Mechanical behaviour of strain aged dual phase steels

Dual phase steels, characterised by good formability and excellent surface finish, are suitable for applications where processing involves cold deform ation. In this context an investigation has been conducted into the cold de formation aging susceptibility of carbon steel API-5L-B and microalloyed st eel API-5L-X52, both with dual phase microstructures. Changes in mechanical properties such as phase microhardness, ultimate tensile strength, and yie ld strength in both types of steel were observed at aging temperatures of 2 5, 80, and 150 degrees C. This aging is associated with dislocation structu res formed on ferrite grains in the vicinity of ferrite/martensite interfac es during intercritical treatments, which become preferential sites for sol ute atom diffusion. MST/4268.