Cold drawing of steel tubes

Precision cold-drawn tubes are produced by cold drawing and cold pilgering. The cold drawing of the tubes is carried out at the so called draw bench, where the diameter of the tube from a larger diameter to the smaller is drawn through the die of certain dimensions. In order to obtain the required thickness of the tube wall and diameter, it is necessary to carry out the annealing before the next draw. This paper presents the results of cold drawn tubes. Research was carried out on steel E355. The tube diameter of 30 mm and wall thickness of 3 mm is drawn to the final dimension of 20 mm diameter and wall thickness of 2 mm. Metallographic tests on optical microscope, static tensile tests and Vickers hardness tests were used for testing tubes after cold drawing. The hardness change in the deformation zone and the degree of hardening during cold deformation in one draw were examined in detail.