Influential factor to dimensional precision of cold-drawn tubes

Elastic-plastic finite element analyses were carried out to sort out the influential factors on the dimensional precision of cold-drawn stainless steel seamless tube for energy industry. Good agreement was obtained between the predicted dimensions and the measured dimensions of tube after drawing experiment for validity check. Geometrical parameters of tools and geometry of parent tube have little influence on the geometrical precision of finished tube. Most influential factor on the geometrical precision of drawn tube is the temperature of tools. Observation and measurement on a production line showed that the temperature of tools increases according to the increase in the number of drawn tubes. Increase in the temperature of tool leads to the change in the geometry of drawn tube. A methodology for evaluating the thermal expansion of tools is shown to take it into consideration the designing procedure of cold-drawing process by using finite element analysis.