Ultrasonic investigation of physical mechanical properties of steels

Abstract

Ultrasonic techniques are primarily used in engineering for the purpose of flaw detection in materials and components. Such techniques can also be used for measuring the ultrasonic parameters such as wave velocity and wave attenuation in a material. These parameters are predominantly affected by the structure of the material through which the ultrasonic wave passes. Structure, in turn, affects the properties of the material. The aim of this research is to investigate such effects and to determine any correlation between the ultrasonic parameters mentioned, and the mechanical properties of metals. Usually material properties such as elastic modulus, strength, hardness, fracture toughness, grain size etc. are determined by destructive tests. Such tests not only result in the destruction of materials, but also have other disadvantages such as, increased cost and inability to give reproducible results. On the other hand non-destructive techniques such as ultrasonic inspection can be used for the determination of properties even after the manufacture of the product/component as well as in service, if a successful method is developed. This research concentrates on steels subjected to different heat treatment processes. The initial work was carried out on 0.36 percent carbon steel (AISI designation 4340). The results obtained and the correlation found, between ultrasonic measurements and destructive tests are presented.