Instrumented indentation testing (IIT) is extensively and successfullyused as an alternative technique for investigations of the mechanical properties of steels, where traditional specimens, such as round bar specimens for tensile tests, are not acquirable. The IIT is based on an assumption that the true stress-strain curve of the analyzed sample follows one of the known constitutive equations, such as the Hollomon, Ludwik, Swift, or other predefined equations. However, steel samples exposed to extreme conditions, such as media with high-temperature or neutron irradiation may exhibit a novel stress-strain relation that follows an unknown constitutive equation. In this situation, the accuracy of the IIT may be doubtful. This article proposes a constitutive model independent technique, called macro-pillar compression testing (MPCT), where constitutive equations are not necessary. The MPCT was conducted on a specimen with pillars and established on the theory of the compression testing. In this study, a modified imaginary radius function was proposed for the pillar to consider its sinking and barreling effect during the compression. Finally, three different types of steel (austenitic stainless, low-alloy and low-carbon steel) were used to verify the accuracy of the MPCT. Both MPCT and round bar tensile tests were performed on each type. The test results show that the true strain-stress curves obtained by MPCT have a good agreement with the corresponding curves by tensile tests.

仪器压痕测试（IIT）已被广泛成功地用作替代钢的机械性能研究的替代技术，而传统的标本（例如用于拉伸测试的圆棒标本）是不可获得的。IIT基于以下假设：被分析样品的真实应力-应变曲线遵循已知的本构方程之一，例如Hollomon，Ludwik，Swift或其他预定义方程。但是，暴露于极端条件下的钢样品（例如带有高温或中子辐照的介质）可能表现出遵循未知本构方程的新型应力-应变关系。在这种情况下，IIT的准确性可能会令人怀疑。本文提出了一种独立于本构模型的技术，称为宏柱压缩测试（MPCT），不需要本构方程的地方。MPCT在具有支柱的标本上进行，并建立在压缩测试的理论基础上。在这项研究中，提出了一种修改后的虚半径函数，该函数考虑了在压缩过程中的下沉和滚沉效应。最后，使用三种不同类型的钢（奥氏体不锈钢，低合金钢和低碳钢）来验证MPCT的准确性。每种类型均进行了MPCT和圆棒拉伸试验。试验结果表明，通过MPCT获得的真实应变-应力曲线与通过拉伸试验得到的相应曲线具有良好的一致性。提出了一种修改后的虚半径函数，用于考虑柱在压缩过程中的下沉和桶形效应。最后，使用三种不同类型的钢（奥氏体不锈钢，低合金钢和低碳钢）来验证MPCT的准确性。每种类型均进行了MPCT和圆棒拉伸试验。试验结果表明，通过MPCT获得的真实应变-应力曲线与通过拉伸试验得到的相应曲线具有良好的一致性。提出了一种修改后的虚半径函数，用于考虑柱在压缩过程中的下沉和桶形效应。最后，使用三种不同类型的钢（奥氏体不锈钢，低合金钢和低碳钢）来验证MPCT的准确性。每种类型均进行了MPCT和圆棒拉伸试验。试验结果表明，通过MPCT获得的真实应变-应力曲线与通过拉伸试验得到的相应曲线具有良好的一致性。