The Effect of Cyclic Preloading on the Magnetic Behavior of the Hot-rolled 08G2B Steel under Elastic Uniaxial Tension

In order to develop methods for diagnosing the stress-strain state of steel products in view of their history in the form of cyclic loading we study the effect of previous zero-to-tension cyclic loading on the magnetic behavior of the 08G2B steel under subsequent static elastic tension along the same direction. Magnetic measurements were made both in a closed magnetic circuit and by means of attached magnetic devices along and across the tension axis. The history in the form of previous cyclic tension affects the behavior of the magnetic parameters of the material under subsequent elastic static tension. Particularly, the growing number of preloading cycles is accompanied by an increase in the magnitude of applied static stresses at which there are extrema of the magnetic characteristics measured longitudinally. This shift of the extrema of the magnetic parameters is explained by residual compressive stresses increasing with the number of previous tension cycles. At applied tensile stresses ranging between 0 and 100 MPa, the magnetic characteristics measured longitudinally on specimens cyclically loaded with various numbers of cycles vary uniquely. The difference in the values of the coercive force measured longitudinally and crosswise decreases monotonically at applied stresses ranging between 0 and 200 MPa.