کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
769070 897370 2010 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A detailed study of the relationship between fatigue crack growth rate and striation spacing in a range of low alloy ferritic steels
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی صنعتی و تولید
پیش نمایش صفحه اول مقاله
A detailed study of the relationship between fatigue crack growth rate and striation spacing in a range of low alloy ferritic steels
چکیده انگلیسی

It was shown that the measured average fatigue striation spacings predicted the fatigue crack growth rates for low alloy ferritic steels to within a range of ±2% to 35% with an overall average error band value of ±10.1%. When we consider the fatigue stress range this average error was reduced to only some ±4%. This was good news to both failure analysts and other workers involved in the field of component remnant life and life extension since such predicted fatigue stress ranges use real fracture characteristics observed at some point on the actual component fracture surface.These findings were applied to a real cracking problem recently reported in a steam raising plant, viz., a cracked attemperator reducer weld. In this case an NDT assessment indicated that the maximum crack depth was 7 mm while the lower bound critical crack depth was estimated at 10 mm. As such, remnant life assessments can be estimated for a series of fatigue stress ranges through the use of a reported 450 °C fatigue crack growth law for C–Mn steels.Remnant life estimates of a 7 mm deep crack for a range of stress ranges varied from 3000 to 4000 starts where the chances of the real remnant life values being greater than the calculated values was only 1 in 2. However when a realistic failure probability which reflected the serious implications of a failure event of E−4 was taken the remnant life values were reduced to around 100 starts or some 6 months of normal service.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Engineering Failure Analysis - Volume 17, Issue 1, January 2010, Pages 168–178
نویسندگان
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