1) Physical phenomenon 
point in heating metal where it appears to cool
[n] - phenomenon that occurs when a metal is being heated and there is a sudden slowing in the rate of temperature increase
A term used in reference to the absorption of heat without a corresponding indrease in temperature, when steel is heated through the ctitical points (phase changes).
A decrease in temperature that occurs while heating metal through a range in which change in structure occurs. 
noun phenomenon that occurs when a metal is being heated and there is a sudden slowing in the rate of temperature increase; slowing is caused by a change in the internal crystal structure of the metal
absorption of heat without a corresponding increase in temperature when a metal has been heated to a critical point.