Abstract

An acoustic method for nondestructive evaluation of variations in the metal structure caused by violations in manufacturing technology or by accumulation of damage during operation has been proposed. The method is based on measuring microstructure-sensitive acoustic parameters, which are determined as normalized deviations of the ratios of the velocities of longitudinal and shear waves from the values characteristic of the “basic state” of the metal structure. Depending on the specific task, for the “basic” one we take the state of metal structure before the start of operation of the test object or the structure of metal in test samples whose strength characteristics are determined by the standard methods of destructive testing and are within acceptable limits. The relationship between the proposed acoustic parameters and the difference between the “basic” and real states of the material (in terms of the integral values of the compliance of microstructural inhomogeneities with respect to shear and longitudinal stresses) is discussed. The effectiveness of the proposed approach to assessing the structure of metal is demonstrated using the results of experimental studies of two essentially different types of structure—with isotropic and anisotropic inhomogeneities. Instrumental verification of the proposed parameters can be used for (1) nondestructive quality control of technological processes in the production of metallurgy and mechanical engineering products; (2) assessment of the degree of in-service metal damage accumulation; and (3) evaluation of mechanical properties, crack resistance characteristics, and other physical properties of metal.

中文翻译：

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声学不均匀性参数用于制造工艺和操作损伤对金属结构的影响的非破坏性估计

摘要

已经提出了一种声学方法，用于非破坏性地评估由制造技术违规或操作过程中的损坏累积引起的金属结构变化。该方法基于对微结构敏感的声学参数的测量，该声学参数被确定为纵向波和剪切波的速度比与金属结构的“基本状态”特征值的归一化偏差。根据特定的任务，对于“基本”任务，我们采取开始测试对象之前的金属结构状态，或者采用强度特征由破坏性测试的标准方法确定并且是在可接受的范围内。讨论了建议的声学参数与材料的“基本”状态与实际状态之间的差异之间的关系（根据微结构不均匀性相对于剪切应力和纵向应力的积分值）。通过对两种基本不同类型的结构（各向同性和各向异性不均匀性）进行实验研究的结果，证明了所提出的评估金属结构的方法的有效性。所建议参数的仪器验证可用于（1）冶金和机械工程产品生产中工艺过程的无损质量控制；（2）评估在役金属损伤累积程度；（3）评估机械性能，抗裂性能，