Effect of friction-induced hardening on the features of magnetic and eddy-current behavior of an annealed structural steel under cyclic loading conditions

Effect of hardening friction treatment with hard-alloy indenter on microstructure, mechanical properties, and deformation and fracture features of constructional steel under static and cyclic tension

“…It should be noted that the formation of dispersed structures and hardening of the surface layer of the steel under the friction treatment can be checked using physical methods of nondestructive testing. Our investigations demonstrated that although the depth of friction hardening is relatively small (the total depth of the layers hardened on two sides accounts for no more than 5% of the thickness of a sample), not only eddy-current, but also magnetic measurements are possible [44]. The structural state of the surface after the friction treatment can be determined from the magnetic parameters (the coercive force in different fields, the residual magnetic induction measured in high and low fields, and the initial magnetic permeability) and the eddy-current characteristics.…”

Certification of hardened surface layers by magnetic and electromagnetic methods

“…5b ); then the contribution of the hardened layer into the processes of reversal magnetization is lowered. Weakening of the contribution of the hardened surface layer into the measured magnetic characteristics upon growth in the total level of deformation of the test piece has been detected [12] under cyclic loading for steel St3 after a hardening friction treatment.…”

“…The coercive force h c measured in weak magnetic fields for particular loops of magnetic hysteresis at maximum magnetic induction b max £ 0.1 T is even more sensitive to friction treatment. This characteristic has grown in experiments by 100% [12].…”

“…As a result of a hardening friction treatment of the surface of steel St3 by a hard-alloy indenter under the conditions of sliding friction the coercive force H c over the major loop of magnetic hysteresis has been shown to grow by 30 -70% with respect to the coercive force in the initial annealed state [12]. This effect is explainable by considerable refining of the structure of the surface layer with a thickness of 70 mm and marked growth in the dislocation density in the layer accompanied by elevation of the surface microhardness from 1.68 to 4.25 GPa.…”

The influence of a combined strain-heat treatment on the features of electromagnetic testing of fatigue degradation of quenched constructional steel

“…It was proposed to use the magnetic, EC, and electromagnetic-acoustic methods for evaluating the accumulated strain and forecasting fracturing under cyclic loading of carbon steels with ferrite-pearlite structures [6][7][8][9], thermostrengthened chromium steel [10], and annealed low carbon steel that was strengthened by frictional treatment [11].…”