Metal Arc Welding of Galvanized Steel

Abstract

The experiment on galvanized steel plate was carried out by manual welding with various types of electrodes and automatic gas-shielded metal-arc welding.
The experimental results were as follows:
1) Good-appearance beads and sound welded joints were obtained by ilmenite, lime-titania and high titanium oxide type electrodes. Appearances of beads by high cellulose and low hydrogen type electrodes were good, but blowholes or slag inclusion in weld metals were observed by the X-ray.
On the other hand, good appearances and sound welded joints were obtained by CO₂, CO₂-O₂, Ar-CO₂ or Ar-O₂ shielded-gas metal-arc welding.
2) Sound welded joints were satisfactory in tensile strength and ductility in comparison with the base metals. Zinc content of weld metal showed no detrimental effect on its mechanical properties.
3) Zinc content of weld metal was the highest by low hydrogen type electrode (0.054%) and it was the lowest by high cellulose type electrode (0.025%).
On the other hand, zinc content of weld metal was the highest by CO₂-O₂ shielding gas (0.037% and 0.044% ) and the lowest by Ar-O₂ shielding gas (0.010% and 0.024%) in the case of high current, high voltage condition and short circuit transfer condition, respectively.
4) Amount of fume of the galvanized steel plate about 2 times as much as that of the not galvanized steel plate in the case of coated electrodes and it was several times with gas-shielded metal-arc welding, especially it was the highest by CO₂-O₂ shielding gas.
And so, it seems that the arc welding of galvanized steel plate has no special difficulty with the precaution of ventilation.