Cold Water Quenching
Liquid quenching, with water is the most popular type of cooling. Water is flexible in its characteristics and composition, so that it can be changed by the varying temperature of the water. Water also provides rapid speeds of cooling necessary for different alloys. Water is best use to quench steels because of the ability to absorb huge amounts of atmospheric gases. The bubbles hide in holes and are normally on the surface of metals.
The cooling rate of the object depends upon the size, composition, and initial temperature of the product being cooled .Water quenching tanks should be changed daily. Water quench tanks should be larger than the material need to be quenched. The temperature of water should not exceed 65°F. This is about the ambient temperature of a room. Once the object is placed in the water, the quench tank water should not raise higher than 20°F during the process. Some heavy parts, or wrought products a higher temperature may occur above 20°.
Two types of cold water cooling are still-bath and flush quenching. Bath quenching, cools material in a metal tank of liquid. The coolant medium flows through canals that are integrated within the tank. The tank is colder than the material to be quenched, and allows for the temperature of material to drop. Flush quenching occurs when a liquid is sprayed onto the surface. This process is used for parts that have hollows that cannot be cooled via still-bath quenching.
