Surface smoothing process for cold drawn tube - uses progressive local fusing combined with mechanical smoothing to produce hair crack free smooth surfaces

摘要

The arrangement is intended for producing a hair crack-free and smooth metal surface, particularly of a cold-drawn tube (1). The surface is fused to a depth to which any flaws extend and the softened layer (7) thus produced is mechanically smoothed (6). The operation may be carried out with fixed or rotating internal and/or external tools. Fusing, shaping and cooling may be carried out in a protective gas atmosphere and in a continuous process. Fusing may be by laser or electron beam, electric induction, electric arc (2) or a flame.