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Influence of electrode wire feed rate on base metal penetration and geometrical dimensions of deposited beads at submergedarc surfacing was studied. Four flux-cored wires of 1.2; 1.6; 1.8 and 2.0 mm diameter were used in the experiments. Feed rate regulation was performed in the range from minimum value Vf.max, at which a stable surfacing process can be in place for these conditions, and up to maximum value Vf.max = 450 m/h, which was determined by the characteristics of the used surfacing unit. It is found that at surfacing with high wire feed rates, there exists such an optimum ratio of feed rate and other surfacing parameters for each wire diameter, at which increase of this rate leads to reduction of penetration depth and share of base metal in the deposited metal at rising surfacing current. Results, obtained in this work, were successfully applied at wear-resistant arc surfacing of 3 mm steel sheets, and can also be used in selection of modes of arc surfacing of other parts, which to the greatest extent meet their operating conditions, and requirements to deposited metal and base metal penetration. [ABSTRACT FROM AUTHOR]

The design of specimens and methods for experimental evaluation of the fatigue life of multilayer deposited specimens under cyclic mechanical loading were developed. The design of specimens imitates the design of real deposited parts, which allows performing a comparative evaluation of the influence of chemical composition of the base metal and deposited layers, as well as methods and technology of surfacing separate beads or layers on their fatigue life. For studies of fatigue life of specimens, the corresponding loading schemes were chosen, which with certain assumptions reproduce cyclic power loads characteristic for real parts: large-scale gears, pressing screws of rolling mills, mill rolls, MCCB rollers, etc. The results of experimental studies of the cyclic life of specimens by the proposed methods are given. It was established that the developed investigation methods should be used for evaluation of the fatigue life of different parts when choosing materials, equipment and technology of restorative or manufacturing multilayer surfacing. [ABSTRACT FROM AUTHOR]

The paper analyzes the available literature data on the properties of different materials currently used in the means of individual armor protection and the methods for improving their bulletproof and other service properties are evaluated. It is shown that at the present time to create the means of individual armor protection, a variety of materials are used: fabric aramid or polyethylene fibers, metal plates based on steels, titanium, aluminum and their alloys, as well as ceramics based on boron and silicon carbides, etc. The main advantages and disadvantages of these armored materials are shown. On the basis of literary data, it was established that for the 3-5 class of protection, the armored plates of structural alloyed steels were widely used. To minimize the disadvantages inherent in steel armored plates, it is necessary to use bimetallic compositions with alternating hard and soft layers, produced, among others, by welding or surfacing methods. 20 Ref., 4 Tab., 3 Fig. [ABSTRACT FROM AUTHOR]

Effect of amplitude and frequency of plasmatron oscillation on formation of deposited beads, nature of base metal penetration as well as structural and chemical inhomogeneity in zone of joining of deposited and base metal was investigated. The plasmatron oscillation frequency has the largest effect on bead shape and its microstructure, increase of amplitude rises bead width and decrease of its height. Effect of plasmatron oscillation frequency on nature of base metal penetration and chemical and structural inhomogeneity in zone of joining of base and deposited metals along deposition direction was also investigated. In deposition with plasmatron oscillations there is a wavy configuration of interface of deposited and base metals in longitudinal direction with larger frequency of projections and depressions, which repeats plasmatron oscillation frequency. It is determined that increase of plasmatron oscillation frequency on projections as well as depressions on fusion boundary promotes decrease of deposited and base metals and content of main alloying elements rapidly falls. [ABSTRACT FROM AUTHOR]