TABLE OF CONTENTS A major advantage of DSC lies in the reduction and/or elimination of the large number of secondary processing steps required to produce strip in an integrated mill. However, DSC produces near-net-gauge strip and both a sound surface condition and internal quality are required since only limited secondary processing is available to alter these parameters. The following discussion, while not exhaustive, outlines some of the common types of quality-related problems associated with strip casting. A more detailed account of the influence of processing conditions on the properties of cast strip products is available in the reviews by Merchant et al. (1989), Cramb (1995) and Blejde et al. (2000a,b).
It was pointed out in 4.3.1.1 that the formation of inclusions in the ladle, tundish and mould can cause nozzle blockages and inclusion/mould interactions at the meniscus region during casting. The size, number and distribution of inclusions must therefore be controlled for adequate internal and surface strip quality. Porosity is also a potential problem in the as-cast strip and is usually associated with uneven solidification which can be avoided by good control of mould condition, melt chemistry and degassing; the removal of hydrogen is particularly important in aluminium casting. Any shrinkage porosity associated with TRC can be reduced by a small degree of hot rolling through the roll bite of the caster.
Depending on alloy type and casting condition, various segregation-related defects can form in twin roll...
