the investigation of temperature and time of step-annealing on microstructures and mechanical properties of aisi3115 steel

the aim of this study is to evaluate the effect of temperature and time step-annealing of the microstructures and mechanical properties of aisi 3115 steel with ferritic-martensitic dual phase (dp) in comparison with conventional quenched. for this purpose prepartion of ferritic-martensitic dual phase specimens with different volume fractions of ferrite and martensite was performed using the method step-annealing at mohten salt buth 600 and 650ᵒc for different times 5, 30, 60 and 120 minute. mechanical tests hardness, elasticity with optical and electron metallographic examination was conducted. the results showed that as the volume fraction of ferrite in the step-annealed specimens at constant temperature increased with increasing holding time. ferritic-martensitic dual phase microstructures with 15% volume fraction of ferrite has the highest tensile strength and flexibility are forms that this phenomenon is caused by the interaction of ferritic and martensitic phases.