Microstructure evolution of roll core during the preparation of composite roll by electroslag remelting cladding technology

In the present study, the comprehensive analyses based on the numerical simulation, in situ observation, and metallographic detection were carried out for the roll core of GCr15/45 carbon steel composite roll manufactured by the new electroslag remelting cladding (ESRC) method. During the ESRC process, the temperature distributions at the different radial and longitudinal positions of the roll core have great changes due to the different degrees of heat conduction from the slag bath, as a result, various microstructure and properties were obtained at the different positions of the roll core. The results illustrated that the ESRC process tended to be stable as the composite height reached a certain value and the high-temperature austenitization process mainly occurred in the radial regions where R > 60 mm, whereas no significant changes occurred at the areas where R ≦ 60 mm. The coarse grains and few Widmanstatten structures with proeutectoid ferrite were generated in the roll core areas near the bimetallic interface, while the fine grains with more proeutectoid ferrite were obtained in the roll core area away from the interface. Therefore, a higher tensile strength and a better plasticity were obtained for the specimens away from the interface.

A pileup of screw dislocations against an inclined bimetallic interface

Pileups of screw dislocations against an inclined bimetallic interface are considered. It is assumed that differently oriented pileups are either under the same remote uniform loading, or under the same resolved shear stress along the pileup direction for any orientation of the interface. The distributions of dislocations and the lengths of pileups are substantially different for differently oriented interfaces, particularly in the case of the same remote loading. The interface stresses are also strongly depended on the pileup orientation. The maximum stress can be higher for a pileup along an inclined direction than along the direction orthogonal to the interface. The back stress behind a pileup is evaluated and discussed.