A study on shrinkage residual stresses,microstructure and mechanical properties of ASS thick pipe welded by GMAW process
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Date
2021
Journal Title
Journal ISSN
Volume Title
Publisher
Materials Research Express
Abstract
In this investigation, AISI 304LN austenitic stainless steel pipes having 25mmthickness and 300mminner
diameter with conventional and narrowgroove were welded by continuous current gas metal arc welding
(GMAW) and pulse current gasmetal arcwelding (P-GMAW) process.Agas tungsten arcwelding (GTAW)
processwas used for the welding of the root pass. Microstructural study was carried out in fusion zone (FZ)
and heat-affected zone (HAZ).Afavourable microstructure characteristic was observed in the P-GMAW
process. The study of transverse shrinkage and shrinkage stresseswere done on the conventional groove with
GMAWand P-GMAWprocess and narrow groove by P-GMAWprocess. It was found that narrowgroove
weld design with controlledwelding parameters can reduce 45%shrinkage as compare to conventional
groove, similarly 30%reduction in shrinkage stress can be achieved.The tensile propertieswere observed to
increased, such as yield strengthwas improved from 260MPato 310MPaand ultimate strength was
improved from 510MPa to 550MPa in the case of narrow grooveweld by theP-GMAWprocess.
Description
Keywords
GMAW process, microstructure, hardness, narrow groove, transverse shrinkage stresses