Pre-hardened Manganese Crossing

This part corresponds to a monoblock crossing, with the only exception of the length of the fishing table. Closure rails are flash-butt welded to the four ends of the central block using a special flash-butt welding technique (intermediate piece welding). The bearing surfaces (seat of the plates) as well as the complete area of the running and head surfaces are milled and/or planed. The thus achieved manufacturing accuracy facilitates optimal wheel overrun and interchangeability of crossings on existing sets of plates.

Materials and quality inspection:

• Rail in line with rails steel within turnout
• Crossing: High-manganese steel (13% Mn) according to EN 15689
• Visual and geometric check
• Penetration test: Flash-butt weld
• Radiography test: Prototypes
• Mn13 casting according to EN 156

Process for increasing the surface hardness of manganese crossings. The hardness of the entire running surface of the crossing is raised through a targeted explosion hardening. In the area of the running surfaces and running head, blasting mats are placed and detonated. Through this procedure, the high-manganese steel is subjected to work-hardening, which corresponds in principle to the work-hardening process during train operation. This explosive hardening provides in advance some of the work-hardening which occurs during train operation and increases the hardness in the wheel contact area to 321 - 350 HB, depending on the requirement. As this procedure is applied not only in the overrunning area but the whole length of the crossing, a constant hardness curve is guaranteed.

Quality inspection:

• Visual and geometric check
• Penetration test - crack test: Complete running surface