The object of research is hypoeutectic cast iron intended for cast parts operating under abrasive friction conditions. Such parts are mixer blades, the operational properties of which include durability, assessed by abrasion resistance and strength. To give the blades such properties, cast irons, which are materials of the blades, are alloyed with elements that contribute to the formation of carbides of various compositions. The main problem that impedes the targeted selection of materials for mixer blades or finished blades from different materials or different chemical composition is the lack of substantiated selection criteria. If the shipment is carried out only with the provision of data on the chemical composition of the alloy, it is necessary to be able to evaluate the expected mechanical properties, in particular abrasion resistance and strength. Using the methods of regression analysis, a mathematical model has been obtained that includes two regression equations, which allows for a targeted selection of the chemical composition that provides the maximum possible value of mechanical properties – ultimate strength and coefficient of wear resistance. Optimization of the chemical composition, carried out according to this model, made it possible to determine the following chemical composition: C=2.94 %, Ceq=3.3 %, Ti=1.56 %, providing the maximum ultimate strength σb=391 MPa; C=2.78 %, Ceq=3.14 %, Ti=1.61 %, providing a maximum wear resistance coefficient Kwr=12 %. In the case of priority of the strength criterion, the calculated optimal chemical composition makes it possible to reduce the mass-dimensional characteristics of the mixing units of the mixers. A procedure is proposed for using this model to select a batch of blades with the expected best performance properties

The efficiency of wheeled agricultural tractors when performing traction technological operations is characterized by two aspects. The first of these is traction efficiency, which mainly depends on the coupling weight of the tractor and the perfection of its running system. Another aspect is environmental friendliness, which is determined by the level of compaction impact on the soil. In general, these aspects are oppositely directed. That is, an increase in traction efficiency requires an increase in the grip weight and, as a consequence, an increase in the radial load on the tires and the internal pressure in them. This leads to an increase in tire pressure on the ground and deterioration in their environmental performance. As a result of excessive soil compaction, the yield of agricultural crops is significantly reduced. To solve this problem, it is necessary to reduce the tire pressure on the ground, which can be achieved by reducing the grip weight or developing and introducing new innovative tire designs. But, even new innovative tire designs have corresponding limitations due to the radial load interval, internal pressure, travel speed and the amount of torque on the wheel. These restrictions form the area of possible operating modes of tractor tires, individual sections of which differ significantly in terms of traction efficiency and environmental friendliness. Within the limits of possible modes of operation of the tire, operating modes must be implemented in areas of high efficiency and environmental friendliness. The materials of this article are basic in the study and substantiation of rational operating modes of tractor agricultural tires, and also provide prerequisites for the formation of recommendations for improving the traction efficiency and environmental friendliness of wheeled tractors

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The proposed method allows evaluating an automobile handling with or without accounting withdrawal, with various types of drive wheels and various steering wheels using partial acceleration. Determination of lateral and tangential reactions on automobile tire while turning in view tire slip allows more accurate evaluating of automobile maneuverability, stability and handling. Determination of vehicle total and partial angular accelerations during its driving into rotation with and without accounting withdrawal allows developing an vehicles handling improving algorithm with different tire types. Using of different ways in vehicle managing is complicating associated with machine design and control process by machine handling characteristics changing during applying the locking devices. The equations of front-wheel drive vehicles and all-wheel drive vehicles rotational motion when driving on curves without removal are the same. Appearance of new ways to perform maneuvers such as turning movement with all the drive wheels (4WS), requires researching of movement trajectory, stability and handling of machines during specified maneuvering. The partial acceleration method allows the assessment of the controllability of vehicles with different types of drives (front-, rear - and all-wheel drive) and with different steerable wheels. The determination of lateral reactions on the wheels of the vehicle when turning allows for a more accurate assessment of the agility, stability and handling of vehicles