Abstract
The materials transformed to fine and coarse lamellar pearlite structures were reduced 75 pct in thickness by cold rolling, then heat treated at 780 degree C (up-quenching) or 650 degree C (annealing) for different periods of time followed by air-cooling. Improvement in yield strength was accompanied by an increase in ultimate tensile strength. Elongations were maintained above 15 pct in 3 cm gage length. The optimal mechanical properties were developed between 30 and 120 seconds during 780 degree C up-quenching for coarse pearlite samples and 100 to 400 seconds for both annealed coarse and fine pearlite specimens. Microstructures in pearlite regions were fine subgrains (or grains) less than 1 mu m in size and dispersed globular carbide particles along the subgrain (or grain) boundaries.