Determination of Tensile Properties of Low Carbon Steel and Alloyed Steel 34CrNiMo6 by Small Punch Test and Micro-Tensile Test

The mechanical properties evaluation of the structural materials is one of the key points for a reliable integrity assessments and correct residual life predictions. However, the experimental material for testing samples is difficult to obtain in many cases. Therefore, non-destructive techniques are being developed as well as testing methods using mini-samples enabling conversion of the obtained results into conventional parameters such as tensile properties. One of the methods of the highest interest is small punch test (SPT). The advantage of the SPT is a requirement of only very small volume of the experimental material. Disadvantage is the way of loading, which is not uni-axial as in the case of tensile test and correlation between SPT and tensile test must be always verified. Considering SPT samples size, there is a chance to machine micro-tensile samples from the same material volume and perform real tensile tests on such samples. This kind of tests would maintain minimal material requirements, the same loading mode of samples as in the case of standard tensile tests and at the same time enable direct results conversion into standard terms. Proposed methods for tensile properties evaluation from small punch tests and micro-tensile test are applied to several materials. The correlation between small punch test results, micro-tensile test result and results of conventional tests are investigated in this paper.