Effect on Manufacturing Conditions on Mechanical Properties of Super Formable IF High Strength Steels

There have been increasing demands for improving safety, fuel economy and dent resistance in the automotive industry. To meet these demands, a super‐formable high strength steel with excellent formability was investigated. The mechanical properties and precipitation behaviour of Ti‐Nb bearing Interstitial Free (IF) steels with various contents of Ti and P were studied. In addition, the effect of processing conditions such as the cold reduction ratio and the annealing temperature on the formability was analysed. Improved mean r‐value was obtained in Ti‐0.01Nb steels with Ti content ranging from 0.015% to 0.025%. This improvement was due to non‐scanvenging effect and FeTiP precipitates. Furthermore, with an increase in P content, the mean r‐value was increased because of grain refinement in the hot rolled strip.