Pitting corrosion resistance with shielded metal arc welding and post weld heat treatment on duplex stainless steel weld overlay

Duplex stainless steels (DSSs) are widely used in the marine environment, petro-chemical refineries, oil and gas industries because of their high corrosion resistance properties and balanced ratio of austenite and delta-ferrite phases. The objectives of this research are to an...

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Main Author: Sim, Bernard Maxmillan
Format: Thesis
Language:English
Published: 2019
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Online Access:http://psasir.upm.edu.my/id/eprint/84367/1/FK%202019%20119%20-%20ir.pdf
http://psasir.upm.edu.my/id/eprint/84367/
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spelling my.upm.eprints.843672022-01-04T01:04:23Z http://psasir.upm.edu.my/id/eprint/84367/ Pitting corrosion resistance with shielded metal arc welding and post weld heat treatment on duplex stainless steel weld overlay Sim, Bernard Maxmillan Duplex stainless steels (DSSs) are widely used in the marine environment, petro-chemical refineries, oil and gas industries because of their high corrosion resistance properties and balanced ratio of austenite and delta-ferrite phases. The objectives of this research are to analyze and evaluate the behavior of pitting corrosion, micro-hardness, microstructure and chemical dilution effects of duplex stainless steel E2209 weld overlay with the hydrogen relief (350°C), stress relief (650°C) and solid solution annealing (1050°C) heat treatments. Shield Metal Arc Welding (SMAW) process with medium heat input produced a reasonable partitioning ratio. The dilution has slightly increased in hydrogen heat treatment and a small reduction for Stress relief heat treatment. Solution annealing with water quenching at above critical point of A3 cooling temperature has shown the disappearance of heat affected zone for low alloy steel substrate. Micro-hardness has indicated a substantial fluctuation of hardness values in fusion zone. The solution annealing has shown a consistent low hardness values at the weld overlay and hardened base metal region with the present of a large amount of maternsite and noticed of equaxied ferrite structures. Ferrite count determination in region of weld metal overlay are increased at hydrogen relief temperatures and decreased at stress relief temperatures due to slow cooling which is more favorable to austenite formation. The amount of ferrite in the weld metals has significantly reduced with the solid solution anneal temperature due to sufficient time for the formation of austenite and giving optimum equilibrium fraction in the welds. The major of alloying elements which can contribute to intermetallic phases are analyzed. C, Cr and Ni chemical elements have shown fluctuation values during PWHT. Whereas, N2 has produced consistent values to prevent critical implication to nitride precipitation. The corrosion weight loss has gradually increased with the increment of PWHT temperatures. At solid solution annealing temperature, the weld metals are being restored with no significant of weight loss. 2019-04 Thesis NonPeerReviewed text en http://psasir.upm.edu.my/id/eprint/84367/1/FK%202019%20119%20-%20ir.pdf Sim, Bernard Maxmillan (2019) Pitting corrosion resistance with shielded metal arc welding and post weld heat treatment on duplex stainless steel weld overlay. Doctoral thesis, Universiti Putra Malaysia. Corrosion and anti-corrosives - Case studies Stainless steel - Heat treatment
institution Universiti Putra Malaysia
building UPM Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Putra Malaysia
content_source UPM Institutional Repository
url_provider http://psasir.upm.edu.my/
language English
topic Corrosion and anti-corrosives - Case studies
Stainless steel - Heat treatment
spellingShingle Corrosion and anti-corrosives - Case studies
Stainless steel - Heat treatment
Sim, Bernard Maxmillan
Pitting corrosion resistance with shielded metal arc welding and post weld heat treatment on duplex stainless steel weld overlay
description Duplex stainless steels (DSSs) are widely used in the marine environment, petro-chemical refineries, oil and gas industries because of their high corrosion resistance properties and balanced ratio of austenite and delta-ferrite phases. The objectives of this research are to analyze and evaluate the behavior of pitting corrosion, micro-hardness, microstructure and chemical dilution effects of duplex stainless steel E2209 weld overlay with the hydrogen relief (350°C), stress relief (650°C) and solid solution annealing (1050°C) heat treatments. Shield Metal Arc Welding (SMAW) process with medium heat input produced a reasonable partitioning ratio. The dilution has slightly increased in hydrogen heat treatment and a small reduction for Stress relief heat treatment. Solution annealing with water quenching at above critical point of A3 cooling temperature has shown the disappearance of heat affected zone for low alloy steel substrate. Micro-hardness has indicated a substantial fluctuation of hardness values in fusion zone. The solution annealing has shown a consistent low hardness values at the weld overlay and hardened base metal region with the present of a large amount of maternsite and noticed of equaxied ferrite structures. Ferrite count determination in region of weld metal overlay are increased at hydrogen relief temperatures and decreased at stress relief temperatures due to slow cooling which is more favorable to austenite formation. The amount of ferrite in the weld metals has significantly reduced with the solid solution anneal temperature due to sufficient time for the formation of austenite and giving optimum equilibrium fraction in the welds. The major of alloying elements which can contribute to intermetallic phases are analyzed. C, Cr and Ni chemical elements have shown fluctuation values during PWHT. Whereas, N2 has produced consistent values to prevent critical implication to nitride precipitation. The corrosion weight loss has gradually increased with the increment of PWHT temperatures. At solid solution annealing temperature, the weld metals are being restored with no significant of weight loss.
format Thesis
author Sim, Bernard Maxmillan
author_facet Sim, Bernard Maxmillan
author_sort Sim, Bernard Maxmillan
title Pitting corrosion resistance with shielded metal arc welding and post weld heat treatment on duplex stainless steel weld overlay
title_short Pitting corrosion resistance with shielded metal arc welding and post weld heat treatment on duplex stainless steel weld overlay
title_full Pitting corrosion resistance with shielded metal arc welding and post weld heat treatment on duplex stainless steel weld overlay
title_fullStr Pitting corrosion resistance with shielded metal arc welding and post weld heat treatment on duplex stainless steel weld overlay
title_full_unstemmed Pitting corrosion resistance with shielded metal arc welding and post weld heat treatment on duplex stainless steel weld overlay
title_sort pitting corrosion resistance with shielded metal arc welding and post weld heat treatment on duplex stainless steel weld overlay
publishDate 2019
url http://psasir.upm.edu.my/id/eprint/84367/1/FK%202019%20119%20-%20ir.pdf
http://psasir.upm.edu.my/id/eprint/84367/
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score 13.211869