Fang WANG
金属学报(英文版)
A new model for the analysis of fatigue crack growth in the metal structures was proposed. This model shows a promising capability of explaining various fatigue phenomena. The new crack growth model is further completed by a continuous empirical formula for estimating the value of variable fracture toughness during crack propagation and a modified continuous equation for the crack tip stress/strain constraint factor used to calculate the stress intensity factor at the opening level. The prediction results are proved to agree well with the observed phenomena in test.
关键词:
Marine structures
,
Crack growth rate
,
Three dimensional stress state
,
Fracture toughness
,
Crack tip stress/strain constraint factor
S.Q. Zhou
,
W. Zhao
,
W.H. Xiong
,
Y.N. Zhou
,
null
,
null
,
null
,
null
金属学报(英文版)
Effect of Mo and Mo2C on the microstructure
and properties of Ti(C,N)-based cermets was investigated in this
article. The results have indicated that the weight percentage of Mo
from 5 to 10 can reduce Ti(C,N) grain diameter and thickness of the
rim, and Ti(C,N) grain can be wetted by Ni-Cu-Mo liquid so as to get
small contiguity of Ti(C,N) grain. In that way, the transverse
rupture strength of Ti(C,N)-based cermets has reached
1800—1900 MPa; the fracture toughness has been due to
16—18 MPa m1/2. But 15wt pct Mo was not more effective
on Ti(C,N)-based cermets, because the thickness of the rim becomes
larger. In the circumstance of Mo 2 C, 5 wt pct Mo 2 C was
good for microstructure and properties of Ti(C,N)-based cermets, but
11 wt pct Mo 2 C has resulted in larger contiguity of Ti(C,N)
grain and big Ti(C,N) grain diameter so as to reduce transverse
rupture strength and fracture toughness. So that, the effect of Mo
on Ti(C,N)-based cermets is better than Mo 2 C.
关键词:
Transverse rupture strength (TRS)
,
null
,
null
