Correction of Expansion Rate of Metal Tube-ring

Tube-ring expanding test is an important part for steel tube’s type approval test. ISO 8495: 2004 has not clearly explained how to value the dimensions of the tested tubes after expanding test. On the basis of a lot of experiments in the way of ISO 8495:2004, correcting formulas about size and expansion rate are put forward in this paper aimed at the samples of which fractures are open. The results show the expansion rates of the test pieces mentioned above are relatively bigger and are more reasonable corrected by the size and expansion rate correcting formulas.