Metall.Trans. 21A, 935-948, 1990
F.D. Fischer¹, F.G. Rammerstorfer² and F.J. Bauer³
¹Institute of Mechanics,
University of Mining and Metallurgy, Leoben, Austria
²Institute of Lightweight Structures and Aerospace Engineering,
TU Wien, Vienna, Austria
³Böhler AG, Kapfenberg, Austria
High-alloyed steel specimens subjected to hundreds of thermal cycles (heating
up in a furnace to about 900&°C, quenching in water, resting in air)
Contrary to standeard "low-cycle fatigue" tests with a cyclically varying
applied mechanical load, the driving "force" is a cyclic temperature field
with self-equilibrating residual stress states.
Despite the cyclic character of this temperature field and no applied
load, a significant monotonic change of the shape and metallurgical
structure of the specimens can be observed depending strongly on the material
and the initial geometry.
Preciptiations along the grain boundaries and remarkable residual stress
states are responsible for internal cracks and damage.
An experimental program is reported and metallurgical and mechanical
interpretations are presented.