Industry Trends

Many large equipment on ships, if damaged, often cause significant economic losses and hazards. For instance, the rotor shaft, a key part of the generator, due to its high operating precision and high rotational speed, once damaged, its output power will be affected. The entire unit will be weakened or even paralyzed. To be on the safe side, damaged parts are usually replaced directly. However, since the parts in the shipbuilding industry are usually quite expensive and the order cycle is long, they cannot meet the needs of ship repair. Therefore, the ship repair industry is confronted with an urgent problem to be solved: developing a new type of ship repair technology that is cheap, fast and highly reliable.

The commonly used traditional repair techniques mainly include ordinary electrode surfacing, spraying and electroplating. For less important components, these traditional techniques can solve the problem, but for important components, these traditional techniques all have varying degrees of defects. For instance, surfacing welding and electric welding are prone to excessive deformation and can only be used in less critical areas. However, the spraying and electroplating methods do not cause deformation, but their repairable thickness is limited, and the adhesion between the repaired layer and the substrate is not strong, making them unsuitable for high-speed, impact, and heavy-load applications.

Laser cladding is a process that uses a high-energy laser beam to irradiate the surface of a metal. After rapid melting, expansion, solidification and cooling, a layer of material with special physical, chemical or mechanical properties is cladding on the surface of the base material, thus forming a composite material that can fully leverage the advantages of both and make up for each other's shortcomings to make up for the deficiency of high performance of the machine body. According to the working conditions of the workpiece, surface coatings that are heat-resistant, wear-resistant, corrosion-resistant, oxidation-resistant, fatigue-resistant or have optical, electrical and magnetic properties can be surfacing.

The advantages of laser cladding

The metallurgical welding between the cladding layer and the substrate is dense, with high bonding strength and is not easy to fall off.

2. When changing or restoring the geometric shape of the workpiece, surface strengthening should be carried out while maintaining the dimensions.

3. The use of functional materials can achieve the customization of the surface properties of workpieces, altering the surface properties of parts, such as wear resistance, high-temperature resistance, and corrosion resistance.

4. The heat-affected zone and thermal deformation of the repaired area are small, and the base of the workpiece remains unchanged

5. The repair process is automatically controlled by the machine to ensure the quality of the workpiece.

6. High repair efficiency and short construction period;

7. It can repair workpieces of various materials. The hardness of the cladding layer is within the range of HRC20 to HRC60 and can be selected according to the application requirements.

As the repair layer produced by laser cladding repair technology is metallurgically bonded, it has a dense structure, high bonding strength and is not easy to fall off. It has gradually become one of the best repair techniques for ships. Combining the characteristics and advantages of laser cladding repair technology, the wear of various steel, cast iron and stainless steel parts on ships can all be repaired by laser cladding technology, and the overall performance after repair can reach or exceed that of new parts.

As for the repair problems that have been a headache for technicians in the ship repair industry in the past, laser cladding repair technology has demonstrated its uniqueness. For instance, in the repair of shafts, laser cladding repair technology can control the deformation within 0.01 to 0.02mm, and larger shafts may not even deform. For the repair of cast iron and stainless steel workpieces, laser cladding repair technology can also solve the problem, and the effect is remarkable with no cracks. Complex-shaped workpieces can also be repaired accurately and efficiently. The most important thing is that the range of cladding materials used in laser cladding repair technology is wide. Not only can materials similar to the substrate be used to achieve the purpose of dimensional repair, but also materials with better performance and superior alloy materials can be used to achieve the purpose of surface modification. These problems are often difficult to solve by traditional repair techniques.

Laser cladding repair technology, as a new process, with its unique advantages, has brought the possibility of repairing important components to the ship repair industry. As mentioned above, the various characteristics of laser cladding repair technology determine that lasers are bound to have broad application prospects in the ship repair industry. With the wide application of laser cladding technology in the ship repair industry, it will bring considerable benefits to ship repair yards and shipowners. At the same time, due to the savings in material consumption and waste products, the remanufacturing and repair of damaged workpieces are in line with the national industrial development. Therefore, the policy also has huge social benefits and is worthy of active promotion and application.