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Arc cladding technology is a low-cost and efficient remanufacturing method.High-chromium cast iron welding wire is one of the common wear-resistant flux-cored wire systems.In order to investigate the effects of Mn and B elements on the microstructure, hardness and wear resistance of the high-chromium cast iron flux-cored wire arc cladding remanufacturing layer on surface of Q345 steel plates, the microstructure, elemental composition, hardness distribution, wear process and mechanisms of the cladding layer were characterized and analyzed using optical microscopy,energy-dispersive spectroscopy(EDS),X-ray diffraction(XRD),friction and wear testing machines,super depth-of-field microscopy and electron microscopy.Results showed that during the arc cladding process, electrolytic manganese and ferroboron powders dissolved and interacted with elements in the cladding layer to form blocky and lath-like primary carbides and eutectic structures.The microstructures of the cladding layers mainly consisted of M7C3(M for Fe,Cr and Mn),M3C,Fe23(C,B)6,martensite and retained austenite phases.With the increase in Mn and B content, the surface hardness of the cladding layer gradually increased.When the Mn content added 0.07%(mass fraction),the hardness of the cladding layer increased by 10.64%.Further addition of 1.20%(mass fraction) of B element resulted in an additional 27.84%increase in surface hardness of the cladding layer.The wear resistance of the cladding layer surface first increased and then decreased with the increase in Mn and B content.The cladding layer with mass fractions of C, Mn and B at 4.00%, 0.80% and 0.80%, respectively, exhibited the highest wear resistance, being 23.06 times that of Q345. |
