Effect of one-step laser processed biomimetic coupling units' degrees on rolling contact fatigue wear resistance of train track alloy steel

摘要

The working life of train track is restricted by rolling contact fatigue wear. The rolling contact fatigue wear resistance of train track alloy steel is a majority in ensuring the safety of rail transit and prolonging the life of track. To improve the rolling contact fatigue wear resistance of train track alloy steel. The wearable surfaces assembled with different degrees' striation biomimetic coupling units were prepared on the alloy steel by one-step laser remelting processing. The microstructures and micromorphologies of bionic units were characterized by optical microscope, scanning electron microscopy and field emission scanning electron microscopy. The specimens with units were tested for rolling contact fatigue wear resistance. The surface appearances of the test specimens were compared to each other. By finite element analysis, mechanism of the unit on enhancing wear resistance was studied. A discussion on the wearable surfaces assembled with the different degrees' striation biomimetic coupling units was had. Due to shift of surface stress concentration, the specimens with the units presented better rolling contact fatigue wear resistance than the blank sample. And it attributed to different effective length support ratios that the specimens with striation units of 30 and 60 get better wear resistance than the one with striation units of 45 degrees. (C) 2015 Elsevier B.V. All rights reserved.