Mining equipment is frequently subjected to high loads, abrasive particles, water, and corrosive fluids. If the right components aren’t used in the design and manufacture of the equipment, the equipment will fail, resulting in downtime that’s both disruptive and expensive.
Anything that reduces wear and increases lifetime can have a real payback, which is why forging is preferred over casting or machining for the design and manufacture of mining equipment.
How Forging Is Different
The primary advantage of forging over casting and machining is its ability to provide optimum grain flow. The machining process disrupts the grain flow pattern of the billet, making the end product more susceptible to stress. Cast parts have no grain flow, and the grains aren’t uniform, resulting in boundary voids that affect the product’s impact and fatigue resistance.
Grain flow is critical because it impacts the final product’s mechanical properties, including its strength, wear resistance, fatigue resistance, and toughness, all of which are important in the mining industry.
Strength
For any given alloy, parts that are forged are stronger than those that are cast or machined. This is due to how the deformation stretches the metal grains along the direction of flow, and to a lesser extent, to how large grains are broken into smaller ones. There’s also a benefit from how internal defects are compressed and how dislocations can’t spread as easily.
When working with you on the design of mining forgings, your manufacturer should take the time to understand the application and the strength needed. This will let them optimize tooling design to maximize strength in the directions the part needs. For mining equipment, that means increased durability and less risk of breakage.
Wear Resistance
The deformation involved in forging raises both the hardness and wear resistance of the surface. This happens through the break-up of large grains, the stretched grain orientation, reduced surface defects, and increased compressive loads.
Wear resistance is important in mining components where abrasive dust is everywhere and coats seals and every moving surface. High wear resistance means lower wear rates, and that, in turn, means better performance for longer.
Fatigue Resistance
Fatigue, the creeping spread of cracks into the structure under load, is a significant problem in metal parts for mining. Forging minimizes the occurrence and spread of these cracks significantly when compared to machining and casting.
Mining forgings have fewer defects and a smaller average grain size with less variation, which makes it harder for cracks to spread through the material. Additionally, the residual surface stress tends to reduce the level of the applied loads, further postponing crack growth.
For equipment used in mining, the benefits are less risk of failure, longer life, and less unplanned downtime.
Toughness
In mining, loads are high and unpredictable, so components need a combination of toughness and ductility.
Forging raises strength and hardness, while post-processing heat treatments increase the mobility of the dislocations, lower hardness slightly, and increase toughness.
The difference between forging and parts made by other methods is that forging creates a harder, stronger structure all the way through, so there’s less risk of failure from impacts and sudden high loads. For machined and cast metals, the hardness is on the outside after heat treatment, with the inside remaining softer, which can lead to cracks and eventual failure, especially under cyclic loads.
Trenton Forging Is Committed to Helping the Mining Industry
Founded in 1967, Trenton Forging is a Michigan-based company with a long history of producing forged metal parts for customers in demanding industries, ranging from agriculture and automotive to railroad and mining.
We’re strongly focused on providing high-quality forged parts, industry-leading turnaround times, and exceptional customer support. As a U.S.-based manufacturer, all components are designed, manufactured, and visually inspected in-house. We can also provide post-processing capabilities, such as heat treatments or machining, if required.
Contact us today to learn more about our capabilities or to request a quote or first article sample.
