On 2018-08-08 14:48:54
Which liquids can be used as heat treatment quenching medium
Heat treatment quenching medium
Quench-heat treatment is the process of rapidly cooling metal parts from solution or austenitizing temperatures, and is usually used for steel in the range of 815 to 870 ° C (1500 to 1600 ° F). High alloy steels and stainless steels can be quenched to minimise grain boundary carbides or improve ferrite distribution, but most steels (including carbon, low alloy steels and tool steels) are quenched to produce controlled microstructures Amount of martensite. Successful hardening usually means achieving the required microstructure, hardness, strength or toughness, while minimizing the possibility of residual stress, deformation and cracking.
The quenching medium commonly used in heat treatment plants is a liquid, and depends on the hardening ability of the specific alloy, the thickness and shape of the cross section involved, and the cooling rate required to achieve the desired microstructure. Common quenching media are liquids or gases.
Commonly used liquid quenching includes oils that may contain various additives, liquid polymers, water that may contain salts or corrosive additives, and median gas quenching, such as inert gases including helium, argon, and nitrogen. These quench gases are sometimes used after austenitizing in a vacuum.
The ability to quench hardened steel depends on the cooling characteristics of the quenching medium. The quenching effect depends on the composition of the steel, the type of quenching or the quenching conditions. The design of the quenching system and the thoroughness of system maintenance also contribute to the success of the process.