Quenching

Heat Treatment

Определение

The rapid cooling of a metal from an elevated temperature, typically by immersion in water, oil, polymer solution, or forced air, to obtain a specific microstructure and improve hardness.

Подробное объяснение

In steel, quenching from above the austenitizing temperature suppresses diffusion-controlled transformations and produces a hard, brittle martensitic microstructure. The quench severity (H-factor) depends on the medium: water is more severe than oil, which is more severe than air. Inadequate quench rates result in softer bainite or pearlite, while too-rapid quenching can cause cracking due to thermal and transformation stresses.