COMBINED PIPE END UPSETTING METHOD Russian patent published in 2015 - IPC B21J5/08 B21D41/04 B21K21/12 

FIELD: metallurgy.

SUBSTANCE: heated end of a drill pipe is deformed on a press in a cavity of a split die by means of a movable puncheon in four subsequent upsetting operations. First, deformation of the pipe end is performed only with reduction of the inner diameter of the upset end. For the first upsetting operation, a puncheon and a split die is used, the diameter of the working cavity of which is equal to diameter of the upset pipe in a hot state. For the second operation, a split die which is specified in the first upsetting operation and a puncheon of a smaller diameter is used. For the third upsetting operation, a die of a larger diameter and a puncheon specified in the second upsetting operation is used. For the fourth upsetting operation, a split die specified in the third upsetting operation and a puncheon the diameter of which provides for obtainment of the specified inner diameter of the upset end of the drill pipe is used.

EFFECT: increasing capacity and reducing the time required for replacement of a tool.

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