All papers in this issue are devoted to the 100th anniversary of the birth of the late M. N. Mikheev, corresponding member of the Russian Academy of Sciences and one of the founders of magnetic structural analysis.Abstract -Results of an experimental study of the anomalous behavior of the residual-magnetization hysteresis of ferromagnetic articles that, under local magnetization and magnetization reversal in a pulsed magnetic field with a variable amplitude, were subjected to heat treatment under different conditions are reported. Parameters of the hysteresis and their dependence on the magnetization and magnetization-reversal conditions, as well as on the magnetic properties of a material, are considered.Magnetic methods occupy a prominent place in the theory and practice of nondestructive testing of ferromagnetic articles' strength properties and heat-treatment quality [1][2][3][4][5]. Among these, a pulsed magnetic method, which was developed at the Laboratory of Magnetic Testing Methods, Institute of Applied Physics, Belarussian Academy of Sciences [2, 6], is widely used at many plants in the CIS and other countries.In a general sense, this method consists of, first, the local magnetization (or magnetization followed by magnetization reversal) of an inspected article in a pulsed magnetic field produced by an attachable solenoid and, second, subsequent measurement of the gradient of the normal component of residual-magnetization field strength (RMFS), ∇ H rn . On the basis of this value, the article's mechanical properties and structure are determined using correlation dependences, which were found beforehand in compliance with GOST (State Standard) 30415-96.The method is characterized by simple execution, high sensitivity to the tested parameters of an article, and a weak dependence on the variable gap between a probe and a test object.The pulsed magnetic method is used successfully for the nondestructive testing of strength parameters of low-carbon (08 ÍÔ , 08 û , 3 ÍÔ , 10 ÍÔ , 15 cÔ , 20 cÔ , and 18 ûA ), medium-carbon (35, 45, 50), and lowalloyed (65 É , 30 ïÉëÄ ) cold-rolled steels; medium-carbon (35, 40, 45, 50) and low-alloyed (65 É , 30 ïÉëÄ , 30 í ) hot-rolled steels; and high-alloyed high-temperature steels ( ï 5 å , 1 ï 13, 12 ï 1 åÉ ) subjected to recrystallization annealing. However, this method is unsuitable for testing the mechanical properties of steel articles containing >0.3% C and subjected to quenching followed by high-temperature (350 − 600 ° C) tempering.The aim of this series of studies is to find additional magnetic parameters of an article, which are measured during a change of the pulsed-magnetization modes and allow one to inspect materials belonging to this class. Characteristics, such as parameters of the anomalous hysteresis of RMFS H r and its gradient ∇ H rn upon local magnetization and magnetization reversal of an article in a pulsed magnetic field with a variable amplitude [7], can be used as additional parameters for testing.
MAGNETIC METHODS
