Case Study: Repairing the Head of an Industrial Sintering Fan Shaft

Keywords: Laser Cladding, Industrial Repair, Remanufacturing, Shaft Restoration, Metallurgical Bonding, Wear Resistance, Industrial Surface Engineering

1. Introduction

In heavy industrial sectors, large rotating equipment such as fans, rolling mills, and compressors often experience wear, corrosion, or fatigue damage on key components (such as shaft ends or bearing surfaces) during long-term high-load operation. Once dimensional deviation or performance degradation occurs, not only does equipment accuracy suffer, but entire production lines may shut down, leading to significant economic losses.

A shaft head of a sintering fan in a large steel plant experienced dimensional reduction due to long-term wear—an issue typical of such operational conditions. After receiving the repair request, the Huiri Technology Team adopted laser cladding technology to execute an efficient and precise restoration. The shaft head’s dimensions and performance were successfully restored, ensuring continuous and stable operation.

2. What Is Laser Cladding Technology?

Laser Cladding—also known as laser additive remanufacturing or laser coating—is a surface engineering process using a high-energy laser beam to melt pre-placed or synchronously fed alloy powder. The molten material forms a metallurgically bonded cladding layer on the surface of the substrate.

By applying alloys with specific characteristics (such as wear resistance, corrosion resistance, or heat resistance), the process restores component dimensions and improves operating performance.

Core Process Steps:

1.Base Material Preparation
Surface cleaning, degreasing, and roughening to ensure bonding strength.

2.Laser Scanning and Powder Feeding
A laser head scans the workpiece while transporting alloy powder to the molten region.

3.Cladding Layer Formation
Powder melts under the laser and bonds metallurgically to the substrate.

4.Post-Processing and Precision Machining
Slow cooling, CNC machining, and grinding ensure dimensional and geometric accuracy.

3. Technical Features and Performance Advantages of Laser Cladding

Laser cladding is increasingly preferred in industrial repair and remanufacturing because of the following core advantages:

1. Metallurgical Bonding with High Strength

The cladding layer achieves a fully metallurgical bond with the substrate, reaching up to 90% of the base material’s strength—significantly higher than spraying or electroplating, preventing peeling or delamination.

2. Low Heat Input with Controlled Deformation

Laser energy concentration produces a narrow heat-affected zone and low thermal stress, allowing high dimensional control—especially suitable for precision shafts and thin-walled structures.

3. Designed Cladding Performance

Alloy powders can be selected based on working conditions (nickel-based, cobalt-based, iron-based, metal-ceramic composites), enabling tailored properties such as wear resistance, corrosion resistance, or heat resistance.

4. High Repair Precision with Minimal Machining

A small laser spot and precise movement enable localized and complex geometry repair. Coating thickness can be controlled within 0.2–3 mm, reducing machining cost.

5. Environmentally Friendly

Unlike electroplating and welding, laser cladding produces no hazardous gas or heavy metal wastewater, aligning with green manufacturing requirements.

4. Advantages and Disadvantages of Laser Cladding

✔ Advantages:

1.Long-lasting repair results; coating performance exceeds substrate.

2.Compatible with steel, cast iron, nickel-based alloys, titanium alloys, and more.

3.Supports digital control and robotic or CNC automation.

4.Extends equipment life and reduces spare parts costs.

✘ Disadvantages:

1.High initial investment: laser source, powder feeder, and robot systems.

2.Complex process parameter tuning (power, scanning speed, powder flow rate).

3.Requires skilled personnel with combined materials and laser expertise.

5. Case Study: Laser Cladding Repair of a Sintering Fan Shaft Head

In this steel plant scenario, the shaft head had experienced dimensional reduction due to long-term wear. Traditional methods, such as welding overlay, posed deformation risks, while full replacement required long procurement cycles and high costs.

After technical evaluation, the team selected laser cladding as the repair solution:

Repair Procedure Summary

1.Damage Assessment and Design:
3D scanning identified worn regions. A high-hardness nickel-based alloy powder was selected.

2.On-Site Cladding Execution:
A 6 kW fiber laser equipped with a coaxial powder-feed system was used. Layer temperature was precisely controlled.

3.Machining and Quality Testing:
Post-cladding, turning and grinding restored the original size. Ultrasonic inspection and hardness testing confirmed repair integrity.

4.Operational Validation:
The repaired shaft ran smoothly after installation, achieving a surface hardness above HRC 55 with significantly improved wear resistance.

6. Conclusion: The Value & Future of Laser Cladding in Industrial Remanufacturing

Laser cladding technology is not merely a repair method but a key enabler of remanufacturing and circular economy strategies. By restoring functionality and enhancing part performance, it reduces maintenance costs and resource consumption.

With dropping laser equipment costs, expanding process databases, and the rising adoption of intelligent robotic control, laser cladding will play an increasingly significant role in aerospace, energy equipment, transportation, and other high-value industries.

The successful repair of this shaft head demonstrates the technology’s strengths in ensuring continuous industrial operation and improving equipment reliability. As technology continues to evolve, laser cladding is expected to become a standard method for maintenance, strengthening, and upgrading of industrial components.