Thin strip casting by a twin roller pilot plant

Water Modeling Evaluation of Metal Delivery in a Twin Roll Strip Caster Using Pool Level and Residence Time Distribution Measurements.

“…Steels such as stainless, 12,13) carbon, 14,15) iron-silicon 16) as well as alloys of nickel 17) and aluminum 18) have already been cast by the twin roll process but those of copper have not been subjected to much experimentation. A research program to evaluate their castability has been undertaken at the Industrial Materials Institute and this study was carried out to identify a suitable nozzle and the effect of key process features related to fluid flow.…”

Review on Vertical Twin-Roll Strip Casting: A Key Technology for Quality Strips

“…This may suggest that solidification is completed at the roll nip point. An increase in roll speed also causes a downward shift of the solidification end point, where the two solidification fronts meet and transverse cracks are found to be eliminated by controlling the roll separating force [18].…”

“…Transverse cracks occur randomly and especially in the initial stage of casting operation which is caused by the fluctuation of the free surface of the molten pool [18,63]. Transverse cracks also related to the hot rolling of the strip before it leaves the roll gap.…”

“…In other words, the supply of liquid metal has to be such that the input and output mass flow rates match. If the metal delivery system is not properly designed, this affects the flow behavior of the liquid metal in the molten pool, which causes free surface fluctuation [18], excessive recirculation of the liquid metal in the molten pool [19], and so forth. The free surface fluctuation on the pool surface and recirculation in the molten pool will affect the solidification phenomena, which results in defects on the strip surface such as (i) thickness deviation caused by pool level fluctuation [20] and (ii) strip roughness which can be worsened by instability in the meniscus shape and so forth [12].…”

“…A thin strip caster has been developed by Shibuya et al [51] which consists of twin cooling rolls to cast 4.5 wt% Si-Fe alloy having 0.2 mm to 1 mm in thickness. A hot model Bessemer type twin-roll caster was established by Fiedler et al [18] to investigate the effect of the key components of this casting machine on product quality and properties of directly cast steel strips. Cook et al [52] developed the twin-roll casting process to overcome some of the shortcomings of the traditional process to increase the productivity and casting of wide range of alloys and avoid the sticking problem.…”