Uncertainty analysis of mechanical properties from miniature tensile testing of high strength steels.

摘要

Boat samples extracted from scheduled maintenance shutdowns of piping and pressure vessels provide opportunities for testing for mechanical properties of the service exposed components. However, it is not clear whether testing of miniature specimens machined from boat samples which are about 2 in. long can be a viable replacement for the standard-sized mechanical testing. Three steels, stainless steel Type 304, sensitized Type 304, and SA516 Grade 70 carbon steel, are tested by standard-sized specimen and miniature specimen tensile tests. Mechanical properties as affected by the specimen geometry and tensile testing procedure for miniature specimen testing are compared to that of conventional specimens tested according to ASTM A370-10. The miniature tensile testing results are analyzed by using Monte Carlo Method (MCM) for uncertainty estimation in order to quantify the probability distribution of mechanical properties. For the steels under study, miniature specimens with a cross-sectional area of 3 mm2 and 12 mm gauge length are found to produce equivalent mechanical properties as tested from standard-sized specimens.