BS EN 14587-1:2018 pdf free
BS EN 14587-1:2018 pdf free.Railway applications – Infrastructure – Flash butt welding of new rails Part 1: R220, R260, R260Mn, R320Cr, R350HT, R350LHT,R370CrHT and R4OOHT grade rails in a fixed plant.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
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3.1 as-welded condition rails that have been welded and trimmed only
3.2 contractor company approved by a railway authority to provide staff and machinery to execute the production of flash butt welds in a fixed plant, which may include staff and machinery from within the railway authority
3.3 die burn damage caused by localized overheating (arcing) on the surface of the rail due to poor contact between the rail and electrode during welding
3.4 dressing removing trimmed upset by grinding or other similar process
4.2 Rail end preparation and horizontal alignment requirements
The rail ends shall always be sawn or disc cut to the tolerances specified by the purchaser. Areas of electrical contact on the rails and the machine shall be cleaned to bright metal to give a consistent and good electrical contact at the interface.
The rail shall not be damaged by the cleaning operation or through poor electrical contact.
Rails of the same profile shall be positioned in the welding machine such that the welding interface is central to the contact electrodes as assessed by visual or mechanical means.
Before welding, rails shall be aligned laterally to the required rail face or edge, i.e. left, or right, or to the rail centreline.
For reasons of asymmetry rails may be welded with the brand marks on the same side throughout the welded string.
4.3 Clamping force
Rails shall be secured in the [lash butt welding machine by a clamping arrangement. The clamping force that is exerted on the rails shall not damage in such a way that subsequent cracking in the rail is generated, see SAl.
4.4 Pre-heating
For the pre-heating, the rail ends shall progress uniformly in a reversible or a continuous process, and perpendicular to the running surface during the whole welding cycle.
4.5 Final flashing
Once initiated the final flashing shall be continuous.
4.6 Upsetting
Upsetting shall immediately follow final flashing. Sufficient forging pressure shall be applied to ensure that voids are closed and oxides are expelled such that they are kept to a minimum at the weld interface. The weld interface shall extend into the upset.
4.7 Unclamping
In order to maintain the alignment, the time between completion of forging and unclamping shall be a minimum of 4 s.
4.8 Slippage
Clamping force shall be maintained to avoid any movement between the contact dies and rails.BS EN 14587-1 pdf free download.
