Piastra di sovrapposizione

Piastra di sovrapposizione: Wear Resistance Mechanism of Hardfaced Weld Layers

Overlay plate (also called hardfaced plate or weld overlay wear plate) is a composite steel product that achieves high wear resistance by depositing a hard alloy layer onto a steel base plate through welding. Its excellent performance does not come from the base steel, but from the metallurgical structure of the overlay layer.

The wear resistance mechanism is mainly based on the interaction between hard carbides, alloy matrix, and surface stress behavior.

1. Hard Carbide Reinforcement Mechanism

Elemento / Phase Function in Wear Resistance
Carburi di cromo (Cr7C3, Cr23C6) Primary hard phase resisting abrasion
Carbonio (C) Forms carbide structures with chromium
Iron-based matrix Supports and holds carbides in place
Elementi di lega (N.B, Mo, V) Refines carbide distribution and improves stability

The hard carbides act like “micro cutting tools” that resist scratching and cutting from abrasive particles.

2. Two-Phase Composite Wear Structure

The overlay layer is a dual-phase structure:

  • Hard phase: Carbides (elevata durezza, resist wear)
  • Tough matrix: Metal binder (absorbs impact and holds structure)

This combination provides both hardness and limited toughness, which is essential for industrial wear conditions.

3. Abrasive Wear Resistance Mechanism

Wear Type How Overlay Layer Works
Abrasione da scorrimento Carbides resist cutting and micro-scratching
Erosione delle particelle Hard surface reduces material loss from impact particles
Friction wear Reduces surface deformation and groove formation

4. Stress Distribution and Crack Behavior

Durante la saldatura, controlled micro-cracks may form on the surface:

  • They help release residual stress
  • They prevent large-scale fracture
  • They do not reduce wear performance

This stress-relief behavior helps maintain long-term stability under heavy wear conditions.

5. Bonding Strength Mechanism

Overlay plates are not mechanically attached—they are metallurgically bonded.

  • Strong fusion between overlay and base plate
  • Nessuna delaminazione in normali condizioni di lavoro
  • Improved load transfer capability

6. Why Overlay Plates Last Longer Than Ordinary Steel

Fattore Effect on Service Life
Elevata durezza superficiale Reduces material loss rate
Carbide reinforcement Prevents cutting wear
Composite structure Balances wear resistance and toughness
Controlled alloy design Improves stability in harsh conditions

7. Teda Ganghua Overlay Plate Supply Capability

Come fornitore professionale di acciaio resistente all'usura, Teda Ganghua provides high-performance overlay plates with optimized carbide structures for mining, cemento, acciaio, e industrie energetiche. We focus on improving wear resistance through controlled alloy design and stable welding processes.

We also support customized cutting, fabrication, and wear system engineering based on real working environments.

Esplora qui i nostri prodotti in acciaio resistente all'usura:
Piastra di overlay in carburo di cromo

Conclusione

The wear resistance of overlay plates comes from hard carbide reinforcement, composite dual-phase structure, and metallurgical bonding. These mechanisms work together to significantly reduce material loss under abrasion, making overlay plates one of the most effective industrial wear solutions.

Piastra di usura in carburo di cromo