Comparison of Tensile Properties of 1.25Cr-0.5Mo Steel Characterized by Miniature Specimen and Standard Specimen

Miniature specimen and standard round bar specimen were used to measure tensile properties of a 1.25Cr-0.5Mo steel. The elastic modulus, the yield strength, the ultimate tensile strength and the strain hardening exponent measured by the above two kinds of specimens were compared with each other. It is found that the strength and the strain hardening exponent measured by miniature specimen is consistent with that measured by standard specimen. While the elastic modulus obtained by the miniature specimen is significantly lower than that obtained by the standard specimen. The finite element analysis (FEA) showed that insufficient stiffness of the micro-test tensile stage is the major reason for the lower elastic modulus, while the difference in strength is caused by the various stress state of the two kinds of specimens.