Fatigue Strength and Fracture Mechanisms of IF28 Steels

2006 ◽  
Vol 15-17 ◽  
pp. 804-809 ◽  
Author(s):  
M.A. Islam ◽  
Yo Tomota
Keyword(s):  
Fatigue Strength ◽  
Thin Sheet ◽  
High Strength Steels ◽  
High Strength ◽  
Fracture Morphology ◽  
Fatigue Properties ◽  
Fracture Mechanisms ◽  
Interstitial Free ◽  
Static Properties ◽  
Type Of Fracture

Interstitial free (IF) steels are widely used as thin sheet in the automobile industries because of their many favorable properties. Although, fatigue properties of IF steels do not have significant importance to auto body makers, however, they are very concerned about the tensile and fatigue strength of the steels used for structural purposes to ensure safety of passengers. So, fatigue results of this steel might help researchers to understand the behaviors of high strength steels. In this study cyclic and static properties have been studied at room temperature in the air. Initiative has also been taken to observe the fatigue fracture morphology of this steel. Experimental results show that the fatigue limit is corresponding to about 40% of tensile strength and 80% of the yield strength of this steel. Fractographic observations reveal a mixed type of fracture mode (intergranular and transgranular cracking) fractures.

Fatigue Properties of Cu-Cr In-Situ Composite

2000 ◽  
Author(s):  
Chitoshi Masuda ◽  
Yoshihisa Tanaka
Keyword(s):  
Fatigue Strength ◽  
Pure Copper ◽  
High Strength Steels ◽  
Axial Loading ◽  
High Strength ◽  
Cold Drawing ◽  
Fatigue Properties ◽  
Face Centered Cubic ◽  
In Situ Composite

Abstract The new electrical conductive material, Cu-15wt%Cr in-situ composite, was developed for the application of lead frame, high field magnet and trolley wire. The Cu-Cr composite was fabricated by casting method in vacuum and forged, solution-treated, and cold drawn (η = 4.66 and 6.94). In this paper the cold drawn Cu-Cr composite was tested under cyclic loading at room temperature in comparison to the data for pure copper. The fatigue stresses decreased with increasing the number of cycles to failure and the double -knees were not seen on the S-N curves for both alloys as in other face centered cubic materials such as aluminum alloys and high strength steels, such as spring steels and carburized steels. The fatigue strength of Cu-Cr composite is double that for pure copper. The fatigue strength of Cu-Cr composite with cold drawing at η = 6.94 is higher than that at η = 4.66 tested under an axial loading (R = 0.1). On the fatigue fracture surface, the fatigue crack initiated from the un-dissolved chromium particle situated beneath the specimen surface and the crack direction was changed along the chromium fiber. In order to improve the fatigue strength of Cu-Cr composite it is very important that the size and amount of un-dissolved chromium particles would be reduced.

scholarly journals Gigacycle Fatigue Properties of Hydrogen Charged High Strength Steels

2013 ◽  
Vol 99 (7) ◽  
pp. 494-501 ◽  
Author(s):  
Hisashi Hirukawa ◽  
Yoshiyuki Furuya
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Fatigue Properties

scholarly journals Liftime Optimization of Hot Forged Aerospace Components by Linking Microstructural Evolution and Fatigue Behaviour

2011 ◽  
Vol 278 ◽  
pp. 162-167 ◽  
Author(s):  
Hermann Maderbacher ◽  
H.P. Gänser ◽  
Martin Riedler ◽  
Michael Stoschka ◽  
Martin Stockinger ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Finite Element ◽  
Fatigue Strength ◽  
Microstructural Evolution ◽  
Manufacturing Process ◽  
Fatigue Behaviour ◽  
Strength Distribution ◽  
Fatigue Properties ◽  
Finite Element Code ◽  
Static Properties

Heavy-duty aerospace components are frequently hot forged to satisfy the high requirements concerning their mechanical behaviour. Only the usage of high-performance materials together with a near-optimum manufacturing process enables the production of parts that are at the same time lightweight and mechanically extremely durable. Not only the static properties, but also the fatigue behaviour of Inconel718 is strongly influenced by the material’s microstructure resulting from the forging and heat treatment processes. Therefore, the static and fatigue properties may be controlled via the microstructural properties by suitably adjusting the parameters of the manufacturing processes. The present work links the complete forging and heat treatment process to the local distribution of the material’s fatigue strength within a component; the effect of the operating temperature is also considered. To this purpose, an empirical model is derived from fatigue tests on specimens with different microstructures at different temperatures. The resulting fatigue strength model is implemented, along with a microstructural evolution model from earlier work [1], into a finite element code in order to predict the local fatigue strength distribution in a component after being subjected to an arbitrary forging process. In a further step, the finite element code is linked to an optimization tool for determining the optimum set of manufacturing process parameters such that the component lifetime is maximized while taking process constraints into consideration.

X-ray Fractographic Study on Alumina and Zirconia Ceramics

1990 ◽  
Vol 34 ◽  
pp. 719-727 ◽  
Author(s):  
Sumio Tanaka ◽  
Yukio Hirose ◽  
Keisuke Tanaka
Keyword(s):  
Fracture Toughness ◽  
Residual Stress ◽  
Fracture Surface ◽  
High Strength Steels ◽  
High Strength ◽  
Fatigue Tests ◽  
Fracture Mechanisms ◽  
Zirconia Ceramics ◽  
X Ray ◽  
Fractographic Study

The residual stress left on the fracture surface is one of the important parameters in X-ray fractographic study. It has been used to analyze fracture mechanisms in fracture toughness and fatigue tests especially of high strength steels.In this paper, X-ray fractography was applied to brittle fracture of alumina (Al2O3) and zirconia (ZΓO2) ceramics.

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