PLASTIC FLOW HETEROGENEITY AND FAILURE OF BIMETAL MATERIAL

The aim of this paper was to display the kinetics of Lüders band (LB) propagation of bimetallic material on the yield plateau at the microscale level. The localization patterns of plastic deformation in the process of uniaxial tension were obtained by the non-contact method of recording the fields of displacement vectors. The microstructure of the interfaces with the user results of optical, atomic force and scanning microscopy showed that in the direction of the pearlite steel to the austenitic form there are structural components: the weakened zone of the ferrite layer; a hardened section of the ferrite layer dark-pickling layer from the side of the austenitic steel. Plastic deformation of a bimetal began from the nucleation of the Lüders band on the boundaries of the bimetal on stress raisers with higher hardness due to the diffusion effect. In the main layer, the Lüders band was limited to a pair of fronts moving in opposite directions along the bimetal axis with different velocities. The cladding layer did not suppress the formation of Lüders bands, led to an increase in the propagation velocity of Lüders band fronts in the base layer.