10 فروردین 1403
محمدعلي مهتدي بناب

محمدعلی مهتدی بناب

مرتبه علمی: دانشیار
نشانی: شهرستان بناب، بزرگراه ولایت، دانشگاه بناب، دانشکده مهندسی مکانیک
تحصیلات: دکترای تخصصی / مهندسی مکانیک
تلفن: 04137745000
دانشکده: دانشکده فنی و مهندسی
گروه: گروه مهندسی مکانیک

مشخصات پژوهش

عنوان
Effect of Microstructural Parameters on Fatigue Crack Propagation in an API X65 Pipeline Steel
نوع پژوهش مقاله چاپ شده
کلیدواژه‌ها
back-scattered electron, energy-dispersive spectroscopy, fatigue crack, pipeline steel, scanning electron microscopy
پژوهشگران محمدعلی مهتدی بناب (نفر اول)، مصطفی اسکندری (نفر دوم)، حسین قائدنیا (نفر سوم)، Sreekanta Das (نفر چهارم)

چکیده

In the current research, we investigate fatigue crack growth in an API X65 pipeline steel by using an Instron fatigue testing machine. To this, first the microstructure of steel was accurately investigated using scanning electron microscope. Since nonmetallic inclusions play a key role during crack propagation, the type and distribution of such inclusions were studied through the thickness of as-received X65 steel using energy-dispersive spectroscopy technique. It was found that the accumulation of such defects at the center of thickness of the pipe body was higher than in other regions. Our results showed that there were very fine oxide inclusions (1-2 lm in length) appeared throughout the cross section of X65 steel. Such inclusions were observed not at the fatigue crack path nor on both sides of the fatigue crack. However, we found that large manganese sulfide inclusions (around 20 lm in length) were associated with fatigue crack propagation. Fatigue experiments on CT specimens showed that the crack nucleated when the number of fatigue cycles was higher than 340 3 103 . On fracture surfaces, crack propagation also occurred by joining the microcracks at tip of the main crack.