CLADDING TECHNOLOGY SHANXI CO., LTDPreparation Process and Wear Resistance of WC/High-Manganese Steel Cladding Layers
Literature Overview
This 2012 study in Metal Heat Treatment by Dong Shizhi, Zhou Peng, Ma Zhuang, Tang Yanxu, and Li Zhichao from Liaoning Technical University investigates the preparation and tribological performance of tungsten carbide (WC) reinforced high-manganese steel (Hadfield steel) cladding layers. High-manganese steels are well known for their exceptional work-hardening capability, which makes them ideal for applications involving impact loading and abrasive wear. The addition of WC particles aims to further enhance wear resistance while maintaining the toughness of the matrix.
Core Technical Approach
The authors prepared WC/high-manganese steel composite cladding layers by submerged arc welding (SAW) using a flux-cored wire with pre-mixed WC particles. The substrate was a low-carbon steel plate. The WC particle size was 45–75 μm, and the WC content was varied from 0 to 30 wt.%.
Microstructural Observations
The as-welded microstructure of the unreinforced high-manganese steel cladding consists of austenite with some retained δ-ferrite. Upon impact or abrasive wear, the austenite transforms to martensite through strain-induced martensitic transformation (SIMT), which is the primary mechanism of work hardening.
With WC addition:
- The WC particles remain largely intact after welding, with minimal dissolution into the matrix
- The austenite grain size is refined due to the presence of WC particles acting as nucleation sites
- The volume fraction of retained austenite increases with WC content due to the carbon enrichment effect of the dissolved WC
| WC Content (wt.%) | Hardness (HV) | Retained Austenite (%) | Wear Rate (mm³/N·m) | Impact Energy (J) |
|---|---|---|---|---|
| 0 | 280 | 65 | 0.85 | 45 |
| 10 | 420 | 72 | 0.42 | 40 |
| 20 | 520 | 78 | 0.25 | 32 |
| 30 | 580 | 82 | 0.18 | 22 |
The wear resistance improves significantly with WC content, while the impact energy decreases due to the increased brittleness of the composite. The optimal WC content for a balance of wear resistance and toughness is approximately 20 wt.%.
Process Parameters and Defect Control
The SAW process parameters were optimized as follows:
- Current: 350–420 A
- Arc voltage: 32–38 V
- Travel speed: 200–300 mm/min
- Flux composition: 70% CaF₂ + 20% CaCO₃ + 10% SiO₂
- Preheat temperature: 150–200 °C
Common defects observed and their countermeasures:
| Defect | Cause | Countermeasure |
|---|---|---|
| Surface porosity | Gas evolution from WC oxidation | Use dry flux, preheat wire |
| Undercut | Excessive current or travel speed | Reduce current by 10–15% |
| Cracking | Thermal stress from WC inclusion | Increase preheat, reduce interpass temperature |
| Incomplete fusion | Low current or high travel speed | Increase current, reduce travel speed |
Engineering Application Considerations
The WC/high-manganese steel composite cladding is particularly suitable for applications involving:
- Abrasive wear with impact loading (e.g., crusher hammers, excavator teeth)
- Slurry erosion (e.g., pump impellers, slurry pipes)
- Mining equipment components
The work-hardening capability of the high-manganese matrix provides a self-reinforcing mechanism: as the surface is deformed during service, the austenite transforms to martensite, increasing the surface hardness and further improving wear resistance. The WC particles provide an additional hard phase that resists abrasive wear through micro-ploughing and micro-cutting resistance mechanisms.
Key Reflections and Study Insights
A key insight from this study is the synergistic interaction between the WC reinforcement and the high-manganese matrix. The WC particles do not merely act as hard inclusions; they also influence the retained austenite content and the strain-induced martensitic transformation behavior. This interaction means that the wear resistance of the composite is greater than the simple sum of the matrix and particle contributions.
Another important reflection is the limitation of WC particle size. Large WC particles (> 75 μm) can act as crack initiation sites and reduce the fatigue life of the cladding layer. For industrial applications, a WC particle size of 45–75 μm is recommended, with a maximum content of 20 wt.% to maintain adequate toughness.
The study also highlights the importance of flux design in SAW cladding with ceramic reinforcement. The flux must be formulated to provide adequate arc stability, slag fluidity, and deoxidation while minimizing gas evolution from the WC particles. This is a specialized area of welding consumable engineering that requires close collaboration between the welding engineer and the flux supplier.