Hardfacing is a welding-based method used primarily to deposit wear-resistant materials onto components subjected to high levels of abrasion, impact, erosion, or other forms of mechanical wear. Hardfacing extends service life by applying a tough, hard layer, often containing high concentrations of carbides or other hard particles, onto the surface of a lower-cost steel or alloy. The deposition process can involve shielded metal arc welding (SMAW), also called manual metal arc welding, gas metal arc welding (GMAW), flux-cored arc welding (FCAW), submerged arc welding (SAW), plasma-transferred arc (PTA), or laser cladding. Each process aims to enhance wear resistance without excessively compromising the component’s underlying structural integrity. Proper dilution control, bead geometry, and heat input ensure consistent hardness profiles and minimize defects such as cracking.
Cladding is a broader term than hardfacing, referencing the application of a different metal or alloy onto a base material to protect against corrosion, high temperatures, or wear. While cladding can also be performed by welding-based methods, it often includes other specialized techniques. Cladding is frequently used in chemical processing, power generation, and offshore applications.
Differences between the two processes primarily involve the intended purpose and material selection. Hardfacing generally targets wear resistance through high hardness overlays, typically in the 55-67 HRC range, with materials that may include chromium carbides, tungsten carbides, or high-manganese alloys. Cladding focuses on corrosion resistance or high-temperature stability, although wear protection can also be a secondary objective. Choosing between a hardfacing or a cladding approach depends on the dominant degradation mechanism: if corrosion is the main threat, cladding might be chosen; if mechanical wear is the primary concern, hardfacing could be more suitable. Both processes include the general concept of adding a layer of material to improve performance in service environments and require attention to welding parameters, heat-affected zone characteristics, dilution control, and proper preheat or post-weld heat treatment when necessary.
Industrial components encounter a variety of wear mechanisms that can negatively affect equipment longevity and performance. Hardfacing and cladding material selection requires matching the chemical composition and mechanical properties of a coating to the dominant wear factors identified in a specific application. At VORAX, we analyze these wear challenges and provide targeted solutions to ensure optimal operational efficiency.
Wear-related costs can range from approximately 1% to 5% of a nation’s Gross Domestic Product (GDP), depending on the degree of industrialization, sector-specific practices, and preventive measures. In real-world environments, abrasion, erosion, and corrosion often act simultaneously, accelerating material degradation. Corrosive conditions weaken protective layers, making surfaces more vulnerable to abrasive or erosive damage. VORAX addresses these compounded effects with precise material selection, multi-functional claddings, and expert engineering, reducing downtime and maintenance costs. Our extensive expertise and advanced technology deliver customized solutions to maximize equipment reliability and improve productivity.
Abrasion occurs when hard particles forcibly remove material from a surface. The hardness difference between abrasive particles and the material influences wear intensity. Industries like mining, construction, and agriculture experience abrasive wear from sand, ore, and other materials in constant contact with component surfaces. Abrasion can represent a large portion of total maintenance expenses, commonly 20% to 50% in heavy-wear industries.
VORAX offers hardfacing materials enriched with carbides to increase surface hardness and extend component service life. High-chromium carbide overlays, deposited via flux-cored welding, are well-known for their hardness and microstructural stability in abrasive environments. Tungsten carbide-based overlays, though more expensive, excel in severe conditions where chromium carbide systems may fail. Multi-carbide and nano-structured carbide formulations further enhance toughness, redistribute stresses, and prolong service life under extreme abrasion.
Erosion arises from the repetitive impact of fluid-borne particles against a surface. Key factors include particle velocity, impingement angle, and hardness differentials. Erosion-related expenses account for 5% to 15% of total maintenance budgets in power generation (especially coal-fired and gas-turbine plants), cement plants, chemical processing, and minerals handling.
VORAX provides erosion-resistant coatings and materials with optimized toughness and durability for demanding environments. Tungsten carbide-based overlays, applied with plasma-transferred arc (PTA) or laser cladding, exhibit exceptional resistance to erosive wear caused by high-velocity particle impacts. The high hardness and toughness of cladded surfaces enable performance retention under dry and wet erosive conditions, making them especially effective in mining and power generation. Industry testing confirms tungsten carbide coatings deliver superior longevity and reduced maintenance costs compared to traditional steels and castings.
Corrosive wear combines chemical or electrochemical reactions with mechanical degradation. Acids, salts, and industrial chemicals can compromise protective layers, intensifying wear. Corrosion alone can represent roughly 25% to 40% of maintenance costs in industries exposed to aggressive environments.
VORAX offers corrosion-resistant options to safeguard equipment, machinery, pipelines, and process vessels, extending service life and preventing downtime. Nickel-based alloys enriched with chromium and molybdenum are widely recognized for forming stable passive films, verified under ASTM G48 testing. These overlays, applied via gas tungsten arc or laser cladding processes, significantly reduce maintenance intervals and help avoid corrosive failures in challenging operations.
Impact wear occurs when surfaces are subjected to repeated or sudden loading, causing localized plastic deformation, micro-cracking, or fracture. Industries such as mining, crushing, and heavy equipment operations see frequent shock loads or collisions, accounting for 10% to 25% of total maintenance expenses in these sectors.
High-manganese austenitic steel overlays (e.g., Hadfield steel) endure repeated impact by deforming plastically rather than fracturing. Carbide-reinforced alloys containing chromium or titanium carbides balance toughness and localized hardness, extending service life in severe impact conditions. These overlays are typically deposited through a flux-cored arc or shielded metal arc welding, enhancing component durability.
Each surfacing technique offers distinct advantages regarding deposition rate, heat input, dilution control, and weld quality. VORAX leverages these processes to provide tailored wear-protection solutions in the mining, cement, construction, oil, and power generation industries.
Solid wires for hardfacing rely on external shielding gases (e.g., Ar/CO₂ mixtures) to protect the weld pool from atmospheric contamination. This approach allows precise control over filler composition to achieve specific properties, such as abrasion or corrosion resistance, making it suitable for a wide range of equipment refurbishment in mineral processing and cement operations. VORAX typically recommends solid wire overlays for applications requiring uniform cladding thickness and consistent microstructure.
Flux-cored arc welding (FCAW) uses a tubular wire containing fluxing agents, alloying elements, and slag formers, often delivering higher deposition rates than solid wires. This method is widely adopted for mining equipment (e.g., bucket teeth, excavator shovels) that undergo heavy abrasive wear from minerals. VORAX gas-shielded FCAW wires alloyed with chromium carbides can significantly prolong service intervals while maintaining a cost-effective deposition rate.
Self-shielded wires were developed to enable hardfacing in environments where external gas shielding is impractical, such as on large open-pit mining excavators or outdoor piping systems in power plants. Their built-in fluxing agents generate the protective gas envelope, reducing equipment requirements and setup complexity. Welding trials show that new generations of self-shielded wires can achieve high deposition rates and robust mechanical properties in demanding field applications.
Gas tungsten arc welding (GTAW), or TIG, delivers superior control over heat input and weld bead geometry by using a non-consumable tungsten electrode. Industries dealing with high-temperature or corrosive environments, such as power plants, often select GTAW for precision hardfacing. VORAX uses GTAW to apply cobalt-based or nickel-based overlays that resist hot erosion while ensuring minimal dilution and excellent clad quality.
Plasma-transferred arc (PTA) uses plasma arc to fuse powder or wire feed onto the substrate with minimal dilution. Well-controlled PTA applications provide uniform carbide dispersion, translating into longer operational life for equipment under severe wear conditions. Tungsten carbide-based PTA overlays from VORAX excel in mining operations that demand high resistance to extreme abrasion and impact, such as mill liners and crusher components.
Laser-based cladding techniques utilize a high-energy laser beam to fuse powder with very low dilution. These processes are notably advantageous for precision repairs and maintaining tight dimensional tolerances. VORAX laser cladding solutions create refined microstructures due to rapid solidification, enhancing resistance against abrasive and erosive forces.
Submerged arc welding (SAW) employs a granular flux that encloses the arc, yielding minimal spatter and exceptionally high deposition rates. It is a time-efficient option for depositing thick protective claddings, reducing downtime and maintenance costs. Thermal and cement plants, along with mines, frequently use VORAX SAW material to deposit protective layers on large-scale components.