Experimental and Numerical investigation of explosive work hardening process on railway frogs

Document Type : Original Article

Authors

1 department of mechanical engineering, university of science and culture

2 Department of chemistry, Iran University of science and technology, tehran, iran.

3 chemistry and chemical engineering research center

4 chemistry and chemical engineering research center, tehran, iran

5 Research Training center of university of Tehran, Tehran, iran

6 Research Training center of university of Tehran, Tehran, Iran

Abstract

In the railway transportation system, frogs play a crucial role. Frogs provide flexibility in the transportation system due to their intersecting different paths. During the transition of the rail, contact and impact forces are applied to the main body and nose of the frog, causing degradation and wear. Furthermore, impact forces cause extensive wheel damage and higher maintenance costs. As a result, the frog's wear resistance needs to be improved in order to prevent unusual plastic deformations and wear degradation under cyclic loadings. Explosive work-hardening is one of the most effective and cost-effective methods for increasing the hardness of Hadfield's steel to match the properties of railway materials. The hardness of the frog's running surface is between 320 and 390 HBW, according to relevant Standards. The experimental results were validated against FE analysis after calculating optimal explosive energy using a numerical approach, and then the DOI were adopted based on numerical results. According to the FE model, the critical thickness of explosive material is 4 mm, and increasing the thickness of explosive plate significantly increased the hardness. Furthermore, the FEM results revealed that the 5- and 7-mm thicknesses of explosive plate produced the best results in the rail hardening process. The hardness of railway frogs was increased from 161 HBW to 326 HBW and 347 HBW, respectively, by using 7 mm thick explosive plate in the hardening process.

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Iranian Journal of Manufacturing Engineering
Volume 8, Issue 9
November 2021
Pages 23-36

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