Abstract: The hydro-forming bursting tests of the designed sample of automobile axle housings is done in the commen press, with the utlization of the ultrahigh pressure hydro- forming device integrating the supercharger and the filler within the sliding bulging die. The bulging limit diagram is drawn, according to the different loading path which indicates the matching relation between the bulging pressure and the tubular axial compression. The function between the bulging limit coefficient and the tubular axial strain is revealed , that is, , and kr is related to the percentage elongation of material. The bursting strain criterion and the bursting stress criterion are given, that means the wall-direction strain is equal to the percentage elongation and the circumferencial stress is equal to two times of the strength limit of the material. The results offers a basis to the theoretical research and the practical applying.

Key words: Automobile axle housings, Bulging limit coefficient, Bursting criterion, Hydro-forming, Ultrahigh pressure integrating device