Ductile iron manhole covers are a type of ductile iron product. Below is a detailed introduction to ductile iron manhole covers:

I. Material Characteristics

Ductile iron is obtained through spheroidization and孕育 treatment, resulting in spherical graphite. This microstructure endows ductile iron with excellent mechanical properties, including:

● Excellent toughness: Impact value is similar to medium-carbon steel, 10 times greater than gray cast iron material.

● Excellent Corrosion Resistance: The spray corrosion test shows that the corrosion after 90 days is only 1/40 of that of steel pipes and 1/10 of gray cast iron pipes.

● Long service life: Twice the lifespan of gray iron pipes and five times that of ordinary steel pipes.

● Excellent plasticity: Elongation ≥ 7%, comparable to high-carbon steel, while gray iron material has zero elongation.

● High strength: Tensile strength ≥ 420MPa, yield strength ≥ 300MPa, same as low carbon steel, three times that of gray iron.

In addition, ductile iron has superior vibration reduction capabilities compared to cast steel, which is beneficial for stress reduction, and it is also more cost-effective.

Section II: Application Scope

Ductile iron manhole covers are widely used in various applications due to their excellent performance:

Road Traffic: Installed on road maintenance holes or drainage outlets, capable of withstanding the weight of vehicles and pedestrians, protecting the facilities below from damage.

Drainage System: Used for rainwater collection pipes, sewage pipes, etc., to prevent blockages and damage to the pipes, while ensuring the smooth operation of the drainage system.

Environmental Protection: Effectively prevents leakage of wastewater and the spread of odors, reducing pollution to the surrounding environment. Additional sealing devices can be installed to further enhance environmental protection.

Public Safety: Covering holes or sunken areas on roads to prevent pedestrians and vehicles from being injured or involved in accidents. The surface usually features anti-slip design to enhance safety for passage.

Additionally, ductile iron manhole covers are widely used on facilities such as industrial water pipelines and power communication pipelines, ensuring the integrity and safety of these installations.

III. Key Features

● Anti-theft: A hidden anti-theft box can be installed under the well ring to enhance anti-theft effectiveness.

● Anti-fall: The manhole cover features an anti-fall grid inside to prevent people or objects from falling in.

● Anti-displacement: Bolts are used to secure the well ring, preventing the well cover from shifting.

● Noise Reduction: The contact surface between the manhole cover and the ring has been processed to ensure there is no noise when vehicles pass over.

● Anti-slip: The surface of the manhole cover features a textured design to prevent slipping.

IV. Production Process

The manufacturing process of ductile iron manhole covers primarily includes the following steps:

● Raw Material Preparation: Select common carbon steel scrap, pig iron, and silicon iron as raw materials, and strictly control their composition and quality.

● Proportional Weighing: Weigh and proportion various raw materials in a specific ratio.

Furnace Melting: Add raw materials to the melting equipment and melt them into iron in high-temperature conditions.

● Component Adjustment: Continuously test and adjust the chemical composition of molten iron during the smelting process.

● Spheroidizing Operation: Add spheroidizing agent for spheroidizing treatment, transforming the graphite into a spherical shape.

● Nurturing Treatment: Multiple nurturing treatments are performed to enhance the structure and performance of cast iron.

● Mold Preparation: Pre-make molds for the manhole covers.

Pouring molten iron: Pouring the molten iron, which has been completed with spheroidizing and孕育 treatment, into the mold.

● Cooling and Demolding: Allow the manhole cover to cool and solidify naturally in the mold or use an accelerated cooling method, and then remove it from the mold.

● Cleaning and Polishing: Surface cleaning and polishing for the manhole cover.

● Machined installation holes: Machined installation holes on the well cover.

Corrosion Treatment: Apply anti-corrosion coating and anti-oxidation treatment to the manhole cover.

Quality Inspection: Inspect the appearance quality, dimensions, and mechanical properties of the manhole covers.

● Packaging and Storage: Package and store the manhole covers that pass the quality inspection.

Fifth, Price

The price of ductile iron manhole covers varies due to size, weight, specifications, customization requirements, and manufacturer factors. Specific prices must be inquired with relevant manufacturers or suppliers for quotes.