Effects of post-weld heat treatments on the microstructure, mechanical and corrosion properties of gas metal arc welded 304 stainless steel
ISSN: 1708-5284
Article publication date: 31 January 2020
Issue publication date: 19 February 2020
Abstract
Purpose
The purpose of this study is to determine the effects of post-annealing and post-tempering processes on the microstructure, mechanical properties and corrosion resistance of the AISI 304 stainless steel gas metal arc weldment.
Design/methodology/approach
Gas metal arc welding of AISI 304 stainless steel was carried out at an optimized processing condition. Thereafter, post-annealing and post-tempering processes were performed on the weldment. The microstructure, mechanical and electrochemical corrosion properties of the post-weld heat treated samples, as compared with the as-welded, were investigated.
Findings
The as-welded joint was characterized with sub-granular grain structure, martensite formation and Cr-rich carbides precipitates. This made it harder than the post-annealed and post-tempered joints. Because of slower cooling in the furnace, the post-annealed joint contained Cr-rich carbides precipitates. However, the microstructure of the post-tempered joint is more refined and significantly devoid of the carbide precipitates. Post-tempering process improved the elongation (∼23%), tensile (∼10%) and impact (∼31%) strengths of the gas metal arc AISI 304 stainless steel weldment, while post-annealing process improved the elongation (∼20%) and impact strength (∼72%). Owing to the refined grain structure and significant elimination of the Cr-rich carbide precipitates at the joint, the post-tempered joint exhibited better corrosion resistance in 3.5 Wt.% NaCl solution than the post-annealed and the as-welded joints.
Originality/value
The appropriate post-weld heat treatment that enhances microstructural homogeneity and quality of the AISI 304 gas metal arc welded joint was determined.
Keywords
Acknowledgements
The authors appreciate the technical support provided by the LAFBART Automobile Company, Akure, Nigeria. The technical assistance rendered by the technical staff of the Industrial and Production Engineering Department and Mechanical Engineering Department, Federal University of Technology, Akure, is also appreciated.
Citation
Abioye, T.E., Omotehinse, I.S., Oladele, I.O., Olugbade, T.O. and Ogedengbe, T.I. (2020), "Effects of post-weld heat treatments on the microstructure, mechanical and corrosion properties of gas metal arc welded 304 stainless steel", World Journal of Engineering, Vol. 17 No. 1, pp. 87-96. https://doi.org/10.1108/WJE-11-2019-0323
Publisher
:Emerald Publishing Limited
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