eutectoid change

…the change is called the eutectoidic transformation. Pearlite has a diamond pyramid hardness (DPH) of approximately 200 kilograms-force per square millimetre (285,000 pounds per square inch), compared with a DPH of 70 kilograms-force per square millimetre for pure iron. Cooling steel with a lower carbon content (e.g., 0.25 percent) results…