Author: E. R. PARKERPublisher:
ISBN:
Category :
Languages : en
Pages : 47
Book Description
Enhancement of Fracture Toughness in High Strength Steel by Microstructural Control
Author: E. R. PARKERThe Effect of Microstructure on the Fracture Toughness of a High Strength Steel
Author: N. E. ClarkAnalysis of Fracture Toughness Mechanism in Ultra-fine-grained Steels
Author: Toshihiro HanamuraPublisher: Springer
ISBN: 4431544992
Category : Technology & Engineering
Languages : en
Pages : 71
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.
Enhancement of Cryogenic Fracture Toughness Through Microstructural Control in a Ferritic Fe-12 Ni-0.25 Ti Alloy System
Author: Sungho JinThe Relationship of Microstructure to Strength and Toughness in High-strength Steel
Author: John Henry BucherPublisher:
ISBN:
Category : Fractography
Languages : en
Pages : 138
Book Description
This report deals with the relationship of elements of microstructure to the fracture characteristics of a group of commercially produced steels, heat-treated to ultra-high strength levels. The microstructures were characterized in terms of optical microscopy, electron diffraction, and electron fractography. Fractographic studies were made of fractured surfaces broken in impact at +25 and -196 C as a function of tempering temperature, in slow bending at ambient temperature, in a modified bend test in which slow and fast propagation stages were effected, and on surfaces produced in tensile fractures. The fracture characteristics were studied by means of an instrumented bend test and in terms of the plastic instability generated in the torsion test. The instrumented bend test yielded data on criteria for the onset of slow crack propagation and for the onset of rapid propagation, including the effect of the total stored energy in the system. Plastic instability in torsion was studied as a function of specimen section size in AISI 4340 steel. A 250,000 psi yield strength Maraging steel was studied in a standard size test bar. (Author).
Microstructure and Fracture Toughness of a High-strength Low-alloy Steel
Author: Marie Therese MiglinPublisher:
ISBN:
Category : Steel, High strength
Languages : en
Pages : 308
Book Description
Research Toward High Strength High Toughness Steels
Author: CALIFORNIA UNIV BERKELEY.Publisher:
ISBN:
Category :
Languages : en
Pages : 82
Book Description
Several different ways of microstructural control were attempted in maraging type steels in order to achieve a combination of high strength and high toughness. In Section I, the composition, processing and mechanical properties of Fe-Ni-Ti alloys are described. It is found that high nickel content and high aging temperature are beneficial for toughness. This alloy system, however, does not exhibit high toughness due to the extensive grain boundary precipitation during aging. In Section II, the well-known toughening mechanisms, i.e., grain refinement, retained austenite, and the TRIP mechanism are incorporated to a 250 grade maraging stee. The improvement in fracture toughness is obtained only when the retained austenite remains stable during deformation. The microduplex maraging steel preserves its high fracture toughness upon high strain rate fracture in contrast to most of the martensitic steels. In Section III initial success is reported with an alternate toughening technique: the introduction of a dense mobile dislocation density through rapid phase transformation of a partially maraged structure.
Scientific and Technical Aerospace Reports
Author: Nuclear Science Abstracts
Author: Fracture Toughness of High-strength Steels for Military Applications
Author: J. E. CampbellPublisher:
ISBN:
Category : Steel, High strength
Languages : en
Pages : 22
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).