CLADDING TECHNOLOGY SHANXI CO., LTDTiangongyu Super Metal Repair Agent and Special Wear-Resistant Overlay Welding Electrodes
Literature Overview
Published in 2000 by Li Chun and Sun Weijun of Beijing Tiangongyu Industry and Trade Co., Ltd., this publication introduces a proprietary "Super Metal" repair agent and a range of special wear-resistant overlay welding electrodes. The work represents a commercialization effort in the field of advanced hardfacing consumables, targeting the demanding repair and maintenance needs of heavy industry including mining, cement, power generation, and metallurgy.
Core Technical Content
The Super Metal Repair Agent
The "Super Metal" repair agent is a composite material designed for cold application or low-temperature curing to repair worn or damaged metallic surfaces. Unlike traditional welding repairs, this agent can be applied without heat input, making it suitable for:
- Thin-walled components where welding heat could cause distortion
- Components in service where hot repair is impractical
- Precision parts where dimensional accuracy must be maintained
- Repair of areas with high residual stress where additional heat input could induce cracking
Typical Performance Characteristics
| Property | Typical Value | Application Significance |
|---|---|---|
| Compressive strength | 800–1200 MPa | Load-bearing capability |
| Hardness (as-cured) | 60–70 HRC | Wear resistance |
| Adhesion strength | 25–40 MPa | Bonding to base metal |
| Temperature resistance | Up to 300 °C | Operational temperature limit |
| Gap filling capability | Up to 5 mm | Repair of deep wear areas |
| Curing time | 2–24 hours | Downtime minimization |
Special Wear-Resistant Overlay Welding Electrodes
The accompanying welding electrode product line covers multiple hardfacing categories:
- Type A — High-carbon martensitic: Carbon content 2.0–3.0%, hardness 55–65 HRC, suitable for abrasion resistance in mining and cement applications.
- Type B — Medium-alloy austenitic: With Cr, Mo, and Ni additions, hardness 40–50 HRC, suitable for impact wear and moderate temperature service.
- Type C — Co-Cr alloy (Stellite-type): Cobalt-based with 25–30% Cr, hardness 40–50 HRC, suitable for high-temperature wear and corrosion resistance.
- Type D — Fe-Cr-C hardfacing: With 20–30% Cr and 3–5% C, hardness 55–65 HRC, suitable for severe abrasion.
Process Analysis
Welding Process Selection
The choice of welding process for applying these electrodes depends on the component geometry, accessibility, and production requirements:
| Process | Applicability | Deposition Rate | Dilution Control |
|---|---|---|---|
| SMAW (shielded metal arc) | Field repair, all positions | Low–Medium | Moderate |
| SAW (submerged arc) | Large flat/horizontal surfaces | High | Low |
| GMAW (flux-cored) | High productivity, horizontal | High | Moderate |
| Oxy-fuel | Small repairs, edge preparation | Low | High |
Dilution Management
Dilution is a critical factor in hardfacing applications because it directly affects the hardness and wear resistance of the overlay layer. The following strategies are recommended:
- Multiple passes: Build up the overlay in 2–3 passes, with the final pass using the hardfacing electrode to minimize dilution in the top layer.
- Higher current, faster travel: Increases the ratio of deposited material to base metal melted.
- Wire electrode vs. stick electrode: Flux-cored wire generally produces lower dilution than stick electrodes of equivalent composition.
- Pre-machined groove: A shallow groove allows the first pass to penetrate the base metal while subsequent passes deposit primarily overlay material.
Engineering Practice Cases
Mining Equipment Application
In mining applications, wear-resistant overlay electrodes were applied to excavator bucket teeth, conveyor rollers, and crusher hammers. The typical results showed:
- 3–5 times extension of service life compared to uncladded carbon steel parts.
- Hardness maintained at 55–60 HRC in the as-welded condition.
- No significant cracking or spalling observed after 6 months of service in abrasive material handling.
Cement Industry Application
In cement plants, the Super Metal repair agent was used for:
- Repair of worn kiln shells and lining anchors.
- Restoration of dimensionally critical roller surfaces.
- Emergency repair of thin-walled ducts and hoppers where welding was not feasible.
The repair agent provided immediate restoration of function with minimal downtime, although its temperature limitation restricted use to ambient-to-moderate temperature applications.
Key Reflections
This work highlights the complementary relationship between cold-applied repair agents and hot welding consumables in industrial maintenance. The Super Metal agent fills a niche that welding cannot address — situations where heat input is unacceptable or impractical. Meanwhile, the welding electrodes provide permanent, high-performance overlays for components that can tolerate thermal cycling.
An important insight is the commercialization pathway: developing proprietary consumables requires not only metallurgical expertise but also deep understanding of end-user needs, field conditions, and maintenance practices. The success of such products depends on demonstrating reliable performance in real operating environments, which requires extensive field testing and user feedback integration.
The product philosophy reflected here — offering a complete system of solutions rather than individual products — is a mature approach to industrial hardfacing technology. Engineers should consider both the consumable properties and the application process when selecting repair strategies for critical components.