3D imaging and quantification of porosity in electron beam welded dissimilar steel to Fe-Al alloy joints by X-ray tomography

Kar

et al. 2018

Vacuum

Self Cite

Zircaloy-4 to Zircaloy-4 (Zr-4) similar butt joints were prepared using Electron Beam Welding (EBW) technique under different weld conditions such as with beam oscillation, without beam oscillation and at different welding speeds. Three-dimensional (3D) visualization of porosity in weld joints was carried out using X-ray computed tomography (XCT) technique. Quantification of porosity such as the average size, number and shape of the pores were evaluated and compared among weld joints produced under different conditions. XCT results show that the porosity of the welds increased substantially with the increase in the weld speed. More interestingly, the results also show that there is a significant decrease in porosity of the joint produced with beam oscillation condition. An increase in weld speed from 700 mm/min to 1000 mm/min resulted in a significant increase in pore density (from 16 to 313 per mm3) and it was observed that the average size of the macro pores increased from 96.4 µm to 121.5 µm. The joints prepared with beam oscillation produced least number of pores with minimum percentage of macro pores and maximum percentage of spherical pores in it. Raman spectroscopy results confirmed the presence of hydrogen gas in pores of all the weld joints.

Section: A C C E P T E D Accepted Manuscriptsupporting

confidence: 61%

Effect of weld parameters on porosity formation in electron beam welded Zircaloy-4 joints: X-ray tomography study

Bandi

Kar

et al. 2018

Vacuum

Self Cite

“…The lowest number of pores (64nos) was found to be in joint-2 prepared using oscillating beam with lower oscillation diameter of 1mm.The average pore diameter for each joint has also been measured, and it was found that the joint-3 possessed coarser pores having largest pore with diameter of 201µm and smallest pore with diameter of 30µm followed by joint-1 (176µm and 16µm, respectively).Out of the three joints, joint-2 had shown the best results with largest and smallest pores having diameter of 121µm and 11µm, respectively. The morphology of each pore was characterized using a sphericity calculation as given in equation-1 [23]. For such calculations, pores having diameter below 10µm were excluded to avoid uncertainty in estimating their actual surface area.…”

Section: Characterization Techniquementioning

confidence: 99%

X-ray tomography study on porosity in electron beam welded dissimilar copper–304SS joints

Kar

Roy

et al. 2018

Vacuum

Self Cite

Dissimilar joining of copper (C10300) to AISI-304 Stainless Steel (SS) sheets was performed using Electron Beam Welding (EBW) process. EBW was performed for two weld conditions such as with beam oscillation and without beam oscillation. X-ray Computed Tomography (XCT) technique was used for three-Dimensional (3D) visualization and quantification of porosity in the weld region. It was observed that the application of beam oscillation resulted in less porosity and the average pore size was found to be smaller as compared to without beam oscillation condition. Also, pores were found to be uniformly distributed in the weld incase of with beam oscillation as compared to without beam osicllaition condition. Further, it was observed that there exists an optimum beam oscillation diameter beyond which there is no positive effect of beam oscillation in controlling the porosity formation in the weld joint.

“…Due to low heat input, very high power density and 3 zero environmental contamination in EBW, the chances of defect formation is less in EBW dissimilar joints [11].…”

mentioning

confidence: 99%

Microstructure and mechanical properties of electron beam welded dissimilar steel to Fe–Al alloy joints

Materials Science and Engineering: A

Roy

et al. 2016

Self Cite

Electron beam welding (EBW) technique was used to perform dissimilar joining of plain carbon steel to Fe-7%Al alloy under three different weld conditions such as with beam oscillation, without beam oscillation and at higher welding speed. The effect of weld parameters on the microstructure and mechanical properties of dissimilar joints was studied using optical microscopy, SEM, EBSD, hardness, tensile and erichsen cup tests.