Effects of factors on the stability of casting in horizontal continuous casting.

The horizontal continuous casting machine of 2 ton laboratory scale was installed to investigate the basic problems associated with casting round billets of carbon steels and stainless steels.The main results obtained are as follows:(1) The intermittent withdrawal is essential for the prevention of breakout during casting of the billets in the operation of the horizontal continuous casting without mould oscillation.(2) For joining the mould to the tundish, the gap between the mould and the refractory nozzle of the tundish has to be minimized to prevent the molten steel penetration into the gap forming fin shape solidification shell which results in breakout. Nitride refractories, e.g, boron nitride refractory, has been found to give satisfactory results.(3) The deference of the inner diameter of the mould and the refractory nozzle has to be minimized to decrease the discontinuity of solidification morphology beneath the surface of the pull mark.(4) The friction force between mould and solidified shell of stainless steel is larger than that of carbon steel. Nickel plating with solid particle dispersion as a lubricating agent enormously decreases the friction force between the mould and the solidified shell, which enabled casting 150-260mmφ stainless steel billets.