Requirements for making copper ,mould tubeAt present, the copper mould tube of domestic tubular crystallizer are mainly extruded on horizontal or vertical pres

Requirements for making copper ,mould tube

At present, the copper mould tube of domestic tubular crystallizer are mainly extruded on horizontal or vertical presses using convex and concave dies. For copper mould tubes with larger cross-sectional dimensions, the pressure of the press is required to be greater than 800 tons, and the number of extrusion passes should be appropriately increased.

The key to the manufacturing process is the fit between the copper mould tube and the crystallizer, that is, the inner cavity size of the copper mould tube must fully conform to the manufacturing accuracy of the crystallizer. There are two main factors that affect fit:

①The choice of wall thickness deformation

If the amount of deformation of the copper mould tube is selected to be small during the extrusion process, the inner surface of the copper mould tube cannot produce enough plastic deformation, resulting in the copper mould tube not being molded; The wall is straightened, so choosing the appropriate amount of extrusion deformation is the key to affecting the accuracy of the inner cavity of the copper mould tube;

② stress deformation control of copper mould tube forming.

For copper mould tubes with larger wall thicknesses, the deformation of the inner and outer surfaces is different during extrusion deformation: the metal on the outer surface is stretched for a long time, while the inner surface has small deformation or even no local deformation, which causes there is a lot of internal stress in the copper mould tube.

In the subsequent machining of the copper mould tube, these stresses will be released and cause the copper mould tube to deform. Therefore, appropriate technological measures must be taken during the copper mould tube forming process to eliminate internal stress and obtain qualified products.