Anti-abrasion vs. Anti-corrosion weld overlay materials: How to choose the right
In harsh industrial environments, pipelines and fittings face constant threats from both mechanical wear and chemical degradation. Whether you are managing a mining slurry line or an offshore oil platform, the right weld overlay materials can significantly extend the service life of your assets. However, anti-abrasion and anti-corrosion weld overlays are engineered to counter different forms of damage – and understanding these differences is critical to making the right choice.
Weld overlay process in FNS Pipeline facility with automated systems
The Core Difference: Mechanical vs. Chemical Attack
To understand the materials, you first need to understand the threats they counter:
Abrasion: This is a mechanical form of wear. It happens when a material’s surface is physically removed by friction, impact, or sliding contact with other particles, such as sand, cement, or slurry. The primary defense against abrasion is material hardness and toughness.
Corrosion: This is a chemical form of degradation. It occurs when a material reacts with its environment (e.g., acids, saltwater, gases), causing it to decompose or be eaten away. The primary defense against corrosion is chemical stability and passivity.
Comparison Table: Anti-Abrasion vs. Anti-Corrosion Weld Overlay Materials
| Aspect | Anti-Abrasion Weld Overlay | Anti-Corrosion Weld Overlay |
|---|---|---|
| Primary Threat Addressed | Mechanical wear (sliding, impact, erosion) | Chemical attack (acid, chloride, oxidation) |
| Key Properties | High hardness (≥ 55 HRC), high compressive strength, toughness | Chemical stability, passivation, resistance to pitting/crevice corrosion |
| Common Materials | Chromium Carbide, Tungsten Carbide, Iron- or Cobalt-based hard-facing alloys | Nickel-based alloys (Inconel, Hastelloy), Stainless Steel (300 Series, Duplex), Titanium alloys |
| Typical Applications | Mining slurry pipelines, dredging equipment, cement processing | Petrochemical refineries, offshore platforms, acid plants, seawater systems |
| Service Life Expectation | Up to 3–5× longer in abrasive conditions | Up to 10× longer in corrosive environments |
| Cost Considerations | Lower initial cost, high ROI in abrasive media | Higher initial cost, essential in corrosive service |
Technical Parameters
Anti-Abrasion Weld Overlay
- Hardness Range: 55–70 HRC
- Compressive Strength: 1,000–2,000 MPa
- Max. Operating Temperature: 600°C (depending on alloy type)
- Standards: AWS A5.21 (Hard-facing), ASTM G65 wear resistance test
Anti-Corrosion Weld Overlay
- Corrosion Rate: <0.05 mm/year in specified corrosive medium
- Pitting Resistance Equivalent Number (PREN): >40 for seawater applications
- Max. Operating Temperature: Up to 1,100°C for certain Nickel alloys
- Standards: ASTM G48 pitting test, ASTM B622 (Nickel alloys)
MAG Overlay Welding applied on pipeline product for corrosion protection
Anti-Abrasion Weld Overlay Materials
Anti-abrasion materials are designed to resist mechanical wear. Their performance is directly related to their physical properties, particularly high hardness and compressive strength. These materials create a hard surface that is difficult for abrasive particles to remove.
Key Properties: High hardness, toughness, and compressive strength.
Common Examples:
- Chromium Carbide: Highly effective for resisting sliding and impact abrasion.
- Tungsten Carbide: Extremely hard and durable, used for the most severe abrasive applications.
- Hard-facing Alloys: Specialized iron-based or cobalt-based alloys designed for superior wear resistance.
- Typical Applications: Mining slurry pipelines, cement processing equipment, dredger components, and any piping handling abrasive particulate matter.
Anti-Corrosion Weld Overlay Materials
Anti-corrosion materials are designed to resist chemical degradation. Their effectiveness depends on their ability to remain chemically inert and form a stable passive layer when exposed to a corrosive environment.
Key Properties: Chemical stability, passivation ability, and resistance to specific chemical attacks.
Common Examples:
- Nickel-based Alloys: Inconel, Hastelloy. These alloys offer exceptional resistance to acids, chlorides, and high-temperature corrosion.
- Stainless Steels: 300 series stainless steels or Duplex stainless steels provide robust protection against a wide range of corrosive fluids.
- Titanium Alloys: Known for their excellent resistance to seawater and other highly corrosive media.
Typical Applications: Petrochemical refineries, acid plants, offshore platforms, and piping systems transporting seawater or corrosive gases.
FNS Pipeline’s Solution: The Right Material for the Job
There is no single material that is the best for every situation. A material that excels in a highly corrosive environment may not be hard enough to resist severe abrasion, and vice versa. Choosing the correct weld overlay material is a crucial engineering decision that directly impacts the lifespan and safety of your system.
At FNS Pipeline, we specialize in providing tailored solutions. We don’t rely on a one-size-fits-all approach. By consulting with our clients to understand the specific threats-whether it’s pure abrasion, pure corrosion, or a combination of both-we precisely select and apply the optimal weld overlay material. This ensures that your pipes and fittings get the right kind of protection, giving you peace of mind and long-term value.
