Vanadium
Vanadium forms hard carbides and nitrides that suppress grain growth during annealing or welding. This increases the strength and toughness of the steel.
Physical-Chemical Mechanism of Action
Vanadium forms hard carbides (VC) and nitrides (VN) in the molten phase. These compounds have very high hardness and grow slowly during annealing or welding. They bind oxygen, promoting deoxidation.
Metallurgical Relevance & Welding Risks
The hard vanadium complexes suppress grain growth and prevent porosity. This increases the strength and toughness of the steel, but can also lead to increased stress concentration. At too high vanadium content, uncontrolled grain growth can occur, compromising weld integrity.
Workshop Practice & Procedures
• Use vanadium in steels with low carbon content (≤ 0.2 %) to benefit from its positive properties.
• Watch the correct welding temperature and time to control grain growth.
• Avoid excessive vanadium concentrations (over 0.1 %), as they can lead to uncontrolled grain growth.