自动球压痕法测试材料力学性能的机理和普适性研究

In this proposal, the non-destructive testing method for steels used in process industry equipment and its theoretical basis will be studied by theoretical analysis, material`s destructive testing，automated ball indentation testing, and finite element numerical simulation methods, et al. The research content includes: (1)To research the mechanism of ball indentation deformation and its relation with the material rupture properties, and to establish a method reversing stress-strain relationship from the automated ball indentation test results; (2)To give a method of estimating the yield strength and tensile strength of non-power law hardening materials，which is based on the automated ball indentation test results and stress-strain relationship; (3)To propose a method of estimating material`s impact absorption energy and fracture toughness by the automated ball indentation test results and impression microanalysis; (4)To research the variation rule of the stress concentration and residual stress caused by the residual impression, to analyze and evaluate the effect of the residual indentation on the surface durable properties of materials in service, and to propose ball indenter selection criterion. The researchers will build a reliable technical method of the non-destructive testing for industrial material properties in service, demonstrate the univerality of the method, and provide the theoretical basis and scientific guarantee for the service safety of industrial equipment.

本课题采用理论分析、材料破坏性和自动球压痕无损试验研究、有限元数值模拟等方法，研究过程工业装备常用钢力学性能的无损测试方法及测试理论基础，主要包括：（1）研究球压痕变形及其与材料破坏性能相互关联的机理，提出由自动球压痕试验结果反求材料应力应变关系的方法；（2）以反求的应力应变关系和自动球压痕试验结果为基础，给出估算非幂强化材料屈服强度和抗拉强度的方法；（3）基于自动球压痕试验和压痕显微分析结果，提出估算材料冲击吸收能量和断裂韧度的方法；（4）研究残余压痕的应力集中和残余应力变化规律，分析评价对材料表面服役性能的影响，提出球压头选择准则。本课题研究为服役材料性能的无损测试提供可靠技术手段和方法，论证方法的普适性，并建立和完善测试理论体系，为工业装备的安全服役提供科学保障。

采用理论分析、传统材料破坏性和球压头压入试验研究、有限元数值模拟等方法，研究了常规压力容器、核容器、离心压缩机叶轮常用钢和钛合金力学性能无取样测试的方法及理论基础，主要包括：（1）揭示了球压痕变形及其与材料破坏性能相互关联的机理，通过引入试验终了时的压痕塑性区半径，提出了在不预设材料本构关系条件下，由自动球压头压入试验结果获得材料应力应变关系的方法；（2）通过自动球压头压入试验获得的应力应变关系为基础，给出了估算强化和非幂强化材料屈服强度和抗拉强度的方法；（3）基于自动球压头压入试验与拉伸、剪切、压缩、I型和II型裂纹断裂试验试样的显微分析，揭示了估算材料断裂韧度的机理，给出了估算材料断裂韧度方法；研究材料冲击吸收能量的估算（4）研究了残余压痕的应力集中和残余应力变化规律，分析了评价对材料表面服役性能的影响，提出了球压头选择准则。本课题的研究为服役材料性能的不取样测试提供了可靠技术手段和方法，论证了方法的普适性，并建立和完善了测试理论体系，为工业装备的安全服役提供科学保障。