| Due to the poor working environment and complex soil types,the plowshare was worn easily,with large farming resistance and short service life.Frequent replacement of the plowshare not only delays farming time but also wastes resources.In view of the above problems,the wear resistance and drag reduction performance of the ploughshare shovel tip are studied,and the ploughshare spatula tip with wear resistance and drag reduction structure are designed.Through the simulation test and field test,it was found that the wearresistant and drag reducing structure designed in this paper can effectively improve the wear resistance of the plowshare and reduce the tillage resistance of the plowshare.The main contents of this paper are as follows:(1)The wear process,wear failure form,abrasive characteristics,factors affecting the wear of the plowshare,the forces on the three wedges,the normal section of the plowshare,and the forces on the cutting edge of the plowshare blade were analyzed.The wear resistance of common plowshare was tested in the field,and the distribution position of the wear-resistant and drag reducing layer on the plowshare was determined.(2)According to the wear characteristics,mechanical properties and the distribution of wear-resistant layer,the plough tips of B,C,D and E with different wear-resistant and drag reducing layer structures were designed,and the discrete element simulation of the tillage process was carried out.The simulation results show that the wear-resistant and drag reducing properties of B,C,D and E are better than that of A;The Fe base alloy wear-resistant layer and Ni base alloy wear-resistant layer were prepared by plasma spray welding on the plowshare tip based on 28MnB5.The hardness.metallographic structure and impact toughness of each wearresistant layer were studied.The field wear-resistant tests of the plowshare tips with different alloy wearresistant layers were carried out,which provided a reference for the selection of the alloy for the wearresistant and drag reducing layer of the plowshare tip.(3)In order to obtain the wear-resistant and drag reducing layer of plasma spray welding with excellent performance,the orthogonal test of four factors and three levels was designed,with spray welding current,spray welding speed,powder feeding speed and ion gas as factors,dilution rate and hardness as indicators.The best parameter combination of plasma spray welding was determined by range analysis,variance analysis and comprehensive balance method.(4)In order to test the rationality of the design of the wear-resistant drag reduction plough shovel tip and the accuracy of the discrete element simulation model,five different wear-resistance drag reduction structure ploughshare shovel tips were prepared and the resistance and wear resistance test was carried out,the test results show that the wear resistance of the plough shovel tip is E>D>B>C>A,and the drag reduction performance is E>B>D>C>A,compared with the ordinary plough shovel tip A,the wear resistance of the ploughshare shovel tip with wear resistance and drag reduction structure is increased by an average of 20%,and the tillage resistance is reduced by an average of 14.13%.The wear resistance and drag reduction performance are consistent with the discrete element simulation results,and the average drag reduction error is about 2.42%. |
