Recent research  has shown that grain refinement can also be accomplished through intercritical (IC) heat treatment. In those studies, a fine-grained mixture of acicular martensite, or acicular pearlite, in ferrite can be produced by heating to and cooling from a temperature just below the upper critical temperature. Laboratory heat treatment experiments... more

Recent research  has shown that grain refinement can also be accomplished through intercritical (IC) heat treatment. In those studies, a fine-grained mixture of acicular martensite, or acicular pearlite, in ferrite can be produced by heating to and cooling from a temperature just below the upper critical temperature. Laboratory heat treatment experiments demonstrated that a combination of high strength and high tensile elongation could be achieved by this technique. Zinardi reported similar microstructures and mechanical properties for an “IDI” (isothermal ductile iron) alloy using a proprietary heat treatment method. less