Effect of Post-Tempering on Damage in DP1000 Automotive Steels
This research is focused on studying the effect of heat treatments on the mechanical properties of dual-phase (DP) strip steel used for automotive applications.Local deformation and damage development in the microstructure of as-annealed and post-tempered DP1000 steels has been investigated using tensile tests conducted inside a scanning electron microscope (SEM).Digital image correlation (DIC) was used to compute strain distributions over areas of the various microstructures.For all investigated conditions deformation localises in the ferrite phase during strain hardening and damage initiates through cracking of the martensite phase.Damage is,much more visible in the heat treated microstructures and occurs at much lower applied strains than in the as-annealed condition.For samples tempered at 240℃ and 365°C the onset of cracking is observed at a local tensile strain value of approximately 10%.Despite early damage in martensite the elongation to failure of the heat treated steels is much higher compared to that of the as-quenched material.This suggests that final failure is controlled by damage in the ferrite phase.The optimal performance,in terms of compromise between strength and ductility,is obtained after heat treatment at 240℃.
digital image correlation in-situ tensile microstructural analysis damage analysis tempering heat treatment
ROHAIZAT Nurrasyidah I. PINNA Christophe GHADBEIGI Hassan HANLON Dave
Dpt. of Mechanical Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK Tata Steel Ijmuiden, The Netherlands
国际会议
成都
英文
383-386
2016-11-16（万方平台首次上网日期，不代表论文的发表时间）