Choosing Hardfacing Electrodes or Wire for Abrasive Applications

[MikePhua]

The Role of Hardfacing in Equipment Longevity
Hardfacing is a welding process that deposits wear-resistant material onto surfaces subject to abrasion, impact, or erosion. It’s widely used in industries like mining, forestry, and construction, where components such as grinder hammers, excavator buckets, augers, and mud tools endure constant friction and material wear. A well-executed hardfacing job can extend service life by thousands of hours, reduce downtime, and lower replacement costs.
In one example, a Morbark grinder component lasted over 5,000 hours before requiring re-hardfacing—a testament to the effectiveness of proper material selection and application technique.
Terminology Annotation
- Hardfacing electrode: A stick welding rod containing alloy materials designed to resist wear.
- Flux-cored wire: A tubular wire filled with flux, used in MIG welding for hardfacing applications.
- Dual-shield wire: A flux-cored wire used with external shielding gas, offering deeper penetration and cleaner welds.
- Hexavalent chromium: A toxic compound released during welding of certain alloys, requiring ventilation or respiratory protection.
- Admixture: The dilution of hardfacing alloy with base metal during welding, which can reduce hardness if excessive.
Electrode vs. Wire for Field Repairs
When deciding between stick electrodes and wire for hardfacing, several factors come into play: equipment availability, job size, location, and desired wear characteristics. Stick electrodes like Lincoln’s Wearshield MI (moderate impact) are favored for field repairs due to portability and simplicity. They’re ideal for small jobs or remote sites where engine-driven welders are used.
Wire options, such as Lincore 60-O or 60-G, offer higher deposition rates and consistent bead profiles, making them suitable for shop environments or large-scale rebuilds. With a suitcase feeder and a Trailblazer 325 engine drive, wire welding becomes viable even in the field, especially when depositing several pounds of weld.
Recommendations:

• Use stick electrodes for small, mobile jobs or when access is limited
  
• Use flux-cored wire for high-volume applications or when uniformity is critical
  
• Match wire diameter to existing bead size for aesthetic and structural consistency
  
• Ensure DC polarity compatibility with your welder setup
  

Material Selection and Equivalent Products
Stoody 35 by ESAB is a popular hardfacing alloy known for its high chromium content and excellent abrasion resistance. However, availability can be limited in certain regions. Lincoln Electric offers comparable products such as Wearshield ME and Lincore 50, which provide similar wear profiles and impact resistance.
Cross-reference suggestions:

• Stoody 35 ≈ Wearshield ME (stick)
  
• Stoody 35 ≈ Lincore 60-O or 60-G (.045 wire)
  
• For moderate impact: Wearshield MI (5/32", 150–160 amps DC+)
  
• For high impact: Wearshield 44 or Lincore 50
  

One technician noted that Airgas misidentified Outershield 71M as a hardfacing wire, which is incorrect—it’s a general-purpose flux-cored wire not designed for abrasion resistance. This highlights the importance of consulting manufacturer datasheets or experienced welders when selecting materials.
Safety Considerations and Ventilation
Hardfacing alloys often contain chromium, manganese, and other elements that release hazardous fumes during welding. Hexavalent chromium, in particular, poses serious health risks. Welding outdoors or in well-ventilated areas is essential. For indoor work, supplied-air hoods or fume extraction systems should be used.
Precautions:

• Always weld hardfacing alloys in open-air environments when possible
  
• Use respirators or air-fed hoods for enclosed spaces
  
• Keep fire suppression tools nearby—grinder chambers and augers may contain flammable residues
  
• Avoid welding near hydraulic lines or fuel tanks without proper shielding
  

One operator routinely carries a trailer-mounted pressure washer and buckets of water when performing hot work on grinders, ensuring safety and fire prevention.
Economic and Logistical Considerations
Local welding supply shops may not stock specialty hardfacing products, and chain stores often lack technical expertise. Ordering directly from manufacturers or online distributors can be more efficient. Some welders bundle rod orders with steel purchases to receive bulk discounts.
Tips:

• Order hardfacing rods with steel shipments to reduce cost
  
• Maintain a cabinet of commonly used electrodes and wire for field readiness
  
• Use auto-set MIG machines for simplified wire setup, but verify settings manually for hardfacing
  
• Document successful material combinations for future reference
  

In Missouri, one welder continues to use Miller equipment purchased decades ago, citing reliability and consistent arc quality. His electrodes come from a steel supplier offering 30% lower prices than retail stores.
Conclusion
Choosing between hardfacing electrodes and wire depends on job scope, equipment, and wear conditions. Stick electrodes offer flexibility and simplicity, while wire systems provide speed and consistency. Matching alloy properties to the application—whether severe abrasion, moderate impact, or a combination—is key to success. With proper safety measures, sourcing strategies, and technical understanding, hardfacing becomes not just a repair method but a long-term investment in equipment durability.