Rail Grinding Study
dc.contributor.author | Börjesson, Maria | |
dc.contributor.author | Emanuelsson, Per | |
dc.contributor.department | Chalmers tekniska högskola / Institutionen för industri- och materialvetenskap | sv |
dc.contributor.department | Chalmers University of Technology / Department of Industrial and Materials Science | en |
dc.contributor.examiner | Ahlström, Johan | |
dc.contributor.supervisor | Steyn, Erika | |
dc.date.accessioned | 2024-10-09T11:57:40Z | |
dc.date.available | 2024-10-09T11:57:40Z | |
dc.date.issued | 2024 | |
dc.date.submitted | ||
dc.description.abstract | During maintenence grinding of pearlitic railway, the microstructure of the rails’ surface layer can transform into martensite. This can have detrimental effects, such as crack formation, due to the brittleness of martensite. To investigate this phenomenon, an industrial grinding machine was used to grind the surface of specimens extracted from rail heads of two different rail grades. These were subsequently examined to see how different grinding parameters contribute to the martensite formation. Among other things, the thickness of the martensite layers was measured, the shape of the layers was examined and hardness in the heat affected region was measured. The main takeaway from this study was that the thickness of the martensite layers decreased with an increased feedrate caused by the shorter contact time between grinding wheel and surface at higher feedrates. This motivates using a high train speed during railway grinding in-field. Several additional discoveries were made during examination. Surface discoloration correlated to different feedrates was found on the ground specimens’ surfaces. A slight fluctuation in martensite layer thickness along the grinding direction was discovered and deemed to be caused by oscillations of the grinding wheel with each revolution. Tests also revealed that the difference in hardness between martensite layers formed in the two different rail grades was smaller than the initial hardness difference of the original pearlitic microstructures. Simulations of the process were made using the finite element method and analytical formulas, in an attempt to estimate the martensite layer thickness. This proved difficult and could only be done by tuning of the energy input to match the computed martensite thickness with the experimentally measured thickness. Further research is needed to predict the martensite layer thickness. | |
dc.identifier.coursecode | IMSX30 | |
dc.identifier.uri | http://hdl.handle.net/20.500.12380/308896 | |
dc.language.iso | eng | |
dc.setspec.uppsok | Technology | |
dc.subject | grinding | |
dc.subject | rail | |
dc.subject | railway | |
dc.subject | martensite | |
dc.subject | pearlite | |
dc.subject | tempered martensite | |
dc.subject | hardness | |
dc.subject | finite element analysis | |
dc.subject | white etching layer (WEL) | |
dc.title | Rail Grinding Study | |
dc.type.degree | Examensarbete för masterexamen | sv |
dc.type.degree | Master's Thesis | en |
dc.type.uppsok | H | |
local.programme | Applied mechanics (MPAME), MSc | |
local.programme | Materials engineering (MPAEM), MSc |