Lattice Parameter of Cementite Phase in Pearlite Structure

The lattice parameter of cementite in a pearlite structure was measured using the in situ heating neutron diffraction method. The lattice parameters of the cementite phase of the b- and c- axes in the pearlite structure were smaller than those in the martensite structure and Reed’s results [3]. The lattice parameter of the a-axis in the pearlite structure was almost equal to that in the martensite structure and Reed’s results [3]. The thermal and misfit strains, caused by the differences between the thermal expansion rate and lattice parameter of the cementite and ferrite phases, should affect the lattice parameter of cementite in the pearlite structure.