In the elevator industry, the traction sheave is the core power-transmission component and is subjected to continuous steel-wire-rope friction, impact loads, and complex environmental influences. Traditional ductile-iron traction sheave grooves often face insufficient wear resistance: the groove surface tends to develop uneven wear, reducing elevator ride smoothness and potentially causing wire-rope slippage and safety risks. In addition, casting-related defects such as inclusions and porosity can further accelerate wear, shorten equipment lifespan, and compromise operational safety.

To solve these challenges, it is critical to apply an advanced surface-engineering technology capable of forming a high-hardness, wear-resistant coating with strong metallurgical bonding on traction sheave grooves. This enhanced traction layer significantly improves durability, ensures stable transmission performance, and strengthens the overall reliability and safety of high-speed elevator systems.

Application Solution for Specific Components
For wear-resistance enhancement of high-speed elevator traction sheaves (ductile iron), laser cladding technology is used to deposit a cobalt-based alloy traction coating on the groove surface. The solution includes:

Coating Material
A cobalt-based alloy powder specifically optimized for ductile iron substrates. The system forms chromium carbide hard phases through carbon and chromium, while boron and silicon improve wettability. Nickel, molybdenum, and tungsten are added to enhance corrosion resistance and high-temperature wear performance.

Process Implementation

• Semiconductor laser system (2500–3000 W power range)

• Precise 3 mm laser spot control with scanning speed of 800–1200 mm/min

• 45%–50% overlap to ensure uniform coating deposition

• Direct metallurgical bonding to ductile iron, no buffer layer required

Process Control

• Preheating to 150–250°C to suppress crack formation

• Post-tempering at 550–650°C to eliminate residual stress

• Fully automated robotic operation to ensure uniform coating thickness

This solution delivers a dense, well-bonded, high-performance traction layer, providing enhanced wear resistance, improved groove durability, and stable traction capability for high-speed elevator systems.

Application Results

• Wear resistance improved to more than five times that of the base material

• Significant improvement in wear uniformity across grooves, with groove wear variation ≤ 1 mm

• Effective elimination of wire-rope slippage, ensuring operational safety

• Maintenance cycle extended by approximately three times, reducing total life-cycle cost by 40%

This technology has been successfully implemented for mass repair and performance enhancement of high-speed elevator traction sheaves. It provides a reliable technical solution for safe elevator operation and has become a benchmark application in the field of laser strengthening for mechanical components.