Draw press method for making seamless steel tube, includes calibration step carried out after normalisation following drawing and cooling

摘要

Normalisation of the hollow block or tube is carried out after the final drawing step and after an intermediate cooling. A calibration step is carried out following normalisation. The tube has an external diameter of 200-1550 mm and a wall thickness of 20-250 mm. The draw-press method comprises heating a cast or extruded block of steel to a temperature at which it is deformable, then pressing to form a hollow block with a base, and then carrying out single or multi-step drawing with intermediate cooling to give the desired end dimensions. After cooling the base is removed and then the tube is normalised and cooled.