Abstract: The math models of slag detachability for basic self-shielded flux-cored wire (SSFCW) are presented. The prescription with good slag detachability is adjusted through the material-mixed regression design. The effects of flux-cored composition and slag microstructure on slag detachability are investigated for both the self-made wires and NR331, made by Lincoln Electric Co. ,Ltd. The results indicate that there is a different slag microstructure in different surfaces of the slag. The main factors affecting slag detachability are white strip, nodular and granular calcite, which have an influence on liner expansion coefficient, transformation stransformation stress and constrain stress of the slag respectively. This study is helpful in improving the quality of basic SSFCW.

Key words: Material mixed regression design, Self-shielded flux-cored wire (SSFCW), Slag detachability