36 巻 (2018) 1 号 p. 60-67
Submerged arc welding (SAW) is widely used in heavy industry fields, such as ship buildings or steel pipe mills. Some papers pointed out that recycle use SAW slag to SAW flux is effective to conserve natural resources and also to save flux cost. In this paper, we have compared chemical compositions, crystal structure, and melting behavior between flux and slag in SAW process. Most of chemical compositions of slag were the same as those of flux except Fe and P. Fine metallic steel particles were recognized in slag and the size of them were very similar to welding fume. Major differences were not detected in crystal structure and melting behavior in comparison between flux and slag.