A new hardfacing alloy within the Fe-Ti-Nb-Mo-V-C alloying system was utilized to restore the working surfaces of cone crusher rotors using Flux-Cored Arc Welding (FCAW). TiC, NbC, Mo2C, VC, Mn, and ferromanganese powders were selected as the base materials for manufacturing the welding wire. The resulting hardfaced layer exhibits a composite structure, with manganese austenite as the matrix and complex solid solution reinforcements with a NaCl structure, closely resembling the formula (Ti0.3Nb0.3Mo0.3)C. The primary advantages of this hardfacing alloy include its capacity for intensive deformation hardening along with high abrasion resistance. The hardness of the hardfaced layer is approximately 47 HRC in the as-deposited state and increases to around 57 HRC after work hardening, surpassing typical hardfacing alloys derived from high manganese steel by about 10 HRC. The efficacy of the alloy was tested in restoring rotors made of Hadfield steel in a PULVOMATIC series crusher model 1145, during the milling of sand-gravel mixtures ranging from 25 to 150 mm into spalls measuring 5 to 20 mm. With an average productivity of approximately 60 tons per hour and a production volume of 300 tons, the utilization of this hardfacing alloy enabled multiple restorations of the rotor while maintaining productivity at a level of 15 thousand tons of spalls.
Using the example of washing machines using the linear theory of vibrations, the dynamics of horizontal rotary drum machines is investigated and the basic requirements for their layout are formulated to reduce vibration activity. The mathematical equations of vibrations of the multiply connected system tub-drum on elastic suspensions are compiled for main types of washing machines and centrifuges with horizontal axis of rotation. The problem is solved in a linear setting based on the Lagrange equation of the second kind. The accuracy and adequacy of the mathematical model was tested directly on a full-scale object by measuring noise, vibrations, support forces and stress distribution in individual elements and units of the washing machine in the entire range of drum rotation frequencies. Investigations of the nature of system vibrations depending on changes in the position and attachment points of elastic and damping elements were carried out using simulation in the Simulink environment. As a result of the research, the basic requirements for the layout of horizontal rotary drum machines were experimentally confirmed. Experimental verification was carried out to confirm the results obtained. It has been experimentally proven that the improvement of the experimental setup to reduce its vibration activity increases the efficiency of using direct-acting liquid autobalancers.
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