نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار گروه مهندسی مواد و متالورژی-دانشگاه اراک
2 مهندس و کارشناس ارشد-شرکت مالیبل سایپا
3 استایار گروه مهندسی مواد و متالورژی-دانشگاه اراک
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسنده [English]
In this study, effects of over aging treatment and its temperature as well as Nb addition on the microstructure and tensile properties of cold-rolled dual-phase steel were studied. For this purpose, two different steel containing Nb and free Nb were considered. Steels were intercritical annealed at 770C for 5 minute and then were over aged in the salt bath with five different temperatures for 12 minute and finally were slow cooled in the air to the room temperature. Samples microstructures were evaluated by scanning electron microscopy. Uniaxial tension test was used for study of tensile properties. The obtained results implied that the over aging temperature affects microstructure and tensile properties of both steels significantly. This effect is also different in high and low temperature regime. In the low temperature regime; increasing of the over aging temperature, decreases yield and tensile strength significantly while elongation increases by a sharp rate. In high temperature regime; increasing temperature has not noticeably effect on the elongation. However, yield strength increased and tensile strength decreased. The consideration of dual-phase Nb steel showed that Nb addition increases strength significantly. Also, it was caused increasing in the strength stability in high temperature. Results were discussed through relation microstructure and tensile properties.
کلیدواژهها [English]