Quenching Oil

Listing ID #3346754

The word quenching means:

• Rapid cooling from a high temperature by immersion in a liquid bath of oil or water.       
• About 85% of quenching fluids are mineral oil based as the quenching power of water falls rapidly with increase in temperature, whereas that of oil remains fairly constant up to the range 60°C to 80°C. The rise in temperature of oil produces drop in viscosity, a change which assists cooling and so offsets the reverse influence of rise in temperature itself, whereas water does not possess such compensating effect.
• Quenching is the process by which the desired mechanical properties and hardness of a metal is achieved by controlled cooling from an elevated temperature using a quench fluid. Quenching is usually used with metals that are alloyed with small amounts of other metals. At high temperature the alloying metals are dissolved in the base metal. If the material is cooled slowly, the alloy elements have time to precipitate out separately. If the metal is quenched, the alloying metals are trapped within the crystal grains, making them harder.       
• Optimal quench uniformity is essential if the potential for cracking, distortion, residual stress and spotty hardness is to be minimized. This means that heat transfer must be as uniform as possible throughout the quenching process. Further optimal uniformity of quenchant flow around all surfaces is necessary. One of the most important factors affecting quench uniformity is the design of the quench system. Agitation is one of the most critical areas of system design. Propeller agitation of the quench oil is necessary if uniform heat transfer throughout the quenching operation, producing less cracking and distortion has to be achieved.       
• The performance of quenching oil can be characterized by its ability to extract heat from the part surface. Previously, aqueous quenching media were employed. The aqueous fluids provided extremely rapid cooling setting up excessive amounts of internal stress in the object. Mineral oil based fluids avoided this difficulty. Further, they possess sufficient durability, cleanliness and consistency. Durability refers to additive lifetime after being exposed to thermal stressing while consistency relates to constant additive performance over time and cleanliness relates to amounts of deposits on the work piece and/or staining thereof.