Fatigue crack growth in ductile iron
2005 (English)In: Valtion Teknillinen Tutkimuskeskus. VTT Symposium, ISSN 0357-9387, Vol. 237, 287-310 p.Article in journal (Refereed) Published
Crack initiation and propagation of two ductile irons are studied. The main reason for the study is to propose a common set of reliable fatigue data based on fracture mechanics. Material in this investigation is one standard feritic/pearlitic ductile iron (SGJ 500-7) and one silicon alloyed ductile iron with a solution hardened ferritic matrix (SS 140725). Basically the threshold value and the scaling constants in Pan's equation are evaluated. The data used at Volvo Truck has been gathered and re-evaluated. Complementary experiments have been conducted. All experiments have been in accordance with ASTM-647. Scaling constants in Paris equation is set to m= 4,5 and C= 9,4 10(-14) (m/cycle)/MNm(-3/2) for the standard grade material and m= 5,0 and C= 1,9 10-14 (m/cycle)/MNM-3/2 for the silicon alloyed material. These results are valid for -I < R < 0,5. The difference in the slope between the materials is due to different fracture behaviour. Threshold values for the materials can be found in Tables 2 and 3. Crack closure and the influence on crack propagation is expressed in a in a new algorithm. The new algorithm is valid for -I < R < 0,5 but should be used with caution due to meagre statistical foundation.
Place, publisher, year, edition, pages
2005. Vol. 237, 287-310 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-14053ISI: 000231578700017ScopusID: 2-s2.0-42149131532OAI: oai:DiVA.org:kth-14053DiVA: diva2:329431
Updated from manuscript to article in journal.
QC 201007122010-07-122010-07-122014-12-05Bibliographically approved