Abstract

ESPIN-LAGOS, Segundo Manuel et al. Influence of atmospheric oxygen content in the argon purge process in TIG welding in AISI 304 stainless steel pipe. Dyna rev.fac.nac.minas [online]. 2019, vol.86, n.208, pp.355-361. ISSN 0012-7353.  https://doi.org/10.15446/dyna.v86n208.70364.

TIG welding was performed on AISI 304 stainless steel pipes purged with argon, the amounts of atmospheric oxygen in the purge chamber analyzed in this work were 999, 500, 200, 100, 50, 25 and 10 ppm that used to determine as the amount of oxygen affects the superficial quality of the heat affected zone (HAZ) in the internal part of the pipe. In this study, mechanical tests, metallographic analysis and morphological study were carried out. We determined that the levels of discoloration in the HAZ are directly influenced by the amount of atmospheric oxygen present in the purge, with amounts between 50 to 10 ppm the discoloration is according to AWS D18.1 and AWS D18. 2 standards. While was evidenced good resistance in the welded joint because the failure occurs in the base metal and not in the HAZ which has not influence of surface discoloration corresponding to 10 ppm.

Keywords : purged; atmospheric oxygen; discoloration; heat-affected area; mechanical strength.

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