Vanadium alloying tends to promote which effects during heat treatment?

• A. Promotes fine grain structure during heat-treatment process - tends to promote hardenability
• B. Decreases grain size
• C. Increases corrosion resistance
• D. Produces brittleness

Answer: (A)

Vanadium acts as a microalloying element that refines the grain structure during heat treatment, and that refinement helps increase hardenability. It forms very fine vanadium carbide particles that pin grain boundaries, so austenite grains can’t grow as large during heating and subsequent cooling. With smaller grains, the transformation to martensite during quenching occurs more deeply into the section, giving harder regions further from the surface. In short, the fine grain structure promoted by vanadium carbides directly enhances hardenability. This is not primarily about corrosion resistance or brittleness, and while grain refinement is the key effect, it’s the combination with improved hardenability that makes the statement accurate.