Abstract
The authors studied to find the most suitable grain size of the flux materials with which to coat the arc welding electrodes.
Three kinds of fluxes respectively with five, two and only one material and five kinds of grain sizes, 200, 120, 70, 50 and 35 meshes respectively were taken.
The coating of coated electrodes, welded conditions and some properties of all deposit metals were tried for investigation.
Coating with large grains under 50 meshes was not satisfactory with regard to appearance and uni. formity. For some grains, many spatterings were found on the welded parts.
Of mechanical properties, impact resistance was better for small grains, while tensile strength, and elongation were the highest for 70 mesh grain size.
The authors concluded that small grains did not always give better properties, but that the range between 70 and 120 meshes or proper combination of grain sizes was most suitable.
