Hardfacing plate is a wear-resistant steel product made by depositing a hard alloy layer onto a steel substrate through a welding-based surface treatment. The substrate provides structural support, while the deposited layer is designed to resist abrasion, erosion, impact, or other forms of surface wear.

In many industrial wear applications, chromium-carbon alloy systems are used to create carbide-rich hardfacing layers. The final performance depends not only on overlay hardness, but also on carbide morphology, layer thickness, dilution, bonding quality, welding parameters, and substrate selection.

What Is Hardfacing?

Hardfacing is a surface engineering process in which a wear-resistant alloy is deposited onto the working surface of a component. The deposited material becomes the protective surface, while the original component remains as the structural base.

The objective is simple: keep the expensive or load-bearing substrate while adding a more wear-resistant working layer where material loss is expected.

This principle is used both to manufacture new wear-resistant plates and to restore worn components such as crusher parts, chutes, hoppers, rollers, blades, and other industrial equipment.

How Does Hardfacing Make a Wear Plate?

The production process begins with a suitable steel substrate. A selected alloy welding consumable is then deposited onto the working surface. Depending on the required metallurgy and production scale, the process may use open-arc welding, submerged-arc welding, plasma transferred arc, or other suitable deposition technologies.

Hardfacing Welding Process Overview

There is no single hardfacing process for every application. The deposition method should be matched to the required alloy, component geometry, production volume, layer thickness, and service condition.

The welding current, voltage, travel speed, wire feed rate, heat input, shielding conditions, and interpass temperature all influence the resulting overlay. Parameters should therefore be established through process qualification rather than copied from a generic table.

Why Are Cr-C Welding Alloys Common?

Chromium-carbon alloy systems are widely used for abrasive wear because they can form hard chromium carbide phases during deposition. Cr₇C₃ is a major carbide phase in many chromium-rich hardfacing systems.

The resulting microstructure normally consists of hard carbide particles or networks distributed through a metallic matrix. The carbide phase resists penetration and cutting by abrasive particles, while the matrix provides support and helps maintain the integrity of the deposited layer.

Therefore, a higher hardness number does not automatically guarantee longer service life. Carbide morphology, volume fraction, spacing, crack pattern, dilution, and substrate support can all affect performance.

Hardfacing Layer Design

The deposited layer should be designed according to the expected wear depth and component geometry. Three variables are particularly important: layer thickness, number of passes, and surface coverage.

Many commercial hardfaced plates use overlay thicknesses in the approximate range of 3–8 mm, but the correct value depends on the wear mechanism and engineering design. Multiple passes may be used when a thicker working layer is required.

Hardfacing vs. Thermal Spray and Laser Cladding

Hardfacing is only one form of surface engineering. Thermal spraying and laser cladding can also create wear-resistant surfaces, but their deposition mechanisms and typical applications are different.

For large steel wear plates, welding-based hardfacing remains attractive because it can deposit substantial amounts of wear-resistant alloy over large areas. For precision components or localized repair, laser cladding may offer tighter process control.

Quality Control for Hardfacing Plates

Quality should be evaluated at both the surface and the composite interface. A wear plate with high surface hardness can still perform poorly if the overlay has inadequate bonding, excessive dilution, unsuitable carbide morphology, or significant unprotected areas.

• Overlay thickness: confirms the available wear allowance.
• Hardness: verifies that the deposited alloy meets the specified range.
• Bonding condition: checks the integrity of the interface between overlay and substrate.
• Microstructure: evaluates carbide morphology, distribution, and matrix structure.
• Surface condition: checks cracks, bead profile, overlap, and local defects.
• Dimensional accuracy: confirms plate size, flatness, and fabrication tolerances.

Controlled surface cracking can occur in some high-chromium hardfacing systems because of the metallurgical characteristics of carbide-rich overlays. Such cracks should not automatically be classified as unacceptable defects. Their size, direction, spacing, depth, and effect on service performance must be assessed according to the applicable product specification and application.

Hardfacing Plate Applications

Hardfaced plates are used where ordinary steel loses material too quickly under abrasive or erosive conditions.

Hardfacing for New Plates and Worn Components

The same technology can be used for two different purposes. In new-product manufacturing, hardfacing creates a wear-resistant plate before installation. In repair work, the process restores a worn component and can extend its operating life.

For repair applications, the existing substrate must first be evaluated. Remaining thickness, cracking, distortion, contamination, previous hardfacing layers, and metallurgical condition can all affect the repair procedure.

A repair should therefore begin with an inspection rather than simply adding another hardfacing layer over the worn surface.

Teda Ganghua Hardfacing Capability and Service

Teda Ganghua provides wear-resistant steel products and related processing solutions for industrial applications where abrasive wear is a major operating concern. Hardfacing requirements can be evaluated according to substrate selection, overlay alloy, thickness, hardness, dimensions, and the actual wear mechanism.

For customers requiring more than standard plate supply, the technical review can include cutting, sizing, fabrication, and application-oriented processing. The objective is to match the deposited wear layer with the structural requirements of the finished component rather than selecting the overlay only by hardness.

For wear-resistant steel and related product requirements, the wear plate product range provides a starting point for reviewing suitable material solutions.

What to Include in a Hardfacing Inquiry

• Existing or required substrate grade
• Overall plate or component thickness
• Required overlay thickness
• Target hardness or hardness range
• Abrasive material and particle size
• Impact and material-flow conditions
• Operating temperature
• Required plate dimensions or equipment drawings
• Cutting, drilling, bending, or welding requirements

With these details, the hardfacing process and overlay design can be selected according to the actual operating condition instead of relying on a generic “hardfacing plate” description.

Frequently Asked Questions

What is a hardfacing plate?

A hardfacing plate is a steel substrate covered with a wear-resistant alloy layer deposited by a hardfacing process. The substrate provides structural support, while the deposited layer protects the working surface from wear.

What welding process is used for hardfacing?

Open-arc and submerged-arc welding are widely used for large wear surfaces. Plasma transferred arc and other deposition technologies may be selected for specialized components or localized repair.

Why is chromium-carbon alloy used for hardfacing?

Chromium-carbon alloys can form hard chromium carbide phases during deposition. These phases provide strong resistance to abrasive penetration and cutting, making the system suitable for many severe abrasion applications.

Is a harder hardfacing layer always better?

No. Hardness is only one performance factor. Carbide morphology, volume fraction, matrix toughness, bonding quality, overlay thickness, substrate strength, and the actual wear mechanism must also be considered.

Can hardfacing be used to repair old equipment?

Yes. Hardfacing is commonly used to restore worn components. The original substrate should first be inspected for remaining thickness, cracks, distortion, contamination, and previous repair layers before a new deposition procedure is selected.