11 Fatigue Analysis of Dissimilar Metal Welded …
375
Fig. 11.6 HAZ/fusion zone
Monel
Fig. 11.7 Monel base metal
Monel alloy with little amount of twinning is randomly observed. Etching has also
revealed rolling direction in Monel base metal region.
11.6 Fatigue Testing
Shimadzu Servopulser (100 kN) dynamic testing machine has been used for fatigue
testing with constant amplitude stress-controlled cycle loading with R ratio = 0.1.
R ratio is the ratio of minimum to maximum stresses with a frequency range of 20–
45 Hz. The maximum stress level was fixed based (K × σ y ) on the yield stress of
the material (284.1 MPa). Initial loading factor K varies from 0.6 to 0.8. The loading
coefficient is adjusted to obtain the fatigue limit for the tests [16]. The experiments
were conducted up to 2 million cycles depending on the loading condition.
375
Fig. 11.6 HAZ/fusion zone
Monel
Fig. 11.7 Monel base metal
Monel alloy with little amount of twinning is randomly observed. Etching has also
revealed rolling direction in Monel base metal region.
11.6 Fatigue Testing
Shimadzu Servopulser (100 kN) dynamic testing machine has been used for fatigue
testing with constant amplitude stress-controlled cycle loading with R ratio = 0.1.
R ratio is the ratio of minimum to maximum stresses with a frequency range of 20–
45 Hz. The maximum stress level was fixed based (K × σ y ) on the yield stress of
the material (284.1 MPa). Initial loading factor K varies from 0.6 to 0.8. The loading
coefficient is adjusted to obtain the fatigue limit for the tests [16]. The experiments
were conducted up to 2 million cycles depending on the loading condition.