Title: Electrochemical nondestructive testing for deducing physical and mechanical properties of steels

Authors: Sayed H. El-Nekhaly

Addresses: Delta Steel Mill Co., P.O. Box 13 Cairo, Cairo, Egypt

Abstract: A new idea of nondestructive testing was applied for low and medium carbon steel, and high manganese steel known as Electrochemical Nondestructive Testing (ECNDT). ECNDT depends on the potential data of steel in different concentrations of mineral acid (HCl used for this work). The area under curve in the relation between potential data and corresponding concentrations of HCl could be a representation of metal microstructure in mathematical form. Also, the application of ECNDT depends on selected groups of standard samples, which have two types of elements (main elements and secondary ones). Designed software would be used for dividing the area under curve to a multitude of areas having different values (n)|s. Each n represents a quantity of alloying element of the used alloy. (n) Values will be calculated for both types of elements, but the values of (n)|s for main elements are larger than those of secondary. One part of the software program is used for drawing statistical relationship between mechanical and physical properties data of standard samples (data collected by destructive methods), and (n)|s values of every element. The designed software can be used to calculate mechanical and physical properties of an unknown sample if the chemical composition and hardness value of that sample is available, where the effect of every element in the unknown sample on its mechanical and physical properties can be deduced from the comparison between the data of the same element in the standard samples. In this work, tensile strength, yield strength, elongation, and microscopic structure of 15 standard steel samples of low and medium carbon steel were determined by using destructive testing methods.

Keywords: nondestructive testing; electrochemical NDT; ECNDT; steels; casting; heat treatment; electrochemistry; mechanical properties; physical properties; hardness values; tensile strength; yield strength; elongation; microstructure.

DOI: 10.1504/IJMMP.2007.015317

International Journal of Microstructure and Materials Properties, 2007 Vol.2 No.3/4, pp.402 - 419

Published online: 07 Oct 2007 *

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