Esilämpökarkaisupäästökäsittely

Esilämpökarkaisupäästökäsittely is a heat treatment process used in metallurgy. It combines two distinct stages: preheating and quenching, followed by tempering. The purpose of this treatment is to achieve a specific combination of hardness and toughness in steel components.

The initial step involves preheating the steel to a predetermined temperature, typically above its critical transformation point. This ensures that the entire cross-section of the material reaches a uniform, austenitic phase. Following the preheating, the steel is rapidly cooled, or quenched, in a medium such as oil, water, or a polymer solution. This rapid cooling transforms the austenite into a very hard, brittle microstructure called martensite.

The high hardness achieved through quenching, however, comes at the cost of reduced toughness, making the material susceptible to fracture. To mitigate this, the quenched component then undergoes a tempering process. Tempering involves reheating the steel to a temperature below its critical point and holding it there for a specific duration before cooling. This controlled reheating allows for some of the internal stresses from quenching to be relieved and precipitates to form, which increases the material's ductility and toughness while only slightly reducing its hardness. The specific temperatures and times for each stage are carefully controlled based on the steel alloy's composition and the desired final properties of the component. Esilämpökarkaisupäästökäsittely is commonly applied to tools, machine parts, and other components that require both high wear resistance and sufficient durability.