New rails for extraordinary abrasion conditions
Program: RETOS COLABORACIÓN 2017
The high-speed market in desert climates has specific characteristics. The influence of the sand on the maintenance of the infrastructure and railway operation is a subject of special attention: not only can the presence of sand in the contact area between the rail and the wheel significantly influence the wear of the rail and the wheel, and the corrosion of the rai, it can also it will change the conditions of adherence of the vehicle to the road. Similarly, the great variations in temperature during the day and the very low humidity constitute exceptional conditions for the rail and ballast. The lack of specific technology for the key elements of the infrastructure (rail and ballast) can mean that the costs of maintenance are triggered by wear, corrosion, cracks in welds and early degradation of the ballast.
Objectives of the project:
In this context, RAILSAND aims to develop the key technological elements indicated below:
The first objectives are to design the chemical composition of a suitable steel and develop thermomechanical and thermal treatments, and develop a new type of rail that is capable of increasing resistance to abrasion from desert sand and preventing corrosion.
The second objective is to define an optimal process for chemically reducing of cast iron slag in order to remove CaO to a level that allows for its use in desert climate infrastructures.
The third objective is to develop a software application that allows the cost of the lane life cycle to be calculated, taking into account the characteristics of the infrastructure, the characteristics of the service (vehicle, speeds, accelerations, adherence) and the manteinance (for example rail grinding costs, rail replacement costs, inspection costs). This tool facilitates the determination of the best type of lane for an infrastructure and operating conditions can be determined, as well as the optimal maintenance strategy.
This tool will be based on the EN60300-3-3  standard, which generically includes the calculation of the life cycle cost, and the adaptation of the concepts to the railway environment is foreseen. The tool will allow sensitivity analyses to be carried out and it will offer reference values that will allow the parameters to be used in an agile way even when not all the information about the infrastructure is available.
Additionally, the following secondary objectives need to be met in order to achieve the above objectives:
Design tribological models for the predicition of lane degradation due to wheel-rail contact in the presence of sand depending on vehicle dynamics, track layout and grain size. These models are the basis for calculating the life cycle cost of the rail.
Identify variations in the friction conditions of the wheel-rail contact in the presence of sand. This permits safe operating conditions (eg minimum braking distance) to be analyzed for high speed vehicles in situations of reduced grip.
Identify the sand deposition model as the train passes by the suction generated. This model will make it possible to know the sand conditions on the road, the starting point for obtaining the degradation prediction models and the variations in the friction conditions.
Modeling the degradation of the ballast from foundry slag to the passage of railway vehicles.
Ceit's role in the Project
Ceit will lead the development of the infrastructure degradation models (where the participation of ARCELORMITTAL AND COPASA will be necessary) and operating risk models. It will also develop an application for calculating the life cycle cost of Arcelor Mittal lanes in order to evaluate new designs and materials and their impact on the life cycle.
Ceit will also actively participate in the tests on the specimens developed by ARCELORMITTAL in collaboration with ITMA.