1. Key Lab. of Advanced Materials of Yunnan Province, Kunming University of Science and Technology, Kunming 650093, Yunnan, China;2. Institute for Structural Materials, Central Iron and Steel Research Institute, Beijing 100081, China
Abstract: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 lamellas the nonuniform deformation of different pearlitic blocks are observed and with the increase of reduction rate the microstructure undergoes a course of “uniformity→nonuniformity→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.