engleski

An uneven microstructural distribution in some cold worked tubes

In manufacturing of cold drawn tube some changes in mechanical properties were obserwed. In accordance with literature and results of earlier investigation those changes were atributed to an uneven microstructural distribution. To verify this hypotesis the model sample were used. The samples were prepared from finished rolled tube and finished rolled tube annealed and straightened on a bar straighter with tree pairs of hyperbolic rollers. One with good and other with poor mechanical properties. For measurement samples were cut as pieces of tube using emulsfied coolant. Pieces of the tube that had been removed successively as 1 mm thick tube layers. The obtained pieces were cut into 10 x 10 mm plates and using planning machine successively removed. Thick layer, before measurement the sample surface was prepared by grinding and etching by nital. The X - ray diffraction patterns were collected at room temperature by means of back reflection method and using a Philips counter diffractometar with monochromatizid CoK radiation. The X - ray powder patterns obtained were analyzed visually and by the mathod of Warren Averbach.

microstructural distribution; wall thickness; cold worked tube; mechanical propreties; x-ray diffraction

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