The Concept Of Dual Phase Steels - 1146 Words

â€Å"Production process for ferrite-martensite DP600 steel with 30-35% total elongation† Team Members- Kishan - B.Tech (Juniour Undergraduate), Dept. of Metallurgical Engineering, IIT (BHU) – 13145020 Lal Babu Singh - B.Tech (Juniour Undergraduate), Dept. of Metallurgical Engineering, IIT (BHU) – 13145024 Contents: 1. The Concept of Dual Phase steels. 2. Factors influencing mechanical properties of Dual Phase steels. 3. The Challenge: Increasing total elongation without compromising other mechanical properties. 4. References. 1. The Concept of Dual Phase steels The need for reduction in weight of heavy vehicles is increasing day after day. Reduction of weight results in reduced fuel consumption which results in a†¦show more content†¦Table 1. Chemical composition of DP600 steel Steel grade C Max Si max Mn Max P Max S Max Al Nb Max Cr+Ni+Cu Max DP 600 0.14 0.50 1.40 0.085 0.008 0.02-0.06 0.009 1.30 Dual phase steel has a microstructure which consists of two phases, Ferrite and Martensite (Fig.1). Generally, DP600 steels have a tensile strength of around 600 MPa and total elongation of about 20-25% (Fig2). The tensile strength of DP600 steel can vary from 580-670 MPa.Write uses . Other advantages of DP600 steels are better work-hardening and bake-hardening properties with excellent fatigue strength. Fig 1. The microstructure of DP600 steel at different magnifIATions with dark martensite grains in a white ferrite matrix. Fig 2. Engineering stress vs engineering strain curve for DP 600 steel(source: autosteel.org) There are three basic approaches by which DP steels are produced commercially: 1. During the hot rolling cycles, only dual phases can be formed. 2. Hot or cold rolled strip is uncoiled, and continuous annealing is done at the Intercritical annealing temperature. 3. Batch annealing could also be done. Hot or cold rolled strip is annealed under coiled condition. 2. Factors influencing mechanical properties and failure mechanism of Dual Phase steels. Damage mechanism of a given dual phase steels are affected by their chemical