Study On Friction Behavior Between Cultivated Sand With High-speed Plow Share In Southern Xinjiang

The friction behavior between soil and metal is widely used in the work of the soil touching parts of agricultural machinery.The wear of the share parts of high-speed plow is especially serious in the sandy soil.Due to the complex composition of soil,the different materials and processing technology of ploughshare parts,and the change of working conditions in actual tillage,the friction behavior between sand and ploughshare parts is very complicated.Moreover,the wear condition in the field is subject to the coupling effect of multiple factors,so it is difficult to analyze the friction mechanism of each factor.To clarify the friction mechanism of each factor has become the focus of the research on optimizing the soil touching parts.Relevant experimental research can provide theoretical basis for structural design optimization and material selection of high-speed plow.Based on the friction and wear testing machine,this paper carried out laboratory tests,designed test components,simplified the friction pair in the actual cultivation of high-speed plow,and simulated the friction behavior between the high-speed plow share and the sandy soil in southern Xinjiang.The main research contents are as follows:(1)Part of the research results,the latest development trends and the main existing problems of the research on abrasive wear of the earth-touching parts of agricultural machinery and its optimization methods were reviewed.Based on the actual ploughing wear condition,the actual friction pair was simplified.Aiming at the problems such as the difficulty in analyzing the friction behavior in the actual ploughing process,the single factor test was carried out based on the sand soil and working condition factors of cultivated land in southern Xinjiang.(2)According to relevant standards,field sampling of cultivated sand soil in southern Xinjiang was carried out,and physical and chemical parameters such as soil moisture content,soil particle size classification,p H value and hardness value were analyzed,and some factors were selected to carry out experiments.Based on the rotary test bench of friction and wear testing machine,independently designed and made abrasive wear test parts,determined the research factors and the optimal level range through the pre-experiment,and improved the test parts to meet the test needs.Five factors including soil moisture content,soil particle size,load,revolution and friction duration were selected to carry out single-factor and multi-level friction and wear tests.By analyzing the variation trend of the friction coefficient in the friction system and the wear amount of the 65 Mn steel high-speed plow share sample with each factor level,the process and characteristics of the change of friction coefficient and wear quality were studied.The wear morphology was characterized by various means to reveal the wear mechanism varying with the level of various factors.The single factor analysis of variance was carried out to compare the experimental results of each factor,and the experimental factors which had a significant influence on the friction coefficient and wear were obtained.(3)With the increase of soil moisture content,the friction coefficient is negatively correlated with the increase of soil adhesion force and lubricating water film,and the wear mass shows a second-order parabola law.The friction coefficient and wear mass are negatively correlated with the decrease of the contact area with the increase of average particle size.With the increase of load,the increase of microcutting or abrasive crushing makes the friction coefficient increase slightly,and the wear quality increase greatly.With the increase of rotational speed,the change of friction coefficient and wear quality is moderate.With the increase of friction time,the friction coefficient and wear amount increase,and the friction between soil abrasives and metals changes to the friction between soil.The wear morphology shows that the metal wear surface is always accompanied by furring,fatigue and spalling caused by abrasive wear,and the soil salt and alkali in southern Xinjiang send corrosion wear to the metal,and the abrasive wear and corrosion wear interact with each other to aggravate the metal wear.The single factor analysis of variance shows that the average particle size and friction time have greater influence on the friction coefficient of sand and 65 Mn steel high-speed plow share samples.Compared with the five factors,the average particle size has the greatest influence on the wear of 65 Mn steel high-speed plow share samples.In this paper,the friction and wear test of cultivated sand soil on 65 Mn steel high-speed plow share sample in southern Xinjiang was carried out,and multidisciplinary research including tribology and soil science was carried out to clarify the conditions and working parameters of cultivated sand soil in southern Xinjiang and the friction mechanism of 65 Mn steel high-speed plow share sample,which is of great significance for promoting agricultural modernization construction in southern Xinjiang.