hot rolled pulley

hot rolled pulley

The Difference Between Hot Rolled Pulleys and Cast Steel Pulleys

Hot-rolled pulleys and cast steel pulleys are two types of crane pulleys that are widely used and used in large quantities. So what is the difference between the two? Let’s take a look.

1. Different materials

Hot rolled pulley, generally with low carbon steel or medium carbon steel (toughness is good) rolling processing, there is a tempering process, increase the hardness of the material, improve the texture of the crystal structure, improve strength, improve wear resistance.

The general material code of cast steel pulley is ZG, and the steel grade behind it is ZG240. This material performance is similar to steel, but it is not steel, it is castings. Casting into blank and processing into finished products, semi-finished products.

2. Different production processes

Hot rolled pulley production process

Cutting: Use a profiling cutter to cut the outer circle, inner hole and process hole of the pulley piece.

Lathe plate: Use a lathe to machine the outer circle, inner hole and chamfering of the inner hole.

Whole plate: When feeding the plate, control the flatness of the plate. After blanking, the pulley sheet still needs to be flattened to ensure the accuracy of rolling.

Rolling: Hot rolling according to drawing requirements.

Welding: Use 50-6 gas shielded welding wire for welding.

Rough machining: Leave allowance for the outer circle and inner hole.

Shot blasting: Shot blasting is performed on the surface of the pulley, and the oxide layer generated during hot rolling in the rope groove is removed (in order to achieve better results during quenching treatment).

High-frequency quenching: Perform high-frequency quenching treatment on the pulley rope groove to make the surface hardness of the rope groove meet the technical requirements (HB280-HB320).

Finishing: Finishing in place according to drawing requirements.

Product self-inspection: Conduct self-inspection according to standard requirements and issue a self-inspection report.

Paint: primer + topcoat.

Cast steel pulley production process

To put it simply, the production process of cast steel pulleys is to pour molten steel directly into the manufactured mold and cast it. After it cools, subsequent mechanical processing, deburring, trimming, polishing, etc. is performed. After passing the inspection, it will be packed and put into storage.

3. Production speed and cost are different

The process of hot-rolled pulleys is complicated, but its main process is hot-rolling, and the overall production speed is faster than that of cast steel pulleys. Moreover, the cutting amount of hot-rolled pulleys is much less than that of cast steel pulleys, saving raw materials and reducing processing time. However, hot-rolled pulleys also have higher production equipment and technical requirements, and the overall production cost is still high.

4. Different performance

The cast steel pulley process includes smelting, casting, cooling and forming, etc. The castings will have defects such as looseness, pores, and oxidized inclusions. Due to the different cooling sequences, the mechanical properties of different parts will vary greatly. The casting process is affected by multiple processes such as smelting, degassing, tempering, and casting. The process has a great impact and the quality fluctuates greatly.

The overall performance of hot-rolled pulleys is better and has obvious advantages. The characteristics of hot-rolled pulleys include light weight, easy installation, wear resistance, hardness is greatly improved after heat treatment, high production precision, and simple and beautiful appearance, which makes them more popular among the public.

5. Prices are different

Also because of the better performance of hot-rolled pulleys, the price of hot-rolled pulleys of the same specifications is higher than that of cast steel pulleys.

Selection of hot rolled pulleys and cast steel pulleys

Both types of pulleys have their own merits. When making a selection, economy is generally the main consideration. On the premise of meeting the needs of use, the appropriate crane pulley is selected.

GloryRail has been selling crane pulleys for many years and has rich experience in supplying sheave pulleys. Based on the crane track system, provides customers with one-stop solutions for the crane industry. We can produce all kinds and specifications’ crane sheaves, both standard and non-standard products can be produced. Welcome to inquire!