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Pitting corrosion of welds in UNS S32304 lean duplex stainless steel
Author(s) -
Sicupira D. C.,
Frankel G. S.,
de F. C. Lins V.
Publication year - 2016
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.201508502
Subject(s) - welding , metallurgy , materials science , shielded metal arc welding , gas metal arc welding , base metal , heat affected zone , pitting corrosion , arc welding , submerged arc welding , corrosion , filler metal , gas tungsten arc welding , electrochemical noise , composite material , electrochemistry , electrode , chemistry
The pitting corrosion of welded joints of lean duplex stainless steel (LDSS) UNS S32304 was studied. LDSS S32304 thick plates were welded by different processes commonly employed in the manufacture of equipment and piping: shielded metal arc welding, gas metal arc welding, and flux cored arc welding. The electrochemical behavior of different weldment zones (fusion zone, base metal, and heat affected zone (HAZ)) was characterized both independently, using an electrochemical microcell, and together by testing the whole welded area. The electrochemical testing was performed in acidified glycerin, a process fluid of the biodiesel industry. The HAZ was the most susceptible zone for pitting corrosion for all samples. The results were correlated to the microstructural features of the materials. Finally, the results from the microcell and whole weld approaches were compared. According to the results, the gas metal arc welding process with 2209 as filler metal was found to be the optimum for application of 2304 duplex stainless steels in the acidified glycerin environment.