Effect of a weak magnetic field on stepwise deformation of lead in the large strain region

Precision measurements of the strain rate of lead at constant stresses in a magnetic field and without field and changes in the strain rate resulting from field turn-on and -off have been performed by the interferometric method. It has been shown that the entire stress-strain curve in the field and without field consists of steps of different amplitudes and lengths: from several tens of nanometers to several hundreds of micrometers. The magnetic field causes a certain strain enhancement and the redistribution of contributions of steps of different values. The magnetic field turn-on during creep results in a sharp increase in the strain rate, followed by its drop to the values larger than or close to those before the field turn-on. The field turn-off is accompanied by the reverse effect. The characteristics of strain steps at various scale levels and the magneto-plastic effect depend on the strain rate and the strain value. The observed features in the behavior of lead are related to its possible multiple recrystallization during creep.