Abstract
Althouth it is well-known that the weld metal by CO2 welding has better toughness and static mechanical properties than those by coated electrode manual arc welding, CO2 welding gives more rough andirregular bead shape in comparison with other welding processes using flux.
Therefore, it is not clear, whether CO2 welded joint with higher toughness and ductility may give the higher fatigue strength than coated electrode welded joint, because fatigue strength of welded joint is strongly influenced by geometry at the toe of bead.
This study was carried out to compare fatigue strength of full- and semi-automatic CO2 welded joint with that of coated electrode manual arc welded joint of previous report.
The obtained results were as follows;
1) Fatigue strength by full-and semi-automatic CO2 welded joint was almost the same level.
2) Full-and semi-automatic welded joint had a little lower fatigue strength than that of coated electrode welded joint; This was attributed to the sharp toe geometry.
3) Fatigue design strength may be proposed as 14kg/mm2 for CO2 flat positoned full-and semi-automatic, and vertical positioned semiautomatic welded joints.
