Abstract: Aiming at the serious wear of the copper plate of the mould of the ultra-wide slab continuous casting machine, the reasons were analyzed in combination with the actual situation of the production site and the improvement measures were proposed. By controlling the runout of the foot roller to be no more than 0.5 mm, the accuracy of the zero section and the first section of the segment was increased to ±0.30 mm, which significantly reduced the wear of the wide surface of mould. The coating material of copper plate used a cobalt-nickel alloy, and the surface used thermal spraying surface modification technology and a heat treatment process, the hardness of the coating was increased from the highest 276 HV to 391 HV, an increase by 41.7 %, which enhanced the wear resistance of the coating. After adopting the above measures, the service life of the mould of the ultra-wide slab continuous casting machine can be stabilized to over 800 furnaces, and the improvement effect is obvious.

Key words: ultra-wide slab, mould, cobalt-nickel alloy, longevity