What is quenching?
Quenching refers to heating the steel above the critical temperature, holding it for a certain period of time, and then rapidly cooling (greater than the critical cooling rate) to obtain a martensitic heat treatment process. The purpose of quenching is to obtain martensite,with the appropriate tempering process to improve the mechanical properties of steel. Quenching is the most important reinforcement method of steel and one of the most widely used heat treatment processes. As the ultimate heat treatment of various machine parts, tools and molds, quenching is the key process that gives the final performance of the part.
Cooling is the key to quenching, cooling directly determines the quality of the quenched steel after the organization and performance. Cooling medium should be able to ensure the workpiece to obtain small deformation, not cracking martensite. Slow cooling above 650 ℃ to reduce thermal stress; 650 – 400 ℃ rapid cooling, preservation of austenite does not decompose; 400 ℃the following slow cooling, reducing the phase transition stress martensitic transformation. Common quenching cooling medium, oil.
Post time: Nov-16-2017