IIW commission II round robin of flux analysis

Abstract

Five commercially available fluxes for submerged arc welding (SAW) were obtained from their manufacturers. The flux identities were coded to prevent identification. These were divided into small quantities and distributed to twelve laboratories for chemical analysis and classification according to ISO 14174:2012. The twelve laboratories were also coded to prevent identification of any particular data set with the participating laboratory. The round robin results showed high reproducibility of analysis of the major flux constituents used for classification, Al₂O₃, CaF₂, Fe/FeO, MgO, MnO, SiO₂, TiO_2, and ZrO₂, except for CaF₂ with the flux Q that is high in iron. CaO is not analyzed according to ISO 14174:2012 but is calculated from whatever Ca remains after subtracting stoichiometric CaF₂ based on F analysis. In most cases, more than one classification according to ISO 14174 could be assigned to a given flux by any of the participants, which is considered unsatisfactory for a classification system.