt weld in the line. That reflector proved to be cracking that was 90% through-wall. The cracking was not visible on the outside surface of the pipe. The cracking was type III creep cracking, and had initiated in the mid-wall region within bands of coarse-grained material. From that mid-wall position, cracking had propagated outwards towards the OD surface, and inwards to reach the ID surface. There was no evidence of the involvement of any weld flaws in the initiation or the growth of the cracking. Stress analysis of the piping system, using commercially available software, indicated that the stress in the major area of cracking exceeded that allowed by the ASME B31.1 design code.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
