Effect of MAG welding transfer mode on sigma phase precipitation and corrosion performance of 316L stainless steel multi-pass welds

Autor(es)

Guilherme, L. H. ^[1] ; Benedetti, A. V. ^[2] ; Fugivara, C. S. ^[2] ; Magnabosco, R. ^[3] ; Oliveira, M. F. ^[4]

Afiliação do(s) autor(es)

^[1] Soudap Engn Co, Engn Dept, Araraquara, SP - Brazil

^[2] Sao Paulo State Univ UNESP, Chem Inst, Araraquara, SP - Brazil

^[3] Univ Ctr FEI FEI, Mat Engn Dept, Sao Bernardo Do Campo, SP - Brazil

^[4] Univ Sao Paulo, Sao Carlos Sch Engn, Mat Engn Dept, Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T; v. 9, n. 5, p. 10537-10549, SEP-OCT 2020.
• Citações Web of Science: 0

Resumo

The effect of multi-pass MAG welding transfer modes on the sigma phase precipitation and corrosion performance of AISI 316L thick plate were investigated. The evolution of the microstructure was examined by optical and electron microscopy as well as ferritscope measurements and energy dispersive X-ray spectrometry. An electrochemical microcell was then used to characterize the electrochemical behaviour of the different weld regions. The fusion line was the most critical zone for pitting corrosion for all welding procedures, due to the sigma phase precipitation, alloy elements partitioning and galvanic coupling between base metal and weld metal. It was observed the formation of sigma phase after short-circuiting or spray-arc modes, with no evidence of it to the pulsed-arc, which obtained the best corrosion resistance performance. The results evidenced the selective corrosion around sigma phase due to the depletion in Cr and Mo, with subsequent pitting nucleation. A strong correlation between the MAG welding transfer modes and the sigma phase morphology was observed. The influence of weld parameters on microstructure evolution and corrosion resistance performance was discussed. The corrosion resistance performance of the MAG welding procedures was ranked as: pulsed-arc > short-circuit > spray-arc. (C) 2020 The Authors. Published by Elsevier B.V. (AU)

• Processo FAPESP: 19/23063-4 - Qualificação, validação e monitoramento de equipamentos e utilidades industriais de aplicações assépticas ou corrosivas
• Beneficiário: Luis Henrique Guilherme
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisa Inovativa em Pequenas Empresas - PIPE