TY - GEN
T1 - Crack initiation mechanisms and fatigue lifetime of AISI 420 steel under constant and variable loading
AU - Zettl, B.
AU - Stanzl-Tschegg, S.
AU - Mayer, H.
PY - 2007
Y1 - 2007
N2 - Ultrasonic fatigue tests are performed with AISI 420 steel up to 10 10 load cycles. The material is tested in hardened and tempered condition and does not show a fatigue limit in S-N tests. Different crack initiating mechanisms are found, depending on the numbers of cycles to failure. At lifetimes below approximately 107 load cycles, crack initiation is preferentially at surface inclusions. In the regime from about 107 to 109 cycles to failure, cracks initiate at interior inclusions. When specimens fail at higher numbers of cycles (between 109 and 1010 cycles), cracks initiate at the surface and no inclusions are found. Two-step variable amplitude tests are performed in the VHCF regime. In contrast to the constant amplitude loading, crack initiation at interior inclusions was found in all tests, and specimens failed at low damage sums.
AB - Ultrasonic fatigue tests are performed with AISI 420 steel up to 10 10 load cycles. The material is tested in hardened and tempered condition and does not show a fatigue limit in S-N tests. Different crack initiating mechanisms are found, depending on the numbers of cycles to failure. At lifetimes below approximately 107 load cycles, crack initiation is preferentially at surface inclusions. In the regime from about 107 to 109 cycles to failure, cracks initiate at interior inclusions. When specimens fail at higher numbers of cycles (between 109 and 1010 cycles), cracks initiate at the surface and no inclusions are found. Two-step variable amplitude tests are performed in the VHCF regime. In contrast to the constant amplitude loading, crack initiation at interior inclusions was found in all tests, and specimens failed at low damage sums.
KW - AISI 420
KW - Martensitic chromium steel
KW - Ultrasonic resonance testing
KW - Variable Amplitude loading
KW - Very high cycle fatigue
UR - http://www.scopus.com/inward/record.url?scp=58349083669&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:58349083669
SN - 9780873397049
T3 - VHCF-4 - 4th International Conference on Very High Cycle Fatigue
SP - 123
EP - 128
BT - VHCF-4 - 4th International Conference on Very High Cycle Fatigue
T2 - 4th International Conference on Very High Cycle Fatigue, VHCF-4
Y2 - 19 August 2007 through 22 August 2007
ER -