Structure and fatigue properties of 08Kh18N10T steel after equal-channel angular pressing and heating

2012 ◽  
Vol 2012 (11) ◽  
pp. 954-962 ◽  
Author(s):  
S. V. Dobatkin ◽  
V. F. Terent’ev ◽  
W. Skrotzki ◽  
O. V. Rybalchenko ◽  
M. N. Pankova ◽  
...  
Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1191
Author(s):  
Ryuichi Yamada ◽  
Shoichiro Yoshihara ◽  
Yasumi Ito

A stent is employed to expand a narrowed tubular organ, such as a blood vessel. However, the persistent presence of a stainless steel stent yields several problems of late thrombosis, restenosis and chronic inflammation reactions. Biodegradable magnesium stents have been introduced to solve these problems. However, magnesium-based alloys suffer from poor ductility and lower than desired fatigue performance. There is still a huge demand for further research on new alloys and stent designs. Then, as fundamental research for this, AZ31 B magnesium alloy has been investigated for the effect of equal-channel angular pressing on the fatigue properties. ECAP was conducted for one pass and eight passes at 300 °C using a die with a channel angle of 90°. An annealed sample and ECAP sample of AZ31 B magnesium alloy were subjected to tensile and fatigue tests. As a result of the tensile test, strength in the ECAP (one pass) sample was higher than in the annealed sample. As a result of the fatigue test, at stress amplitude σa = 100 MPa, the number of cycles to failure was largest in the annealed sample, medium in the ECAP (one pass) sample and lowest in the ECAP (eight passes) sample. It was suggested that the small low cycle fatigue life of the ECAP (eight passes) sample is attributable to severe plastic deformation.


1999 ◽  
Vol 11 (7) ◽  
pp. 925-934 ◽  
Author(s):  
A Vinogradov ◽  
S Nagasaki ◽  
V Patlan ◽  
K Kitagawa ◽  
M Kawazoe

Author(s):  
Mohammad Bagher Limooei ◽  
Morteza Zandrahimi ◽  
Ramin Ebrahimi

In the present work, equal channel angular pressing of commercial pure aluminum 1070 was performed up to 4 passes using route Bc. For equal channel angular pressing operation, a suitable die set was designed and manufactured. X-ray diffraction analysis was used to determine the microstructure of the equal channel angular pressing-ed material. The fracture surface morphology and microstructure after fatigue were investigated by scanning electron microscopy. Mechanical properties of the equal channel angular pressing-ed material were evaluated by hardness and tension tests. Also, cyclic deformation behavior of severe plastic deformation Al1070 has been studied and results show a significant variation in hardness, ultimate strength and fatigue properties in high cycle fatigue life. Coefficient of fatigue strength σ′f and Bridgman correction factor have been obtained by S-N curve and tension test specimens, respectively, and compared before and after equal channel angular pressing process. Also an useful relation has been derived between fatigue life ( Nf) and stress amplitude ( σa) in high cycle fatigue region. Results indicated that there was not clear relation between fatigue strength coefficient and true corrected fracture stress in this case.


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