Process stability in the thin strip casting process of steel has been investigated with a laboratory pilot caster. Depending on the steel grade and the process parameters irregular process states could be observed. It has been proved experimentally that the observed behaviour is not caused by the regulation system. Investigations of microsections on the cast strips have shown evidence of periodical changes in heat flux during solidification and strip formation as the reason for observed oscillating process variables. Similar to conventional flat rolling forward and backward slip between strip and casting rolls during the joining of the shells can occur. Under certain combinations the process parameters and the cast material a backward‐slip can lead to local lift‐offs of the solidified shells. This circumstance significantly disturbs the heat flux and consequently the solidification, even periodically.

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In industrial applications, filter materials are often chosen according to cost as well as their processing and thermomechanical properties, but rarely in terms of their behavior during filtration, which is largely due to there being insufficient information available on the influence of filter materials and surface quality on filtration behavior. In this study, the manufacture of functionalized Al2O3 nanofilters was investigated, along with their filtration performance in short- and long-term filtration trials. In addition, sessile drop tests were performed to measure the contact angle of the nanofunctionalized materials, and yielded an approximately 10 deg (11 pct) higher contact angle for nanocoated materials sintered at 800 °C and 1250 °C than for those sintered at 1600 °C and an approximately 23 deg (23 pct) higher contact angle compared to surfaces without a nanocoating. The filtration mechanism was assessed by means of Porous Disk Filtration Analysis (PoDFA) and Liquid Metal Cleanliness Analyzer (LiMCA) monitoring systems, as well as by analysis of the used and infiltrated filters using Scanning Electron Microscopy and Energy Dispersive X-ray analysis (SEM/EDX) technology. Both short-term and long-term filtration trials showed that the filtration behaviors of the reference and nanocoated filters were comparable. It was therefore determined that nanocoating of such filters with Al2O3 does not provide any improvement with regard to filtration performance.

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