Tungsten Steel Sleeve Heat Treatment Manufacturing Process
1. Hot Processing: A heat treatment technique for steel or steel components, involving heating to an appropriate temperature above the critical point AC3 or ACM, maintaining that temperature for a specific duration, and then cooling in air to achieve a pearlitic microstructure.
2. Annealing: A heat treatment process where the hypoeutectoid steel workpiece is heated to above AC3 by 20-40 degrees, held at this temperature for a period, and then cooled slowly in the furnace (or buried in sand or lime) until below 500 degrees, followed by air cooling.
3. Solid Solution Heat Treatment: A heat treatment process that involves heating the alloy to a high-temperature single-phase region and holding it at a constant temperature to allow the excess phase to dissolve completely into the solid solution, followed by rapid cooling to obtain a supersaturated solid solution.
4. Time Effectiveness: The phenomenon that the properties of the alloy change over time after undergoing solid solution heat treatment or cold plastic deformation, when kept at room temperature or slightly above it.
5. Solution Treatment: The tungsten steel sleeve ensures complete dissolution of various phases in the alloy, strengthening the solid solution and enhancing toughness and corrosion resistance. This process eliminates stress and softening, facilitating further processing and shaping.
6. Time-sensitive Treatment: The tungsten steel sleeve is heated and maintained at a temperature to precipitate the reinforcing phase, which allows for precipitation and hardening, thereby enhancing its strength.
7. Quenching: A heat treatment process that involves austenitizing steel and then cooling it at an appropriate rate to induce martensite and other unstable microstructures throughout the cross-section or within a specific range of the workpiece.
Tungsten steel bushes are inserted into the bore of the pin ears with a certain interference fit. To reduce the amount of axial deformation of the tungsten steel bushes after compression and enhance their fatigue life, shorter multi-section bushes are typically used instead of longer solid bushes. The stress concentration in tungsten steel bushes leads to fatigue failure, manifested as cracking in the stress concentration areas, peeling in the bonded sections, and wear in the folded and bent areas on the compressive side. To prevent stress concentration and facilitate the insertion of the bushes without damage, the bush ends should be designed with rounded corners.
Wolfram carbide sleeve track pads are equipped with cylindrical rubber bushes. These rubber bushes are vulcanized to the rigid metal track pins and press-fitted into the inner holes of the track pad pins. The design and calculations typically involve rubber bushing stress analysis, determination of assembly interference fit, pre-torsion angle determination, and selection of bushing rubber material. During the torsional stress analysis calculation of the bushing twist, the shape of the rubber bushing before and after deformation is always confirmed to be cylindrical with concentric circular layers. The outer layer of the bushing withstands torque M.
Tungsten carbide bushes offer excellent wear resistance. Copper bushes have a tightly packed internal structure, preventing excessive looseness. They are free of pores and sand holes, giving them a bright appearance and a unique color. Moreover, their hardness is relatively high. Another key feature of tungsten carbide bushes is their corrosion resistance, which is quite good. They are primarily used in atmospheric and freshwater environments, which are relatively favorable. During the use of copper bushes, it is generally uncommon to encounter sticking issues. The corrosion resistance of copper bushes is evident in their resistance to elements like dilute sulfuric acid, hydrochloric acid, and fatty acids, making them highly resistant to corrosion. The reason they do not stick is mainly due to their distinctive and high-quality performance, which allows them to function normally even without lubricants or water-based lubrication, maintaining their sliding and self-lubricating properties. Tungsten carbide bushes also possess good compressive strength, capable of withstanding significant lateral pressure on bearings and operating under high-load pressure conditions.
