CLADDING TECHNOLOGY SHANXI CO., LTDExperimental Comparison of Two Cemented Carbide Cladding Electrodes
Literature Overview and Research Motivation
This 2020 paper, authored by researchers from Hunan University of Technology in collaboration with Hunan Yishu Intelligent Manufacturing Co., Ltd., presents an experimental comparison of two cemented carbide cladding electrodes. The research was supported by the Hunan Provincial Natural Science Foundation (Grant No. 2018JJ4060) and a national college student innovation and entrepreneurship training program. The work was published in the journal Hot Working Technology (热加工工艺), reflecting its practical orientation toward manufacturing applications.
Cemented carbide materials, particularly tungsten carbide (WC) and chromium carbide (Cr3C2) based systems, are among the most wear-resistant materials available for hardfacing applications. They are widely used in mining, construction, agriculture, and material processing industries where extreme abrasion resistance is required. The selection of an appropriate cemented carbide cladding electrode is critical to achieving the desired wear life and economic performance.
Electrode Composition and Microstructural Characteristics
The two cemented carbide cladding electrodes compared in this study differ in their carbide composition, binder phase, and alloying additions. The first electrode is based on a WC-Co system, while the second incorporates additional alloying elements such as chromium, molybdenum, and vanadium to enhance specific properties.
| Property | Electrode Type A (WC-Co) | Electrode Type B (WC-Co-Cr-Mo-V) |
|---|---|---|
| WC content (wt%) | 70 to 80 | 50 to 60 |
| Co content (wt%) | 12 to 18 | 10 to 15 |
| Cr content (wt%) | 0 to 2 | 8 to 12 |
| Mo content (wt%) | 0 to 1 | 3 to 5 |
| V content (wt%) | 0 to 1 | 2 to 4 |
| As-welded hardness (HV) | 1200 to 1500 | 1000 to 1300 |
| Bond strength (MPa) | 200 to 300 | 250 to 350 |
| Cracking tendency | Moderate | Low |
The microstructure of the WC-Co based electrode (Type A) consists of hard WC particles dispersed in a relatively soft cobalt binder matrix. The WC particles provide the primary wear resistance, while the cobalt binder provides toughness and ductility. The microstructure of the modified electrode (Type B) includes additional carbide phases such as Cr7C3 and M23C6, which contribute to secondary hardening and improve the overall wear resistance under more severe conditions.
Wear Performance and Mechanical Properties
The researchers conducted comprehensive mechanical property tests and wear tests on the cladding deposits produced with both electrodes. The results revealed distinct performance characteristics that are relevant to different application scenarios.
Type A (WC-Co) exhibited higher as-welded hardness, which is advantageous for pure abrasion conditions where material removal is the primary wear mechanism. However, the higher hardness was accompanied by reduced toughness, making the deposit more susceptible to chipping and spalling under impact loading. The bond strength was adequate but lower than Type B, likely due to the formation of brittle intermetallic phases at the interface.
Type B (WC-Co-Cr-Mo-V) exhibited slightly lower as-welded hardness but demonstrated superior wear resistance under combined abrasion-impact conditions. The additional alloying elements improved the toughness of the binder phase, reduced cracking susceptibility, and enhanced the bond strength to the substrate. The Cr7C3 and M23C6 phases contributed to oxidation resistance and secondary hardening, extending the service life under thermal cycling conditions.
| Test Condition | Type A Performance | Type B Performance | Relative Improvement |
|---|---|---|---|
| Dry sliding abrasion (quartz) | Baseline | 1.1 to 1.3x | 10 to 30% |
| Impact abrasion (rock) | Baseline | 1.5 to 2.0x | 50 to 100% |
| Slurry abrasion (mining) | Baseline | 1.3 to 1.6x | 30 to 60% |
| High-temperature wear (600 C) | Baseline | 1.8 to 2.5x | 80 to 150% |
Engineering Selection Guidelines and Practical Recommendations
The experimental comparison provides clear guidance for the selection of cemented carbide cladding electrodes based on the specific service conditions. Type A (WC-Co) is recommended for applications involving pure abrasion at ambient temperatures, such as conveyor wear plates, mill liners, and grinding media. Type B (WC-Co-Cr-Mo-V) is recommended for applications involving combined abrasion and impact, thermal cycling, or corrosive environments, such as mining equipment, crusher components, and high-temperature processing equipment.
The bond strength difference between the two electrodes is particularly significant for engineers involved in pressure vessel and heavy equipment fabrication. Adequate bond strength is essential to prevent delamination failure under cyclic loading, and the superior bond strength of Type B makes it the preferred choice for critical structural applications. The reduced cracking tendency of Type B also facilitates easier welding and reduces the risk of defects that could compromise the integrity of the cladding layer.
Study Insights and Industry Implications
This research demonstrates that the selection of cemented carbide cladding electrodes should be based on a comprehensive evaluation of the service environment rather than simply maximizing hardness. The modified electrode (Type B), while exhibiting slightly lower as-welded hardness, provides superior overall performance under realistic operating conditions due to its enhanced toughness, bond strength, and thermal stability. This finding challenges the common industry practice of selecting hardfacing materials based solely on hardness values and underscores the importance of understanding the underlying wear mechanisms.
For engineers involved in bimetal product manufacturing, the key takeaway is that alloy design for hardfacing applications must balance hardness, toughness, and bond strength to achieve optimal performance. The addition of chromium, molybdenum, and vanadium to the WC-Co system provides a practical pathway to achieving this balance, and the resulting material system offers a compelling solution for a wide range of industrial applications. The research also highlights the value of systematic experimental comparison in materials selection, providing engineers with data-driven guidance for making informed decisions.