The material fatigue failure of the roller surface of the roller press refers to the phenomenon that the roller surface material cracks, peels off or even breaks after a certain number of cycles under cyclic load, resulting in the degradation of the performance of the roller surface material and the inability to work normally. This is a headache for enterprises in the process of using roller presses. Our company mainly produces roller press accessories. In terms of solving these problems, after years of production and construction experience, we have summarized a set of wear-resistant solutions that can help some enterprises solve these problems and increase production capacity. The following will introduce our solutions in detail:
1. Improve the compressive strength of the base material and reduce fatigue
The compressive strength of the base wear-resistant layer is increased to more than 2000MPa, which is 3 times the compressive strength of the base of the surfacing roller and 2 times the compressive strength of the base of the stud roller. At the same time, the thickness of the wear-resistant layer is increased to more than 90mm. The ultra-high base compressive strength and sufficient thickness of the wear-resistant layer ensure that when the roller surface is subjected to peak pressure during use, fatigue cracks are not easy to appear inside the base.
2. Prevent fatigue crack extension and prevent fatigue cracks from connecting into pieces
The material is designed with many tiny "crack-stopping elements". If surface fatigue cracks occur in local areas after the roller body is subjected to extreme pressure, the cracks will stop at the "crack-stopping holes" and will not continue to extend to cause large-scale shedding of the roller surface. It also avoids the situation where the roller sleeve bursts due to high crack sensitivity of high-speed steel alloy rollers.
3. The one-line pattern realizes room temperature welding, getting rid of the problem of limited process conditions for surfacing rollers: the roller base wear-resistant layer is designed and manufactured as a material that can be welded at room temperature. There is no need to heat the roller body during on-site maintenance, and ideal welding process conditions are easy to achieve.
4. The base wear-resistant layer material has good welding performance, ensuring that the life of the pattern will not decay after each maintenance of the roller surface.
5. Make full use of the "material cushion layer" formed by the material to protect the roller surface base and extend the service life of the roller surface.
(1) One-line pattern design
(2) The wear-resistant carbide on the surface of the substrate automatically forms a protective pad
During the manufacturing process of the roller sleeve, coarse primary carbides of special materials will be formed. Primary carbides have excellent wear resistance and serve as the main wear-resistant phase in the self-protecting super-wear-resistant alloy roller. In addition, after the roller surface is used, a layer of material pad of about 1mm will be formed on the surface of the roller surface based on the surface morphology of the primary carbide to protect the roller surface substrate.
6. Further improve the hardness and wear resistance of the substrate and pattern
(1) By optimizing the alloy composition and heat treatment process of the roller sleeve wear-resistant layer, the substrate hardness of the roller sleeve wear-resistant layer is increased to about HRC55;
(2) By developing a new type of pattern layer welding wire, while ensuring the welding performance, the pattern hardness is increased to HRC63~66, ensuring that the single service life of the roller surface pattern is increased by more than 50% compared with the conventional roller surface pattern.
The above are our company's suggestions and practices for roller press roller repair. I hope it will be useful to everyone. If you have a better solution, you can contact us via email at cnwearparts@lyzhili.com for discussion.
