Differences Between Wear-Resistant Steel Plates and Bimetallic Composite Wear-Resistant Plates
Differences Between Wear-Resistant Steel Plates and Bimetallic Composite Wear-Resistant Plates
Wear-resistant steel plates and bimetallic composite wear-resistant plates differ in composition, manufacturing processes, and applications. Below is a detailed comparison to help in selecting the appropriate material for specific needs.
1. Definition
- Wear-Resistant Composite Steel Plate:
This plate consists of a high-alloy wear-resistant layer welded onto a standard steel plate by surfacing. It combines the wear resistance of the alloy layer with the load-bearing capacity, deformability, and weldability of the base plate. The hardness of the wear-resistant layer ranges from HRC52 to HRC64. - NM Wear-Resistant Steel Plate:
These are low-alloy steel plates that have been quenched and tempered to enhance wear resistance. They are commonly referred to as quenched and tempered steel plates, with hardness levels between HB350 and HB500. Examples include NM400, NM450, and NM500.
2. Wear Resistance Mechanism
- Wear-Resistant Composite Steel Plate:
The alloy layer contains a high concentration of carbides (approximately HV1600) embedded in the matrix. These carbides provide exceptional wear resistance, similar to cemented carbide materials. The microhardness of the alloy layer far exceeds its macrohardness, making it highly effective in resisting wear. - NM Wear-Resistant Steel Plate:
The plate undergoes overall quenching and tempering, forming a martensitic structure that ensures uniform hardness. The microhardness and macrohardness are nearly identical, resulting in reliable wear resistance. - Comparison:
Composite steel plates outperform NM plates in wear resistance due to the presence of carbide particles in the alloy layer.
3. Temperature Resistance
- NM Wear-Resistant Steel Plate:
Performance declines above 250°C due to annealing, which reduces hardness and wear resistance. Welding can also lower hardness near the weld zone. - Wear-Resistant Composite Steel Plate:
These plates retain hardness and exhibit secondary hardening at elevated temperatures. They can operate effectively at temperatures up to 650°C.
4. Drilling and Cutting Methods
- NM Wear-Resistant Steel Plate:
These plates can be drilled using mechanical methods. High-speed steel (HSS) or cobalt alloy drill bits are recommended for precision. - Wear-Resistant Composite Steel Plate:
Mechanical punching is not possible. Cutting requires plasma methods, followed by step holes created with a gas gun.
Summary of Key Differences
| Feature | Wear-Resistant Composite Plate | NM Wear-Resistant Plate |
|---|---|---|
| Hardness | HRC52–64 | HB350–500 |
| Wear Resistance | Higher due to carbide presence | Moderate due to martensite |
| Temperature Limit | Up to 650°C | Up to 250°C |
| Drilling | Plasma cutting only | Mechanical drilling possible |
When selecting a material, consider the application’s temperature, wear resistance needs, and machining requirements.
