Abstract: In view of low steel passthrough amount phenomenon of mould copper tube in small billet continuouscasting, the factors influencing the service life of copper pipe from the mold assembly and process were analyzed. Through optimizing mould copper tube material, size, taper and water slot width, improving the cool water quality, water pressure and the cooling water flow rate and reducing liquid steel superheat in tundish and properly decreasing casting speed, average steel passthrough amount per mould copper tube has been increased to 7 820 t after the optimization, the highest one being 9 510 t per copper tube, and numbers of nonnormal casting stop per month has been decreased by 10 times averagely, which saved 180 min. As a result, the production costs has been reduced, the production stability has been ensured and the economic benefit of the enterprise has been increased.

Key words: billet continuouscasting； mould copper tube；service life；equipment improvement, process optimization