Hard weld overlay

Main Types of Hard Overlay Welding

Hard overlay welding is often used for wear protection in industrial conditions and can be made from various materials depending on the requirements for strength and corrosion resistance. The main types include:

• Steel Hard Overlay Welding: A combination of carbon or alloy steel with high impact toughness and abrasion-resistant steel.
• Hard Overlay Welding with Hard Alloys: Usually a combination of soft steel with tungsten carbide or ceramic inserts, providing high wear resistance.
• Nickel Hard Overlay Welding: Combines nickel with other metals to improve corrosion resistance and hardness.

Depending on the dominant type of wear, Weartech specialists select the composition of the overlay layer based on their extensive experience:

• CrC – Erosion, abrasive wear, deformation
• B – Strength, wear resistance
• Nb – High velocities of fine particle fractions
• Mo, V – Critical temperatures

The main focus when choosing a hard overlay welding for a specific application is the percentage of carbides in the composition of the overlay layer, and hardness in this case is not a key argument.

Main Advantages of Hard Overlay Welding

Hard overlay welding has several advantages that make it an ideal tool for industrial applications:

• Extended Service Life: Due to high resistance to wear and corrosion, hard overlay welding can significantly increase the operating time of equipment.
• Cost Savings: Reduced costs for equipment repair and replacement due to increased maintenance intervals.
• Improved Efficiency: Maintaining optimal equipment performance by reducing wear.
• Recyclability: Some types of hard overlay welding can be recycled, contributing to sustainable development.

Despite numerous advantages, hard overlay welding also has its drawbacks:

• Relatively High Cost: Initial investments in hard overlay welding can be significantly higher compared to traditional materials.
• Complexity in Installation and Maintenance: Specialized knowledge and tools are required for the installation and repair of hard overlay welding.
• Limited Application: Some types of hard overlay welding are not universal and may not be suitable for all operating conditions.

Application of Hard Overlay Welding in the Mining Industry

Main Types of Wear in the Mining Industry

The mining industry faces various types of wear, with the most common being:

1.Abrasive Wear: This is the most common type of wear caused by the impact of hard particles on equipment surfaces. An example is the wear that occurs during ore processing or transportation.

2.Impact Wear: Occurs when equipment experiences strong impacts or collisions with large and heavy pieces of ore or rock.

3.Corrosive Wear: Moist environments and chemically active substances can cause metal corrosion, accelerating equipment wear.

4.Erosive Wear: Occurs when equipment is exposed to prolonged exposure to water or other liquids, especially if they contain abrasive particles.

Effective Application of Hard Overlay Welding in the Mining Industry

Hard overlay welding is especially effective for protecting the following types of equipment used in the mining industry:

• Crushers: Used to crush ore to the desired size. Hard overlay welding elements increase the wear resistance of crushing plates and reduce the need for frequent replacement.
• Mills: In ball and rod mills, hard overlay welding helps reduce wear on internal surfaces exposed to abrasive action during ore grinding.
• Conveyors: In transportation systems where ore is moved over long distances, hard overlay welding elements can protect critical areas such as blades and belts.
• Feeders and Scrapers: These devices constantly contact abrasive materials, and the use of hard overlay welding helps extend their service life.

Using hard overlay welding in these areas can significantly increase equipment service life, reduce downtime due to less frequent repairs and component replacements, and improve the overall efficiency of the production process.

Application of Hard Overlay Welding in the Cement Industry

Main Types of Wear in the Cement Industry

Cement production is associated with several specific conditions that lead to equipment wear. The main types of wear include:

• Abrasive Wear: The main type of wear caused by the impact of hard and abrasive particles of cement and other additives on equipment. The abrasiveness of materials in the cement industry is especially high during mixing and grinding.
• Corrosive Wear: The chemical impact of raw material components and products, including acids and alkalis, can lead to the corrosion of metal elements.
• Thermal Wear: High temperatures, especially in clinker kilns, can weaken metal components and change their properties.
• Impact Wear: Sharp and frequent impacts of hard materials can cause microcracks and gradual destruction of equipment parts.

Effective Application of Hard Overlay Welding in the Cement Industry

Hard overlay welding is especially effective for protecting the following types of equipment used at various stages of cement production:

• Crushers: Used to crush large pieces of raw materials (limestone, clay) to sizes suitable for further processing. Hard overlay welding can significantly extend the life of wear parts.
• Mills (Ball and Vertical): In these devices, clinker is ground to a powder state. Abrasive wear is a significant factor, and hard overlay welding can significantly reduce its impact.
• Transport Systems: Conveyor belts and rotary feeders that move raw materials and finished products can also be protected with hard overlay welding to increase their wear resistance.
• Valves and Dampers: These elements are often exposed to abrasive and impact wear when regulating the flow of bulk materials.

Hard overlay welding in these applications not only extends equipment life but also reduces maintenance and repair costs, which is crucial in the continuous production process characteristic of the cement industry.

Application of Hard Overlay Welding in the Metallurgical Industry

Main Types of Wear in the Metallurgical Industry

The metallurgical industry faces significant challenges in terms of equipment wear, especially in steel production. The main types of wear include:

• Abrasive Wear: Occurs due to contact of equipment with abrasive materials such as ore and coke, which can quickly wear metal surfaces.
• Thermal Wear: High temperatures characteristic of metallurgical production can change material properties and accelerate wear.
• Corrosive Wear: Chemical exposure from slags and other aggressive environments in the melting process promotes metal corrosion.
• Impact Wear: Powerful impacts and loads from processing heavy metals can cause equipment destruction and deformation.
• Fatigue Wear: Regular exposure to variable loads can cause fatigue cracks and material defects.

Effective Application of Hard Overlay Welding in Steel Production

Hard overlay welding finds effective application in various units and assemblies of the metallurgical industry, especially in steel production:

• Converters and Furnaces: Exposed to high temperatures and aggressive chemical exposure. Hard overlay welding can protect internal surfaces from wear and extend their service life.
• Rolling Mills: Equipping work rolls with hard overlay welding helps reduce wear from abrasive materials and thermal impact, ensuring higher precision and quality of rolled products.
• Transport Systems: Using hard overlay welding elements in conveyor system components, such as belts and rollers, increases their wear resistance and resistance to abrasive impact.
• Loading and Unloading Mechanisms: These devices, often in contact with abrasive and corrosive materials, benefit from hard overlay welding, reducing wear rates and extending maintenance intervals.

Using hard overlay welding in the metallurgical industry significantly improves equipment performance and reliability, reduces maintenance and repair costs, and enhances the overall economic efficiency of production processes.