Overbygning/Aluminiotermisk sveiseprosess
| Fagområde / Discipline | Overbygning / Permanent way |
| Tilhører rammeavtale / Frame agreement | K.xxxxxxxxx |
| Utarbeidet av / Prepared by | Frode Teigen |
| Godkjent av / Approved | Christopher Schive |
| Revisjon / Revision | 08 |
| Utgitt / Issued | 18.02.2025 |
Innhold
[skjul]1 Purpose / Scope
This specification applies to consumables and equipment supplied for aluminothermic welding of rail joints on Bane NOR lines. This specification sets out objective requirements concerning the product to be supplied, to enable suppliers to design, produce, inspect and deliver welding consumables and equipment that meets the expectations of Bane NOR.
2 Functional requirements
The welding method must comply with the functional requirements specified below.
2.1 Welding moulds
a) The welding moulds must be prefabricated to fit the following rail profiles, in accordance with EN 13674-1:
- 49E1
- 54E2
- 54E3 / 54E4
- 60E1 / 60E2
b) For all the above profiles, it must be possible to seal the moulds sufficiently to allow rails with up to 15 mm wear at the side and 14 mm wear at the top to be welded satisfactorily.
c) The welding process shall include specific comprimise moulds to allow for up to 9 mm wear difference between the two rail to be welded
d) It must be possible to weld together the following combinations of different rail profiles using transition moulds:
- 49E1 to 54E3/54E4
- 54E3 to 60E1/60E2
2.2 Welding portion
The welding portion must be ready mixed and ready for use. The welding portion must be suitable for use with the following rail grades, in accordance with EN 13674-1:
- R200
- R260Mn
- R320Cr
- R350HT
- R370CrHT
- R400HT
2.3 Axle loads
- Welding processes for welding of rails with grade R200, R260Mn, R320Cr and R350HT shall be suitable for use in tracks with axle loads up to 25 ton.
- Welding processes for welding of rails with grade R370CrHT and R400Ht shall be suitable for use in tracks with axle loads up to 35 ton.
2.4 Crucible
a) The crucible must be of a light type designed for single use.
b) The weight of the crucible minus the welding portion must not exceed 12 kg.
c) The crucible must be able to be placed in a stable position and must prevent overflow on track with a cant of up to 180 mm.
d) Crucibles must have a built-in plug for automatic tapping.
2.5 Tolerances for welding work
The welding method must be capable of accommodating the following discrepancies/tolerances while still complying with the quality requirements specified in EN 14730-1:
| Tolerance for welding gap | ± 2 mm |
| Tolerance for positioning of welding moulds | ± 2 mm in longitudinal direction of rail |
| Tolerance for height of blowpipe | ± 3 mm |
2.6 Welding in tunnels
For welding in tunnels, the welding process must be adapted for use with a filter system to remove most of the welding fume during the reaction.
3 Qualification of welding process
Qualification of welding process shall be in accordance with EN 14730-1. The supplier shall provide all necessary documentation of the qualification tests. For established welding processes which are previous accepted by Bane NOR and have been in use on the Bane NOR network for a longer period, new qualification tests are not necessary provided that no change in the approved welding process has happened.
3.1 Additional requirements
3.1.1 Preheating
a) A mixture of oxygen/propane or air/propane must be used to preheat the rails.
b) The preheating system must be capable of use at temperatures as low as 0°C without any reduction in the throughflow of gas.
c) The preheating system must be capable of use at temperatures as low as -5°C without any reduction in the throughflow of gas when suitable gas or bottle heating system is used.
3.1.2 Ignition
As an alternative to traditional ignition rods, an electronical ignition system shall be available to start the aluminiothermic reaction.
3.1.3 Weld collar geometry affected by riser removal
The fracture surface left under the removed risers shall not contain any remaining shrinkage cavities or other impressions.
3.1.4 Width of heat-softened zone
The width of the heat-softened zone, as defined in EN 14730 annex I, shall not exceed 30 mm.
3.1.5 Fatigue requirements
The fatigue strength shall be determined from the “staircase” testing method according to EN 14730-1, annex J.
The minimum accepted fatigue strength is 210 N/mm2 with 5 million cycles. Standard deviation is maximum 15 N/mm2
3.1.6 3 point bending test
EN 14730-1 requires 3-point bending test (EN 14730, kap.7.3 and appendix E). In addition to fracture load, Bane NOR requires the deflection to be recorded. Min. deflections are given in Tabell 1
| Rail grade | Min deflection |
|---|---|
| R200, R260Mn, R350HT | 12 mm |
| R320CR, R370CrHT, R400HT | 10 mm |
4 Production, testing and acceptance
A quality plan including all quality documents in relation with the acceptance of materials and manufacturing of the consumables shall be established and approved by Bane NOR. The quality plan shall include:
- description of test for each consumable (welding portion, mould, crucible, luting material and igniter)
- frequency of testing
- procedure used to increase the testing frequency when defects or irregularities are identified
- actions to be taken in the case of defects or irregularities being found to ensure remedial works and recheck for compliance or not acceptance for delivery
- document control system that ensures control, status and traceability of documents
5 Documentation
5.1 Welding procedure / manual
The supplier shall produce a written process manual according to EN 14730, chapter 5.4.1.
The supplier shall provide translation of the process manual to Norwegian.
5.2 Test records
a) Test records for qualification tests shall be submitted.
b) All production and quality records are to be retained by the supplier for a period of minimum 5 years. Bane NOR shall have the right to access to view these records.
6 Labelling and packaging of consumables
6.1 Moulds
The moulds must be packed in a way that protects them from impacts and moisture.
The packaging must be labelled with the following information:
- Date of manufacture
- Serial number
- Welding process
- Rail profile
6.2 Welding portions
The welding portions must be packed either in watertight plastic packaging or included in the crucible.
The packaging/crucible must be labelled with the following information:
- Date of manufacture
- Serial number
- Welding process
- Rail profile
- Rail grade
6.3 Igniters
Ignition rods must be packed in separate watertight packaging well apart from the welding portions.
6.4 Crucibles
The crucibles must be packed in a way that protects them from impacts and moisture.
The packaging shall be labelled with the following information:
- Date of manufacture
- Serial number
- Welding process
- Rail profile (in case of portion included in crucible)
- Rail grade (in case of portion included in crucible)
7 Transport and storage
- All consumables shall be stored and transported frostfree
- All consumables shall be stored and transported protected from any moisture that can cause degradation of the material.
8 Reference documents
- EN 13674-1: 2011+A1 2017 Railway applications – Track – Rail – part 1: Flat bottom symmetrical railway rails 46kg/m and above
- EN 14730-1: 2017 Railway applications – Track – Aluminiothermic welding of rails – part 1: Approval of welding processes
