Effect of electromagnetic stirring on the microstructure and wear behavior of iron-based composite coatings

The effect of electromagnetic stirring on the microstructure and wear behavior of coatings has been investigated. A series of iron-based coatings were fabricated by the plasma-transferred arc cladding process by applying different magnetic field currents. The microstructure and wear resistance of the composite coatings were characterized by scanning electron microscope (SEM), energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD), and wet sand rubber wheel abrasion tester. The experimental results showed that the microstructure of the coatings was mainly the γ-Fe matrix and (Cr, Fe)₇C₃ carbide reinforced phase. The coatings were metallurgically bonded to the substrate. With increasing magnetic field current, the amount of the block-like (Cr, Fe)₇C₃ carbide reinforced phase increased at first, reached a local maximum, and then decreased sharply. When the magnetic field current reached 3 A, the block-like (Cr, Fe)₇C₃ carbides with high volume fraction were uniformly distributed in the matrix and the coating displayed a high microhardness and an excellent wear resistance under the wear test condition.