CLADDING TECHNOLOGY SHANXI CO., LTDApplication of Wear-Resistant Cladding Materials in China's Cement Industry
Literature Overview
This comprehensive review by Wei Jianjun, Pan Jian, Huang Zhiquan, Xu Jian, Wang Xin, and Zhang Yongsheng from the Special Welding Materials Research Laboratory of Zhengzhou Mechanical Research Institute (published in China Surface Engineering, 2006) documents the application of wear-resistant cladding materials in China's cement industry. The cement industry presents unique and severe wear challenges due to the abrasive nature of cement raw materials, clinker, and grinding media. This literature provides valuable insights into the practical application of weld overlay technology in a major industrial sector.
Core Technical Points
The cement industry faces wear challenges at multiple points in the production process, each with distinct wear mechanisms and material requirements:
Wear Locations and Mechanisms
| Component | Wear Mechanism | Abrasive Material | Typical Wear Rate | Service Life (Uncladded) |
|---|---|---|---|---|
| Ball mill liners | Abrasion + impact | Clinker, grinding steel balls | 2–5 mm/month | 6–12 months |
| Mill trunnion sleeves | Abrasion | Slurry, dust | 1–3 mm/month | 12–18 months |
| Crusher jaws | Impact-abrasion | Limestone, clay | 3–8 mm/month | 3–6 months |
| Conveyor rollers | Abrasion | Cement, dust | 0.5–2 mm/month | 12–24 months |
| Rotary kiln wear plates | Abrasion + thermal | Clinker, kiln dust | 1–4 mm/month | 6–12 months |
| Fan blades | Abrasion | Cement dust, fines | 1–3 mm/month | 12–18 months |
| Chutes and hoppers | Abrasion | Raw meal, clinker | 1–3 mm/month | 6–12 months |
Wear-Resistant Cladding Material Selection
The study categorizes cladding materials by composition and application suitability:
| Material Type | Typical Composition | Hardness (HV) | Application Area |
|---|---|---|---|
| High-chromium cast iron | 20–30% Cr, 3–5% C | 600–900 | Ball mill liners, chutes |
| High-chromium alloy (powder) | 25–35% Cr, 2–4% C, 5–10% Mo | 800–1200 | High-abrasion areas |
| Medium-chromium alloy | 10–20% Cr, 2–3% C | 500–700 | Moderate abrasion areas |
| Hardfacing steel | 4–6% Cr, 1–2% C, 3–5% Mo | 500–800 | Impact-abrasion areas |
| Ceramic-reinforced composite | Fe-Cr-C + WC/TiC | 1000–1500 | Extreme abrasion |
| Austenitic manganese steel | 10–14% Mn, 0.8–1.2% C | 200–300 (work-hardened to 500–700) | Impact-abrasion |
Application Case Studies
Case 1: Ball Mill Liner Cladding
Ball mill liners represent the highest-value application of wear-resistant cladding in cement plants. The study reports that applying high-chromium alloy overlay to carbon steel or low-alloy steel liner blanks provides:
- Life extension: 3–5× compared to uncladded steel liners
- Cost reduction: 40–60% reduction in total liner cost over the service life
- Production improvement: Reduced downtime for liner replacement
- Typical overlay thickness: 10–20 mm on the working surface
The recommended cladding approach uses multi-layer SAW or FCAW with high-chromium alloy flux-cored wire, with a controlled dilution rate of 15–25% to optimize the hardness-toughness balance.
Case 2: Crusher Jaw Cladding
Crusher jaws experience severe impact-abrasion wear from limestone and clay materials. The optimal cladding material for this application is a medium-chromium alloy with good impact resistance:
- Overlay composition: 10–15% Cr, 1.5–2.5% C, 3–5% Mo
- Hardness: 500–700 HV
- Overlay thickness: 8–15 mm
- Life extension: 2–4× compared to uncladded jaw plates
- Welding method: SAW or GMAW with appropriate consumables
Case 3: Rotary Kiln Wear Plates
Rotary kiln wear plates face combined abrasion and thermal wear from hot clinker and kiln dust. The cladding strategy must account for:
- Operating temperatures of 800–1200°C
- Thermal cycling stress
- Abrasion from clinker particles
- Possible chemical attack from SO3 and alkali compounds
The recommended approach uses heat-resistant high-chromium alloys with Mo and V additions, applied by SAW or FCAW with appropriate interlayer materials to manage thermal expansion mismatch.
Quality Control Considerations
For cement industry applications, the following quality control measures are essential:
- Pre-weld preparation — Surface cleaning to remove scale, rust, and contaminants; bevel preparation for multi-layer builds
- Interpass temperature control — Typically maintained below 200°C for high-chromium alloys to prevent excessive grain growth
- Dilution monitoring — Chemical analysis of the overlay layer to verify dilution rate is within specification
- Hardness verification — Surface hardness testing at specified intervals to confirm wear resistance
- Visual inspection — Surface quality assessment for undercut, porosity, and incomplete fusion
- Impact testing — For impact-abrasion applications, Charpy V-notch testing of representative coupons
Key Reflections
This literature review demonstrates that wear-resistant cladding technology has matured significantly in China's cement industry, with well-established material selection guidelines and application practices. The key insight is that material selection must be driven by the specific wear mechanism at each component location — abrasive, impact-abrasive, or thermal-abrasive — rather than applying a single material universally. The economic justification for cladding is compelling: even with the additional cost of overlay consumables and welding labor, the extended service life typically results in significant net savings. Engineers working in this field should emphasize the importance of proper welding procedure qualification and consistent production quality, as the benefits of cladding are fully realized only when the overlay layer is properly bonded and free from defects.