Thesis is devoted to the development of technology for the restoration and hardening of plowshares, which takes into account the conditions of their use. The process hardening of plowshares by applying wear-resistant layers has been investigated.
It was found that according to the influence of the wear capacity on the nature and intensity of wear of the plowshares, it is advisable to divide the soil according to the content of abrasive particles with a size of ≤ 1 mm by:
- clay and clay loamy, where the plowshares reach the limiting state through bluntness and wear in width;
- sandy and sandy loamy, where the plowshares reach the limit state due to wear by thickness.
For a plowshare with parameters: blade width Вл = 120 mm, toe width Вн = 143 mm and limit width Вгр = 90 mm the rational value of the coefficient of wear intensity of the plowshare elements is determined Ki = 0,57.
The theoretical dependence of the rational diameter d of point hardening in the sock part on the relative wear resistance of materials for hardening the sock and the plowshare blade is established.
For material steel 65G, at speed of electroarc V = 0,01 m / s, temperature of the liquid environment Tр = 20 oC, angles of sharpening of a plowshare β = 15 degrees, thickness of a plowshare δ = 0,01 m, rational values of power of electric current P, which is 16971-26518 watts.
It was found that for sandy and loamy soils the coefficient of plowing was equal to 0.88, and for clay and loamy soils - 0.96. The coefficient of plowing was 0.12 for sandy and loamy soils, and 0.04 for clay and loamy soils.
The geometrical parameters of repair inserts of blades (590х30х10 mm) and socks (160х60х10 mm) of plowshares were determined and the designs of devices for their welding were developed.
Rational modes of electroarc of plowshares for conditions of their use in sandy soils are established: current I - 400-450 A, voltage U - 50-55 V.
Rational modes of electroarc of plowshares for conditions of their use in clay soils are established: current I - 380-430 A, voltage U - 50-52 V.
Rational modes of spot surfacing of details are established: current I - 200-250 A, voltage U - 35-40 V.
Rational schemes of plowshares operated on soils of different wear capacity have been established: for sandy and loamy soils the electroarc of the blade is carried out from the working side to a width of 20-25 mm, and the sock is additionally hardened by spot surfacing; for clay and loamy soils, the electroarc of the blade is carried out from the non-working side to a width of 20 to 25 mm and the end points of the blade are additionally hardened by electroarc to ensure the width of the plowshare.
It was found that on sandy and loamy soils serial plowshares are discarded prematurely due to linear wear of plowshares in thickness with the formation of radial – 6 ha, and the resource R of reinforced plowshares is 1.3 times greater and is - 7.9 ha. The wear rate of serial plowshares is 0.48 mm / ha, hardened - 0.37 mm / ha.
It was found that on clay and loam soils serial plowshares reach the limit state due to linear wear of the sock in width at 19.5 and the resource of reinforced plowshares R3 is 1.4 times greater than that of serial plowshares, and is - 28.1 ha, the intensity of wear of socks and blades of serial plowshares is 2.53 mm / ha and 1.39 mm / ha, respectively, and socks and blades of reinforced plowshares, respectively, 1.82 mm / ha and 1.01 mm / ha.
Group processes of restoration and hardening plowshares of were developed taking into account the conditions of their use on soils of different wear capacity with productivity of process of 20 plowshares / h, which provides the following operations:
- for clay and loamy soils: trimming of the worn part; making blades and socks; welding of blades and socks to a skeleton; electroarc; point hardening.
- for sandy and loamy soils: trimming of the worn part; making blades and socks; welding of blades to a skeleton; electroarc of socks and welded blades; welding socks to the frame with a welded blade; point hardening.
The parameters of the bay on restoration of plowshares have been substantiated.
Processes of restoration and hardening of plowshares, taking into account the conditions of their use on soils of different wear capacity, were introduced in four agricultural enterprises.
The estimated annual economic effect from the implementation of the developed processes in the state enterprise “Research farm “Tuchin”, Rivne region, Goshchansky district, village Tuchin (1636.7 ha of clay and loamy soils and 327.3 ha of sandy and loamy soils) is UAH 20018.93.
