| Electrical and Magnetic Properties of D6ac Steel |
JUL 2007 |
42 pages |
| Authors:
S. K. Burke; M. E. Ibrahim; DEFENSE SCIENCE AND TECHNOLOGY ORGANIZATION VICTORIA (AUSTRALIA) MARITIME PLATFORMS DIV
|
 | The room temperature electrical and magnetic properties of the high strength steel D6ac are documented in this report. These data were used to support a wider study on the application of magnetic rubber testing (MRT) for the structural integrity management of the RAAF F-111 aircraft. While the immediate purpose of this report is to provide documented supporting data for MRT applied to the F-111 application, the results will also benefit ... |
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| Strategies for Mitigation of Hydrogen Environment Assisted Cracking of High Strength Steels |
2006 |
|
| Authors:
John R. Scully; Beth A. Kehler; Yongwon Lee; Richard P. Gangloff; NATIONAL ASSOCIATION OF CORROSION ENGINEERS HOUSTON TX
|
 | Modem ultra high strength alloy steels (UHSS) have been developed with outstanding combinations of strength and fracture toughness. Such steels are characterized by high purity and nanoscale strengthening clusters/coherent precipitates in a complex precipitation hardened, martensitic microstructure. However, the performance of such steels is degraded dramatically by internal hydrogen embrittlement (IHE) and hydrogen environment embrittlement (HEE). Thus, the development of an UHSS that is immune to hydrogen embrittlement is of ... |
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| Evaluation of Corrosion Preventive Compounds for Aviation Materials Applications |
APR 2005 |
149 pages |
| Authors:
Brian E. Placzankis; Chris E. Miller; Scott M. Grendahl; Tracey L. Miller; Stephanie M. Piraino; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Corrosion preventive compounds (CPCs) were evaluated using substrates comprised of five commonly used rotary wing aviation materials. The materials used were magnesium alloy AZ31B-H24 aluminum alloy 2024-T3, 4130 low alloy steel. 4340 high strength steel, and AM-355 stainless steel. The relative performance of each CPC was assessed in combination with the materials under several different tests. These tests consisted of general corrosion resistance. resistance to crevice corrosion attack. stress corrosion ... |
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| Damage Evaluation and Analysis of Composite Pressure Vessels Using Fiber Bragg Gratings to Determine Structural Health |
JAN 2005 |
10 pages |
| Authors:
Marley Kunzler; Eric Udd; Stephen Kreger; Mont Johnson; Vaughn Henrie; BLUE ROAD RESEARCH GRESHAM OR
|
| With the augmented use of high performance composite materials in critical structures, it has become increasingly important for smart' systems to monitor these materials and provide rapid evaluation. Using fiber Bragg gratings embedded into the weave structure of carbon fiber epoxy composites allow the capability to monitor these composites during manufacture, cure, general aging, and damage. Fiber optic sensors allow greater insight into damage progression and can be used to ... |
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| Corrosion Behavior of Friction Stir Welded High Strength Aluminum Alloys |
27 OCT 2004 |
12 pages |
| Authors:
J. B. Lumsden; M. W. Mahoney; G. A. Pollock; ROCKWELL SCIENTIFIC CO THOUSAND OAKS CA
|
| Friction stir welding (FSW), a relatively new solid state joining process, is used to join aluminum alloys of all compositions including alloys essentially considered unweldable. During FSW, a rotating tool provides a continual hot working action, plasticizing metal within a narrow zone at the join line, while transporting metal from the leading face of the probe to the trailing edge as the tool moves along the interface. Although melting does ... |
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| The Influence of Processing on the Microstructure and Properties of the Titanium Alloy Ti-5111 |
SEP 2004 |
20 pages |
| Authors:
Amy C. Stauffer; Ernest J. Czyryca; Donald A. Koss; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD
|
| The physical, mechanical, and corrosion properties of titanium and its alloys are attractive for applications in the U.S. Navy in view of design requirements for increased reliability with reduced maintenance and weight. The Naval Surface Warfare Center, in cooperation with Titanium Metals Corporation, developed the Ti-5Al-1Sn-1Zr-1V-0.8Mo (Ti-5111) alloy as a lower cost alternative to previous high-strength titanium alloys exclusive to Navy applications. The influence of heat treatment on the microstructure ... |
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| Effective Use of Weld Metal Hydrogen Trapping and Advance Diffusible Hydrogen Sensing |
2004 |
40 pages |
| Authors:
David L. Olson; Yeong-Do Park; COLORADO SCHOOL OF MINES GOLDEN DEPT OF METALLURGICAL ENGINEERING
|
| The development of an advance measuring apparati for diffusible hydrogen content based on electronic, optical and magnetic property measurements was investigated. The effort was to develop a rapid and accurate determination for both steel weld metal diffusible hydrogen content and its distribution. This investigation used the instrumentation acquired by the DURIP grant program. Thermoelectric (Seebeck) coefficient measurements are used to assess hydrogen content in higher strength low alloy steel, nickel-aluminum ... |
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| Environmentally Assisted Cracking: Concerns for Cadmium Replacement |
DEC 2003 |
20 pages |
| Authors:
Scott M. Grendahl; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| Recently, cadmium replacement has become the topic of an Environmental Security Technology Certification Program. As a direct result of this program, replacement coating systems will be developed and scrutinized. A fundamental starting point for corrosion-resistant coatings development work consists of a target for the overall chemical potential (galvanic series) and pH of the coating system and the substrate. This work developed the data necessary to determine the target for several ... |
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| Dynamic Tensile Testing of Sheet Steels and Influence of Strain Rate on Strengthening Mechanisms in Sheet Steels |
03 JUL 2003 |
271 pages |
| Authors:
Denise M. Bruce; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH
|
| The capability to conduct dynamic tensile testing of sheet steels was established and the influence of strain rate on strengthening mechanisms in sheet steels was investigated in this work. Several different automotive sheet steels were studied, including interstitial free (IF) steel, high strength low alloy (HSLA) steel, dual phase steel and transformation induced plasticity (TRIP) steel. |
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| Experimental Data, Numerical Fit, and Fatigue Life Calculations Relating to the Bauschinger Effect in High-Strength Armament Steels |
APR 2003 |
19 pages |
| Authors:
Edward Troiano; Anthony P. Parker; John Underwood; Charles Mossey; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS
|
| The uniaxial Bauschinger effect has been evaluated in several high strength steels being considered for armament use. Tests were conducted at plastic strains up to 3.5%. Results of testing show a progressive decrease in Bauschinger effect up to plastic strains of approximately 1% (for all materials investigated), after which there is little further decrease. |
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| Critical Fracture Processes in Army Cannons: A Review |
MAR 2003 |
26 pages |
| Authors:
John H. Underwood; Edward Troiano; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS
|
| Fast fracture in cannons can well be described using elastic-plastic fracture toughness, in combination with comparisons of cannon section size relative to the size required to maintain plane-strain fracture. Fatigue fracture of cannon tubes is modeled from results of full-size fatigue tests that simulate cannon firing. These tests are also the basis of fatigue-intensity- factor modeling of fatigue life, which incorporates material strength, initial crack size, and Bauschinger-modified autofrettage residual ... |
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| Yield Pressure Measurements and Analysis for Autofrettaged Cannons |
MAY 2002 |
17 pages |
| Authors:
John H. Underwood; David B. Moak; Michael A. Audino; Anthony P. Parker; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS
|
| Yield pressure for a small permanent strain was measured in quasi- static laboratory tests of autofrettaged ASTM A723 steel cannon pressure vessels. Yield pressure was found to be a consistent ratio of the yield strength measured in close proximity to the area of observed yielding. Comparable yield pressure measurements for cannons firing with typical 5-ms pressure pulse duration gave 14% higher yield pressures, attributed to strain%rate effects on plastic deformation. ... |
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| The Evaluation of Ambient-Temperature Processes for Repair Bonding of Aluminum Alloys |
JAN 2002 |
33 pages |
| Authors:
Daniel B. McCray; DAYTON UNIV OH RESEARCH INST
|
| On-aircraft adhesive bonding of metal substrates typically requires the use of impractical surface preparation processes in order to attain the desired bonded joint strength and durability. Surface preparations currently used for on-aircraft repairs rely on hazardous materials and/or inconvenient processing steps, or they do not yield adequate bond performance. Many U.S. Air Force Technical Orders (T.O.s) require the use of surface preparations such as phosphoric acid anodize (PAA) or acid ... |
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| Hall and Seebeck Measurement System for the Evaluation of Alloy Phase Stability, Microstructure, and Properties |
12 SEP 2001 |
7 pages |
| Authors:
David L. Olson; Timothy R. Ohno; COLORADO SCHOOL OF MINES GOLDEN DEPT OF METALLURGICAL ENGINEERING
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| Hall and Seebeck measurement systems have been specified, purchased, facilitated and calibrated. These systems are assisting in research efforts to develop new analytical approaches, based on electronic tools which have served the electronic industry well, to assess structural materials used in defense assemblies and structures. These electronic systems will develop multiple measurements techniques to assess alloy phase stability, aging, microstructure and properties. Seebeck coefficient measurements have already been correlated with ... |
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| Probabilistic Simulation of Fatigue Crack Initiation |
SEP 2001 |
47 pages |
| Authors:
Anthony Ingraffea; CORNELL UNIV ITHACA NY
|
| Many fatigue-related studies have been conducted on the workhorse alloys for airframe construction over the past 20-30 years. The body of empirical knowledge related to establishing relationships between loading conditions and fatigue life or fatigue crack growth rates, including environmental effects is vast. One consistent observation is that the number of cycles it takes to initiate a fatigue crack (imitation life) in high strength aluminum alloys, like AA 7075, is ... |
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| Failure Beneath Cannon Thermal Barrier Coatings by Hydrogen Cracking; Mechanisms and Modeling |
SEP 2001 |
23 pages |
| Authors:
John H. Underwood; Gregory N. Viglante; Edward Troiano; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS
|
| Army experience with hydrogen cracking failures of cannons is described, including extensive testing of high-strength steel and nickel-iron base alloys to address the failures. Cracking of cannon pressure vessel steels just under bore thermal barrier coatings is now common, and can be explained by the combined action of hydrogen-bearing combustion gases and thermally induced tensile residual stresses. Above-yield transient thermal compression and resultant residual tension stresses beneath the coating are ... |
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| Optimizing the Strength and SCC Resistance of Aluminum Alloys used for Refurbishing Aging Aircraft |
07 MAY 2001 |
113 pages |
| Authors:
Charles P. Ferrer; NAVAL ACADEMY ANNAPOLIS MD
|
| The focus of this report is on the mechanical end corrosion properties of high-strength aluminum alloys. Aluminum alloy 7075, a common material in the aerospace industry, is susceptible to stress-corrosion cracking (SCC) in the T6, or peak-aged temper. The susceptibility of this temper to SCC is alleviated through the use of the T73, or overaged temper. This temper exhibits significantly better SCC resistance, but at a 10-15% strength loss compared ... |
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| System Design of Hierarchically Structured Materials |
27 NOV 2000 |
55 pages |
| Authors:
Gregory B. Olson; NORTHWESTERN UNIV EVANSTON IL
|
| Research extended the SRG systems design approach to more complex materials by establishing methodology and fundamental principles for rational design of higher levels of structural hierarchy, while incorporating increased dynamic character in the form of adaptive system concepts via synergistic integration of materials science and applied mechanics. Research addressed both the methodology of rational design at new levels of materials complexity, and the fundamental principles of specific materials behaviors necessary ... |
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| Corrosion and Corrosion Fatigue of Airframe Materials |
JUL 2000 |
79 pages |
| Authors:
Robert P. Wei; LEHIGH UNIV BETHLEHEM PA DEPT OF MECHANICAL ENGINEERING AND MECHANICS
|
| This report summarizes research performed under Grant 92-G-0006 and complementary programs sponsored by the Air Force Office of Scientific Research under Grants F49620-96-1-0245 and F49620-9g-1-0198. The objectives of these programs are (1) the development of a basic understanding of the processes of localized corrosion and corrosion fatigue crack nucleation and growth in high strength aluminum alloys used in airframe construction, (2) the formulation of ... |
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| Dynamic Fracture Toughness Characterization of HY-100 Under-Matched Welds |
FEB 2000 |
92 pages |
| Authors:
Stephen M. Graham; Michael D. McLaughlin; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD SURVIVABILITY STRUCTURES AND MATERIALS DIRECTORATE
|
| Welds in marine structures are typically fabricated such that the yield strength of the weld metal is higher than the base plate (over-matched). Allowing the weld metal yield strength to be less than the base metal (under- matching) can increase productivity and weld metal toughness; however, there is some concern that under-matching increases the crack driving force and decreases the weld metal tearing resistance. This study examined fracture behavior of ... |
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| High Cycle Fatigue Science and Technology Program 1999 Annual Report |
JAN 2000 |
154 pages |
| Authors:
UNIVERSAL TECHNOLOGY CORP DAYTON OH
|
| This third annual report of the National Turbine Engine High Cycle Fatigue (HCF) Program is a brief review of work completed, work in progress, and technical accomplishments. This program is a coordinated effort with participation by the Air Force, the Navy, and NASA. The technical efforts are organized under eight Action Teams including: Materials Damage Tolerance Research, Forced Response Prediction, Component Analysis, Instrumentation, Passive Damping ... |
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| High Cycle Fatigue (HCF) Science and Technology Program 2000 Annual Report |
JAN 2000 |
219 pages |
| Authors:
Brian Garrison; UNIVERSAL TECHNOLOGY CORP DAYTON OH
|
| This fourth annual report of the National Turbine Engine High Cycle Fatigue (HCF) Program is a brief review of work completed, work in progress, and technical accomplishments. This program is a coordinated effort with participation by the Air Force, the Navy, and NASA. The technical efforts are organized under eight Action Teams: Materials Damage Tolerance Research, Forced Response Prediction, Component Analysis, Instrumentation, Passive Damping Technology, Component Surface Treatments, Aeromechanical Characterization, ... |
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| Evaluation of Aluminum-Manganese as a Cadmium Replacement |
2000 |
12 pages |
| Authors:
Michael Kane; Craig Matzdorf; James Green; NAVAL AIR WARFARE CENTER AIRCRAFT DIV PATUXENT RIVER MD
|
| Aluminum-manganese is currently being evaluated as a replacement for cadmium plating. Aluminum-manganese is applied by electroplating in molten salt and as such the process can plate internal diameters, complex geometries, and threaded applications. The salt bath is operated at 190 degrees Celsius and is compounded of aluminum chloride, sodium chloride, potassium chloride, and a small amount of manganese chloride. Aluminum-manganese has potential for use in ... |
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| Localized Damage Process in Metal Structures Under High Velocity Deformation |
DEC 1999 |
89 pages |
| Authors:
Stefan Vodenicharov; Angei Baitov; Ganka Ziateva; Zanka Karnenova; Ivailo Katzarov; BULGARIAN ACADEMY OF SCIENCES SOFIA INST OF METAL SCIENCE AND TECHNOLOGY OF METALS
|
| The ASB initiation and growth in high strength steel are investigated. An integrated energy theoretical approach is suggested for modeling ASB development and identifying post critical structure state in the bands. Criteria are formulated for both micro cracks and macro cracks initiation along the band length. On that basis a numerical simulation model is developed for axially symmetric body. The process of ASB initiation and ... |
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| Report to the Senate and House Appropriations Subcommittees on Defense. Regarding a Plan for the Utilization of Rock Island Arsenal |
DEC 1999 |
16 pages |
| Authors:
MARINE CORPS WASHINGTON DC
|
| Congress expressed concern in the Fiscal Year 2000 Defense Appropriations Conference Report 106-371 to the 2000 Department of Defense Appropriations Act that the Marine Corps and Army are not utilizing the expertise of Army arsenals in the development and design of the Lightweight 155mm Howitzer (LW155). In particular, Congress requested a plan to include Rock Island Arsenal (RIA) in producibility and manufacturing aspects of LW155 ... |
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| Cold Expansion Tests for Plates Containing Elongated Holes |
OCT 1999 |
|
| Authors:
M. Heller; R. L. Evans; R. B. Allan; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION CANBERRA (AUSTRALIA)
|
| Cold-expansion testing of D6ac plates containing an elongated (non- circular) hole, of 2:1 aspect ratio, has been undertaken using an AMRL designed interference fit plug/sleeve arrangement The aim has been to determine the practical viability of the process as an option for addressing the cracking problem at the non-circular fuel flow vent hole number 13 in the wing pivot fitting of the F-111C aircraft in ... |
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| Effects of Foreign Object Damage From Small Hard Particles on the High- Cycle Fatigue Life of Ti-6Al-4V |
SEP 1999 |
268 pages |
| Authors:
Joseph L. Hamrick Ii; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH
|
| Thin rectangular samples of Ti-6Al-4V were damaged by four methods to represent foreign object damage found in turbine engine blades: 1) impact with 2 mm and 5 mm diameter glass spheres at 305 m/s, 2) impact with 2 mm and 4 mm diameter steel spheres at 305 m/s, 3) quasi-static displacement controlled indentation using steel chisels with 1 mm, 2 mm and 5 mm diameter tips and 4) ... |
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| Hydrogen and Preheat Management in Welded High Strength Steel for Defense Applications |
15 JUL 1999 |
187 pages |
| Authors:
David L. Olson; COLORADO SCHOOL OF MINES GOLDEN
|
| With the need for new approaches to improve hydrogen management in higher strength steels, three tasks, each with its special focus and potential contributions, were established to promote cooperative research with TTCP operating assignment 013. These efforts are timely due to the introduction of even higher strength steels in Naval structures and defense hardware. These steels use new concepts of strengthening (i.e. precipitation) and not ... |
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| Implementation of a Unified Constitutive Model into the ABAQUS Finite Element Package |
JUN 1999 |
|
| Authors:
R. J. Wescott; K. C. Watters; M. Heller; AERONAUTICAL AND MARITIME RESEARCH LAB MELBOURNE (AUSTRALIA)
|
| Unified constitutive models have previously been developed at AMRL and implemented into the PAFEC and ABAQUS Finite Element packages to predict the stress-strain response of structures that undergo multi-axial, rate dependent, cyclic plasticity. In this work, the ABAQUS version of the model has been enhanced to account for advances in unified constitutive modelling, and for consistency with the existing PAFEC version of the model. Numerous test ... |
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| Mechanical Threshold Stress Constitutive Strength Model Description of HY-100 Steel |
16 APR 1999 |
46 pages |
| Authors:
D. M. Goto; J. Bingert; R. K. Garrett Jr.; Shuh- Rong Chen; George T. Gray III; NAVAL SURFACE WARFARE CENTER INDIAN HEAD DIV MD
|
| The mechanical threshold stress (MTS) approach is employed to characterize the constitutive stress-strain response of HY-100 steel. A generalized, three-term MTS strength model currently considers athermal, thermal, and strain-hardening contributions to flow stress. Aspects of the MTS framework pertinent to Navy HY steels are discussed, and a calibration methodology is presented for determining MTS strength model parameters. In addition, a linear strain-hardening modification to ... |
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| Use of the Instrumented Bolt and Constant Displacement Bolt-Loaded Specimen to Measure In Situ Hydrogen Crack Growth in High Strength Steels |
AUG 1998 |
29 pages |
| Authors:
Gregory N. Vigilante; John H. Underwood; Daniel Crayon; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS
|
| Aggressive environments experienced by large caliber gun tubes during processing and firing have lead to a great deal of investigation on the hydrogen-induced cracking susceptibility of high strength steels. The constant displacement bolt-loaded specimen has been used to determine the hydrogen crack growth rates and threshold stress intensity of AF1410 - both conventionally and isothermally heat treated - and AerMet 100. Additionally, the severe susceptibility ... |
|
| The Pacific Rim International Conference (3rd) on Advanced Materials and Processing Held in Honolulu, Hawaii on 12-16 July 1998. Volume 1 and 2 |
JUL 1998 |
1654 pages |
| Authors:
Alexander Scott; TMS WARRENDALE PA
|
| Partial contents: Microstructural Analysis of Vanadium Bearing High Manganese Precipitation Hardening Stainless Steel; Ti-B2 - Particle - Reinforced High Modulus Steel; Structure and Mechanical Properties of Ultra Low Carbon/Ti Added Steels; Interaction Between Melts and Refractory in Process of Smelting Reduction with Iron Bath; The Effect of the Titanium Traces on the Mechanical Properties of an Ultra High Strength Steel; Microalloying of Steel 16 Mn With Niobium; Microstructure and Mechanical ... |
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| Synthesis & Fundamental Studies of Bulk Metallic Systems Based on Unusual Microstructures |
15 MAY 1998 |
5 pages |
| Authors:
S. J. Poon; G. J. Shiflet; VIRGINIA UNIV CHARLOTTESVILLE DEPT OF PHYSICS
|
| We have performed integrative studies of thermal and mechanical effects on the synthesis and properties of bulk titanium-based alloys with nanoscale morphological structures. Alloys are examined by calorimetry, mechanical-property testing, and x-ray and electron diffraction including high- resolution analytical microscopy. New titanium alloys with unusual structural and physical properties are found and preliminary studies of various phase formation pathways have begun, several key results are reported: (1) A series of ... |
|
| Micromechanisms of Fracture and Fatigue-Crack Growth in Bulk Metallic Glass Alloys |
10 MAR 98 |
21 pages |
| Authors:
Christopher J. Gilbert; Robert O. Ritchie; CALIFORNIA UNIV BERKELEY DEPT OF MATERIALS SCIENCE AND MINERAL ENGINEERING
|
| The recent development of metallic alloy systems which can be processed with an amorphous structure over large dimensions, specifically to form metallic glasses at low cooling rates (tilde 10 K/s), has permitted novel measurements of important mechanical properties. These include, fatigue crack growth and fracture toughness behavior, representing the conditions governing the subcritical and critical propagation of cracks. In the present study, bulk plates of a Zr41.2 Ti13.8 Cu12.5 Ni10 ... |
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| Corrosion and Corrosion Fatigue of Aluminum Alloys: Chemistry, Micromechanics and Reliability |
1998 |
29 pages |
| Authors:
Robert P. Wei; D. G. Harlow; LEHIGH UNIV BETHLEHEM PA DEPT OF MECHANICAL ENGINEERING AND MECHANICS
|
| Lehigh University undertook a 3-year, multidisciplinary program of research, under AFOSR Grant No. F49620-98-1-0198, to further develop a basic mechanistic understanding of the damage evolution processes of localized corrosion and corrosion fatigue crack nucleation and growth in aluminum alloys used in aircraft construction, and to formulate mechanistically based probability models for reliability assessment and life-cycle management based on this understanding. Research was initiated on 1 February 1998 and was extended ... |
|
| Development of the Microstructure Based Stochastic Life Prediction Models |
18 JUL 97 |
433 pages |
| Authors:
Marek A. Przystupa; CALIFORNIA UNIV LOS ANGELES DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| The goal of this program was to develop a methodology for predicting fatigue lives of structural alloys based on their microstructural characteristics and mechanical properties. Such methodology has been successfully implemented and verified by predicting fatigue lives of the four different variants of the aluminum airframe 7050-T7451 plate alloy and, with modifications, of the butt welds of the ship hull HSLA-80 steels. The key features of the method is the ... |
|
| Corrosion and Fatigue of Aluminum Alloys: Chemistry, Micro-Mechanics and Reliability |
12 MAY 97 |
35 pages |
| Authors:
Robert P. Wei; LEHIGH UNIV BETHLEHEM PA DEPT OF MECHANICAL ENGINEERING AND MECHANICS
|
| Lehigh University undertook a multidisciplinary program of research to develop a basic mechanistic understanding of localized corrosion and corrosion fatigue crack nucleation and growth in aluminum alloys used in aircraft construction, and to begin to formulate mechanistically based probability models for reliability assessments based on this understanding. The objectives of the program are: (1) the development of basic understanding of the processes of localized corrosion and corrosion fatigue crack nucleation ... |
|
| Ambient Temperature Testing of Metallic Materials Exposed to Propellant Combustion Environments Containing Hydrogen |
MAR 97 |
11 pages |
| Authors:
G. N. Vigilante; P. J. Cote; J. H. Underwood; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS
|
| Combustion gases containing hydrogen can cause severe environmental degradation and cracking in the high strength steels used in gun tubes. Although the hydrogen is evolved at the elevated temperatures of combustion, the deleterious effects of hydrogen on steel are most severe near ambient temperature. |
|
| Atmospheric Corrosivity of Defence Bases in Northern and Eastern Australia |
FEB 97 |
|
| Authors:
B. S. Smith; E. J. Duxbury; B. T. Moore; DEFENCE SCIENCE AND TECHNOLOGY ORGANIZATION CANBERRA (AUSTRALIA)
|
| A series of exposure trials has been conducted to characterise the corrosivity of the atmosphere at 16 Defence bases in Eastern and Northern Australia. Atmospheric corrosivity was assessed by measuring the corrosion rates of specimens of steel, zinc and two high strength aluminum alloys when exposed on racks in the open air for periods of one to four years during the period 1988 to 1993. The results are presented in ... |
|
| Hydrogen and Preheat Management in Welded High Strength Steel for Defense Application. (TTCP Workshop and Joint Seminar). Volume I: Workshop Report |
28 JAN 97 |
137 pages |
| Authors:
D. L. Olson; J. L. Davidson; B. F. Dixon; COLORADO SCHOOL OF MINES GOLDEN
|
| A joint seminar and workshop on hydrogen management in high strength steel weldments were performed to assess the state of the art and science to assess the progress of the TTCP-S11 research activities, to make mid-course corrections to the research activities and to plan for technology transfer and round-robin tests. Achievement highlights, the reorganization of activities to promote cooperative research and operation plan are described. |
|
| Hydrogen and Preheat Management in Welded High Strength Steel for Defense Application. (TTCP Workshop and Joint Seminar). Volume II: Joint Seminar Papers |
28 JAN 97 |
248 pages |
| Authors:
D. L. Olson; J. L. Davidson; B. F. Dixon; COLORADO SCHOOL OF MINES GOLDEN
|
| A joint seminar and workshop on hydrogen management in high strength steel weldments were performed to assess the state of the an and science to assess the progress of the TTCP-S11 research activities, to make mid-course corrections to the research activities and to plan for technology transfer and round-robin tests. Achievement highlights, the reorganization of activities to promote cooperative research and operation plan are described. |
|
| Evaluation of Oxide Dispersion Strengthened (ODS) Molybdenum Alloys |
1997 |
46 pages |
| Authors:
Robert Blanco; R. W. Buckman Jr; BETTIS ATOMIC POWER LAB WEST MIFFLIN PA
|
| A series of fourteen (14) novel high-strength molybdenum alloy compositions containing a dispersion of very fine (98% cold work) condition and for as-swaged material in the heat treated condition. Extremely fine oxide particle sizes (<1000 A) were observed by Transmission Electron Microscopy (TEM) for a number of the experimental compositions in the as-swaged condition. A one hour recrystallization temperature as high as 3990 deg F was measured and a ductile-to-brittle ... |
|
| Proceedings of the Joint Seminar; Hydrogen Management in Steel Weldments, Melbourne, Australia, 23rd October 1996 |
1997 |
|
| Authors:
D. L. Olson; I. Maroef; C. Lensing; R. D. Smith; W. W. Wang; COLORADO SCHOOL OF MINES GOLDEN
|
| Despite 50 years of research into the prevention of hydrogen induced cracking in weldments, this form of cracking is still the most serious problem facing the steel fabrication industry today. Increased performance for defence platforms requires stronger lighter structures which have largely been obtained using high strength steels. As the strength is increased, so is the risk of hydrogen induced cracking after welding. To address this issue, the management of ... |
|
| Development of Intelligent Processing Methodology for Intermetallic Matrix Composites |
97 |
6 pages |
| Authors:
MATSYS INC ARLINGTON VA
|
| It is proposed to develop processing tools for a broad, new family of in-situ metal matrix composites based upon the innovative use of multilithic reinforcement strategies. Intermetallic matrix composites (IMCs), reinforced with a dispersed ceramic phase, will be incorporated into metallic matrices to serve as reinforcing entities within the resulting multilithic reinforced composite (MRC). IMC-reinforcement in metallic matrices is particularly novel since they can be created to possess low temperature ... |
|
| Weld Detail Fatigue Life Improvement Techniques |
DEC 96 |
145 pages |
| Authors:
K. J. Kirkhope; R. Bell; L. Caron; R. I. Basu; MIL SYSTEMS ENGINEERING OTTAWA (ONTARIO)
|
| Fatigue cracks in steel ships often occur at welded joints where stress concentrations due to the joint geometry are relatively high and the fatigue strength of the weld is reduced in comparison to that of the base metal. This becomes more critical in ships built of High Strength Steels (HSS) because the fatigue strength of steel in the a welded condition does not increase in proportion to the yield or ... |
|
| Grain Boundary Development in Superplastic Aluminum Alloys |
DEC 96 |
232 pages |
| Authors:
Michael E. McMahon; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Superplasticity may be defined as the capability of certain polycrystalline materials to deform to extensive plastic elongations prior to failure, often without formation of a neck. Typically, superplasticity refers to tensile elongations greater than 200%, although some elongations have been reported in excess of 5000% Ref 1. While it has been suggested that bronze metals in use in ancient civilizations may have possessed superplastic properties Ref 2, most historical reviews ... |
|
| Progress Report - Mechanical Properties Evaluation of ASTM A945 (HSLA- 65) Steels |
SEP 96 |
17 pages |
| Authors:
Eric M. Focht; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD SURVIVABILITY STRUCTU RES AND MATERIALS DIRECTORATE
|
| This report documents the mechanical properties of steel plates for Navy use. These plates conform to American Society for Testing and Materials (ASTM) Standard A945, High-strength, Low-alloy (HSLA), Class 65. Plates of various thickness were purchased from two different producers to determine if the steel could be obtained on a production scale, as opposed to a custom order. Tensile and Charpy V-notch impact tests were performed on the steels, and ... |
|
| Low-Carbon, Age-Hardenable Steels for Use in Construction: A Review |
SEP 96 |
53 pages |
| Authors:
Robert A. Weber; Bruce R. Somers; Eric J. Kaufmann; CONSTRUCTION ENGINEERING RESEARCH LAB (ARMY) CHAMPAIGN IL
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| High-strength low-alloy (HSLA) steels are being used extensively in U.S. Naval shipbuilding and are being substituted for quenched and tempered HY- 80 steel plate. This report examines other applications for the use of HSLA steels. They were studied to determine possible uses in U.S. Army Corps of Engineers construction projects, the current technology gaps, and the research necessary to fill those gaps. HSLA steels offer some benefits over conventional steels ... |
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| Stress Concentrators and Rate Effects in Formation of Adiabatic Shear Bands (Revised Version) |
31 AUG 96 |
66 pages |
| Authors:
Janusz R. Klepaczko; METZ UNIV (FRANCE) LAB OF PHYSICS AND MECHANICS OF MATERIALS
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| The phenomenon of shear instability and flow localization is investigated in this Report. The ultrahigh strength steel VAR 4340, approx. 52 HRC was tested in shear at wide range of the imposed velocities, from quasi- static to 120 m/s. A new experimental technique of direct impact on double shear specimen was used. Four specimen geometries were tested with different stress concentrators, from standard to a very sharp notch. At loading ... |
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| Fatigue Life Assessment of Steel Pressure Vessels with Varying Stress Concentration, Residual Stress, and Initial Cracks |
JUL 96 |
23 pages |
| Authors:
J. H. Underwood; A. P. Parker; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS
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| A single-parameter representation of local stress range, initial crack size, and material yield strength is proposed for describing the intensity of the fatigue loading of a structural component. A logarithmic plot of single- parameter fatigue life results provides a single straight-line description of fatigue life behavior over a broad range of material, configuration, and loading conditions. Expressions for calculating the local stress range at the failure site are outlined, including ... |
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Reports by Keyword(s)
HIGH STRENGTH ALLOYS
