Corus has supplied the rails for parts of the Channel Tunnel.
Eurotunnel wanted to increase the life of some of its bainitic and MHH extra-hard rails by 50%. Its rails are affected by cracks and have to be replaced every six years. Its rails in the terminal loops in the UK and France wear quickly because of the small curve radius of the track.
The Channel Tunnel is the most heavily used railway line in Europe, with annual traffic of more than 100Mt. To solve the problem Corus supplied two types of its steel. Its bainitic grades are designed for the tracks in the tunnel. It is known for its fatigue resistance in the mechanical engineering industry, but has been a revelation in the rail industry.
Its MHH extra-hard heat-treated rails were laid in the two terminal loops. Their production is made possible by the development at the Hayange, Corus plant of a heat treatment procedure which avoids the need for roller straightening in the final stage. This procedure leaves a low level of residual stress in the rails, which reduces the risk of crack propagation in the web of the rail.
The MHH test rails were laid in April and September 2007. The bainitic rails were laid in January and March 2007. The results are on target but the study will not be completed until 2013. The aim is to replace the 56km of double track in the tunnel and the 15km totalled by the loops in France and England.
About 15kt of heat-treated rails were supplied to Eurotunnel by Corus.