1. Introduction to New High-Pressure Roller Wear-Resistant Overlay Welding Technology

The new high-pressure roller wear-resistant overlay welding technology is a series of advanced techniques developed on the basis of traditional overlay welding, aimed at meeting higher requirements for wear resistance, spalling resistance, and service life of high-pressure roller mill rollers under harsh conditions (high pressure, high wear, impact, corrosion). Its core goal is to significantly improve the performance and service life of the roller surface wear-resistant layer, reduce downtime for maintenance, and lower overall operating costs.

2. Core Materials and Performance Characteristics

High-pressure roller wear-resistant overlay welding technology significantly enhances wear resistance and extends equipment service life by overlay welding wear-resistant materials on the surface of high-pressure rollers. The core of this technology lies in selecting suitable overlay welding materials. Currently, mainstream materials include wear-resistant welding rods and overlay welding wires, which have the following key properties:

High hardness and wear resistance: For example, D047 wear-resistant welding rods are specially designed for rolling mill extrusion rollers, with overlay layer hardness reaching above HRC58; tungsten carbide alloy rods (such as D708) enhance wear resistance through tungsten carbide hard phases, suitable for overlay welding of wear parts under high temperature and high pressure conditions.

High temperature stability: Some welding rods (such as D917) can withstand temperatures up to 860°C, meeting the high-temperature environment requirements of mechanical charcoal plant screw conveyors, steel alloy equipment, etc.

Impact and crack resistance: Overlay welding wires (such as YD256, YD266 high manganese steel wires) adjust alloy composition (e.g., high carbon and high chromium) to combine impact resistance and machinability, minimizing crack formation during welding.

3. Classification of High-Pressure Roller Wear-Resistant Overlay Welding Materials and Application Scenarios

1. Material Classification

Based on differences in material composition and performance, high-pressure roller overlay welding materials can be divided into the following categories, each suited to specific application scenarios:

4. Key Points and Operating Specifications of High-Pressure Roller Overlay Welding Technology

Material Selection Principles

Condition Matching: Select materials based on high-pressure roller operating temperature (ambient/high temperature) and medium (abrasive/corrosive environment). For example, D917 tungsten carbide rods are preferred for high-temperature and high-pressure environments, while DH-04 special rods are recommended for coal mining equipment.

Base Material Compatibility: For carbon steel substrates, D036 edge welding rods can be directly overlaid; for dissimilar metal welding (e.g., stainless steel to carbon steel), nickel-based rods (ENiCrFe-1) must be used.

Welding Process Control

Preheating and Post-heating: High hardness rods (such as D708) require preheating the workpiece to 200-300°C before welding and slow cooling after welding to avoid cracks; low-hydrogen rods (such as D027) can be welded without preheating but must control interlayer temperature ≤250°C. 1。

Welding Methods: Oxy-acetylene overlay welding is suitable for small-area repairs requiring high surface finish with low dilution rate (melting layer depth ≤0.1mm); large-area overlay welding is recommended with arc welding combined with flux-cored wires (such as YD507) to improve efficiency. 3。

Quality Inspection Standards

Hardness Testing: The surface hardness of the overlay layer must meet design requirements (e.g., HRC58-62), which can be tested on-site using a Rockwell hardness tester.

Non-destructive Testing: Penetrant testing (PT) or magnetic particle testing (MT) is used to detect cracks, porosity, and other defects in the overlay layer to ensure no through defects.

5. Applications and Advantages

This technology has been widely applied in mining, building materials, chemical industries, etc. Typical cases include:

Mining machinery: Overlay welding repair of high-pressure roller mill rollers using D047 rods extends service life by 3-5 times.

Cement industry: Vertical roller mill extrusion rollers overlaid with tungsten carbide rods (D708) can withstand continuous impact wear from clinker particles.

Coal processing: Scraper conveyor chutes overlaid with DH-04 rods improve resistance to abrasive particle wear by more than 40%. 1。
Compared to traditional roller replacement methods, overlay welding technology can reduce maintenance costs by 60%-80%, while also decreasing equipment downtime, offering significant economic benefits.

Advantages

Significantly extended service life: Compared to traditional overlay welding, the new technology can usually increase the wear layer life of roller surfaces by 50% or even more than 100%. The WC-enhanced overlay layer life extension is especially remarkable.

Outstanding fatigue spalling resistance: Improved toughness and gradient design effectively suppress crack propagation and large-scale spalling of the wear-resistant layer, allowing the roller surface to remain intact for longer.

Higher wear resistance: Optimized types, quantities, and distribution of hard phases combined with a high-toughness matrix provide exceptional resistance to abrasive wear.

Reduced downtime: Extended service life means longer intervals between replacements/repairs.

Efficient automated overlay welding shortens single repair times.

Good spalling resistance reduces unexpected downtime.

Lower overall costs: Although the initial overlay welding cost may be higher (especially with WC materials), the significantly extended service life and reduced downtime and maintenance expenses greatly decrease operational costs (OPEX) and material handling costs per ton over time.

Improved equipment operational stability: Even wear on the roller surface with minimal spalling ensures continuous and stable working pressure and output of the high-pressure roller mill.