COMPREHENSIVE AND DIVERSE WELDING OPERATIONS
MATISA has therefore kitted out its construction and production departments with the very best equipment. Out of a total 500 employees, 100 are engineers who look after the different levels of electrical and mechanical structures in the trains. Of the 400 staff in the production department, 50 are fitters and welders.
MATISA is EN 15085-certified and processes metal sheets and profiles made from conventional construction steel (S355) with thicknesses of between 10 and 200 millimeters to construct the trucks, bogies, and superstructures. The welding operations are diverse and comprehensive, accounting for around one-third of the time needed to build a tamper. Even for relatively simple products, such as transport wagons, hundreds of meters of weld seams are needed. After all, these wagons are 25 meters long, made out of metal plates with different widths, and are welded together from prefabricated five-by-five meter long box sections.
Each truck must comply with a geometrical dimensional record with extremely tight tolerances. The joining of the box sections with a 25 mm penetration depth is monitored through ultrasound and magnetic testing.
WITH FRONIUS POWER SOURCES – AND ALMOST EXCLUSIVELY MANUAL LABOR
Experts manually weld these and all other weld seams up to two meters long using conventional filler metal (1.2 m Böhler EMK 8 solid wire electrode). Welding is mostly carried out using the spray arc welding process (with plate thicknesses starting at 5 mm), but with longer longitudinal seams, the company uses a type FDV 22 MF battery-powered longitudinal chassis instead, which has a permanent magnet and optional oscillation. The MAG power sources used for manual welding at MATISA are also a Fronius solution.
The five parts of the trucks for the transport wagons are clamped on a positioning device in order to prevent out-of-position welding and to ensure the specified tolerances are met. Now the welders can start welding the box sections together. So that the frame does not buckle or become warped, specific welding sequences must be followed and the frame is turned around regularly to prevent deformation. Finally, the weld seams are subjected to both visual and non-destructive ultrasound and magnetic testing, as these are classified as a welded, safety-related component.