Introduction to the production process of marine anchor chains-Part 3

VI. Anti-corrosion Treatment and Final Inspection

1. Surface treatment

- Shot blasting cleaning: Use a suspended shot blasting machine to clean the surface, with a shot blasting volume of 200-400 kg/min.

- Rust removal treatment: Remove surface oxides and rust to enhance the adhesion of the paint.

2. Anti-corrosion Coating

- Galvanizing treatment: Immersing the anchor chain in a molten zinc bath at a temperature above 400°C to form a silver-colored anti-corrosion layer.

- Painting treatment: Covering the surface with epoxy asphalt paint to enhance the overall wear resistance and corrosion resistance.

- Using Dream Energy Graphene Low Surface Treatment Primer for painting, providing long-term protection.

3. Final Inspection

- Polishing and Grinding: Smoothens the surface of the anchor chain and gives it a distinctive shine.

- After passing the third-party professional inspection, a steel stamp is applied before the product can be shipped.

VII. Special Process Requirements and Standards

1. Classification Society Certification

- The production of anchor chains must comply with the requirements of the "Material and Welding Specifications" of institutions such as the French Classification Society (BV).

- It needs to pass through stages such as factory approval, selection of typical samples, and type tests.

2. Material Standards

- The CM690 material is widely used in the marine anchor chain industry and possesses advantages such as high fatigue strength and small quenching deformation.

- The anchor chain material must meet the requirements of the international standard ISO 24061 "Ships and Marine Technology - Large Lifting Balance Anchor".

3. Key Points of Quality Control

- Position for marking the test block: It should be marked at the middle position of the thicker part of the casting.

- Cold bending test: For products produced by the medium-frequency furnace, it is recommended to conduct regular spot checks during routine inspections.

- Non-destructive testing: The coverage area should be expanded as much as possible. Surface roughness affects the testing results.

The production process of carbon steel ship anchors demonstrates the perfect combination of high-precision engineering and strict quality control. Every step must be precisely controlled, and any minor defect could lead to the failure of the entire anchor chain. China has become the world's largest exporter of anchor chains, thanks to the continuous optimization of production processes and strict adherence to quality standards. Modern anchor chain manufacturing not only focuses on strength and durability, but also extends the service life by optimizing heat treatment processes and adopting advanced anti-corrosion technologies, ensuring the safe berthing of ships in various marine environments.