Study on Wall Thickness Eccentricity of Seamless Steel Tube
Wall thickness is measured by a micrometer on shells after piercing, hollows after rolling and tubes after stretch reducing in an Assel production line for seamless steel tubes. The characteristics of wall thickness eccentricity are exhibited, and the heredity and origin of wall thickness eccentricity are analyzed. Finally, the factors influencing wall thickness eccentricity are discussed. The results show that: (1) Wall thickness eccentricity originates from temperature eccentricity in cross section of round billets, comes into being on shells in piercing process, and is passed down to hollows and finally to tubes; (2) Bigger feed angle of piercing, smaller plug diameter and less stability of plug bar will increase wall thickness eccentricity, while complying to the influence of temperature eccentricity on round billets.
Xianghua Liu, Zhengyi Jiang and Jingtao Han
Q. G. Lv et al., "Study on Wall Thickness Eccentricity of Seamless Steel Tube", Advanced Materials Research, Vols. 148-149, pp. 1071-1074, 2011