Tungsten Carbide Bonding via Localized Carbon Enrichment

The patent applies local quality by creating a high carbon concentration region only at the bonding surface (0-0.5mm depth) of the stainless steel member, while maintaining lower carbon concentration (0.03-0.10 mass%) in the bulk material. This localized carbon enrichment suppresses carbon penetration from the tungsten carbide alloy at the interface without causing embrittlement throughout the entire component, thus resolving the contradiction between bonding strength and mechanical properties.

The patent utilizes parameter changes by controlling the carbon concentration gradient through carburization treatment parameters (temperature, time, atmosphere). By optimizing these parameters, the carbon concentration is increased specifically at the bonding surface region while maintaining appropriate carbon levels in the bulk material, achieving both high bonding strength and preserved mechanical properties.

The patent applies preliminary action by performing carburization treatment on the stainless steel member before bonding to pre-establish a high carbon concentration region at the bonding surface. This preliminary carbon enrichment creates a protective interface that prevents carbon depletion from the tungsten carbide alloy during subsequent high-pressure forming operations, thereby preventing embrittlement and wear under pressure.

The patent converts the potentially harmful carbon penetration that causes embrittlement into a beneficial high carbon concentration region at the bonding surface. By controlling and localizing this carbon enrichment, the harmful effect is transformed into a protective layer that actually prevents excessive carbon loss from the tungsten carbide alloy during high-pressure operations.