Influence of Density and Porosity Size and Shape on Fatigue and Fracture Toughness of High Strength FL4405 P/M Steel

Influence of Density and Porosity Size and Shape on Fatigue and Fracture Toughness of High Strength FL4405 P/M Steel PDF Author: RI. Stephens
Publisher:
ISBN:
Category : Constant amplitude
Languages : en
Pages : 30

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Book Description
Density and sintering temperature effects were investigated with FL4405 low alloy P/M high strength steel. Monotonic tensile stress-strain, plane strain fracture toughness and fatigue behavior of smooth, notched and cracked specimens were investigated under both constant and variable amplitude loading. Two density levels, 7.0 and 7.4 g/cm3 and two sintering temperatures, 1120 and 1315‡C, were evaluated. The increased density resulted in smaller pore size and pore volume and the increased sintering temperature resulted in greater pore roundness. All final fracture surfaces were brittle at the macro level while containing ductile dimples at the micro level. Fatigue surfaces contained cleavage only, ductile dimples only or mixed cleavage and ductile dimple morphology with no striations nor beachmarks. Increasing the density resulted in significant higher tensile strength, elastic modulus, ductility, fracture toughness and fatigue resistance. Increasing the sintering temperature, and hence increasing pore roundness, resulted in additional enhancement of these properties. However, this increase was not as significant as that of the density increase.

Influence of Density and Porosity Size and Shape on Fatigue and Fracture Toughness of High Strength FL4405 P/M Steel

Influence of Density and Porosity Size and Shape on Fatigue and Fracture Toughness of High Strength FL4405 P/M Steel PDF Author: RI. Stephens
Publisher:
ISBN:
Category : Constant amplitude
Languages : en
Pages : 30

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Book Description
Density and sintering temperature effects were investigated with FL4405 low alloy P/M high strength steel. Monotonic tensile stress-strain, plane strain fracture toughness and fatigue behavior of smooth, notched and cracked specimens were investigated under both constant and variable amplitude loading. Two density levels, 7.0 and 7.4 g/cm3 and two sintering temperatures, 1120 and 1315‡C, were evaluated. The increased density resulted in smaller pore size and pore volume and the increased sintering temperature resulted in greater pore roundness. All final fracture surfaces were brittle at the macro level while containing ductile dimples at the micro level. Fatigue surfaces contained cleavage only, ductile dimples only or mixed cleavage and ductile dimple morphology with no striations nor beachmarks. Increasing the density resulted in significant higher tensile strength, elastic modulus, ductility, fracture toughness and fatigue resistance. Increasing the sintering temperature, and hence increasing pore roundness, resulted in additional enhancement of these properties. However, this increase was not as significant as that of the density increase.

The Influence of Pore Size and Shape on Smooth and Notched Variable Amplitude Fatigue Behavior of FL4405 High Strength Powder Metal Steel Alloy

The Influence of Pore Size and Shape on Smooth and Notched Variable Amplitude Fatigue Behavior of FL4405 High Strength Powder Metal Steel Alloy PDF Author: Dente Duncan Poland
Publisher:
ISBN:
Category :
Languages : en
Pages : 174

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International Aerospace Abstracts

International Aerospace Abstracts PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 974

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Analysis of Fracture Toughness Mechanism in Ultra-fine-grained Steels

Analysis of Fracture Toughness Mechanism in Ultra-fine-grained Steels PDF Author: Toshihiro Hanamura
Publisher: Springer
ISBN: 4431544992
Category : Technology & Engineering
Languages : en
Pages : 71

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Book Description
In this book, advanced steel technologies mainly developed at the National Institute for Materials Science (NIMS), Japan, for structure control, mechanical properties, and the related mechanisms are introduced and discussed. NIMS has long worked on developing advanced steel techniques, namely, producing advanced steels by using only simple alloying elements such as carbon, manganese, and silicon, and also by utilizing steel scrap. The hope is that this approach will lead to a technology of a so-called steel-to-steel recycling process, with the ultimate goal of a recycling process such as an automotive-steel-to-automotive-steel recycling process to take the place of the current cascade-type recycling system. The main idea is to utilize ultra-grain refining structures and hetero structures as well as martensite structures. In particular, the focus of this book is on tensile strength and toughness of advanced steels from both the fundamental and engineering points of view. Fundamentally, a unique approach to analysis is taken, based on fracture surface energy as effective grain size is employed to better understand the mechanism of property improvement. From the engineering point of view, in fracture toughness such factors as crack tip opening displacement (CTOD) of advanced steels are evaluated in comparison with those of conventional steels.

Influence of Work Hardening Exponent on Crack Propagation in High-strength Materials

Influence of Work Hardening Exponent on Crack Propagation in High-strength Materials PDF Author: G. L. Hanna
Publisher:
ISBN:
Category : Alloys
Languages : en
Pages : 84

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Book Description
The influence of work hardening exponent on the variation of fracture toughness with material thickness was studied for high strength steel, aluminum, and titanium alloys. A variety of materials could be compared by employing normalizing parameters to represent the toughness in terms of the relative plastic zone size and representing the relationship on a logarithmic plot. Using this method the normalized fracture toughness parameter in the region of 100% slant fracture was proportional to the square of the work hardening exponent for the body-centered cubic metals. In the fracture mode transition region, however low work hardening was beneficial and the thickness at which the transition occurred decreased as the work hardening exponent increased. The influence of work hardening exponent on cyclically-induced crack growth rates in AISI 4340 steel and 13V-11Cr-3A1 titanium was also evaluated. In the steel the growth rate was slightly less for the material with the lower work hardening exponent while the titanium exhibited so significant trend as a function of work hardening characteristics. The specimen thickness had the greatest effect on the cyclically-induced crack growth with decreased growth rates present in the thicker specimens. Attempts were also made to control the process zone size by adding zirconia particles to a high strength steel matrix through powder metallurgy techniques.

Fatigue and fracture Toughness - cryogenic behavior

Fatigue and fracture Toughness - cryogenic behavior PDF Author: C. F. Hickey
Publisher: ASTM International
ISBN: 9780803103436
Category : Technology & Engineering
Languages : en
Pages : 196

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Fracture Toughness of High-strength Materials: Theory and Practice

Fracture Toughness of High-strength Materials: Theory and Practice PDF Author:
Publisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 190

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The Influence of Crack Length and Thickness in Plane Strain Fracture Toughness Tests

The Influence of Crack Length and Thickness in Plane Strain Fracture Toughness Tests PDF Author: Melvin H. Jones
Publisher:
ISBN:
Category :
Languages : en
Pages : 40

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Fracture Toughness of High-strength Steels for Military Applications

Fracture Toughness of High-strength Steels for Military Applications PDF Author: J. E. Campbell
Publisher:
ISBN:
Category : Steel, High strength
Languages : en
Pages : 22

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Book Description
The Memorandum discusses the current situation on the inclusion of fracture-toughness testing requirements in specifications for high-strength steels used for military applications. The Memorandum was prepared at the request of The Technical Cooperation Program (TTCP), and contains information from Canadian and British members of that program, as well as U.S. information. Military applications discussed include missile motor cases, aircraft landing gear, gun tubes, armor plate, and hydrofoils. (Author).

Metals Abstracts

Metals Abstracts PDF Author:
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 1014

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Book Description