Analysis of Strength Margins for Austenitic Stainless Steel Pressure Vessels

Austenitic stainless steel is widely used for boiler and pressure vessels, however the actual stress-based method to determine the allowable stress limits the full usage of plastic metals such as austenitic stainless steel that with low ratio of yield to tensile strength. The parts of ASME and European codes of pressure vessels have been attention of it and some measures have been taken to increase the allowable stress by decreasing the design factors or change the specified yield strength from 0.2% proof strength to 1.0% proof strength etc.; the other important method is to increase the yield strength by pressure strengthening. A series theoretic computation and experimental analysis were carried out based on the systematical survey of these codes including Chinese GB150, ASME VIII-1, ASME VIII-2, EN13345 and EN13458 etc, and the result showed the difference of allowable stress among these codes and indicated that Chinese GB150 is most conservative with high strength margin, whereas EN13458 attendance with pressure strengthening is the best solution to increase the allowable stress as well, which increased the allowable stress 99.3% than that of GB150.