Many copper mould tube manufacturers are trying to improve their service life.
First, the single cone of copper tube inner wall was designed as multi cone, and then developed to parabolic surface.
From the copper tube raw materials, from pure copper, phosphorus copper to silver copper and chromium zirconium copper. Promote thermal conductivity, improve deformation resistance and service life.
However, the traditional process of hard chromium coating is still used in the inner wall of copper tube. The chromium coating has high hardness and good wear resistance, but the coating is thin with fine cracks.
In addition, the coefficient of thermal expansion of chromium is quite different from that of copper. More transverse cracks will appear at high temperature. In the continuous casting process, molten steel penetrates into the copper surface through cracks, producing more cracks. Therefore, in the long-term corrosion of molten steel, the chromium plating layer will be powdered and fall off, and its wear resistance will be greatly reduced. The chromium plating layer will wear quickly in the casting process, and its wear resistance is limited and its service life is short.