硬质合金覆盖板

硬质合金覆盖板 is a wear-resistant steel plate produced by welding a hardfacing alloy layer onto a steel base. One of the most important factors that determines its performance is the chemical composition of the welding wire, especially the chromium content.

When low-chromium welding wire is used, the microstructure and wear performance of the overlay layer change significantly.

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Role of Chromium in Overlay Layer

Chromium is the key element in forming hard carbide structures during the welding process. These carbides (如Cr₇C₃) are the main reason for high wear resistance.

When chromium content is reduced:

• Fewer hard carbide particles are formed
• The hardness of the overlay layer decreases
• The wear resistance becomes weaker

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What Happens When Low Chromium Wire Is Used

Using low-chromium welding wire in 硬质合金覆盖板 production leads to several changes in material performance.

1. Reduced Carbide Formation

Lower chromium content results in fewer and smaller carbide particles. The microstructure becomes more dominated by softer iron-based phases.

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2. Lower Surface Hardness

Because carbides are the main hard phase, reduced chromium directly lowers surface hardness. This makes the surface more susceptible to abrasion.

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3. Increased Wear Rate

Without sufficient hard carbide protection, the material wears faster under:

• 滑动磨损
• 冲击磨损
• High-volume particle flow (沙, 矿石, 熟料)

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4. Reduced Service Life

The most important effect is shortened service life.

• High-chromium overlay plates: long-term wear resistance in severe environments
• Low-chromium overlay plates: faster wear and more frequent replacement

在许多工业应用中, service life may be reduced significantly depending on working conditions.

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性能比较

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Application Impact

Low-chromium Carbide Overlay Plate is generally not suitable for severe wear conditions such as:

• Mining and ore handling
• Cement clinker systems
• Coal transportation
• Heavy industrial abrasion zones

It may only be used in:

• Light abrasion environments
• Cost-sensitive applications
• Temporary or non-critical wear protection