Vanadium carbonitride hardening
Vanadium carbonitride precipitation hardening improves strength and tempering resistance of steels through fine vanadium compounds that form during welding.
Physical-Chemical Working Mechanism
Vanadium carbonitride precipitation hardening results from the reaction of vanadium in the molten pool with carbon and nitrogen. These compounds form fine particles that remain in the steel's structure and improve its mechanical properties.
Metallurgical Relevance & Welding Risks
This hardening increases the strength and toughness of the weld, especially under high loads. However, too high a vanadium content can cause fusion issues or contaminate the structure, leading to cracks and distortion.
Workshop Practice & Action Items
To utilize vanadium carbonitride hardening, keep the vanadium content in the molten pool between 0.1% and 0.3%. Cool slowly to ensure uniform grain coarsening. If cooling is too fast, vanadium cannot react sufficiently, which can reduce hardness.