Zhuojin Pipe Fitting Co., LtdApplication of ESAB Strip Electrode Surfacing Technology in Heavy Industry
Literature Overview
The 2013 publication in "Electric Welder" (Vol. 43, No. 5, pp. I0014-I0017) provides a comprehensive overview of ESAB's strip electrode surfacing technology and its industrial applications. The paper covers submerged arc strip electrode surfacing (SAW-SES) and strip electrode electroslag welding (ESW-SES), highlighting their advantages in deposition rate and dilution rate control for large-scale industrial applications including pressure vessels, heat exchanger tube sheets, hydroelectric turbine components, mining and construction equipment, and nuclear power plant internals.
Technology Comparison
The paper presents a clear distinction between two variants of strip electrode surfacing technology:
| Feature | Submerged Arc Strip Electrode (SAW-SES) | Electroslag Strip Electrode (ESW-SES) |
|---|---|---|
| Arc voltage | 25-35 V | 35-45 V |
| Current density | Lower | Higher |
| Penetration | Moderate | Deep |
| Dilution rate | 20-40% | 10-25% |
| Deposition rate | 3-5x wire SAW | 5-8x wire SAW |
| Surface quality | Acceptable | Smooth |
| Flux consumption | Moderate | Higher |
| Equipment complexity | Standard SAW | Specialized ESW |
| Substrate thickness | Any | Typically >6 mm |
| Position flexibility | Horizontal preferred | Horizontal only |
The critical insight from the paper is that while submerged arc welding (SAW) is the most frequently applied process in general welding, when high production efficiency and low dilution rate are both required, electroslag surfacing (ESW) is typically recommended. This distinction is particularly important for applications where the overlay composition must be maintained close to the nominal strip composition, such as corrosion-resistant overlays on pressure vessel internals.
Industrial Application Domains
The paper identifies several key application areas where strip electrode surfacing technology delivers significant value:
- Pressure vessel and reactor internals: Large-diameter vessels in chemical processing, petrochemical, and nuclear power applications require extensive corrosion-resistant overlays on carbon steel shells and heads. Strip electrode surfacing provides the deposition rates necessary to complete these operations within economic schedules.
- Heat exchanger tube sheets: Tube sheets in large heat exchangers require overlay layers to protect against corrosion from process fluids. The flat geometry of tube sheets is well-suited to strip electrode surfacing, and the low dilution rate ensures that the overlay composition maintains its corrosion resistance.
- Hydroelectric turbine components: Turbine runners, guide vanes, and penstocks experience severe erosion and cavitation damage. Hardfacing overlays applied by strip electrode surfacing provide wear resistance while maintaining the structural integrity of the base components.
- Mining and construction equipment: Large structural components such as crusher hammers, conveyor rollers, and bulldozer blades require wear-resistant overlays. Strip electrode surfacing provides the high deposition rates needed to rebuild and protect these components economically.
Process Considerations
The application of strip electrode surfacing technology requires careful attention to several process factors:
| Factor | Requirement | Impact if Not Controlled |
|---|---|---|
| Substrate preparation | Clean, flat surface; preheat if required | Poor fusion, porosity |
| Flux coverage | Uniform, adequate flux blanket | Arc instability, spatter |
| Strip electrode feeding | Constant feed speed, no jams | Bead geometry variation |
| Travel speed | Synchronized with feed rate | Dilution rate variation |
| Interpass temperature | Controlled to prevent excessive grain growth | Reduced mechanical properties |
| Post-weld treatment | Stress relief if required | Residual stress cracking |
The paper emphasizes that the selection between SAW-SES and ESW-SES depends on the specific application requirements. For applications where surface quality is critical and dilution must be minimized, ESW-SES is preferred despite its higher equipment requirements. For applications where surface roughness can be tolerated and equipment flexibility is needed, SAW-SES provides a good balance of performance and practicality.
Engineering Practice Reflections
The ESAB strip electrode surfacing technology represents a mature industrial solution that has been refined over decades of application development. The paper's value lies in its practical orientation, providing engineers with clear guidance on when to select strip electrode surfacing and which variant to choose for specific applications. The emphasis on deposition rate and dilution rate as the primary selection criteria reflects the economic and metallurgical realities of industrial surfacing operations.
For engineers evaluating surfacing technology options, this paper provides a useful framework for comparing strip electrode methods against conventional wire electrode processes. The key decision factors are: required overlay thickness, acceptable dilution rate, production schedule constraints, equipment availability, and surface finish requirements. When multiple of these factors favor high deposition rates and low dilution, strip electrode surfacing technology offers a clear advantage over conventional methods. The paper serves as a practical reference for process selection decisions in heavy industry applications.