Changes in the structure and properties of high chromium cast iron soldered with carbide encapsulation in a charge of powdered wire
On the basis of the conducted experiments, the effectiveness of the introduction of chromium carbide from the powder wire charge in the form of dispersed particles, previously covered with a protective layer of plastic, during arc welding has been proven. To achieve this powder wire of the brand WELTECH-N630-O was used. The conducted metallographic analysis revealed a difference in the shape, amount and distribution of carbides in the cross-section of the deposited layers of alloys, which are close in composition to high-chromium white cast iron. An increased proportion of carbides in the upper part of the formed layers and a smaller number of cracks is considered a positive fact, which should contribute to resistance during their wear. For the final determination of the type of carbides and matrix in the structure of the deposited layers, microhardness measurements were performed. The addition of plastic to the charge caused a decrease in the initial hardness of the metal of the applied layer by 5.3% compared to the case of using a standard wire. However, the wear test according to the “metal-metal” scheme recorded a decrease in the mass loss of the samples welded with the experimental wire: 0.158 g against 0.208 g in 12 hours rolling friction under a load of 1…1,5 kN.