NDTnet 1998 Aug, Vol.3 No.8

Abstract

In accordance with the specific example of relations of strength value Gb, yielc strength _y, percentage elongation ₅, coercivity H_c, remanent magnetic induction B_r, and maximum magnetic permeability µ_max to final rolling temperature in the case of plates of the St3sp steel grade (the GOST 380-71 standard) with different reduction levels (from 20 to 76 %), it has been demonstrated that the coercivity is a most suitable parameter for nondestructive evaluation of mechanical properties. Correlations of _b, _y and ₅ to H_c for cold-worked and heat-treated pipes of the 20k steel grade are represented. Correlation _b and _y to H_c is positive and linear. Correlation of percentage elongation is negative and nonlinear: dispersion of experimental data observed at low H_c values is relatively large, and ₅ abruptly diminishes with the growth of H_c so as to facilitate a reliable rejection of pipes by H_c at low ₅ values.Plates of the 09G2 steel grade (the GOST 5058-65 standard) having their thickness from 18 to 20 mm were inspected by the KWM-1 coercimeter, and the suitable interval of indicated value I_rc was determined to inspect mechanical properties (among them - percentage reduction of area, , and impact strength at -40°C, KCU(40)) of the plates at the confidence level 0.95.The method for nondestructive evaluation of mechanical properties of rolled lowcarbon and low-alloy steel products has been introduced at many metallurgical and tube plants in Russia. The annual amount of tested metal accounts for more than 20 million tonnes.

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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