Effects Of Morphology Coupling And Characteristic Value On The Fatigue Wear Of U71Mn Steel

Steel rail is an important component of the railway transportation system, railwaytransport efficiency and traffic safety is greatly dependent on the quality and property ofsteel rail, with the acceleration of China’s railway system and the development ofhigh-speed rail, the failure caused by fatigue wear on the rail steel is becoming more andmore serious, To reduce the cost of railway operation and ensure the safety of the traffic, it’sessential for us to study fatigue wear and its related problems. Based on previousexperimental results and a deep understanding and mastery of typical biological couplingmechanism, we made hard bionic units with certain geometry on the surface of biomimeticsamples, then, the difference of the fatigue wear performance was compared when themorphology and shape of bionic unit changed, at the same time, the study also focused onthe effect of the distance of bionic units on the fatigue wear properties of biomimeticsamples.Research results show that during the process of bionic coupling treatment, the liquid inthe molten pool is rapidly cooled to form a martensitic structure that Contains a mass ofdislocations, bionic units can hinder the expansion of the fatigue crack because it’s strongability to resist plastic deformation. Besides, the existence of bionic units will generate stressconcentration and decrease the stress of the substrate, so the fatigue wear performance ofbionic coupling samples increase significantly.Deepness of the bionic units is the main factor influencing the fatigue wear performanceof biomimetic samples. When the depth of bionic units increases, the wear resistanceproperties of materials tend to be enhanced. The tensile strength and yield strength ofspecimens with reticulate units is greater than the specimens with punctate and striate units,and the stress concentration of specimens with reticulate units is higher than others style,these reasons make the specimens with reticulate units have the best fatigue wear property. If the samples have the same morphology coupling, the smaller of the distance of bionicunits, the better performance that biomimetic specimens will have. When transverse distanceis5mm and longitudinal distance is4mm, the samples possess best fatigue wear properties.When the distance is greater or less than this optimal value, the performance of biomimeticsamples will decline.