Railroads rely heavily on the efficiency and reliability of their rail network infrastructure. In the USA, railroads spend billions of dollars on rail networks for replacement, improvement, and expansion. Trackwork frogs and crossing points are a particularly special component that requires constant and special attention. These are major track components for passing lines, turnouts, switching, and classification yards. These frogs are cast austenitic manganese steel (AMS) or Hadfield steel due to their excellent work-hardening characteristics and high toughness.
However, this chemistry creates a unique challenge when welding repairs in the field. Primarily, the traditional weld buildup repairs often only last weeks to six months before requiring additional maintenance, leading to a vicious cycle of repeat damage and repair and finally replacement. This is costly from a component and labor cost but, more importantly, tracks downtime or reduces operational speeds.
This article describes a patented laser additive technology to repair manganese steel castings for dramatically better and longer-lasting solutions.
Understanding the Challenge of Repairing Manganese Steel Castings
Repairing manganese steel castings poses unique challenges due to the material’s properties. Manganese steel is very heat sensitive, making it difficult to weld. Excess heat during the traditional welding leads to material changes resulting in cracking and spallation.
Another challenge is the presence of impurities and inclusions that can make it even more difficult to repair. In addition, these impurities can lead to porosity in the weld, reducing its strength and durability. Moreover, the high carbon content of manganese steel can make it prone to cracking and heat-affected zone (HAZ) embrittlement during the welding process. This can result in weak or brittle welds susceptible to failure.
Adding to these challenges, repairs are often needed in remote locations along the railway line. This can make it difficult to access the damaged components, schedule track time, and perform repairs quickly and efficiently. As a result, it is crucial to choose a reliable and fast welding process to repair special trackwork frogs in challenging railway environments that don’t reduce track utilization time.
Overcoming Repair Challenges With Laser Additive Technology
Specialized welding techniques and filler materials are required to address the challenges of repairing manganese steel castings. One innovative solution that has been developed is using laser cladding or laser additive technology.
The Union Pacific first proposed this approach, and Titanova was tasked with exploring its potential benefits. To further develop this strategy, we partnered with Holland Engineering to refine the technology and create a robust solution for repairing manganese steel castings.
Laser cladding is the solution for repairing worn steel surfaces or adding surface materials to steel products. This method uses a high-intensity laser beam to melt powdered metal materials onto a substrate. Another technique is hot wire laser cladding, which involves using a MIG welding unit to preheat the welding wire through resistive heating. Afterward, the laser completes the melting process.
Laser additive technology provides several advantages, including reduced heat input, lower dilution, near-net shape deposits, and faster processing times than traditional welding methods. Furthermore, it is a highly automated process that guarantees consistent, high-quality results.
The results are significant. Laser additive repaired track frogs outlast traditionally fixed frogs by 10X to 20X. In addition, the laser-clad repaired frogs’ lifetimes are even surpassing new frogs. This is a game changer in the industry which will save a significant amount of money and improve the supply chain for the USA.
Titanova: Your Trusted Partner for Manganese Steel Repairs
If you’re struggling to repair high manganese steel components, Titanova is here to help! With our extensive experience in Hatfield high manganese steels, we are the ideal partner for repairing components made from these materials. Our laser cladding services are designed to help you overcome these challenges and achieve high-quality results. We guarantee superior solutions for improving manganese steel.
Contact us today to learn more about how our laser additive cladding services can help you!