Wettability of Mold Flux with Various Droplet Size on Stainless Steel Substrate

Wettability of mold flux on stainless steel is a very important index to reflect the possibility of slag entrapment during the continuous casting process. In this study, the wetting behavior of mold flux droplet with different size on stainless steel is investigated using sessile drop method. Results show that the contact angle at 1573 K increases from 64.62 +/- 0.25 degrees, 62.56 +/- 0.2 degrees to 61.46 +/- 0.2 degrees and 60.56 +/- 0.2 degrees, with the size of the original flux sample increasing from 3, 4 to 5 and 6 mm. No chemical reaction occurs at the interface between mold flux and steel substrate via the thermodynamic calculation and microstructure analyses. Furthermore, the line tension of flux droplet/stainless steel/Ar-5%H2 system ranges from 160.55 to 125.19 mN m-1 at the temperature range of 1473-1573 K. It is due to the positive line tension (line energy) which decreases the wettability of flux droplet on steel substrate and results in an increase of contact angle when the droplet size reduces. The contact angle decreases with the increase of flux droplet size as suggested by the sessile drop test. The line tension is positive at the temperature from 1473 to 1573 K, which indicates that it is the line energy that decreases the wettability of flux droplet and results in an increase of contact angle with the reducing of droplet size.image (c) 2024 WILEY-VCH GmbH