Thus increasing the content of cementite results in a harder and stronger material. Fine pearlite exhibits greater hardness and strength than coarse pearlite because dislocations must pass through more boundaries during plastic deformation. This microstructure consists of spherelike particles of Fe3C embedded in a continuous a phase matrix. There is less boundary area per unit volume in spheroidite than in pearlite, and therefore this results in a relatively soft and weak material. Another microconstituent of the austenitic transformation is bainite , which is composed of very fine ferrite and cementite phases.
Bainitic steels are generally stronger and harder than pearlitic ones.
Its strength and hardness are attributed to its atomic structure rather than microstructure. Procedure This laboratory unit should be completed in two weeks. The first week, the students will be divided into 4 groups. Each group will receive 2 iron-carbon alloy tensile bars. Use the proper anvil.