Patent EA-000181-B1 (EA)
Title: Method for heat treatment of welded rail ends and use of burners spaced predeterminedly therefor
Inventor: KUSTER FRANK
IPC: C21D1/52
Filed: 1996-11-06
Abstract: 1 Method for heat treatment of welded rail ends to obtain at least partial fine-grained normalized structure in the welded zone characterized in that said welded zone is normalized immediately after the welding to use to the maximum residual heat of the welded metal in zones between adjacent rail ends and in particular in the zone of rail bottom. 2. Method according to Claim 1 characterized in that the zone of rail head (7) is also normalized. 3. Method according to Claim 1 or 2 characterized in that the normalization of the heat-treated zone(s) is allowed to cool in ambient temperature. 4. Method according to Claim 1 or 2 characterized in that the normalization of at least one heat-treated zone is performed by a sudden cooling for example by compressed air. 5. Method according to Claims 1-4 characterized in that the heat supplied to the adjoining zones is symmetrically transferred in lateral and longitudinal directions towards the welded zone (15), the heat is transferred to the rail head (7) via side walls (12, 13) in the welded zone (15), while the heat is transferred to the rail bottom (2) by both sides of the welded zone (15). 6. Method according to Claim 5 characterized in that such heat transfer parameters as heating speed, time delay and cooling speed are chosen so as to improve wear resistance and tensile strength of the rail head (7) and toughness of the rail bottom (2). 7. Apparatus for heat treatment according to any of the preceding Claims in particular a system of burners characterized in that said burners (10, 11, 20, 21) are arranged symmetrically towards the vertical longitudinal plane (22) and passing perpendicular to it cross medium plane (14), wherein said burners are directly connected to the distribution unit (3) at the end of which a device is mounted for gas supply, while the apparatus itself can be placed above the rail ends to be welded. 8. Apparatus according to Claim 7 characterized in that the direction of burning mixture flow of at least of one of burners arranged on both sides of the longitudinal medium plane (22) lies in the cross medium plane (14). 9. Apparatus according to Claim 7 or 8 characterized in that the burning mixture flow is directed to the side walls (12, 13) of the rail head. 10. Apparatus according to Claims 7-9 characterized in that at least one burner is arranged along each side of the longitudinal medium plane (22) and along each side of the cross medium plane (14) and the burning mixture flow directed parallel to the cross medium plane (14) and lies at some distance from it. 11. Apparatus according to Claim 10 characterized in that the burning mixture flow is directed mainly to the rail bottom (2) in the zone to be welded. 12. Apparatus according to any preceding Claims 7-11 characterized in that support elements (23) are provided on both sides of the rail bottom along the welded gap and arranged symmetrically towards the longitudinal medium plane (22) and the cross medium plane (23). 13. Apparatus according to any preceding Claims 7-12 characterized in that the burners (10, 11, 20, 21) are connected to the distribution unit (3) via by-pass pipes (8, 9, 18, 19) and adjustable supports (25, 26) arranged along the rail head for keeping the predetermined distance from the burners to the rail surface to be heated.