| 摘要 |
The invention relates to a method for producing bimetallic pipes, consisting of a thin-walled inner pipe made of a high-alloyed or alloyed steel, and an outer pipe made of a non-alloyed or unalloyed steel, which, after being inserted one into the other, are form-fittingly interconnected by expansion under internal pressure, as well as to a device for carrying out said method, comprising sealing heads (3) that can be placed against the pipes (1; 2) to be expanded, for the purpose of supplying the pressure medium. The device is characterised in that a retainer (5) comprising a radially inward-projecting projection (7) is provided on said sealing head (3) for the purpose of securing the inner pipe (1, 1') being expanded, and this can be brought to engage with a peripheral groove (6) on the inner pipe (1; 1'). |
