White Etching Layer (WEL) formation in different rail grades after grinding operations in the field

Abstract

Three different rail grades (R260, R350HT and R400HT) were ground in a metropolitan railway using the same parameters of a standard grinding procedure. After the grinding tests, two cross sections of each rail grade were extracted to characterize the microstructure through metallography and microhardness measurements. A White Etching Layer (WEL) was found for the three rail grades. The thickness, angular distribution, and total length of the WEL varied along the rail's head depending on the rail grade. The analysis of the grinding parameters used showed that the conditions imposed involve higher pressures than those typically reported in literature. The results of this study will contribute to improve grinding procedures in the field for specific rail grades used in commercial lines.