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Grovetown, GA, United States

Fu N.,University of Alberta | Tang X.,University of Alberta | Li D.Y.,University of Alberta | Parent L.,Suncor Energy | Tian H.,GIW Industries Inc.
Journal of Solid State Electrochemistry | Year: 2014

Different phases in a multiphase alloy may act as micro-electrodes, resulting in local or internal galvanic corrosion. Using an electrochemical-atomic force microscope (EC-AFM), we investigated local aqueous corrosion of a high-Cr cast iron in spots at different distances from the primary carbide. Results of the study demonstrated that carbides in the cast iron may not act as effective cathodes due to their high electrical resistivity. Instead, the carbide/matrix interfacial mismatch makes the regions in vicinity of the interface highly anodic, which act as anodes while the regions away from the interface act as cathodes. As a result, the corrosion rate at the interface can be considerably larger than that of regions apart away from the interface. Efforts are made to elucidate relevant mechanisms. © 2014, Springer-Verlag Berlin Heidelberg.

Wang Y.P.,University of Alberta | Li D.Y.,University of Alberta | Parent L.,Suncor Energy | Tian H.,GIW Industries Inc.
Wear | Year: 2011

This study was conducted with attempt to break through the bottleneck using a new concept - high-entropy microstructure. It has been recently demonstrated that an alloy containing more than five elements with the concentration of each element in the range of 5-35% could have a so-called high-entropy microstructure, which is very fine without large-sized intermetallic phases that reduce the resistance to fracture during high-stress wear and impact wear. In this study, this new concept was applied to modify a white cast iron by adding a few carbide-forming elements to the material simultaneously. The carbide-forming elements mutually competed to form their own carbides and this competition also helped to suppress the growth of the carbides, so that carbide refinement could be achieved. Strong carbide-forming elements, Ti, V, Mo and W, were simultaneously added to Fe-20Cr-5C alloy. As the amount of added elements increased, primary M7C3 in the original white cast iron was eliminated with the formation of various finer carbides, including eutectic M7C3, MC and M6C. Compared to unmodified white cast iron, the modified alloys have demonstrated promising improvement in the wear resistance. © 2011 Elsevier B.V.

GIW Industries Inc. | Date: 2011-06-22

Wear resistant, metal claddingfor pumps, cyclones, pipelines and other solids handling equipment.

GIW Industries Inc. | Date: 2012-01-18

Wear resistant white iron for pumps, clycones, pipelines and other solids handling equipment.

Taylor P.,GIW Industries Inc. | Tian H.,GIW Industries Inc.
Materials Science and Technology Conference and Exhibition 2015, MS and T 2015 | Year: 2015

An unusual high temperature failure is presented involving the bearings and drive shaft of a centrifugal slurry pump. The unique characteristics of the failure are explored including localized heating and interactions between the ductile iron bearing collar and the shaft material. Maximum surface temperature of the shaft at the time of failure is estimated to be 2100-2300°F. Partial melting of the ductile iron bearing collar and softening of the shaft appears to have resulted in a form of friction stir welding (FSW). Hardness values in excess of 900 Vickers were recorded around the material interface. It is theorized that rapid diffusion of carbon into the shaft material occurred during failure facilitated by mechanical mixing due to severe high temperature deformation. Graphite nodularity and phase analysis of the ductile iron collar and an embedded ductile iron fragment were conducted by means of microscopy and image analysis. © Copyright 2015 MS&T15.

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