NDTnet 1998 Aug, Vol.3 No.8

Abstract

Carbon steel is a material, most often used in modern industry, and the assessment of its structure is an actual problem. Despite the classical destructive tests, researchers use now modern non-destructive ultrasonic and magnetic methods to solve this problem (1,2). One of the basic structure characteristics is the average size of material grains (D) . It is also proved in a number of studies that steel mechanical properties are determined by the grain size. A metal forming regime can be prescribed such that the material gain a complex of needed exploitation characteristics.

Materials can have distributions of grain sizes. These distributions can have effects on the material's mechanical properties that are more complicated than average grain-size dependence. The omission of distribution effects on properties is understandable in view of the difficulties in the experimental measurement of grain volume distribution. This study uses a new approach for the determination of grain size of a steel, employing the function of volume distribution of the grain size F(D) (1,2). The aim of the paper is to develop methods of non-destructive estimation of the grain size distribution by measuring the ultrasonic attenuation, the spectrum of reflected ultrasonic signals as well as the magnetic Barkhausen noise signals. A general class of Fredholm equations of the first kind is used in order to solve this problem.

1. Nicoletti D., A. Anderson, J. Acoust. Soc. Am. 1997, 101,2.
2. RanjanR., D.C. Jiles, O. Buck, R.B. Thompson, J. Appl.Phys.,1987, 61,8.
3. Ivanov V. V., Numerical Methods for Digital Computers Handbook, Kiev, 1986.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

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