Operational results on casting round strands using a resonance mould

A resonance mould incorporating a 180-mm-diameter copper tube was installed for testing in one strand of the six-strand round easter operated by Hutte nwerke Krupp Mannesmann (HKM). The mould exhibited good movement accuracy b oth under idle motion and casting conditions. There was no displacement fro m the sinusoidal curve, even at high frequencies. The strand friction was determined on the basis of the driving forces under idle motion and cai-sting conditions. It increases with the casting speed and the stroke length. The asymmetry of the sine movement also has an influ ence on friction. The casting powder consumption relative to the strand sur face decreases with casting speed. The strand surface resulting with a reso nance mould is smoother than that from a standard mould, and the oscillatio n mark depth is not so great. This is presumably attributable to the higher stroke frequency. Increasing carbon levels in the steel also have a favour able effect. Negative asymmetry is more conducive to surface roughness than a uniform sine movement or positive asymmetries. The smoother strand surfa ce leads to less surface defects on hot-rolled tubes and pipes. The casting powder consumption depends on the type of mould movement. Negat ive sine movement asymmetries are less favourable in this respect than posi tive asymmetries. The breakout rate remains unchanged for the different mou lds.