bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selection of Chemical Protective Clothing Using Permeation and Toxicity Data
Authors: Forsberg K 
Published: December 2008

Recommendation of chemical protective clothing should be based on chemical resistance test data, assessment of the chemical in question, and the time workers are at risk of chemical exposure.
The availability of the ASTM standard test method has increased the amount of permeation data in the literature. By measuring breakthrough time, the method can be used to estimate the maximum protection time from chemical exposure under conditions of continuous contact. The second variable in permeation data is permeation rate, that is, the method can be used to identify protective clothing materials that limit chemical exposure to acceptable skin contact levels.
In this paper materials have been grouped in different classes based on permeation data. Three intervals of breakthrough time and five levels of steady-state permeation rate are proposed. The authors also recommend applying a labeling and classification system to provide information for risk assessment of chemical exposure hazards in protective clothing.
Risk assessment and recommendation of chemical protective clothing materials have to be carried out by a competent person.
Survey of Use and Maintenance Procedures for Chemical Protective Total Encapsulation Garments
Authors: Moore JA 
Published: December 2008

This investigation essentially determined that all total encapsulation garments require basically the same use and maintenance procedures, regardless of base material or manufacturer. A few important differences exist between suits, however, and these differences tend to be concentrated in the closure systems, dump valves, glove to sleeve joints, and pressure sealing zippers. Other areas in which there is a slight disagreement or missing information include “buddy” systems, decontamination, laundering, and drying.
It also needs to be emphasized that input from users fell far below the hoped-for amounts; thus, this paper's input is heavily slanted in favor of the manufacturers.
A Critical Appraisal of Test Methods for Thermal Protective Clothing Fabrics
Authors: Hoschke BN , Holcombe BV , Plante AM 
Published: December 2008

This paper discusses the merits and deficiencies of some existing and proposed test methods for the evaluation of fabrics intended for protection against radiant heat and flame. Modifications to improve the apparatus and the procedures are suggested.
The factors investigated include (1) the means used to obtain a given radiant or convective heat flux; (2) the type, design, and construction of the heat sensor; and (3) the specimen mounting.
Standard Test Methods British Standard for Clothing for Protection Against Intense Heat for Short Periods (BS 3791), ISO Test for Evaluation of Thermal Behaviour of Materials and Materials When Exposed to a Source of Radiant Heat (ISO 6942-1981) and ASTM Test for Thermal Protective Performance of Materials for Clothing by Open-Flame Method (D 4108-82) are considered, together with the radiant heat test method proposed in the Federal Aviation Administration's Proposed Flammability Standard for Commercial Transport Flight Attendant Uniforms (FAA-RD-75-176).
Thermal Insulative Performance of Single-Layer and Multiple-Layer Fabric Assemblies
Authors: Baitinger WF , Konopasek L 
Published: December 2008

A variety of cotton fabrics treated to confer flame resistance characteristics were examined with the use of highly specialized laboratory equipment and procedures to predict their potential for thermal protection. Thermal sources based on convective (flame) and radiant exposures that approximate possible high-risk situations were employed. At 1.0 and 2.0-cal/cm2/s heat flux levels of exposure, fabric weight or thickness was found to be directly related to the amount of thermal energy passed through to the sensor.
Several investigators are currently examining the properties of wool, Nomex, flame resistant (FR) cotton, and other protective fabrics by similar approaches. Our work emphasizes the state of the art with flame resistant cotton fabrics. Very little has been published previously on multiple-layer assemblies and the effect of air spaces in such assemblies, so only a few model systems have been reported. Air spacing in multiple-layer systems has been found to be a significant contributor to insulation.
The Effect of Alloying Elements and Steelmaking Processes on the “A” Segregation Occurrence in Large Ingots
Authors: Kim JT , Pyo MR , Chang YS , Chang HS 
Published: December 2008

Investigations on segregation in various sizes of ingots of 13, 25, 54, 104, 180, 210, and 430-ton weight were carried out at Korea Heavy Industries and Construction Co.
The results of the segregation examined reveal that silicon-deoxidized (SD) carbon steel ingots have much more segregation than have vacuum carbon-deoxidized (VCD) low-alloy steel ingots. That is, the total carbon segregation ratio is 41% in the 210-ton SD carbon steel ingot, whereas it is 38% and 21% in the 430 and 104-ton VCD, low-alloy steel ingots, respectively. From these results, “A” segregation is not found when the ratio of carbon segregation is less than 30 to 40% in both steel ingots. Since silicon and manganese increase the change of liquid density during solidification and molybdenum decreases it, it is possible to minimize the macrosegregation by increasing molybdenum and decreasing silicon and manganese within the specified range.
The Development of New Materials for Nonmagnetizable Retaining Rings and Other Applications in the Power Generating Industry
Authors: Stein G 
Published: December 2008

Long before the first forged retaining rings were manufactured, our company, Schmiedewerke Krupp-Klöckner, was concerned with the development of nonmagnetizable steels for the manufacture of retaining rings. In addition to our company, only a few manufacturers are manufacturing rings that meet the requirements of present-day specifications.
As various steel brands developed beginning early in this century, the requirements of our customers concerning the mechanical properties and the corrosive environmental conditions became greater and greater. This led us in the late seventies to a material that meets present and future requirements regarding both mechanical properties and full corrosion resistant behavior.
This paper will show the main steps in the development of retaining ring production by our company. Today we use as starting material for our retaining rings cast electrodes of electric furnace steel which are remelted in our electroslag remelting plant. The ingot undergoes several forging and reheating operations to produce a ring blank. The blanks are rough turned, solution heat-treated, and then work-hardened so as to obtain the desired 0.2% proof stress. This operation is followed by a stress-relieving heat treatment and a finish-machining operation. This production requires continuous monitoring of the production procedure as well as extensive in-process and final tests.
In the last 30 years, about 18 000 retaining rings have been manufactured from a material with 0.5% carbon, 18% manganese, 4.5% chromium, and 0.1% nitrogen. Physical and mechanical properties could be met with this material even in customers' advanced specifications. There is only one disadvantage: The material is susceptible to stress corrosion cracking. Some failures of retaining rings in recent years were due to the occurrence of stress corrosion cracking. The best way to avoid stress corrosion cracking is to use a nonsusceptible material. Such a material has been developed for the manufacture of retaining rings in our company. Up to now we have produced more than 400 rings with 0.2% proof stresses up to 1250 N/mm2.
This paper will show the chemical analysis, mechanical properties, residual stresses, stress corrosion properties, susceptibility to hydrogen-induced cracking, fracture toughness properties, sensitization at elevated temperatures, and stress relaxation behavior.
Even with this extraordinary material, we have not stopped the development of retaining ring material. Three years ago our company installed the only full-size pressure electroslag remelting equipment in the world. With this equipment we can increase the nitrogen content of any material above the normal solubility limit. This will lead to higher 0.2% proof stresses and more homogeneous mechanical properties without losing the corrosion-resistant behavior of the new retaining ring material.
Manufacturing of Large and Integral-Type Steel Forgings for Nuclear Steam Supply System Components
Authors: Kawaguchi S , Tsukada H , Suzuki K , Sato I , Onodera S 
Published: December 2008

Forgings for the reactor pressure vessel (RPV) of the pressurized heavy water reactor (PHWR) 700 MWe, which is composed of seven major parts and nozzles totaling about 965 tons, were successfully developed. These forgings are: 1. Flanges: an outside diameter of 8440 mm and a weight of 238 tons max, requiring an ingot of 570 tons. 2. Shells and torus: an outside diameter of about 8000 mm with large height. 3. Cover dome: a diameter of 6800 mm and a thickness of 460 mm, requiring a blank forging before forming of 8000 mm in diameter and 550 mm thick.
The material designation is 20Mn-Mo-Ni 5 5 (equivalent to SA508, Class 3).
Even with greater dimensions and weight than the current largest forgings, the manufacture and the qualities achieved were satisfactory. These successful results were obtained by recent developments in the manufacturing technology of steels, such as steel making, metal-working processes, and heat treatment, which are vital to the quality of large-sized and heavy-walled steel forgings.
In this paper, the manufacturing of and the properties of such large and integral forgings are discussed, including an overview of manufacturing processes for ultralarge-sized forgings over the last two decades.
Advanced Technology of Heavy-Section Tube Sheets for Nuclear Power Generation
Authors: Skamletz TA , Grimm WW 
Published: December 2008

Considered in particular were the toughness requirements at low temperatures, the safe weldability, and the minimum sensitivity against temper embrittlement at stress-relieving temperatures of Steel 20 MnMoNi 5 5, corresponding to ASTM A 508 Class 3. High-temperature tensile and creep properties up to 450°C had to be met.
These targets were achieved by applying the production steps as follows: 1. The steelmaking was done according to the Buderus calcium-argon blowing (CAB) process. The low sulfur contents of 0.002% and lower and the special pouring technology to achieve low segregation rates are the basic reasons for the outstanding toughness and the isotropy of the material properties. 2. The forging technology, in particular the temperature range and the deformation rate, was designed to produce fine-grain structure already in the as-forged condition. 3. A newly developed, three-step, quality heat treatment is most important for the hardening through and the toughness level of the heavy section. 4. The report submits a discussion of the dimensional limits for 20 MnMoNi 5 5 forgings produced according to different technologies.
Survey of New Developments in Forging Techniques and Equipment
Authors: Kramarow NM 
Published: December 2008

This paper discusses the introduction into commercial practice of a number of new forging press and control technologies developed by press builders for the forging of high-temperature alloys and special stainless steels.
The paper categorizes forging technologies by forging characteristics and press characteristics. A number of specific fields are then surveyed: 1. Warm die forging to produce finished gear profiles without further machining. 2. Isothermal and hot die forging, in which the die temperature and the billet temperature are identical or very close, for forging high-temperature materials used in gas turbine engines and similar applications. The presses and controls required for these different applications are described in some detail. 3. Precision forging, also known as draftless forging in the aircraft industry, is described. The sophisticated controls needed for this type of forging are discussed. 4. Multiaxis forging, not a new technique, used for the production of items weighing several tons for severe duty. Again, modern controls and press design make these forging technologies commercial practice. 5. Automation is now moving into the forge shop; items such as the ring preforms for ring mills, which formerly were hammered to shape, are now produced at high speeds on automatic ring preform presses. 6. Computer controls have now been applied to preform forging to eliminate the open die in the hand shaping of preforms before finishing. This operation now can be fully programmed at great savings in labor and energy.
The paper concludes with a discussion of a very large installation for the production of thick-walled forged tubes and a new mechanical screw press which can deliver very large amounts of energy on each blow.The paper concludes with a discussion of a very large installation for the production of thick-walled forged tubes and a new mechanical screw press which can deliver very large amounts of energy on each blow.
Forging Force Requirements with Special Regard to Shear Resistance of the Forge Material
Authors: Javorik LJ 
Published: December 2008

The purpose of this development project was to precalculate forging forces. This is important not only to design the most economical machine to do the job, but also because knowledge of the exact forging force enables us to carry out the desired metallurgical change in the material.
While the work on strength, work hardening, the effect of speed on the virtual strength of the material, temperature, and friction offers little novelty and serves mostly as a summary, the formulas developed are still the results of a new and independent theoretical and experimental work; emphasis was put on developing a theory to calculate shear resistance offered by the forge material because the author found no publication dealing with this subject in spite of the fact that such forces by shear characteristically range around one third of the total forging force requirement.
The author faced the difficulty that all regular (bidirectional) shear formulas are strongly restricted in their range of validity, and, if this limited range is exceeded, the formulas suffer greatly in accuracy. Therefore, the author briefly explains existing shear theories and their ranges of validity and gives new and revised formulas for the ordinary bidirectional shear that no longer are restricted by location thickness, or by other dimensions of the material. Then the author uses the newly developed general shear theory, converting the theory to monotool shear calculation as is the case in forging.
Failure Analysis of Hot Forging Dies
Authors: Ebara R , Kubota K 
Published: December 2008

Impact failure of hot forging dies occurs frequently from surface cracks due to mechanical or thermal fatigue. However, useful information regarding failure analysis of hot forging dies is scarce because few data exist on the fracture behavior and fractography of hot forging die steels.
In this paper, what is mainly described is dynamic fracture toughness, low cycle fatigue behavior, and fracture surface appearances of hot forging die steels. A couple of quantitative analyzed examples of fracture toughness and temperature by use of stretched zone width measurement for hot forging die failure are described.
Variable Flaw Shape Analysis for a Reactor Vessel under Pressurized Thermal Shock Loading
Authors: Yang CY , Bamford WH 
Published: December 2008

A study has been conducted to characterize the response of semi-elliptic surface flaws to thermal shock conditions which can result from safety injection actuation in nuclear reactor vessels. A methodology was developed to predict the behavior of a flaw during sample pressurized thermal shock events. The effects of a number of key variables on the flaw propagation were studied, including (1) fracture toughness of the material and its gradient through the thickness, (2) irradiation effects, (3) effects of warm prestressing, and (4) effects of the stainless steel cladding.
The results of these studies show that under thermal shock loading conditions the flaw always tends to elongate along the vessel inside surface from the initial aspect ratio. However, the flaw shape always remains finite rather than becoming continuously long, as has often been assumed in earlier analyses. The final shape and size of the flaws were found to be rather strongly dependent on the effects of warm prestressing and the distribution of neutron flux.
The improved methodology results in a more accurate and more realistic treatment of flaw shape changes during thermal shock events and provides the potential for quantifying additional margins for reactor vessel integrity analyses.
Interactive Effects of High and Low Frequency Loading on the Fatigue Crack Growth of Inconel 718
Authors: Petrovich A , Bessler W , Ziegler W 
Published: December 2008

The effect of a loading profile containing a high frequency (200 Hz) loading component superimposed on a low frequency (∼0.05 to 0.5 Hz) loading component on fatigue crack growth of Inconel 718 at 650°C was investigated. The high frequency sinusoidal loading was added during the upper level hold period of the low frequency trapezoidal waveform.
Fatigue crack growth tests were carried out on Inconel 718 with a constant low frequency ΔK and an increasing high frequency ΔK in such a manner that the regimes in which crack growth is low frequency cycle and high frequency cycle dominated were investigated. Particular attention was devoted to the interaction of the two loading components in the low frequency dominated crack growth regime and the dependence of the transition to high cycle domination on factors such as low frequency cycle ΔK and hold time. The effects of hold times in the range of 2 to 180 s and low frequency ΔK in the range of 15 to 40 MPa√m were investigated.
In the high cycle dominated regime, the relationship between crack growth rate and high frequency ΔK had the characteristics of threshold crack growth data. In the low cycle dominated regime the high frequency cycle retarded crack growth under certain circumstances.
Evaluation of Environmentally Assisted Cracking of a High Strength Steel Using Elastic-Plastic Fracture Mechanics Techniques
Authors: Hackett EM , Moran PJ , Gudas JP 
Published: December 2008

The objective of this investigation was to assess the feasibility of determining the environmentally assisted crack growth characteristics of a high strength 4340 steel during cathodic polarization in seawater using J-integral techniques. A secondary objective was to demonstrate the capability of using these techniques for investigating stress corrosion cracking-hydrogen embrittlement mechanisms in high strength steels.
It was concluded that stress corrosion-hydrogen embrittlement crack growth behavior in a high strength steel can be characterized using techniques developed for the study of stable elastic-plastic crack growth. In the case of environmentally assisted cracking, an added dimension results from the rate dependence of the process, giving results which are displacement-rate dependent. Cathodic polarization of 4340 steel specimens in seawater resulted in up to a four-fold decrease in the energy required for fracture initiation (JIc). The extent of this decrease was a strong function of both pre-exposure time and displacement rate. A good correlation was obtained between fracture morphology changes predicted from the material J-R curves and actual fracture surface measurements. The technique should therefore be a useful tool in mechanistic studies of environmentally assisted crack growth in high strength steels.
Stress Intensity Factors for a Circular Ring with Uniform Array of Radial Cracks of Unequal Depth
Authors: Pu SL 
Published: December 2008

The plane problem of a uniform array of unequal depth radial cracks originating at the internal boundary of a pressurized circular ring is considered. The 12-node quadrilateral isoparametric elements with collapsed singular elements around crack tips are used to compute stress intensity factors at crack tips.
In a previous study of equal depth radial cracks, the weakest configuration (having highest values of stress intensity factors) was a ring with two diametrically opposed cracks. The current study shows that if for any reason one of the two cracks should grow a little faster than the other, the stress intensity factor at the tip of the longer crack increases at a much faster rate to enhance the faster growth of the longer crack.
Numerical results are also obtained for cases of three and four radial cracks. They show the same trend: that once one or two cracks grow a little more than the rest, the stress intensity factors at these deeper cracks will be increased progressively higher to keep the faster pace of growth. This explains why failure caused by a single major crack has been observed most frequently.
The finite element results show that the relationship between the stress intensity ratio and the crack depth ratio is approximately linear. This approximation enables us to estimate stress intensity factors at unequal depth cracks by a simple numerical method. The estimations thus obtained are close to stress intensity factors computed from the finite element method.
Comparison of Ductile Crack Growth Resistance of Austenitic, Niobium-stabilized Austenitic, and Austeno-ferritic Stainless Steels
Authors: Balladon P , Heritier J 
Published: December 2008

Fracture toughness and ductile crack growth properties are compared at room and elevated temperatures by using the J integral concept for three grades: (1) an austenitic stainless steel water-quenched from different temperatures, (2) a niobium-stabilized austenitic stainless steel containing niobium carbides and niobium carbonitrides in an austenitic matrix, and (3) an austeno-ferritic stainless steel that contains about 50% ferritic phase in an austenitic matrix and shows higher tensile properties compared with the two other grades.
The J-R curves of the two austenitic grades are mainly dependent upon the inclusion content and the direction of the crack growth plane. Some results show the influence of residual stress level on J-R curves.
The JIc and dJ/da values for the austeno-ferritic grade cannot be explained only by the roles of the inclusion content and the crack growth plane direction; a specific behavior of the ferritic phase in this duplex steel may decrease JIc compared with the two austenitic grades.
Monitoring Stress-Corrosion Cracking by Acoustic Emission
Authors: Martin P , Dickson JI , Baïlon J-P 
Published: December 2008

Acoustic emission (AE) is well suited for laboratory studies of stress corrosion cracking (SCC) since the crack velocity is often approximately proportional to the AE rate. For 7075-T651 and 2024-T351 aluminum alloys, this proportionality is shown to be particularly good. For 7075-T651, less scatter is obtained in SCC crack velocity when these are based on the cumulative AE counts than on surface crack length measurements. The curve of AE rate versus time after addition of fresh solution into the crack depends on the type of transducer employed. Using either a broad-band or a resonant transducer, it was possible to distinguish between SCC and corrosion signals from their frequency spectrum.
The applicability of employing AE to detect SCC in an industrial environment is considered. Possible solutions to some of the difficulties expected in cases where SCC produces low-amplitude AE signals are discussed.