Microstructure Evolution and Mechanical Hardening of Hyper-Eutectoid Steel During Cold Rolling

Microstructure evolution of hypereutectoid steel duning cold rolling with different reduction rate （from 0 to 81.6%）was studied by SEM and TEM. The results showed that due to orientation multiplicity of pearlitic lame-llas the non-uniform deformation of different pearlitic blocks are observed and with the increase of reduction rate the microstructure undergoes a course of “uniformity→non-uniformity→uniformity”; results of XRD analysis indicated that cementite doesn’t decompose and dissolve into ferrite; mechanical test results suggested that relationship between ReL (yield strength)and ε (true strain)is in accord with Hollomon relationship and yield strength of the steel under different reduction rate can be predicted by the equation ReL=1465ε0.18.