To reduce the elution of hexavalent chromium from unmelted flux and slag (the one in which unmelted flux is contained) generated in welding operation so as to satisfy environmental standards.
A flux raw material containing metallic Cr, a Cr-containing alloy and/or a tervalent Cr compound and a binder are mixed and granulated, and after that, baking is performed at ≤600°C, by which the amount of hexavalent chromium to be eluted (the value by a measuring method defined in 65.2 of the Japanese Industrial Standards K0102, a measuring method mentioned in the attached list 1 of the Notification No. 59 of the Environment Agency in December, 1971 or an elution test equal to those methods) in the flux for submerged arc build-up welding is controlled to ≤0.05 mg/l.
YASUDA KOICHI
NISHIO KANAME
