bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of 5280 Rolling Bearing Steel for Improved Performance and Productivity
Authors: Dimitry PV , McDonough PJ , Beck G , Eberhard R , Zock HW
Published: September 2009

A new optimized steel analysis has been developed in which the carbon and chromium are reduced and the manganese increased to improve the solidification during continuous casting. The aim of this new grade is a steel far more suitable for continuous casting than 52100 (100Cr6).

The bearing steel 52100 (100Cr6) has a proven track record throughout the world as the high carbon material of choice. With the increased production from the continuous casting process and the efficiencies of direct rolling, in combination with higher stress conditions for bearings, certain weaknesses have been recognized with the grade 52100 (100Cr6). Due to the high productivity rates of modern continuous casters, the long homogenizing cycles to minimize carbide segregation in 52100 are no longer practical. Without these long homogenizing cycles the result is more pronounced forms of segregation and adverse carbide distributions. These disadvantages can result in restricted mechanical and thermo-mechanical physical properties leading to difficulties in conventional and induction heat treatments.

The new grade under development can be classified 5280 (80CrMn4) and has been evaluated from both the steel production aspects as well as metallurgical behavior. With regard to the decisive properties of microstructure, life and processing the 5280 (80CrMn4) was equivalent to or better than the 52100 (100Cr6) steel. Continuous casting improved significantly; porosity, cracks or cavities were not present. The carbon segregation index was reduced. Carbide distributions measured according to SEP 1520 were at a minimum level, without excessive soaking prior to direct rolling. Heat treatment response was slightly modified to lower quenching temperatures, tempering at 220°C and 240°C resulted in the same values for hardness and retained austenite as in the case of 52100 (100Cr6). After martcnsitic heat treatment the hardness stabilization in 5280 (80CrMn4) required no process change from 52100 (100Cr6) to achieve the same degree of stabilization.

Mechanical properties of tensile strength, impact bending and notch impact strength; wear resistance and rotating bending strength were evaluated with direct comparisons to 52100 (100Cr6). Rolling contact fatigue tests were carried out on angular contact ball bearings of type 7205B where the inner rings were the test specimens. Test conditions were selected in such a way that it would be possible to make comparisons with 52100 (100Cr6) under diverse types of stress. The fatigue life of the 5280 (80CrMn4) was equivalent to the 52100 (100Cr6) base data.
Appropriate Techniques for Internal Cleanliness Assessment
Authors: Auclair G , Daguier P
Published: September 2009

In the steels used for bearing applications, one of the most important functional properties is fatigue endurance, which is closely related to the micro and macro cleanliness of the metal. Like other bearing steel producers throughout the world (Timken, SKF, Daïdo, Sanyo, etc.), Ascometal has expended considerable effort to attain the very high quality level required to ensure optimum performance in service. To obtain this quality level, the Ascometal philosophy has been to equip its bearing steel plants with appropriate systems for characterizing cleanliness levels both during melting and refining and for the semi-finished products. In particular, optical emission spectroscopy (OES-PDA), quantitative metallography (QM) and ultrasonic testing (high frequency US) were chosen to meet these goals. The equipment available in the different steel plants and the recent improvements made in OES-PDA and US testing procedures are widely described in this paper and examples of the use of this recent knowledge to predict endurance level on the semi-product are presented.
Rolling Contact Fatigue Under Water-Infiltrated Lubrication
Authors: Matsumoto Y , Murakami Y , Oohori M
Published: September 2009

This paper describes bearing life under water-infiltrated lubrication, which is often much shorter than the calculated bearing life. Bearings that failed in the field under water-infiltrated lubrication were analyzed to identify the mechanism. However, this was difficult due to insufficient information of the failure process. New fatigue life test methods were then developed to reproduce short life under water-infiltrated lubrication, to precisely observe the flaking process, and to study what material parameters affect the bearing life. It was found that failure under water-infiltrated lubrication initiates from nonmetallic inclusions on the rolling contact surface and propagates initially following grain boundary and then cutting through the grain, which eventually results in flaking. Higher cleanliness, which means less failure initiations, and nickel (Ni), which strengthens grain boundaries, improves bearing life under water-infiltrated lubrication. Hydrogen-induced failure is also experimentally studied to further understand water-induced failure. Hydrogen-induced failure is different from water-induced failure in the mechanism.
Microstructural Optimisation of Bearing Steels for Operation Under Contaminated Lubrication by Using the Experimental Method of Dented Surfaces
Authors: Böhmer H-J , Eberhard R
Published: September 2009

The damage mechanisms of antifriction bearings operating under debris contaminated lubrication have been investigated experimentally. A particular experimental procedure has been designed to simulate natural foreign particle indentations and to allow a quick reproducible fatigue test comparison on material and heat treatment variants. Additionally, the scattering of the fatigue test results could be reduced significantly.

The different phases of the damaging process are described. From these results measures have been derived to increase the bearing performance and lifetime under these stress conditions, which are governed by geometrical notch effects and localized metal-to-metal-contact and plastic deformation. The effectiveness in laboratory tests has been checked versus field applications.

An optimization of the materials microstructure was found to be an efficient means to counteract such problems. This was done by modifying the alloying content of the bearing steel and the surface composition respectively and changing the heat treatment in a way to generate a certain amount of very stable retained austenite. This particular microstructural component could be proved to have inherent self-healing capabilities against indentations produced by the overrolling of debris particles and the subsequent reflattening of the raised edges around the dents. This effect can be demonstrated by base-alloying of through-hardening grades as well as by surface alloying of case-hardenable steels.

The actual amount and the stability of the retained austenite against mechanical or thermal-induced transformation are important properties to achieve the tolerance to dent effects. Results of laboratory fatigue tests of different development routes and field experiences are presented. The consequences of these measures on the dimensional stability of the bearings are explained.
Development of Long Life Rolling Bearings for Use in the Extreme Conditions
Authors: Shibata M , Goto M , Ohta A , Toda K
Published: September 2009

As the service conditions of automobiles and industrial machines are becoming more extreme in recent years, higher bearing performance has been required for those applications. Especially, a demand for maintenance-free bearings is really high, that is, a demand for the extension of bearing life has been increasing. To satisfy those customers' demands, various measures as to materials and heat treatment have taken, those of which are KE bearings developed for automobiles and KUJ7 steel for semi-high temperature bearings. The characteristics in material and heat treatment necessary to extend bearing life and the direction of measures to each factor are described, then the characteristics of KE bearings and KUJ7 steel are also described.
The Effect of V, Al and N on the Fatigue Life of a Carbonitrided Bearings
Authors: Yoo S-J , Choi S-W , Han S-K , Lee J-S , Jung B-J , Song B-H , Park C-N
Published: September 2009

The effect of chemical composition on microstructure and mechanical properties was investigated. Optimum contents of Al and N for appropriate prior austenite grain size were determined to avoid the formation of microcracks during oil quenching after a carbonitriding heat treatment. The microhardness and fatigue life of microalloyed steels based on SAE 5140H were compared with those of conventional steels. The surface hardness was increased due to finely distributed V-carbonitrides precipitated during double reheat process at the range of intercritical temperatures. The fatigue life was increased due to a large amount of retained austenite in the steel obtained by a carbonitriding heat treatment.
Development of a New Material for Guide Roll Bearings for Continuous Casting Machine
Authors: Yamamura K , Oohori M
Published: September 2009

The guide roll bearings for a continuous casting machine (CCM) are used under extremely low rotation speed, high load, and debris-contaminated and water-infiltrated lubrication. Therefore, raceway surfaces usually wear severely and outer rings are sometimes fractured.

The purpose of this study is to prolong the CCM bearing life by material and heat-treatment technologies. We investigated the fracture process of CCM bearings and developed a new material, case hardened steel, that shows superior wear resistance to SAE 52100 steel. Optimum control of retained austenite and hardness extends rolling contact fatigue life under contaminated lubrication. In the simulation tests of a CCM guide roll, superior wear resistance was confirmed under water-infiltrated lubrication conditions.
The Effect of Bearing Steel Composition and Microstructure on Debris Dented Rolling Element Bearing Performance
Authors: Carlson D , Pitsko R , Chidester AJ , Imundo JR
Published: September 2009

Because of continuous improvements in bearing steel cleanliness, surface damage created by debris has become more influential in determining the life of rolling element bearings. The metallurgical structure of a bearing raceway can be modified to optimize strength and damage tolerance. The correct balance between raceway strength and damage tolerance can significantly improve bearing life in contaminated environments.

Retained austenite is known to add a degree of damage tolerance to hardened bearing steel. Samples made of ASTM A295 52100 steel were heat treated to obtain increasing amounts of retained austenite. Indentations were placed into the steel sample surfaces using a Rockwell 30N Superficial Hardness Tester. These indentations were examined and measured using light interferometry. The changes in the dent morphologies with increasing amounts of retained austenite will be discussed.

A test program has been developed to investigate the influence of microstructure on the life of debris dented rolling element bearings. Groups of 35 mm bore radial ball bearings were dented with either a Rockwell 30N Superficial Hardness Tester, or with hard powder metal particles. These bearings were then fatigue tested with uniform contact stress, speed and clean lubricant with a marginal lubrication film. The performance of different bearing steels and heat treatments were investigated, and test results from the two denting methodologies will be provided.
Progress in the Evaluation of CSS-42L™: A High Performance Bearing Alloy
Authors: Tomasello CM , Burrrier HI , Knepper RA , Balliett S , Maloney JL
Published: September 2009

This paper presents a technical update on the on-going evaluation of CSS-42L™ (US Patent #5,424,028).[1] The alloy is a case carburizable, stainless steel alloy which has been demonstrated to have a key combination of properties suited for ideal bearing performance: High surface hardness, hot hardness for usage up to 427°C (800°F), high fracture toughness, and corrosion resistance. Initial rolling contact fatigue data suggested that the alloy should have superior bearing life. This paper concentrates on data generated since the last ASTM bearing symposium[2] Both bearing life test data and wear resistance test data illustrate the alloy has excellent properties. Bearing life tests have been performed which illustrate superior life to both M50 and 52100. Wear resistance tests have also been performed. In a contaminated wear test environment of Al2O3, CSS-42L steel performs very well in comparison with M50 and Cronidur-30. Wedeven wear resistance tests on case components also show excellent behavior.
Application of a New Physically Based Model to Determine the Influence of Inclusion Population and Loading Conditions on the Distribution of Bearing Lives
Authors: Lormand G , Piot D , Vincent A , Baudry G , Daguier P , Girodin D , Dudragne G
Published: September 2009

The principal cause of failure in bearings under E.H.D. conditions is deep spalling initiated beneath the surface. The corresponding damage mechanisms have been clearly identified (fatigue “butterflies,” crack nucleation and propagation to the surface). In this context, a statistical model, based on a mixed approach combining micromechanics and physical metallurgy, has been developed for predicting the distribution of bearing lives from the inclusion population in the steel. The model has been validated by comparing its predictions with experimental failure probability curves determined from flat washer fatigue tests performed on a steel whose inclusion distribution had been accurately established. The existence of non zero survival rates for very long lives indicates that Weibull distribution [1] is not suitable to represent the complete life distribution for modern bearings. The predictive capabilities of the model have been used to study the influence of parameters, such as the applied load, the specimen size, etc.
Codes and Standards Affecting Glass in Buildings: The U.S. and Beyond
Authors: Block VL
Published: September 2009

This paper examines the development and adoption process of building code requirements and standards related to glass in buildings in the United States. Issues covered include safety glazing, skylights, handrails, and glass strength. The relationship between the building codes and consensus-based standard organizations, such as the American Society for Testing and Materials (ASTM), American National Standards Institute (ANSI), American Society for Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE), the National Fenestration Rating Council (NFRC), and the International Organization for Standardization (ISO) will be reviewed. Specific U.S. glass requirements for safety glazing performance and glass quality will be compared to existing Mexican and Canadian requirements. At the international level, this paper will review the work of ISO Technical Committee 160, its working groups, current activities, and the interrelationship of national and international standards in the workplace.
The Impact of Self-Cleaning Glass
Authors: Barry CJ , O'Day T
Published: September 2009

Today there is yet one more invisible coating available to improve the properties of window glass. At first there were the nearly invisible, low-emissivity coatings, which admit daylight. Some of them can also admit beneficial passive solar gain. These prevent winter heat loss by reflecting, or not emitting, long-wave (10 micrometer wavelength) infrared thermal radiation. These low-emissivity coatings also enhance the effectiveness of heat absorbing solar control tinted glass, and reflective coatings, by preventing absorbed solar heat from radiating towards the room side of a window. Now clear, self-cleaning coatings are available for the outer surface of the window. These coatings act in different ways to prevent the deposition and build-up of dirt. Some can rinse inorganic dust off the glass with rain or water by their hydrophobic, or hydrophilic properties. Some of them can break down deposited organic dirt using a catalytic action powered by the ultraviolet component of daylight.
In-Situ Dew-point Measurement to Assess Life Span of Insulating Glass Units
Authors: Torok GR , Lichtenberger W , Major A
Published: September 2009

Replacement of insulating glass (IG) units in buildings is expensive. Replacement costs can be estimated fairly accurately. However, timing is less certain. In the author's experience, time estimates for replacement are often based on poor understanding of the causes of IG unit “failure” (water vapour condensation on glass surfaces facing the IG unit cavity) and previous negative experience, and thus are reactive rather than predictive.

The life span of insulating glass units in service is not well known. Insulating glass units have been made in North America since the late 1950s. Laboratory test methods developed in Canada in the late 1950s and early 1960s, subsequently used as the basis of most IG unit test methods worldwide, were intended to assess the likelihood of successful performance through the IG unit manufacturer's warranty period, not to determine service life span. In the 1980's, based on in-situ testing for the “Field Correlation Study” by the Sealed Insulating Glass Manufacturers Association (SIGMA) in the USA, Spetz proposed that one component of the laboratory test method, dew-point measurement of cavity gas fill, could be used to estimate time to failure of IG units in service. This technique is examined in this paper and modifications are suggested to improve accuracy.
Development of Design Methodology for Rectangular Glass Supported on Three Sides to Resist Lateral Uniformly Distributed Loads
Authors: El-Shami MM , Norville HS
Published: September 2009

The forthcoming version of Practice to Determine the Load Resistance of Glass in Buildings (E 1300-02) will contain several new features. These include new procedures to determine load resistance of laminated glass, revised procedures to determine load resistance of insulating glass, and procedures to determine load resistance of rectangular glass supported on 1, 2, and 3 sides. This paper discusses the development of load resistance charts for rectangular glass supported on three sides with one side free. It presents the nonlinear finite element model used to determine stresses and deflections. The load resistance charts use maximum edge stress as the criterion for determining load resistance. The value of maximum edge stress derives from a failure prediction approach for glass edges rather than surface stresses. The paper describes load-induced stresses along the edge of an unsupported side and over the glass surface for glass supported along three sides. It compares probability of breakage based upon surface stresses with that derived from the maximum edge stress criterion.
Wind Load Resistance of Large Trapezoidal Glass Lites
Authors: Norville HS , El-Shami MM , Jackson R , Johnson G
Published: September 2009

Large trapezoidal annealed window glass lites glaze airport control tower cabs. The authors have developed a design methodology for these lites as discussed in this paper. In developing the methodology, the authors conducted failure tests of large, trapezoidal, weathered window glass lites, obtained from the U.S. Federal Aviation Administration, under uniform pressure. They used a nonlinear finite element analysis technique for thin plates coupled with failure prediction techniques that underlay ASTM Practice for Determining the Load Resistance of Glass in Buildings (E 1300-00) to develop their design methodology. The paper summarizes the experimental data, load-induced stresses in large trapezoidal window glass lites, and the load resistance of large trapezoidal lites relative to that of rectangular window glass lites. It presents the design methodology and illustrates it with an example.
Window Glass Design Software
Authors: Morse SM
Published: September 2009

Standards Design Group, Inc., (SDG) produces software to aid engineering and design professionals in the building industry with lengthy and often tedious design procedures. The paper describes recent rapid improvement in computing technology and the corresponding increase in complexity of engineering design standards. It provides justification for development of software that incorporates long computation procedures with logical decisions to achieve designs with just a few simple input operations on the part of the designer and engineer. The paper goes on to discuss specifically modifications that SDG incorporated into its window glass design software in conjunction with the forthcoming revision of E 1300. It presents design examples to illustrate some of the differences that will result with this revision.
Retrofitting Commercial Structures with Laminated Glass to Withstand Hurricane Effects
Authors: Beers PE , Pilcher MA , Sciaudone JC
Published: September 2009

There is an enormous inventory of buildings in the United States. The majority of these buildings have not been designed to resist hurricane effects, namely high winds and windborne debris.

Commercial structures have a history of damage during previous hurricanes. Many large buildings in downtown Houston, Texas suffered extensive glass breakage during Hurricane Alicia in 1982. This was the first documented instance of windborne debris causing significant glass breakage in an urban area. Before Alicia, it was thought that high winds alone were responsible for hurricane damage. However, recently there have been several more instances of glass breakage during hurricanes have occurred, including the Kendall area in Dade County, Florida during Hurricane Andrew in 1992.

While mitigation efforts for newly constructed buildings are very important, this activity only benefits a small percentage of the built inventory. The vast majority of the built commercial building inventory is not protected. Without retrofitting, it will take many years before a significant percentage of commercial buildings are protected, even if all newly constructed buildings were designed for hurricane effects.

Protecting commercial structures from hurricane elements, namely wind and windborne debris, requires unique considerations. Many buildings have glass areas too large to accommodate shutters. Even if shutters can be employed it may be impractical to install them in advance of a storm. Often the best solution for a commercial building is to use impact-resistant laminated glass. With laminated glass, there is no special preparation required in advance of a storm as the protection is always in place. And, it provides invisible protection because it appears as ordinary window glass.

The use of laminated glass for hurricane protection requires special designs. Laminated glass is often thicker than ordinary window glass and it must be attached or anchored to the window frame so it remains in place, if broken. The challenge for retrofitting commercial windows with laminated glass is to find a cost-effective method that does not require replacement of the framing as well. This paper will present methodology for a cost-effective retrofit using laminated glass and the existing window frames.
The Advantages of Glazing in an Overall Security Strategy
Authors: Betten M , Beruhe H
Published: September 2009

The prevailing public sentiment is that glazing materials in a business or home are extremely vulnerable to penetration. One homebuilder recounted his personal feelings on the topic of residential security by saying, “if you want a fortress, don't put any windows in it.” A seemingly simple solution? However, as individuals who routinely consult with citizens on security issues, we must weigh actual threats while addressing the fear of clients. The challenge is to balance the heightened need for security against the fortress mentality.
The Relationship Between Sprinkler Systems and Glass
Authors: Razwick J
Published: September 2009

This paper explores the particular relationship between sprinklers and glass in a building. There are many misconceptions about sprinklers' ability to prevent non-rated glass from breaking during a fire, when in fact sprinklers can actually cause some glass to break. Laboratory testing has shown that unless the conditions can be strictly controlled, sprinklers and non-rated glass are not an adequate combination to prevent the spread of a fire. Specific testing examples and illustrations are cited in the paper.

Sprinklers are also “active” systems, depending on proper maintenance and activation sequences in order to work properly, whereas fire-rated glass is a “passive” system providing compartmentation around the clock.
Evaluation and Remediation of Low Permeability and Dual Porosity Environments
Authors: Sara MN , Everett LG
Published: September 2009

Description

This unique publication provides a global perspective on one of the most complex issues in hydrology: field and laboratory measurement of low permeability and dual porosity materials. Eleven peer-reviewed papers, written by an international group of experts, focus on the development of techniques to evaluate hydraulic conductivity and remediation of fine grained and dual porosity geologic materials.

It deals with a range of issues related to the measurement of both saturated and unsaturated geologic materials, including:

• Test Procedures

• Laboratory and Field Evaluations

• Low Permeability Environments and Remediation Issues

STP 1415 is a valuable resource for geologists, hydrologists, hydrogeologists, environmental and civil engineers, environmental scientists, waste management personnel, landfill owners and operators, and remediation specialists.
Composite Materials: Testing, Design, and Acceptance Criteria
Authors: Zureick A , Nettles AT
Published: September 2009

Description

STP 1416 features 17 peer-reviewed papers covering various aspects of testing, design, and acceptance criteria for composite materials. Topics cover:

• NDT Evaluation

• Material Qualification

• Full-Scale Structural Testing

• Durability

• Test Method Development

• Micromechanics

• Damage Resistance and Tolerance

• Impact

• Bucking

Audience: STP is a valuable research tool for both the civil engineering infrastructure and aerospace communities.
Bearing Steel Technology
Authors: Beswick JM
Published: September 2009

Description

STP 1419 provides the latest global information on bearing steel manufacture and service life endurance, along with an up-to-date perspective on rolling bearing steel technologies. 34 peer-reviewed papers cover:

Bearing Steel Process Developments reviews global bearing steel making technologies, including a description of a billet casting friendly steel grade. Topics also cover never-before published data on the relative segregation levels for ingot and continuously cast 1C-1.5Cr, bearing steel, the effect of steel making processing parameters, and the soaking practice on bearing steel segregation properties.

Steel Technology and Bearing Component Manufacture discusses the machinability parameters in bearing steels within the Swedish bearing industry and relevant testing methodologies. This section also covers modernistic steel technologies related to improved environmental aspects of the hardening heat treatment process.

Developments in Bearing Steel Quality Assessment and Correlation’s with Bearing Life examines the use of ultrasonic techniques for internal cleanliness assessment, the use of statistics of extreme values (SEV), and a new method based on generalized Pareto distribution (GPD) when using optical microscopy.

Developments in Bearing Service Life Testing covers rolling bearing service life, as opposed to "pure" rolling contact fatigue life testing.

Bearing Metallurgy Developments for Improved Service Life describes the technologies pertaining to new alloys, heat treatments and microstructure control for improved served life and extreme conditions.

Developments in High Alloy Steel for Improved High Temperature and Enhanced Corrosion Resistance Properties addresses the demand in the rolling bearing industry, particularly aerospace, for high temperature and corrosion resistance.

Microstructural Changes and its Relationships with Bearing Life and Life Time Predictions focuses on the material physics aspects associated with the Hertzian contact cyclic process in rolling bearing contacts.

Material Factors in Bearing Life Calculations deals with rolling bearing life endurance models.

Audience:

STP 1419 is a valuable resource for bearing and steel manufacturers and purchasers, bearing designers, researchers and technologists, and tribologists.
Repair, Retrofit and Inspection of Building Exterior Wall Systems
Authors: Boyd Jon M. , Johnson Paul G.
Published: September 2009

Description

Eighteen peer-reviewed papers address the complex issues of design, construction, maintenance, evaluation, and repair of building exterior wall systems, both old and new.

Topics cover

System types addressed include facades comprised of vintage masonry, limestone, precast concrete panels, thin stone, exposed cast-in-place concrete, aluminum framing, EIFS, and glass and metal walls.
Radioactive Waste Processing Control, Shippingport Atomic Power Station
Authors: Whirl SF , Tash JA
Published: September 2009

The safe disposal of radioactive waste is a problem common to all nuclear reactors. In a pressurized water reactor (PWR) plant, the major source of these wastes is the primary coolant. At the Shippingport Atomic Power Station, all potentially radioactive liquid wastes are handled and processed in a waste disposal plant.
Analysis for Radionuclides in Aqueous Wastes from an “Atomic” Plant
Authors: Kahn B , Moeller DW , Handley TH , Reynolds SA
Published: September 2009

Waste water from a plant operating reactors and processing spent fuel contains many radionuclides, formed both by neutron capture and by fission. Methods of analysis and typical findings are reported for a variety of aqueous samples including: reactor coolant, water from a settling basin and pits, seepage from pits, underground water, and water from a river. Analysis by radiochemical methods is described, and considerable attention is given to measurement of gamma-emitters by scintillation spectrometry, a versatile technique for identification and quantitative determination. Most of the materials described are characterized by moderate levels of radioactivity. A brief description is given of techniques for measuring extremely small concentrations of radioelements.
Analysis of Environmental Samples for Radionuclides
Authors: Reid DL
Published: September 2009

The production, processing, or use of radioactive materials presents problems relative to their controlled or uncontrolled release to the internal or external plant environs. One phase is associated with the originator's responsibility for controlling and quantitatively defining through appropriate monitoring activities the material released. The analytical experience of a large production installation can be used to advantage in planning the analytical requirements for related smaller scale uses or production of radioactive substances.
Part I. Iron, Carbon Steel, and the Stainless Steels
Authors: Anderson W. K. , Beck C. J. , Kephart A. R. , Theilacker J. S.
Published: September 2009

Data have not been adequately presented in a single place covering the current state of knowledge on properties of reactor structural materials, particularly as affected by nuclear radiation. The authors propose, in a series of four articles, to bring together the more significant data needed by designers on these materials. These articles cover (1) iron-base alloys, (2) alloys of nickel and cobalt, (3) aluminum and titanium, and finally (4) Zircaloy 2.
Abrasive Wear
Authors: Finkin E. F.
Published: September 2009

Abrasive wear is one of the most critical and costly problems faced by an industrial economy. Since 1950 a great deal of empirical and theoretical knowledge has been developed, but impediments seem to exist which hinder the transfer of this information either among researchers or among those who have need of it. It is partially to remedy this situation that the present review of theoretical and empirical findings is offered.
Life Testing of Plain Bearings for Automotive Engines
Authors: Johnson E. T.
Published: September 2009

In the field of automobile engineering, engine bearings have demanded a great deal of attention. The trend of automobile engine development has been towards higher horsepower, higher speeds, greater efficiencies, and smoother operation. This has, in general, meant higher bearing loads and higher operating temperatures. Added to this has been the objective of lifting engine bearings from the classification of “service replacement parts” to that of “parts lasting the life of the automobile.” How successful we have been in accomplishing this latter aim is shown by the following: In 1931 high-speed engine testing showed an average bearing life of about 250 hr. at 3200 rpm.; in 1941, making allowance for the higher test speeds prevailing, but making no allowance for the increase of 49 per cent in unit load which had occurred in the interval, tests averaged approximately 750 hr. before producing a comparable degree of fatigue failure in the bearings—an increase of roughly 200 per cent (see Fig. 1).
Metallographic Observations of Ball Bearing Fatigue Phenomena
Authors: Jones A. B.
Published: September 2009

Much information has been accumulated and a great deal has been published regarding the fatigue of metals, referring most particularly to the lower carbon and alloy steels. However, little information has been available regarding the fatigue characteristics of the higher carbon and higher alloy steels used in the completely hardened martensitic state and which are generally subjected to Compressive loads.
Fatigue Testing of Roller Bearings
Authors: Gibbons H. R.
Published: September 2009

In the early 1900's there was little or no knowledge of the fatigue life of roller bearings. The load-carrying ability of bearings of that era was, similar to plain journal bearings, based on an allowable pressure per square inch of projected bearing area. Effect of speed and the probable life of these bearings were unknown.
Computer Studies of Neutron Irradiation and Annealing in Finite BCC Iron Specimens
Authors: Beeler J. R.
Published: September 2009

The primary damage state in neutron-irradiated α-iron was computed as a function of specimen size and neutron energy. A Monte Carlo technique was used to compute the concentration and energy spectrum of primary knock-on atoms (PKA) produced by neutrons. In a second set of calculations, the number of displaced atoms produced by a PKA was computed as a function of its energy. These calculations consisted of simulating the entire elastic collision cascade of an energetic atom in the exact crystal structure of α-iron. In addition to providing the displacement function for a PKA as a function of energy, they also gave an atomic level description of the defect distribution in a collision cascade (displacement spike). By combining the results of these two sets of computations it was possible to describe the damage state in an iron specimen as a function of its size and of neutron energy. The results strongly suggest that the damage state produced in small specimens is essentially different than that produced in large specimens, as are their annealing characteristics. The conditions of tension test specimen size and shape which insure that annealing kinetics data obtained from irradiated wires are applicable to these specimens were determined. Calculations on the mechanisms for damage saturation, on annealing behavior, and on saturation and embrittlement in pressure shells as a function of depth, are also described.
Effect of Irradiation on Bend Transition Temperatures of Molybdenum- and Columbium-Base Alloys
Authors: McCoy H. E. , Weir J. R.
Published: September 2009

Because of the potential use of refractory metals as structural materials in nuclear reactors, it is necessary that the influence of irradiation on the ductility of these materials be evaluated. The present study is concerned with the development of suitable test equipment for evaluating the ductile-to-brittle transition temperature of irradiated specimens and with the use of this equipment to evaluate the ductile-to-brittle temperature for several irradiated specimens. The equipment developed for this purpose fits in a standard tensile machine and is capable of remote operation over the temperature range of - 73 to 261 C. The materials studied after irradiation to a neutron dosage of the order of 1020 nvt (>1 Mev) include Mo-0.5Ti, Cb-1Zr, welded Cb-1Zr, and D-43 (10W-1Zr-0.1C). The variables studied were: (1) the metallurgical state of the material prior to irradiation, (2) irradiation dose, and (3) post-irradiation annealing. The transition temperature of the Mo-0.5Ti was determined on the basis of the deflection of the material prior to fracture. The behavior of the Cb-lZr and D-43 alloys was analyzed on the basis of the yield strength.
Recovery of Defects in Neutron-Irradiated Tungsten
Authors: Moteit J. , Smith J. P.
Published: September 2009

Isochronal resistivity recovery spectra of irradiated tungsten indicate three resolved peaks at 16, 22, and 31 per cent of the absolute melting temperature of this material. Isochronal annealing of the tungsten hardness increment indicates that the irradiation affects the athermal component of the hardness, observed at temperatures above 0.15 Tm, and not the strong temperature-dependent component which becomes prominent below this temperature. In addition, the hardness recovery occurs at 0.35 Tm; the 0.16, 0.22, and 0.31 Tm peaks being absent. The recovery stages of resistivity at 0.31 Tm and of the hardness at 0.35 Tm in body-centered cubic metals correspond to the recovery stage observed for both types of properties in most irradiated face-centeredcubic metals which occur at approximately 0.50 Tm.
The Effect of Irradiation Temperature on the Post-Irradiation Stress-Strain Behavior of Stainless Steel
Authors: Martin W. R. , Weir J. R.
Published: September 2009

This paper describes the results of an investigation of the influence of irradiation temperatures from 150 to 750 C, and post-irradiation test temperatures of 25 to 850 C on the mechanical properties of AISI Type 304 and 347 stainless steels tested at various strain rates. The irradiations were conducted in an Oak Ridge Research Reactor core position. Subsize tension specimens were irradiated to 7 x 1020 nvt (fast) and 9 x 1020 nvt (thermal).

The yield stress was not affected by irradiation at any test temperature above 600 C. At lower irradiation and testing temperatures the yield and ultimate engineering tensile stresses are strongly dependent upon irradiation temperature. The true tensile and fracture stresses at test temperatures below 600 C were unaffected regardless of the irradiation temperature; they were slightly reduced at test temperatures above 600 C in the high strain-rate tests.

Increases in yield strength due to irradiation were associated with decreases in the uniform elongation, but not fracture strain for test temperatures below 600 C. At higher testing temperatures the radiation effect on the ductility parameters was strongly strain-rate sensitive. The ductility parameters decreased markedly with decreasing strain-rate and increasing deformation temperature.

At this neutron exposure the influence of irradiation at deformation temperatures less than 600 C is reflected only in the stress-strain relationship and not in the fracture stress or strain. However, the irradiation effect for deformation at 600 C and above concerns the fracture process and not the deformation relationship. The effect on the fracture process appears to be a result of changes in the grain boundary fracture behavior.
In-Reactor Stress-Rupture Properties of a 20Cr-25Ni, Columbium-Stabilized Steel
Authors: Venard J. T. , Weir J. R.
Published: September 2009

There is widespread interest in the effect of neutron bombardment on the mechanical properties of the austenitic stainless steels because of their frequent application in reactor structures and fuel claddings. For this reason, a columbium-stabilized austenitic stainless steel (20Cr-25Ni-bal Fe) developed in the United Kingdom for gas-cooled reactor service has been tested inreactor for its stress-rupture characteristics.

The tests were performed by internally pressurizing tubes at temperatures of 550, 650, 750, and 850 C in a neutron flux of approximately 5.0 x 1012 nv fast (>2.9 Mev) and 6.0 13 1013 nv thermal. Duplicate tests were performed ex-reactor. Brief details of test procedures and a discussion of the experimental results are presented.

Only a small effect of irradiation on material strength was seen, but a strong effect of irradiation and temperature on the fracture ductility was observed.
Strain-Cycle Phenomena In Thin-Wall Tubing
Authors: Reynolds M. B.
Published: September 2009

The service life of a nuclear reactor fuel element is related to the ability of its metallic cladding to accommodate severe local plastic strains caused by fuel expansion or external coolant pressure. A technique has been developed for subjecting samples of thin-wall tubing to cyclic plastic strains similar to those experienced in reactor service. By applying gas pressure, the thin tubular specimen is alternately expanded and contracted between rigid concentric mandrels until failure occurs, as indicated by gas leakage. Relative cyclic strain range is determined by mandrel dimension, specimen diameter, and specimen wall thickness. At larger strain ranges, deformation occurs by reverse bending rather than simple tension and compression. These tests have been made at 1300 F on specimens of Hastelloy-X, Inconel-600, Incoloy-800, and Type 304 stainless steel; the last two in-reactor as well as in the laboratory. Specimen life in cycles-to-failure, N, was found to be related to strain range Δ ϵ0 computed from mandrel dimensions by NαΔ ϵ0 = C, in which α varied from 0.6 to 1.35 and C from 0.14 to 3.3 depending on material. Effective strain range was found to be less than Δ ϵ0 because of specimen wrinkling. The fatigue life of Incoloy-800 and Type 304 stainless steel was somewhat reduced by testing in fast neutron radiation. Specimen failure was by longitudinal cracking, with little evidence of gross plastic deformation, although there was evidence of deformation within the grains of the alloy in the vicinity of cracks.
In-Reactor Studies of Low-Cycle Fatigue Properties of a Nuclear Pressure Vessel Steel
Authors: Hawthorne J. R. , Steele L. E.
Published: September 2009

This paper describes an experimental irradiation assembly and associated instrumentation which has been developed and successfully utilized for the performance of dynamic, in-reactor low cycle fatigue tests of reactor pressure vessel steels. The equipment provides for the simultaneous reverse bend testing of as many as 15 sheet-type specimens representing a range of strain amplitudes at controlled temperatures in the range of 300 to 700 F.

The results of an exploratory investigation on the fatigue resistance of ASTM A302-B steel during irradiation at 500 F are presented and compared with data from out-of-reactor control tests.
In-Reactor Creep of Cold-Worked Zircaloy-2
Authors: Holmes J. J. , Williams J. A. , Nyman D. H. , Tobin J. C.
Published: September 2009

The creep properties of 20 per cent cold-worked Zircaloy-2 during neutron irradiation have been determined in the temperature range 275 to 465 C and stress range 20,000 to 35,000 psi. In general, the effects of neutron irradiation on creep are small; however, some differences between in-reactor and ex-reactor tests exist. The activation energy for creep during irradiation is around 90,000 cal/mole. In the absence of irradiation, the activation energy is about equal to the self-difiusion value of 60,000 cal/mole. During reactor outages, a small increase in creep rate occurs. The time required to initiate the increase after a shutdown decreases with increasing temperature.

During irradiation, steady-state creep rates can be expressed as ϵ·=2.5×1020exp(5.31×10-4σ)e-90,000/RT, where: ϵ = creep strain per hour, σ = stress in psi, T = absolute temperature, and R = the gas constant.

In addition, total creep strain prior to the first reactor outage can be expressed in terms of Dorn's parameter =S(σ)f[texp((−90,000)/RT)], where t = time.
Direct Observations on Structure of Ultramicrotomed Metals and Alloys
Authors: Phillips V. A.
Published: September 2009

Slices 100 to 600 Å thick were cut in an ultramicrotome from a variety of nonferrous metals and alloys and examined in an electron microscope. Microtoming appears to introduce high densities of dislocations which anneal out rapidly in the case of low-melting-point materials. High densities of “fault bands” are observed in certain grains of copper and silver. Particles as small as 7 to 20 Å thick by 70 Å or more long may readily be detected, together with the coherency strains round them. Fine holes may also be examined.
Direct Transmission Electron Microscopy of Zirconium
Authors: Young A. P. , Melton C. W. , Schwartz C. M.
Published: September 2009

Although zirconium and titanium are hexagonal close-packed metals, the deformation mechanism is quite different in these metals from that in other hexagonal close-packed metals such as beryllium, zinc, and cadmium. Slip in zirconium and titanium occurs predominantly on prismatic (100) planes with possibly some slip on pyramidal (101) planes. Basal plane slip which predominates in the other hexagonal close-packed metals mentioned is observed rarely if at all in zirconium (1).
The Development of Electron Microscopic Methods for the Study of Metals
Authors: Bigelow W. C.
Published: September 2009

Although the first electron microscopes were built in the early 1930's, electron microscopy did not become established as a widely used experimental method until after 1945 when reliable, refined commercial instruments became generally available. During the period from about 1945 to 1955, biological applications of electron microscopy greatly outnumbered nonbiological applications and exerted a dominating influence on developments in instrumentation and techniques. During the past few years, however, there has been a tremendous increase in the use of electron microscopy in nonbiological areas, and especially in metallurgy. This recent trend has begun to exert a strong influence on the general course of developments in the field of electron microscopy and is contributing much new and valuable information about the structures of metals. Subcommittee XI on Electron Microstructural Studies of Metals (of ASTM Committee E-4 on Metallography) has contributed actively to this progress in nonbiological applications of electron microscopy through its program of work on the development of techniques for electron microscopic studies of metals (1–8).
A Study of the Microstructure of Precipitation Hardening Stainless Steel Sheet
Authors: Wilkins James C. , Pence R. E.
Published: September 2009

Task Group E of Subcommittee XI on the Electron Microstructure of Metals of ASTM Committee E-4 on Metallography is in the midst of thin-section studies of various alloys by direct transmission electron microscopy. The precipitation hardening stainless steels are included in this program for the purpose of observing age hardening phenomena.
X-Ray Diffraction in the Electron Probe Microanalyzer
Authors: Heise B. H.
Published: September 2009

The electron probe microanalyzer is shown to be a useful X-ray diffraction instrument which produces a particular type of diffraction pattern known as Kossel lines. The means by which the crystal orientation and the lattice constant can be obtained from Kossel lines is also demonstrated.
Problems with Dielectric Measurements at Cryogenic Temperatures
Authors: Mathes K. N. , McGowan E. J.
Published: September 2009

Problems with measurements at cryogenic temperatures are described. The long leads which are needed to reach to the bottom of the cryostat introduce a number of difficulties. The very low dielectric losses which may be encountered pose special measurement problems. Optimized solutions to these and other problems are described.