How to choose the correct material for jaw cusher plate?

Metso C80 Jaw crusher are widely used in mining. Their main wear-resistant component is the jaw plate. However, many users lack dedicated engineers or, due to purchasing older, secondhand machines, cannot find relevant information and have little understanding of the materials used for the jaw plates and their heat treatment processes. Today, we will provide a detailed introduction to the practical applications of crusher jaw plates.

The jaw crusher operates on a reciprocating compression principle: the motor drives the belt and pulley, which in turn moves the moving jaw up and down via an eccentric shaft. When the moving jaw rises, the angle between the jaw crusher toggle plate and the moving jaw increases, pushing the moving jaw plate closer to the fixed jaw plate. Simultaneously, the material is crushed or split, achieving the crushing purpose. When the moving jaw descends, the angle between the jaw crusher toggle plate and the moving jaw decreases, and the moving jaw plate, under the action of the return rod and spring, moves away from the fixed jaw plate. At this point, the crushed material is discharged from the bottom of the crushing chamber. With the continuous rotation of the motor, the moving jaw of the crusher performs periodic movements to crush and discharge materials, achieving mass production.

Jaw crusher wear plates are divided into moving jaw plates and stationary jaw plates(Some regions call it mantle concave). Depending on the model of the jaw crusher, there are various tooth profile sizes, generally made of high-manganese steel, i.e., high-manganese steel jaw plates. High-manganese steel has a history of over 100 years. Under conditions of strong impact abrasive wear, high-manganese steel has excellent wear resistance and is therefore commonly used in machinery and equipment in mining, building materials, and thermal power plants. Applicable materials include coal gangue, feldspar, barite, and basalt. Under low-impact conditions, the work hardening effect is not significant, and high-manganese steel cannot fully utilize its material properties.

Research has found that three major factors affect the wear resistance of high-manganese steel jaw plates during the casting process: material, purity of raw materials, and heat treatment process. Material is the fundamental element determining the wear resistance of high-manganese steel jaw plates. Adding chromium to high-manganese steel (Mn18Cr2) directly increases its wear resistance. Some manufacturers use recycled high-manganese steel as raw material, or mixed in the new raw material, which introduces harmful sulfur and phosphorus elements into the newly cast jaw plates, affecting their service life. Finally, regarding the heat treatment process of high-manganese steel jaw plates, rapid heating at low temperatures can cause cracking. Therefore, the correct procedure is to maintain a heating rate of <80℃/h below 350℃ and <100℃ above 750℃, when the casting is in a plastic state and can be rapidly heated. At 1050℃, determine the holding time based on the casting thickness (usually 1 hour/25mm); then rapidly raise the temperature to approximately 1100℃ and hold for half an hour before removing from the furnace. The casting must be immersed in water as soon as possible after removal from the furnace; the time between removal and immersion should not exceed 45 seconds, and even shorter in winter. Slow heating at high temperatures, insufficient holding time, and excessively long intervals between removal and immersion (not exceeding 0.5 minutes) all negatively impact the quality of the high-manganese steel jaw plates.

Striving for greater wear resistance in jaw plates does not necessarily require continuously increasing the proportion of high-manganese steel. Mn13Cr2 and Mn18Cr2 are suitable for most jaw plates, while Mn22Cr2 is suitable for extremely cold regions. For regions with suitable temperatures, choosing Mn22Cr2 compared to Mn18Cr2 will not only fail to significantly extend the service life but will also increase procurement costs. For better results, consider inlaying with cemented carbide, which can achieve a service life 1.5-1.8 times that of Mn18Cr2.

If you are unsure which material is best for your needs, please contact us. Tell us about your raw materials being crushed and the desired results. Our professional engineers will recommend the most cost-effective solution for you.