Abstract:
A case study was undertaken using TIG & Plasma Arc welding techniques for cylindrical shaped vessels of HSLA steel. On longitudinal seam Plasma Arc Welding technique was used, while on circumference, TIG welding technique was used. In case, if any repair generated on longitudinal seam, it was again performed with TIG welding technique. Thus mixed mode welding region was followed and therefore non-uniformly distributed stress zones were created. After welding, the vessels were subjected to Post Weld Heat treatment that included Stress Relieve Annealing, performed at 640°C for about an hour; followed by cooling in air and hardening process. Hardening process consisted of Quenching in oil bath (the temp of the oil bath was about 50°C) followed by tempering at 480°C and then cooling performed in air. The diameters along the circumference of the vessels were recorded at different positions and accordingly diameter differences were calculated. The vessel that reported greater distortion / deformation and inferior mechanical properties was critically analyzed and its possible causes are investigated and highlighted.
Page(s):
73-78
DOI:
DOI not available
Published:
Journal: Proceedings 5th International Bhurban Conference on Applied Sciences and Technology , Volume: 0, Issue: 0, Year: 2007