Low cycle fatigue behaviour of steels for automotive applications: effect of microstructure and metallurgical parameters
The principal object of this research is to gain more extensive information with regard to the influence of microstructural parameters on the low cycle fatigue behaviour of steels for automotive applications. TEM examination of materials submitted to fatigue testing showed the occurrence of a significant increase of dislocation density for all steels examined, with the exception of the 40CrMo(4) quenched and tempered material. The rearrangement of the dislocation substructure into a cell structure was associated with cyclic hardening of the materials whenever formation of the cells was accompanied by an increase of the dislocation density with respect to the initial condition. An inverse correlation appears to exist between cell size and average size of the ferritic grain. The inhibitive influence of microprecipitates on the formation of cells was instead clearly observed. An increase of the pearlite interlamellar distance seems to lead to further cyclic hardening of the material. Using a computer program based on multiple regression criteria, it was possible to interpret statistically the low cycle fatigue behaviour of pearlitic-ferritic steels.
Bibliographic Reference: EUR 11509 IT (1988)
Record Number: 198910037 / Last updated on: 1994-12-01
Original language: it
Available languages: it