Abstract
Arc sprayed coatings from Fe-Cr-B-Y cored wires additionally alloyed by Al, Si, C were studied. SEM and XRD analyses, microhardness characterized their morphology, microstructure, and phase composition. The coatings were also evaluated by two-body abrasive wear test, and heat resistance test in air, 700°C, 100 h. Among compared coatings, the Cr12B5Al5Y one with maximum Al and minimum C content showed better indicators of porosity, adhesion strength, wear- and heat resistance comparing to other coatings alloyed with Si or less content of Al. It is resulted from the largest quantity of the carbon enriched eutectic containing reinforcing carboboride phases (Fe, Cr)2B, Fe2(C, B), and a rational ratio of the alloying elements. As shown, Cr12B5Al5Y coating wear resistance is more than twice as high comparing to the coating from typical wear resistant 150Cr8Ti2Al cored wire. The latter one consists of martensite phase, forming from the metastable austenite during loading, and chromium carbides. Weight loss tests showed that coatings from studied Fe-Cr-B-Y cored wires are of the same heat resistance level as the austenite steels and 1-2 orders of magnitude higher as compared to the pearlite and ferrite-martensitic steels, which are widely used as boiler's materials.
