Differences between GB standard heavy rail and EN standard heavy rail
GB standard heavy rail and EN standard heavy rail have many differences, mainly reflected in the following points:
Standard-making organization and scope of application:
GB standard: formulated by China's State Administration for Market Regulation and China National Standardization Administration, applicable to China's domestic railway construction and related fields, including inter-regional railways (including high-speed railways, heavy-duty railways), inter-city railways, urban railways and subways in urban rail transit.
EN standard: formulated by the European Committee for Standardization (CEN). Applicable to railway projects that adopt European standards in most European countries and some other regions.
Dimensions:
GB standard: Taking 60kg/m and 75kg/m heavy rails as examples, the height of 60kg/m heavy rail is 176mm, the bottom width is 150mm, the head width is 73mm, and the waist thickness is 20mm; the height of 75kg/m heavy rail is 192mm, the bottom width is 150mm, the head width is 75mm, and the waist thickness is 25mm. The length standards are 12.5m and 25m.
EN standard: The size specifications of EN standard heavy rails are different from those of GB standard. For example, the common 60E1 heavy rail has different dimensions such as rail head width and rail waist thickness from the 60kg/m heavy rail in GB/T 2585-2021, and there may be different regulations on length specifications, but the specific values need to be checked in detail according to the corresponding EN standard.
Technical requirements:
Chemical composition: GB standard has clear provisions on the chemical composition of heavy rails, such as 60kg/m and 75kg/m heavy rails, C (carbon) content is 0.72% - 0.82%, etc. The chemical composition requirements of EN standard are different from GB standard, and the content limits of various elements have their own regulations to meet the use requirements of European railways.
Mechanical properties: The tensile strength of ordinary heavy rails in the GB standard is not less than 980MPa, the yield strength is not less than 440MPa, and the elongation is not less than 10%. The mechanical performance index requirements of the EN standard also vary depending on the specific rail type and usage scenario, but there may be differences with the values of the GB standard.
Hardness: The GB standard stipulates that the centerline hardness of the top surface of the rail head is 260-360HBW, and the centerline hardness of the top surface of the heat-treated rail grade H rail head is 320-420HBW. The hardness requirements of the EN standard are not exactly the same as those of the GB standard, and there are different regulations according to different application scenarios and rail types.
Appearance requirements:
GB standard: It stipulates that within the full length of the rail, the bending sagitta is not greater than 10mm, of which the end is not greater than 2mm within 1m, and there shall be no obvious torsion.
EN standard: The shape requirements such as the curvature and torsion of the rail have their own specifications, which may differ from the GB standard in specific values and allowable deviations.