| 摘要 |
PURPOSE:To produce the title casting mold for continuous casting having excellent durability, by treating the melt injecting surface of a casting mold made of a Cu-Ni-Si-Zn copper alloy of a high-Si content with an aq. soln. contg. NH4F.HF, and then plating the surface with an Ni-P or Ni-B alloy. CONSTITUTION:A casting mold is made of a Cu-Ni-Si-Zn copper alloy contg. >=0.1wt% Si. The melt injecting surface of the casting mold is treated with an aq. soln. contg. 10-500g/l ammonium hydrogen fluoride (NH4F.HF) or the aq. soln. mixed with a mineral acid such as sulfuric acid, hence the oxide film consisting essentially of SiO2 is uniformly and rapidly removed without etching the Cu in the base material, and the surface is activated. An Ni-P alloy or an Ni-B alloy is then plated thereon is about 20-500mum thickness preferably by electroplating. By this method, a casting mold for continuous casting having high strength and excellent heat resistance and with the durability improved by the highly adhesive Ni alloy plating is obtained. |
