Production process and applications of tungsten carbide

Heat treatment processes for tungsten carbide bushings

Normalization: Steel material or steel parts are heated above the AC3 or ACM critical point, held for an appropriate time, and then cooled in air to obtain a pearlitic structure by heat treatment.

Annealing: Hypo-eutectoid steel billets are heated to a temperature of 20-40 degrees above AC3, held at that temperature, and then slowly cooled in a furnace (or with sand, lime cooling) to below 500 degrees before cooling in air to complete the annealing process.

Thermal treatment with solution: The alloy is heated to a high-temperature single-phase region, held at a constant temperature to completely dissolve the excess phases in solid solution, and then rapidly cooled to obtain a supersaturated solid solution by heat treatment.

Aging treatment: After an alloy is solution heat treated or cold plastic deformed, it is placed at or just above room temperature and its properties change over time.

Strengthening of solid solutions: Through solution treatment, the various phases of tungsten carbide bushing are completely dissolved, strengthening the solid solution structure, improving toughness and corrosion resistance, eliminating stress and softening phenomena to facilitate subsequent machining and molding.

Age hardening: The tungsten carbide bushing is heated to the temperature at which the hardening phase is deposited and held at that temperature to allow the hardening phase to be deposited, thereby achieving the hardening effect and increasing the strength of the material.

Hardening: Steel is austenitized and then cooled at an appropriate cooling rate to induce a heat treatment process during which all or part of the billet undergoes martensitic or other unstable structural transformation in the cross section.

Applications: and characteristics of tungsten carbide bushings

Tungsten carbide bushings are pressed into the inner bore of the pin lug with a certain amount of force. To reduce axial deformation after compression and to increase fatigue life, shorter, multi-section tungsten carbide bushings are often used instead of long, single-section bushings. Tungsten carbide bushings are prone to cracking at stress concentration points, flaking at bonding points, and wear at compression and bending points. To avoid stress concentrations, facilitate pressing and prevent damage, the ends of the bushings should be made with rounded corners.

Design of rubber bushings for backing plates with tungsten carbide bushings

Rubber bushings for backing plates with carbide bushings are cylindrical in shape, fit tightly to rigid metal backing pins by vulcanization and are pressed with interference fit into the inner bore of the backing plate lug. Their design and calculations include analyzing the stresses in the rubber bushings, determining the interference fit, setting the pre-torsion angle, and selecting the rubber compound for the bushings. In analyzing the shear stresses produced by torsion of the bushing, it is assumed that the rubber bushing remains cylindrical before and after deformation and that the concentric layers are circular, with the outer layer of the bushing carrying the torque M.

Performance characteristics of tungsten carbide bushings

Tungsten carbide bushings feature excellent wear resistance, dense internal structure, no pores or sand holes, bright appearance and unique color. More importantly, they have relatively high hardness. In addition, tungsten carbide bushings have good corrosion resistance, especially in atmospheric and freshwater environments. They are not prone to seizing during use. Their corrosion resistance is mainly expressed in their ability to resist corrosion from chemical elements such as dilute sulfuric acid, hydrochloric acid and fatty acids.

Even in the absence of lubricants or when water-based lubricants are used, tungsten carbide bushings retain good sliding ability and self-lubricating properties. In addition, they have strong compressive strength and can withstand significant bearing-side pressure, making them suitable for high load pressures.Without lubricants or with water-based lubricants, tungsten steel bushings can maintain good sliding and self-lubricating properties. In addition, they have high compressive strength and can withstand significant lateral pressure from the bearing side, making them suitable for high load pressure applications.