Microalloy precipitation hardening
Microalloy precipitation hardening increases strength through small additions of niobium, titanium, or vanadium, which form fine carbides or carbonitrides.
Physicochemical Mechanism of Action
Niobium, titanium, and vanadium are added as microalloys in the melt. These alloys react with carbon in the steel to form fine carbides or carbonitrides. These fine particles spread homogeneously in the microstructure and improve mechanical strength.
Metallurgical Relevance & Welding Risks
Microalloy precipitation hardening increases the toughness of the steel but does not prevent hot cracks or burn-through. Wrong alloy selection can lead to unwanted phase formation and impair mechanical performance.
Workshop Practice & Action Instructions
Use niobium, titanium, or vanadium in small amounts (approx. 0.1 to 0.5 %) for steels with high carbon content. The alloy should be well stirred in the melt and remain homogenized in the cool state. Monitor the temperature during cooling to ensure an even hardness distribution.