bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Carbon Content and Tempering Treatment on the Mechanical Properties and Sulfide Stress-Corrosion Cracking Resistance of AOD-Refined CA6NM
Authors: Nalbone CS
Published: March 2009

Cast Alloy CA15 is presently being used in sour gas environments in accordance with National Association of Corrosion Engineers (NACE) Standard MR-01-75, which requires that the maximum hardness not exceed Rockwell C22. There has been effort to replace CA15 with CA6NM, which has improved toughness properties. However, the 22HRC maximum has been difficult to reproduce in CA6NM. The argon oxygen decarburization (AOD) method of refining stainless steel produces a material with excellent impact properties and allows lower carbon levels to be consistently achieved that were previously difficult to attain. Charpy impact values and tensile properties are described, comparing AOD versus conventional methods of melting. An experimental hardness correlation has been suggested for the alloy. A new version of CA6NM with 0.03 percent maximum carbon, which may appropriately be called CA3NM, shows excellent sulfide stress-cracking (SSC) resistance using the standard NACE test. A threshold value in excess of 90 percent of material yield strength was achieved. The AOD method of refining improves mechanical properties, including toughness, and allows low carbon contents to be achieved with ease. Resultant lower hardness values can then be attained which satisfy NACE requirements for SSC applications.
Weld Procedure, Filler Metal, and Post-Weld Heat Treatment—Their Effect on the Hardness and Quality of Welds in CA6NM Alloy
Authors: Loveless RW , Smith WC , Templeton HC
Published: March 2009

The hardness of repair welds in CA6NM alloy has consistently been higher than the hardness of the base metal, regardless of the post-weld heat treatment used. The purpose of this investigation was to establish the optimum post-weld heat treatment to use in order to obtain the lowest hardness and to establish expected hardness limits for repair welds.

Simulated repair welds 13 mm deep, 25 mm wide, and 51 mm long (½ by 1 by 2 in.) made in cast CA6NM plates 51 by 178 by 305 mm (2 by 7 by 12 in.) by the shielded metal arc weld (SMAW) and gas tungsten arc weld (GTAW) processes using 12Cr-4Ni filler metal were evaluated as to hardness in the as-welded condition and after various post-weld heat treatments. The plates were normalized at 1050°C (1925°F) and double tempered at 675 + 607°C (1250 + 1125°F) prior to welding and conformed to the tensile requirements of ASTM A487, Grade CA6NM. Plate hardness was 255 to 269HB.

As-welded SMAW welds were 387HB to 418HB; the heat-affected zone (HAZ) hardness was 340HB. Single-tempered SMAW welds [temper 607°C (1125°F)] were 302HB. Double-tempered SMAW welds [temper 675 + 607°C (1250 + 1125°F)] were 293HB.

SMAW welds which were normalized at 1050°C (1925°F) followed by tempering were harder than welds tempered only. Single tempering at 607°C (1125°F) resulted in weld hardness of 321HB; double tempering at 675 + 607°C (1250 + 1125°F) produced a weld hardness of 302HB.

GTAW welds (no molybdenum in filler metal) resulted in lower hardness of welds, 241HB to 286HB after double tempering at 675 + 607°C (1250 + 1125°F). Normalizing of GTAW welds followed by the double-tempering treatment produced a weld hardness of 235HB.

A smaller simulated repair 6 mm deep, 13 mm wide, 25 mm long (¼ by ½ by 1 in.) was made in one plate by the SMAW process using nickel-chromium-iron filler metal (Inconel 600). Hardness was determined in the as-welded condition only—weld hardness 170HB to 187HB, HAZ hardness 302 HB.

All plates and welds were nondestructively examined by radiographic, ultrasonic, and penetrant techniques, and met the requirement of Section III of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, as per Table 1.

All welding was done in the flat position without preheat, using procedures qualified in conformance with Section IX of the ASME Code. Root passes of SMAW welds were made with 3.175-mm (⅛ in.) electrodes; 3.968-mm (5/32 in.) electrodes were used for final passes. GTAW welds were made with 3.175-mm (⅛ in.) filler wire throughout.

The lowest hardness of welds made with filler metal of the same composition as the base metal is obtained by a double-temper post-weld heat treatment of 675 + 607°C (1250 + 1125°F). Expected weld hardness will be about 293HB. Minor repair welds can be made with nickel-chromium-iron filler metal with weld hardness and strength compatible with the cast alloy without post-weld heat treatment.
CA6NM: New Developments Based on 20 Years' Experience
Authors: Gysel W , Gerber E , Trautwein A
Published: March 2009

Development of CA6NM cast steel is reported and the present state of the international standards is discussed.

The influence of the argon oxygen decarburization (AOD) process on CA6NM is shown by means of a statistical evaluation of preliminary quality-control test specimens from the four year period 1975–1979. The influences of reducing the carbon content to 0.030 percent and the sulfur content to 0.004 percent on the impact energy are given special attention. The impact energy values were improved by 18 to 73 percent, depending on test specimen shape and test temperature. This resulted in a high average value (Charpy V-notch, + 20°C: 152 ± 21 J) even on heavy-walled castings. A further statistical evaluation verifies that CA6NM cast steel with a strength level of 950 MPa also has excellent impact values (Charpy V-notch, +20°C: 67 ± 19 J).

The increase in steel quality due to the AOD refining process becomes evident especially for large cross sections. These have an improved primary structure. By using massive stepped test blocks with step thickness of up to 500 mm, it is shown that the drop in reduction-of-area and elongation values from surface-to-core location observed in earlier investigations on basic electric-arc furnace products disappears completely. In addition, the corrosion fatigue limit values in the core of 500-mm sections are up to 30 percent higher than for good arc furnace steel. Since the phosphorus level in the AOD test block was purposely aimed at a relatively high level of 0.021 percent, this effect must be attributed to the very low nitrogen, hydrogen, oxygen, and sulfur contents in the AOD steel. As a result of the higher degree of cleanliness, the Charpy V-notch upper-shelf energy level as well as the transition temperature show marked improvement even in the core location.

The optimum welding conditions are described. The importance of welding electrode quality control and the question of post-weld heat treatment are discussed.

To supplement the documentation of the material's potential for low-temperature applications, technical base material data are presented. The conditions for obtaining satisfactory weld properties at temperatures of −110°C, using electrodes of composition similar to the base material, are described. The procedures are applicable for fabrication and repair welding.

In light of a possible replacement of austenitic-ferritic castings by CA6NM for parts used in primary cooling loops of nuclear reactors, it is shown that heats with a high initial impact energy undergo in principle the same long-term aging process which occurs for predominately austenitic cast steel.
Through-the-Thickness Tensile Strength of Fiber-Reinforced Plastics
Authors: Mao TH , Owen MJ
Published: March 2009

The through-the-thickness tensile strength of fiber-reinforced plastics is difficult to measure, but for some purposes it is a significant design property. This property appears to be critically dependent on the test method and specimen preparation. The authors have examined the possibility of producing tensile failures in a disk subjected to diametral compression, a method well known in the field of testing of brittle isotropic materials.

In the isotropic case there is a uniform tensile stress distribution perpendicular to the diameter which is the axis of compression. Slices of round pultruded rod are transversely isotropic, and the method of test gives convenient and consistent results.

Results are also presented for the through-the-thickness strength of laminated materials. The disks were prepared by turning a cylindrical bar from a piece of thick laminate. Stress distributions have been analyzed by finite element analysis and compared with published theory. Both methods have been compared with strain gage results obtained from orthotropic disks. The finite element results agree quite well with published theory, but there is considerable scatter in the strain gage results. Experimental results for the strength of disk samples are consistent and compare well with other methods. The disk method also appears to be economical.
Strength and Fracture Characteristics of Graphite-Glass Intraply Hybrid Composites
Authors: Bhatia NM
Published: March 2009

The strength, stiffness, fracture toughness, and crack propagation characteristics of graphite-glass intraply hybrid uniwoven and biwoven composite fabric materials are evaluated. The hybrid fabric plies were designed by modifying existing all-graphite fabrics in which were added single tows of S-glass spaced 6.35 mm (0.25 in.) apart, and 12.70-mm (0.5-in.)-wide strips of graphite were replaced with S-glass spaced 10.16 cm (4.0 in.) apart. The purpose of this hybrid design was to provide better damage tolerance and damage containment capabilities than the all-graphite system.

The test program involved unidirectional and laminated coupons for strength and fracture toughness evaluation and 30.5-cm (12.0-in.)-wide orthotropic panels for crack arrestment evaluation. The panels were designed with glass strips aligned in discrete and staggered configurations. All tests involved room temperature dry and 121°C (250°F) 1.2 percent moisture-content specimens. The test results showed that the strength and stiffness properties for the hybrid materials were within 10 percent of the comparable all-graphite materials. However, the fracture toughness was approximately 44 percent higher for the hybrid systems and was not degraded by the 121°C (250°F) wet environment. A distinct crack arrestment capability was achieved only with the discrete strip configuration, with ultimate failure strain after crack arrestment in the 0.64 to 0.76 percent strain range.
Predicting Viscoelastic Response and Delayed Failures in General Laminated Composites
Authors: Dillard DA , Morris DH , Brinson HF
Published: March 2009

Although graphite fibers behave in an essentially clastic manner, the polymeric matrix of graphite/epoxy composites is a viscoelastic material which exhibits creep and delayed failures. The creep process is quite slow at room temperature, but may be accelerated by higher temperatures, moisture absorption, and other factors. Techniques are being studied to predict long-term behavior of general laminates based on short-term observations of the unidirectional material at elevated temperatures. A preliminary numerical procedure based on lamination theory is developed for predicting creep and delayed failures in laminated composites. A modification of the Findley nonlinear power law is used to model the constitutive behavior of a lamina. An adaptation of the Tsai-Hill failure criterion is used to predict the time-dependent strength of a lamina. Predicted creep and delayed failure results are compared with typical experimental data.
Indentation Law for Composite Laminates
Authors: Yang SH , Sun CT
Published: March 2009

Static indentation tests have been conducted on glass/epoxy and graphite/epoxy composite laminates with steel balls as the indentor. Beam specimens clamped at various spans were used for the tests. Loading, unloading, and reloading data were obtained and fitted into power laws. It was found that the contact behavior is not appreciably affected by the span. Both loading and reloading curves seem to follow the 1.5 power law, and the unloading curves are described quite well by a 2.5 power law.

An interesting finding is a critical indentation (αcr) that can be used to predict permanent indentations in unloading. Since αcr only depends on composite material properties, only the loading and an unloading curve are needed to establish the complete loading/unloading behavior. According to the present model, no reloading tests are necessary for deriving the reloading law.
Effect of Resin on Impact Damage Tolerance of Graphite/Epoxy Laminates
Authors: Williams JG , Rhodes MD
Published: March 2009

An experimental investigation was conducted to evaluate the effect of the matrix resin on the impact damage tolerance of graphite-epoxy composite laminates. The materials were evaluated on the basis of the damage incurred due to local impact and on their ability to retain compression strength in the presence of impact damage. Twenty-four different resin systems supplied by seven manufacturers in prepreg tape form were evaluated. Materials were not competitively submitted for the purpose of selecting a best material, but were voluntarily provided to study what improvements in damage tolerance the various resin improvements might make. Most of the materials tested had a smaller interior damage region, as determined by C-scan inspection, and less damage on the specimen surface than a baseline control resin which is widely used and whose damage tolerance characteristics have been documented. Five of the systems demonstrated substantial improvements compared with the baseline system, including retention of compression strength in the presence of impact damage. Examination of the neat resin mechanical properties indicates the resin tensile properties influence significantly the laminate damage tolerance, and that improvements in laminate damage tolerance are not necessarily made at the expense of room-temperature mechanical properties. Preliminary results indicate that a resin volume fraction on the order of 40 percent or greater may be required to permit the plastic flow between fibers necessary for improved damage tolerance. Test techniques for evaluating damage tolerance are discussed, including a newly developed multi-span beam shear test for which test results correlate well with damage tolerance trends from impact tests.
Fatigue Life Assessment of Ground Vehicle Components
Authors: Watson P , Hill SJ
Published: March 2009

Fatigue has been a major problem in ground vehicle components for more than 130 years. This paper considers why our increasing knowledge of fatigue has now significantly reduced its importance. A historical review of past work in a wide range of vehicle components is presented. The different aspects of durability assessment—namely, service load measurement, materials testing, stress analysis, and component testing—are concentrated on in turn. The work is brought up to the present by use of examples of how modern methods of fatigue analysis are being applied to contemporary problems.
Applications of Fatigue and Fracture Tolerant Design Concepts in the Nuclear Power Industry
Authors: Jones RL , Marston TU , Tagart SW , Norris DM , Nickell RE
Published: March 2009

To assure the integrity of nuclear power plant components, fatigue and fracture tolerant design concepts have been incorporated into Sections III and XI of the ASME Code; these contain requirements for nuclear power plant design, construction, and in-service inspection. The methods used in the Code to design against fatigue and brittle fracture are described together with the fracture mechanics based procedure suggested in Section XI for the evaluation of flaws detected by in-service inspections. Some aspects of the present Code methods that could probably be improved are identified.
Durability Design Requirements and Analysis for Metallic Airframes
Authors: Rudd JL , Yang JN , Manning SD , Garver WR
Published: March 2009

Air Force durability design requirements are reviewed and durability analysis methodology capable of satisfying these requirements are presented. The proposed methodology includes (1) durability critical parts, (2) guidelines for economic life criteria, and (3) analytical procedures for quantifying overall structural damage due to fatigue cracking. Two analytical formats for quantifying economic life are proposed: probability of crack exceedance and ratio of repair cost/replacement cost. Although the analytical methodology has been developed and verified using a fastener hole crack as the prototype, the basic concepts and methodology apply to cracks in other structural details as well. The durability analysis methodology is based on a fracture mechanics philosophy, using a probabilistic format but with deterministic crack growth. The methodology accounts for initial quality, crack growth accumulation in a population of details, load spectra, and structural properties. Essential elements of the methodology are presented, including an evaluation and illustration of the analytical methodology using test results for the F-16 full-scale durability test article.
Residual Life Prediction of Jet Engine Rotor Disks
Authors: Zako M , Kawashima T , Aono H , Jimboh K , Ohnabe H , Miyoshi T
Published: March 2009

For the application of this study, an aircraft jet engine rotor disk under constant temperature (room temperature) is selected. Assuming crack initiation to occur at the rim slot of an aircraft jet engine rotor disk under constant temperature (room temperature) for the application of this study, and converting the three-dimensional stress into a two-dimensional one, their life prediction is analyzed. The life prediction system was predicated on stress analysis, nondestructive testing, and material properties. The stress at the cracked part of the rim slot is calculated by the finite-element method, and the crack propagation is calculated by Paris's rule. Assuming KIc and the difference between KIc and calculated K—that is, (KIc − K)—to be a Gaussian distribution, safety is estimated by the relationship between fracture probability, Pf, and standard deviation.

In the numerical examples, assuming an elliptic surface crack at four different parts of the rim slot, the crack propagation after 2000 cycles is calculated. The safety factor of rotor disks is judged by the value of (KIc – K).
Strain Hardening and ‘Strain-Rate Hardening’
Authors: Kocks UF
Published: March 2009

The limitations of power-law strain hardening and ‘strain-rate hardening’ descriptions are reviewed. It is found that significant advantages can be gained by using, instead, the Voce relation, especially in the proposed modification that accounts for the rate sensitivities of flow stress and of strain hardening. Considerable further predictive value can be derived from differential constitutive relations, which can be integrated over arbitrary paths. The material parameters to be measured are the (linear) strain-hardening rate and the rate sensitivity of the flow stress, both as a function of (pre)stress and (current) strain rate. These are history independent over substantial regimes of unidirectional deformation, where a mechanical equation of state exists.
Prediction of Deformations During Gas-Tungsten-Arc Stationary Welds
Authors: Duncan DB , Giedt WH
Published: March 2009

Local temperature measurements on the heated and unheated surfaces and strain measurements on the unheated surfaces of unrestrained circular weld specimens of annealed and cold-rolled Nitronic 40 stainless steel during stationary welding are compared with values predicted from finite-element programs for temperature and strain variations. Experimental and predicted temperature histories agree within 10 percent. Predicted and measured hoop strain profiles (using a moiré fringe technique) for the unheated surface are compared, showing significant deviations near the central region. Transient deflection measurements of the unheated specimen surfaces show good agreement with theory during the period the arc is operating. Close agreement in deflection behavior was observed during the cooling portion of the weld cycle for the annealed specimen, whereas substantial deviations occurred for the cold-rolled specimens.
A Deformation Model for Elevated Temperature Including Grain Size Distribution Effects
Authors: Ghosh AK , Raj R
Published: March 2009

It is widely believed that grain boundary sliding, accommodated by diffusion, which leads to a Newtonian viscous behavior (σ ∝ ˙ε) and grain matrix deformation exhibiting a power law creep behavior (α ∝ ˙εm), are the two concurrent deformation phenomena occurring at elevated temperatures in metals, particularly during superplastic flow. A deformation model for this combined behavior has been developed in which the grain size and its distribution are taken into account. Strain compatibility relations have been utilized to predict material flow behavior under loading, load relaxation, and steady-state conditions. Comparison with experimental results shows that the sigmoidal σ-˙ε relationship for superplastic metals is explained well by the model. The model also simulates other experimental aspects as well as internal stress development during elevated temperature flow.
An Elevated Temperature Fatigue Crack Model for Stainless Steels
Authors: Guinemer J-Y , Plumtree A
Published: March 2009

A model has been developed for the prediction of cyclic crack growth rates at different frequencies and has been verified for an austenitic stainless steel at elevated temperature. The model is based on the damage concept, and accounts for the viscoplastic behavior of stainless steels at elevated temperature. The inclusion of a creep component in such a model results in good correlation between the predicted and observed data.
Bulk Density and Shear Strength of Several Deep-Sea Calcareous Sediments
Authors: Lee HJ
Published: March 2009

Deep-sea calcareous sediment commonly consists of chemically active, fragile, biologically derived sand- or silt-size carbonate particles combined with terrigenous silt and clay and biologically derived opaline silica. The shearing strength of these sediments depends on whether the noncarbonate matrix or a carbonate framework dominates and on the physical nature of the noncarbonate matrix. A model based on relations between bulk density and carbonate content is developed to delineate three types of behavior: matrix dominant, transition, and carbonate-framework dominant. The model is quantitatively evaluated using vane shear, bulk density, grain density, carbonate content, and triaxial shear strength measurements from four studies of deep-sea calcareous sediments. The divisions between the three behavior types are found to be determined primarily by the character of the noncarbonate matrix. The presence or absence of opaline silica in the noncarbonate fraction has the strongest influence and is related to the overall sedimentary environment. Vane shearing strength increases with carbonate content through the transition and carbonate-framework-dominant zones. It is independent of carbonate content in the matrix-dominant zone. This trend may be masked by coring disturbance if only the results of laboratory analyses as opposed to in situ tests are considered. The cause of the strength increase with carbonate content may be the granular nature of the carbonate particles (mechanical) or interparticle cementation (chemical).
Engineering Behavior of Carbonate Soils of India and Some Observations on Classification of Such Soils
Authors: Datta M , Gulhati SK , Rao GV
Published: March 2009

It is now well recognized that the presence of carbonate material in submarine soils often affects their engineering behavior significantly because of (1) crushing of carbonate particles under stress and (2) cementation by carbonate material. This paper shows that depending on the nature of carbonate material, the magnitude of crushing and degree of cementation both vary over a wide range and have a markedly different influence on engineering behavior of carbonate soils. Existing classification systems do not take adequate note of this fact and hence are not totally satisfactory from an engineering viewpoint. A system of description is proposed for carbonate soils which, it is hoped, will in due course provide information to evolve a useful engineering classification system.
Electrical Properties of Calcareous Sediments
Authors: Erchul RA , Gularte RC
Published: March 2009

The electrical resistivity or its reciprocal, conductivity, of calcareous sediments ranging from lithified coral to oozes was measured in the laboratory. Similar electrical properties of the interstitial water of these sediments were also measured. Formation factor (the ratio of electrical resistivity of the sediment to the electrical resistivity of the interstitial water) was then compared with the specific porosity of each calcareous sediment. The formation factor-porosity relationship was determined for the calcareous sands and oozes. Formation factors ranged from 1.46 to 6.10 while porosities ranged from 28 to 87 percent. The results showed that the void ratios correlated well with the electrical conductivities of these sediments. Electrical resistivity and conductivity measurements have recently been used as an indirect and in situ technique for predicting index and engineering properties of sediments. The data presented in this paper should be useful in predicting the ranges of electrical resistivity and conductivity values associated with calcareous sediments.
Cone Penetration and Laboratory Testing in Marine Calcareous Sediments
Authors: Beringen FL , Kolk HJ , Windle D
Published: March 2009

The paper discusses in situ cone penetration and laboratory testing of calcareous soils at several offshore locations. These tests indicate a large range in degree of cementation.

The laboratory program includes special strength and deformation tests to further clarify and interpret the results of cone penetration tests. In addition, these tests are designed to provide a better understanding of the behavior of pile foundations.

Based on the preceding results a classification system is proposed for these types of soil with emphasis on in situ measurements. Furthermore, engineering design parameters are discussed and values suggested for skin friction and end bearing for pile foundations.
Strength Characteristics of Caliche Soils of the Tucson Area
Authors: Post JL
Published: March 2009

The physical and chemical composition of caliche soils of the Tucson, Ariz. area were investigated to determine the compressive strength of indurated and crushed calcisols. The results of stabilization of crushed calcisols with portland cement additive were determined and the soil-cement reaction products were investigated.

Soil minerals were identified by X-ray diffraction analysis. The calcisols were found to consist mainly of feldspar and randomly oriented microcrystalline calcite with lesser amounts of quartz and clay minerals.

The strength of the calcisols was found to be inversely related to their clay content, with unconfined compressive strengths varying from less than 1.03 MPa (150 psi) to more than 20.67 MPa (3000 psi). When the indurated caliche was crushed it behaved as an inert granular material with no immediate recementation when compacted.

It was shown that a loss of compressive strength generally occurred in the remolded soil-cement mixtures after 28 days of curing, the maximum 28-day compressive strength, using 10 percent portland cement, varying from 2.51 to 7.80 MPa (364 to 1132 psi). The compressive strength was a function of the amount of portland cement added and of the combined feldspar-calcite content of the soil.

The feldspars of the Tucson basin were found to consist mainly of intermediate microcline with lesser amounts of orthoclase and oligoclase. The weak soil-cement bonding strengths appear to be due to the feldspars and the strength losses which occur are the result of the chemical interaction of the calcite and alkali feldspars with the portland cement in an aqueous environment. Portland cement is an unreliable additive for the effective stabilization of crushed calcisols.
Effects of Cementation on the Compressibility of Pierre Shale
Authors: McKown AF , Ladd CC
Published: March 2009

Natural cementation in cohesive soils can have a significant effect on the apparent maximum past pressure (¯σvm) estimated from one-dimensional consolidation tests. Relatively small amounts of calcium carbonate (CaCO3), above a threshold value of about 2 percent by weight, appear to cement the structure of a Nebraska Pierre shale, causing measured ¯σvm-values several times larger than the maximum past overburden stress inferred from geological history. However, CaCO3 contents in excess of this threshold value (even up to 50 percent or more) produce little further increase in ¯σvm. On the other hand, leaching out relatively small amounts of CaCo3 from a highly calcareous clay shale can increase its compressibility and produce a lower measured apparent maximum past pressure.
Automotive Engine Coolants: A Review of Their Requirements and Methods of Evaluation
Authors: Rowe LC
Published: March 2009

A brief review of early automobiles shows the development of the engine cooling system, and some of the associated problems with these early cars are discussed.

A liquid is commonly used to transfer heat from an operating automobile engine to a radiator where the heat can be dissipated to the air. In order that the liquid perform effectively, it must have the appropriate chemical and physical properties. Of foremost consideration is the capability of the fluid to transfer heat over a wide range of operating conditions. In addition, the fluid must be stable, must not freeze when not in use or boil during or after engine operation, and must not cause or allow excessive corrosion of the parts it contacts.

To determine how well the cooling system is capable of performing its function, it is necessary to perform a variety of tests to evaluate the operational characteristics of component parts, the properties of the coolant fluid and its long-range stability, and the capability of the fluid to minimize corrosion of all materials. Tests range from the shorttime laboratory test to the longer and more comprehensive field test. Operating conditions are often difficult to simulate in the laboratory, and the test tends to be restrictive. Field tests are usually more definitive but can be difficult to control. However, the end result of an effective development program over a number of years has been a cooling system that has provided good durable service.
Experience of the British Standards Institution in the Field of Engine Coolants
Authors: Mercer AD
Published: March 2009

The development in the United Kingdom of specifications and standards for inhibited coolants for internal combustion engines is briefly reviewed. Three types of British Standards that are currently in existence are described. These are concerned respectively with compositional specifications, recommendations for the care and maintenance of cooling systems, and, more recently, performance specifications. The motivation for the preparation of these standards and their technical contents are reviewed and some indications of the direction of future work discussed.
Corrosion Testing of Furnace and Vacuum Brazed Aluminum Radiators
Authors: Naruki K , Hasegawa Y
Published: March 2009

To investigate the internal corrosion behaviors of aluminum radiators processed by vacuum brazing and furnace brazing with flux, respectively, a glassware test was conducted on a specimen and a coolant circulation test on actual radiator units.

It was proved that the furnace-brazed radiator was superior to the vacuum-brazed radiator, as far as the corrosive resistance was concerned, since the former incorporated the zinc diffusion layer in its surface which afforded the sacrificial corrosion.
The Echelle Spectrograph as a Solution to Some Problems Commonly Encountered in Other Instrumental Analysis
Authors: Shope JR
Published: March 2009

The echelle spectrograph, with a direct current plasma jet as the emission source, is used to solve some common analytical problems. The instrument replaces atomic absorption when burner blockage becomes a problem and also when methyl isobutyl ketone (MIBK) must be used with a nitrous oxide (N2O) flame. The system is also shown to be more applicable to analysis than the direct reading emission spectrograph when sample variations are considered.

To ensure a basic understanding of the instrument, its differences and similarities to both atomic absorption and emission spectroscopy are compared. These comparisons are intended for problem solving and are limited to the instrumentation available in this laboratory.
Glass Fiber as Insulation and Drainage Layer on Exterior of Basement Walls
Authors: Tao SS , Bomberg M , Hamilton JJ
Published: March 2009

To provide combined moisture and thermal protection for basements, high-density glass fiberboard was used on the exterior of two prototype basements. This insulation-drainage layer can easily be adapted to current construction procedures and the cost is not excessively high. Performance of the 140-kg/m3 (9 lb/ft3) glass fiberboard installed vertically below grade was monitored. Early results are encouraging. Favorable moisture distribution and compressive deformation were found. After two years of burial the insulation still maintained a thermal resistivity that ranged from 22.6 to 26.8 m·°C/W. It is believed that the concept of an insulation-drainage layer has the potential to keep the basement dry, to provide improved thermal insulation, and to enable better curing of concrete. With refined design details the concept is attractive and worthy of continued study and development. This paper describes methods of installation, monitoring instruments, and some findings obtained from two experimental basements monitored since 1976 by the Division of Building Research/National Research Council of Canada.
Quantifying the Thermal Protection and Comfort Characteristics of Sleeping Bags
Authors: Rohles FH , Munson DM
Published: March 2009

Research on an electrically heated copper manikin has resulted in a rational basis for specifying the lowest temperature at which a sleeping bag will thermally protect its occupant. The manikin, housed in an environmental chamber, was calibrated with a “standard” sleeping bag. The manikin surface temperature, ambient air, and power input readings were used to calculate the thermal insulation (clo) value of the sleeping bags. The clo value was then used in a model to predict the Lower Thermal Comfort Threshold of the sleeping bag under study. These procedures, along with recommendations for determining the comfort of the wearing apparel, are discussed. In addition, the need for educating the consumer on the meaning of clo and the possible inclusion of clo ratings on outdoor equipment and clothing is discussed.
Experimental Determination of the Thickness Effect in Glass Fiber Building Insulation
Authors: Hollingsworth M
Published: March 2009

Thermal insulations which permit significant heat transfer by radiation show an increase in thermal conductivity (or decrease in R-value per unit thickness) as thickness is increased. This thickness effect, for a common type of glass fiber building insulation, was determined in a large heat flow meter apparatus by comparing the R-value of a stack of pieces with the sum of the R-values of the separate pieces. Contrary to widespread belief, this effect, for a change from 38 to 152 mm (1.5 to 6.0 in.) was found to be only in the range of 1.5 to 3 percent. This percentage change will depend upon the thickness used as basis for comparison; for example, if at 152 mm (6.0 in.) the change from 38 mm (1.5 in.) were 2.5 percent, the change from 25 mm (1.0 in.) would be estimated to be about 4 percent.

At greater thicknesses, even after an extensive test program using an apparatus that is exceptionally well guarded and exceeds ASTM requirements, uncertainties exist which point to the need for more strict ASTM requirements and for even larger equipment. However, the high cost, greatly increased test times, and currently unproven accuracy of thick measurements may limit the use of extremely large equipment.

Various other data relating to these tests and to verification of the test equipment are also reported.
Life-Cycle Energy Costs of Thermal Insulation
Authors: Chinneck JW , Chandrashekar M , Hahn CKG
Published: March 2009

The energy cost of thermal insulation production relative to the heating energy savings incurred through its use in single-family houses was investigated by the life-cycle energy cost method. A heat-loss model of an average house was constructed and the house was assumed to be heated by electric resistance or natural gas or fuel oil-fired furnaces. Different levels of insulation were assumed installed in the walls and ceilings, including the proposed minimum levels for Canada. Four different Canadian cities were studied. The energy cost of insulation was found to be insignificant relative to the heating energy savings caused by its use. The proposed minimum insulation standards for Canada were found to be significantly better than the existing standards, although not optimum from an energy viewpoint.
Field Measurements of Heat Flow Through a Roof with Saturated Thermal Insulation and Covered with Black and White Granules
Authors: Shuman EC
Published: March 2009

In the past, thermal effects of moisture and deteriorating effects of moisture on constructions were considered separately rather than as total potential problems that arise from interactions dictated by the laws of physical performance. This paper contributes thermal data on two large industrial buildings; on one the roof insulation had become flooded, on the other the insulation was essentially dry. Also presented are brief examples of adverse effects of moisture in walls and floors. To present only data on excessive heat flow from moisture without also indicating how common problems induced by moisture may arise would not be helpful to those not familiar with the laws of physical performance. Without such associated information, little will be accomplished in overcoming moisture problems through preventive design, construction, and maintenance.

Three times as much heat flowed through the roof with flooded insulation as through the roof on which the insulation remained dry. This ratio of three was also found in the same location when the wet insulation was replaced with dry. During hot days, 35°C (95°F), the reduced peak heat flow from wet to dry insulation to maintain 24°C (75°F) indoors was equivalent to 40 W/m2 [12.8 Btu/(ft2·h)] or about one ton of refrigeration per 92 m2 (1000 ft2).

Roofing granules that reflect sun heat were found to reduce heat-transfer rate into the building, but the indications were that reliable reflectance data on materials being considered for such use are necessary, because light color to the eyes does not necessarily indicate effective reflectance of solar heat.
Selection and Use of Wear Tests for Coatings
Authors: Bunshah RF
Published: March 2009

The selection and use of wear tests for coatings are discussed. Coated materials are vastly different and more complicated than uncoated or monolithic materials. It is therefore necessary to characterize the coating and the coating/substrate interface in terms of physicochemical and mechanical properties. Wear is a multi-faceted phenomena. Various tests used to study the wear properties of coatings are described. They include tests for adhesive wear, abrasive wear, impact erosion wear, and fatigue wear.
Wet-Sand Rubber-Wheel Abrasion Test for Thin Coatings
Authors: Saltzman GA
Published: March 2009

One category of machines for determining the low-stress abrasion resistance of materials uses a rubber wheel rotating in a water-sand slurry and rubbing against a stationary specimen. Using the Wet-Sand Rubber-Wheel Abrasion Test Method being developed by the SAE produces a wear scar on the order of 0.25 mm deep in normalized 1090 steel at HRC 30, and so may be unsuitable for testing thin coatings and surface treated materials. This was confirmed in testing boride coatings on steel, the coatings being penetrated prior to completion of the test.

Modified practices were investigated in order to determine procedures more suitable for wet-sand rubber-wheel testing of coatings. Tests were conducted using the SAE Practice, with three rubber wheels of varying rubber hardness but with reduced numbers of revolutions per wheel, and using single rubber wheels and repeated increments of varying numbers of wheel revolutions. The criterion for acceptance of a modified practice was the correlation of weight loss (wear) ratios obtained for selected materials with those obtained using the SAE Practice. Results are discussed in terms of this correlation, and selected modified practices were evaluated for three highly varied coating types; electroplated chromium, a boride diffusion coating, and plasma-sprayed alumina, all on plain carbon steels.
Methods of Evaluating Materials for Icebreaker Hull Coatings
Authors: Calabrese SJ , Murray SF
Published: March 2009

The choice of suitable bench tests to evaluate the wear of materials must be prefaced by careful consideration of the various modes of wear that may be encountered in the actual application. For example, sliding tests at constant loads and velocities can provide useful information on wear rates and frictional behavior for mechanisms that operate under similar conditions. If the application also involves impact loading and abrasion, however, the wear data obtained from the simple sliding tests may be very misleading. It is essential to select test conditions that realistically simulate the operating conditions.

This article describes the types of bench tests that were used to screen candidate materials for use as coatings on icebreaker hulls. Such coatings are subjected to high impact loads and severe two-body abrasion. Good correlation was found between the results of the bench tests and full-scale tests on actual icebreakers.
Fracture Characterization of a Random Fiber Composite Material
Authors: Alexander RM , Schapery RA , Jerina KL , Sanders BA
Published: March 2009

A short-glass fiber composite materials, SMC-R50, was tested under uniaxial loading at ambient temperature and humidity conditions over two orders of magnitude of loading rate. The test method, experimental results, and analytical characterization of fracture behavior are described. Baseline information on the strength of 1.27-cm and 2.54-cm wide unnotched tension specimens indicate that effects of size and test orientation (relative to molding orientation) are not significant. Fracture behavior of notched samples was studied on specimens of two different widths (2.54 and 5.08 cm); each sample had two symmetrically cut, crack-like notches. For each sample size, the effect of four different notch lengths and loading rates on ultimate strength, ultimate strain, and the overall stress-strain curve were investigated. Loading rate was found to have no significant effect on sample response. The stress-strain curves of notched and unnotched samples in terms of nominal stress σ and strain ϵ obey the power law σ ∼ ϵ0.78 out to failure. In spite of this nonlinearity, it was possible to characterize the fracture stress behavior using linear elastic fracture mechanics theory and a constant fracture toughness. The effect of notch length on sample compliance and on failure strain was found to obey this theory if ϵ0.78 is used in place of ϵ.
Review of Factors That Influence Fretting Wear
Authors: Bill RC
Published: March 2009

Experimental results obtained by the authors and results from the literature are summarized to provide a critical review of the effects of various factors on fretting wear. These factors fall into three broad categories: (1) contact conditions, (2) environmental conditions, and (3) material properties and behavior. Contact load, amplitude and frequency of motion, and contact geometry are included under contact conditions. Environmental conditions include atmosphere, relative humidity, and temperature. The importance of material properties is discussed on the basis of how material properties interact with other factors during fretting. Individually, the effect of contact load, fretting amplitude, temperature, and atmosphere have been fairly well explored for a limited number of materials (mostly mild steel). More work is clearly needed to provide basic understanding of the effects of contact geometry and relative humidity and the interaction of various fretting parameters. A more comprehensive number of materials should be studied to clarify material property effects.
Preliminary Evaluation of Materials for Fluidized Bed Technology in Geothermal Wells at Raft River, Idaho, and East Mesa, California
Authors: Dirk WJ , Allen CA , McAtee RE
Published: March 2009

Corrosion tests of candidate materials for heat exchangers using liquid fluidized bed technology were conducted at the U.S. Department of Energy's geothermal wells at Raft River, Idaho, and at the Geothermal Components Test Facility (GCTF) in East Mesa, Calif. These investigations deal with moderate temperature ranges of 135 to 163°C for electrical generation and nonelectrical applications. The corrosion, erosion, and scale buildup were evaluated. The average penetration of Type 1025 carbon steel was 314 μm/year. Hastelloy alloys G and C276, stainless steels Type 304L, Type 316, Type 347, and Nitronic 50 had average penetrations of less than 2 μm/year.
Problems with So-Called “Direct” Scaling
Authors: Birnbaum MH
Published: March 2009

It was once thought that magnitude estimation was a better method for the measurement of subjective value than the method of category rating. However, recent research shows that magnitude estimations do not have advantages over category ratings and are in fact no more than ordinal scales of subjective value. When subjects are asked to judge “differences” and “ratios” of subjective value, it appears that subjects compute subjective intervals for both tasks. Magnitude estimations of “ratios” appear to be an approximate exponential function of subjective differences, and category ratings appear to be an approximate linear function of subjective differences, though the exact from of these functions depends on the stimulus and response distributions. Scales of subjective value that are derived from the subtractive model of within-mode stimulus comparison appear to be largely independent of the stimulus spacing and the response procedure. Measurements of subjective value should be derived from a theory of empirical relationships, and should show generality across contexts and across empirical domains. So-called “direct” scales have not been successful in predicting empirical relationships, whereas subtractive model scale values have shown promise.
Influence of Residual Stress on the Predicted Fatigue Life of Weldments
Authors: Lawrence FV , Burk JD , Yung J-Y
Published: March 2009

A model was developed that predicts the influence of residual stress and stress ratio on the total fatigue life of a weld. The total fatigue life of a weld was considered to be composed of both crack initiation and crack propagation. Weld toe residual stresses were considered to influence the crack initiation life but not the crack propagation life.

The crack initiation life was estimated using cumulative damage concepts. Actual weld material properties (weld metal and heat-affected zone) were considered in the initiation life estimation. Neuber's rule was used to determine the local cyclic stress-strain behavior at the weld toe, and the fatigue notch factor was evaluated by using Peterson's equation. Residual stresses were introduced into the analysis as a simulated pre-stressing of the weld. Cyclic relaxation of the mean stress established during the set-up cycle was modeled by a power function and allowed relaxation to be considered in the life estimates.

Fatigue tests of steel weldments and aluminum butt welds having tensile and compressive residual stresses were conducted to verify the analytically predicted total fatigue life predictions. Agreement between analytical predictions and experimental results was quite good.