The influence of CMT-MAG and MAG welding-processes on microstructure and mechanical behaviour of C-Mn E410 structural-steels

Abstract

PurposeAn 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/approachMechanical 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.Findings0.04wt.%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/valueA 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.

Editorial: Second issue 2024 and IJSI journal awards

“…According to the authors' findings, this novel approach allows for a better understanding of the interconnected effects of material composition, porosity and foundation support on free vibrations, paving the way for the development of tailored nanomaterials with specific vibrational properties for advanced engineering and technology applications. Khajuria et al (2024) developed a study on the influence of CMT-MAG and MAG weldingprocesses on microstructure and mechanical behaviour of C-Mn E410 structural-steels, where 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, and almost ∼10, ∼12.5 and ∼16% increment in YS, %elongation and toughness of 0.17wt.%C E410 steel is observed with CMT-MAG. Tang et al (2024) presented an extension of the application of the original Goodman-Smith octagonal fatigue limit diagram, which is commonly used for the assessment of structure fatigue stress in engineering.…”

“…Khajuria et al . (2024) developed a study on the influence of CMT-MAG and MAG welding-processes on microstructure and mechanical behaviour of C-Mn E410 structural-steels, where 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, and almost ∼10, ∼12.5 and ∼16% increment in YS, %elongation and toughness of 0.17wt.%C E410 steel is observed with CMT-MAG.…”