Effect of Dynamic Strain Aging on the Plastic Anisotropy and Mechanical Properties of Low-Carbon Phosphorus Steels

The effects of a dynamic-strain-aging treatment, as compared with a static-strain-aging treatment, on plastic anisotropy and mechanical properties has been determined for vacuum-melted low-carbon phosphorus steels containing various amounts of silicon. It was found that prestraining at 185°C, as compared with straining at 22°C followed by aging for four hours at 100°C, resulted in about twice the increase in yield strength (90 versus 48 MPa) on subsequent tension testing at 22°C and an improvement in rm values from about 1.8 to 2.0.Analyses of the textures and dislocation structures of the steels after the two strain-aging treatments and after subsequent deformation at 22°C showed that a greater dislocation density gives rise to the greater strengthening of dynamic-strain-aged specimens, and a finer polyhedral network of dislocation tangles is believed to be the reason for their higher rm values.