Microstructures
by George Langford, Sc.D., Massachusetts Institute of Technology, Cambridge, MA, 1966
Copyright©
2005 by George Langford
Low Alloy Steels - Lesson 2 - Fourth specimen
Spheroidized tool steel at 100X etched
This is a spheroidized hypereutectoid steel, shown at 1000X with a Nital etch.

Now the cementite is no longer the continuous phase; the hard cementite particles do not impinge upon the cutting tool used to machine such a specimen; and the hardness is as low as possible because of the large size of the cementite particles and the large distances between them.

Even high alloy tool steels are cold workable in this condition, for example by bending, cold forging, or wire drawing.

Proceed to Specimen 5.