The influence of CMT-MAG and MAG welding-processes on microstructure and mechanical behaviour of C-Mn E410 structural-steels
International Journal of Structural Integrity
ISSN: 1757-9864
Article publication date: 8 February 2024
Issue publication date: 8 April 2024
Abstract
Purpose
An experimental investigation for developing structure-property correlations of hot-rolled E410 steels with different carbon contents, i.e. 0.04wt.%C and 0.17wt.%C metal active gas (MAG) and cold metal transfer (CMT)-MAG weldments was undertaken.
Design/methodology/approach
Mechanical properties and microstructure of MAG and CMT-MAG weldments of two E410 steels with varying content of carbon were compared using standardized mechanical testing procedures, and conventional microscopy.
Findings
0.04wt.%C steel had strained ferritic and cementite sub-structures in blocky shape and large dislocation density, while 0.17wt.%C steel consisted of pearlite and polygonal ductile ferrite. This effected yield strength (YS), and microhardness being larger in 0.04wt.%C steel, %elongation being larger in 0.17wt.%C steel. Weldments of both E410 steels obtained with CMT-MAG performed better than MAG in terms of YS, ultimate tensile strength (UTS), %elongation, and toughness. It was due to low heat input of CMT-MAG that resulted in refinement of weld metal, and subzones of heat affected zone (HAZ).
Originality/value
A substantial improvement in YS (∼9%), %elongation (∼38%), and room temperature impact toughness (∼29%) of 0.04wt.%C E410 steel is achieved with CMT-MAG over MAG welding. Almost ∼10, ∼12.5, and ∼16% increment in YS, %elongation, and toughness of 0.17wt.%C E410 steel is observed with CMT-MAG. Relatively low heat input of CMT-MAG leads to development of fine Widmanstätten and acicular ferrite in weld metal and microstructural refinement in HAZ subzones with nearly similar characteristics of base metal.
Keywords
Acknowledgements
Author(s) thank to the support from Surface Engineering Lab and Saptarishi – Multidisciplinary Research Centre, IIT Jammu. Author(s) are grateful to institutional funding support through Centre for Strategic and Sustainable Infrastructure, IIT Jammu.
Citation
Khajuria, A., Misra, A. and Shiva, S. (2024), "The influence of CMT-MAG and MAG welding-processes on microstructure and mechanical behaviour of C-Mn E410 structural-steels", International Journal of Structural Integrity, Vol. 15 No. 2, pp. 322-342. https://doi.org/10.1108/IJSI-12-2023-0141
Publisher
:Emerald Publishing Limited
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