Laser glazing process development and optimization for railroad applications

Railroad industry is very important to the U.S. Nearly 60% of the U.S. freight is transported by railroads. Fuel represents about 9.5 percent of the operating cost of a railroad; the industry is aggressively trying to find ways to improve fuel efficiency. One major contributor to the railroad energy losses is the friction between the wheel and the rail. Many technologies have been implemented to reduce the high friction between the wheel and the rail. Such technologies include the application of liquid lubricants as oil and grease to the gage side of the rail. Such lubricants, wash away in the rain, introduce environmental problems, and may cause a train to lose traction if they migrate to the top of the rail. On the other hand, a new technology has recently been developed at Argonne National Laboratory (ANL) showed desirable results. This technology involves the use of laser to treat (glaze) the gage side of the rail. Treating steel rails by "laser glazing" reduces friction between the rails and train wheels by approximately 60%, which may reduce rail cracking by up to 75%. Reducing friction can save an estimated $60 million in fuel costs and $16 million in rail replacements, as well as lower the risk of derailment. This paper focuses on the optimization of the laser glazing process for the railroad applications.