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Sample records for cleanable steel hepa

  1. Requirements for a cleanable steel HEPA filter derived from a systems analysis

    International Nuclear Information System (INIS)

    A systems analysis was conducted to determine customer requirements for a cleanable high efficiency particulate air (HEPA) filter in DOE Environmental Management (EM) facilities. The three principal drivers for cleanable steel HEPA are large cost savings, improved filter reliability, and new regulations; they produce a strong incentive to DOE customers to use cleanable steel HEPA filters. Input for customer requirements were obtained from field trips to EM sites and from discussions. Most existing applications require that cleanable steel HEPA filters meet size/performance requirements of standard glass HEPA filters; applications in new facilities can relax size/weight/pressure drop requirements on a case-by-case basis. We then obtained input from commercial firms on availability of cleanable steel HEPA filters. Systems analysis then showed that currently available technology was only able to meet customer needs in a limited number of cases. Further development is needed to meet requirements of EM customers. For cleanable steel HEPA to be retrofitted into existing systems, pressure drop and weight must be reduced. Pressure drop can be reduced by developing steel fiber media from 0.5 μm dia steel fibers. Weight can be reduced by packaging the steel fiber media in one of the standard HEPA configurations. Although most applications will be able to use standard 304 or 316L alloys, an acid resistant alloy such as Hastelloy or Inconel will be needed for incinerator and other thermal processes

  2. Further development of the cleanable steel HEPA filter, cost/benefit analysis, and comparison with competing technologies

    International Nuclear Information System (INIS)

    We have made further progress in developing a cleanable steel fiber HEPA filter. We fabricated a pleated cylindrical cartridge using commercially available steel fiber media that is made with 1 μm stainless steel fibers and sintered into a sheet form. Test results at the Department of Energy (DOE) Filter Test Station at Oak Ridge show the prototype filter cartridge has 99.99% efficiency for 0.3 μm dioctyl phthalate (DOP) aerosols and a pressure drop of 1.5 inches. Filter loading and cleaning tests using AC Fine dust showed the filter could be repeatedly cleaned using reverse air pulses. Our analysis of commercially optimized filters suggest that cleanable steel HEPA filters need to be made from steel fibers less than 1μm, and preferably 0.5 μm, to meet the standard HEPA filter requirements in production units. We have demonstrated that 0.5 μm steel fibers can be produced using the fiber bundling and drawing process. The 0.5 μm steel fibers are then sintered into small filter samples and tested for efficiency and pressure drop. Test results on the sample showed a penetration of 0.0015 % at 0.3 μm and a pressure drop of 1.15 inches at 6.9 ft/min (3.5 cm/s) velocity. Based on these results, steel fiber media can easily meet the requirements of 0.03 % penetration and 1.0 inch of pressure drop by using less fibers in the media. A cost analysis of the cleanable steel HEPA filter shows that, although the steel HEPA filter costs much more than the standard glass fiber HEPA filter, it has the potential to be very cost effective because of the high disposal costs of contaminated HEPA filters. We estimate that the steel HEPA filter will save an average of $16,000 over its 30 year life. The additional savings from the clean-up costs resulting from ruptured glass HEPA filters during accidents was not included but makes the steel HEPA filter even more cost effective. 33 refs., 28 figs., 1 tab

  3. Further development of the cleanable steel HEPA filter, cost/benefit analysis, and comparison with competing technologies

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; Lopez, R.; Wilson, K. [Lawrence Livermore National Lab., CA (United States)] [and others

    1997-08-01

    We have made further progress in developing a cleanable steel fiber HEPA filter. We fabricated a pleated cylindrical cartridge using commercially available steel fiber media that is made with 1 {mu}m stainless steel fibers and sintered into a sheet form. Test results at the Department of Energy (DOE) Filter Test Station at Oak Ridge show the prototype filter cartridge has 99.99% efficiency for 0.3 {mu}m dioctyl phthalate (DOP) aerosols and a pressure drop of 1.5 inches. Filter loading and cleaning tests using AC Fine dust showed the filter could be repeatedly cleaned using reverse air pulses. Our analysis of commercially optimized filters suggest that cleanable steel HEPA filters need to be made from steel fibers less than 1{mu}m, and preferably 0.5 {mu}m, to meet the standard HEPA filter requirements in production units. We have demonstrated that 0.5 {mu}m steel fibers can be produced using the fiber bundling and drawing process. The 0.5 {mu}m steel fibers are then sintered into small filter samples and tested for efficiency and pressure drop. Test results on the sample showed a penetration of 0.0015 % at 0.3 {mu}m and a pressure drop of 1.15 inches at 6.9 ft/min (3.5 cm/s) velocity. Based on these results, steel fiber media can easily meet the requirements of 0.03 % penetration and 1.0 inch of pressure drop by using less fibers in the media. A cost analysis of the cleanable steel HEPA filter shows that, although the steel HEPA filter costs much more than the standard glass fiber HEPA filter, it has the potential to be very cost effective because of the high disposal costs of contaminated HEPA filters. We estimate that the steel HEPA filter will save an average of $16,000 over its 30 year life. The additional savings from the clean-up costs resulting from ruptured glass HEPA filters during accidents was not included but makes the steel HEPA filter even more cost effective. 33 refs., 28 figs., 1 tab.

  4. Insitu Cleanable Alternative HEPA Filter Media

    International Nuclear Information System (INIS)

    Two types of filter media, sintered nickel metal and ceramic monolith membrane, are being investigated as in situ regenerable/cleanable high efficiency particulate air (HEPA) filters. Particle retention testing was conducted on the filters at the Oak Ridge Filter Test Facility to ensure HEPA efficiency, greater than 99.97 percent. During simulant testing, The filters were challenged using non-radioactive simulated high-level waste materials and atmospheric dust; materials that cause filter pluggage in the field. After plugging the filters they were cleaned in situ using an aqueous solution. This innovative approach of the in situ regenerative filtration system may be a significant improvement upon the shortfalls of conventional disposable HEPA filters

  5. In Situ Cleanable Alternative HEPA Filter Media

    International Nuclear Information System (INIS)

    The Westinghouse Savannah River Company, located at the Savannah River Site in Aiken, South Carolina, is currently testing two types of filter media for possible deployment as in situ regenerable/cleanable High Efficiency Particulate Air (HEPA) filters. The filters are being investigated to replace conventional, disposable, glass-fiber, HEPA filters that require frequent removal, replacement, and disposal. This is not only costly and subjects site personnel to radiation exposure, but adds to the ever-growing waste disposal problem. The types of filter media being tested, as part of a National Energy Technology Laboratory procurement, are sintered nickel metal and ceramic monolith membrane. These media were subjected to a hostile environment to simulate conditions that challenge the high-level waste tank ventilation systems. The environment promoted rapid filter plugging to maximize the number of filter loading/cleaning cycles that would occur in a specified period of time. The filters were challenged using nonradioactive simulated high-level waste materials and atmospheric dust; materials that cause filter pluggage in the field. The filters are cleaned in situ using an aqueous solution. The study found that both filter media were insensitive to high humidity or moisture conditions and were easily cleaned in situ. The filters regenerated to approximately clean filter status even after numerous plugging and in situ cleaning cycles. Air Techniques International is conducting particle retention testing on the filter media at the Oak Ridge Filter Test Facility. The filters are challenged using 0.3-mm di-octyl phthalate particles. Both the ceramic and sintered media have a particle retention efficiency > 99.97%. The sintered metal and ceramic filters not only can be cleaned in situ, but also hold great potential as a long life alternative to conventional HEPA filters. The Defense Nuclear Facility Safety Board Technical Report, ''HEPA Filters Used in the Department of

  6. Testing cleanable/reuseable HEPA prefilters for mixed waste incinerator air pollution control systems

    Energy Technology Data Exchange (ETDEWEB)

    Burns, D.B.; Wong, A.; Walker, B.W.; Paul, J.D. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1997-08-01

    The Consolidated Incineration Facility (CIF) at the US DOE Savannah River Site is undergoing preoperational testing. The CIF is designed to treat solid and liquid RCRA hazardous and mixed wastes from site operations and clean-up activities. The technologies selected for use in the air pollution control system (APCS) were based on reviews of existing incinerators, air pollution control experience, and recommendations from consultants. This approach resulted in a facility design using experience from other operating hazardous/radioactive incinerators. In order to study the CIF APCS prior to operation, a 1/10 scale pilot facility, the Offgas Components Test Facility (OCTF), was constructed and has been in operation since late 1994. Its mission is to demonstrate the design integrity of the CIF APCS and optimize equipment/instrument performance of the full scale production facility. Operation of the pilot facility has provided long-term performance data of integrated systems and critical facility components. This has reduced facility startup problems and helped ensure compliance with facility performance requirements. Technical support programs assist in assuring all stakeholders the CIF can properly treat combustible hazardous, mixed, and low-level radioactive wastes. High Efficiency Particulate Air (HEPA) filters are used to remove hazardous and radioactive particulates from the exhaust gas strewn before being released into the atmosphere. The HEPA filter change-out frequency has been a potential issue and was the first technical issue to be studied at the OCTF. Tests were conducted to evaluate the performance of HEPA filters under different operating conditions. These tests included evaluating the impact on HEPA life of scrubber operating parameters and the type of HEPA prefilter used. This pilot-scale testing demonstrated satisfactory HEPA filter life when using cleanable metal prefilters and high flows of steam and water in the offgas scrubber. 8 figs., 2 tabs.

  7. Development and evaluation of a cleanable high efficiency steel filter

    International Nuclear Information System (INIS)

    We have developed a high efficiency steel filter that can be cleaned in-situ by reverse air pulses. The filter consists of 64 pleated cylindrical filter elements packaged into a 6l0 x 6l0 x 292 mm aluminum frame and has 13.5 m2 of filter area. The filter media consists of a sintered steel fiber mat using 2 μm diameter fibers. We conducted an optimization study for filter efficiency and pressure drop to determine the filter design parameters of pleat width, pleat depth, outside diameter of the cylinder, and the total number of cylinders. Several prototype cylinders were then built and evaluated in terms of filter cleaning by reverse air pulses. The results of these studies were used to build the high efficiency steel filter. We evaluated the prototype filter for efficiency and cleanability. The DOP filter certification test showed the filter has a passing efficiency of 99.99% but a failing pressure drop of 0.80 kPa at 1,700 m3/hr. Since we were not able to achieve a pressure drop less than 0.25 kPa, the steel filter does not meet all the criteria for a HEPA filter. Filter loading and cleaning tests using AC Fine dust showed the filter could be repeatedly cleaned by reverse air pulses. The next phase of the prototype evaluation consisted of installing the unit and support housing in the exhaust duct work of a uranium grit blaster for a field evaluation at the Y-12 Plant in Oak Ridge, TN. The grit blaster is used to clean the surface of uranium parts and generates a cloud of UO2 aerosols. We used a 1,700 m3/hr slip stream from the 10,200 m3/hr exhaust system

  8. Development and evaluation of a cleanable high efficiency steel filter

    International Nuclear Information System (INIS)

    In this work the authors describe the development and evaluation of a high efficiency steel filter that can be cleaned in-situ by reverse air pulses. The filter consists of 64 pleated cylindrical filter elements packaged into a 610x610x292 mm (24x24x11.5 in.) aluminum frame and has 13.5 m2 (145 square feet) of filter area. The filter media consists of a sintered steel fiber mat using 2 μm diameter fibers. An optimization study was conducted for filter efficiency and pressure drop to determine the filter design parameters of pleat width, pleat depth, outside diameter of the cylinder, and the total number of cylinders. Several prototype cylinders were then built and evaluated in terms of filter cleaning by reverse air pulses. The results of these studies were used to build the high efficiency steel filter. The prototype filter was evaluated for efficiency and cleanability. The DOP filter certification test showed the filter had a passing efficiency of 99.99% but a failing pressure drop of 0.80 kPa (3.2 in w.g.) at 1,700 m3/hr (1,000 cfm). Since a pressure drop less than 0.25 kPa (1 inch w.g.) could not be achieved, the steel filter did not meet all the criteria for a HEPA filter. Filter loading and cleaning tests using AC Fine dust showed the filter could be repeatedly cleaned by reverse air pulses. The next phase of the prototype evaluation consisted of installing the unit and support housing in the exhaust duct work of a uranium grit blaster for a field evaluation at the Y-12 Plant in Oak Ridge, TN. The grit blaster was used to clean the surface of uranium parts and generated a cloud of UO2 aerosols. A 1,700 m3/hr (1,000 cfm) slip stream from the 10,200 m3/hr (6,000 cfm) exhaust system was used. 12 refs., 24 figs

  9. Influence of surface finish on the cleanability of stainless steel.

    Science.gov (United States)

    Frank, J F; Chmielewski, R

    2001-08-01

    Stainless steel for fabricating food processing equipment is available with various surface finishes. The objective of this research was to determine the effect of surface finish on cleanability. Nine samples of stainless steel, type 304, from various manufacturers including no finish (hot rolled and pickled), #4 finish, 2B mechanical polished, and electropolished were tested. Cleanability was assessed by using coupon samples soiled with either cultured milk inoculated with spores of Bacillus stearothermophilus or by growth of a Pseudomonas sp. biofilm. Samples were cleaned by immersion in a turbulent bath of 1.28% sodium hydroxide at 66 degrees C for 3 min followed by a sterile water rinse, neutralizing in 0.1% phosphoric acid for 30 s, rinsing in phosphate buffer, sanitizing in 100 ppm hypochlorite, neutralizing in sodium thiosulfate, and drying. To determine residual milk soil, coupon samples were covered with PM indicator agar and incubated for 25 h at 58 degrees C. Other coupons were subjected to an additional 10 soiling or cleaning cycles, and the residual protein was measured by using epifluorescent microscopy and image analysis. Results indicate that the spore count was more precise for measuring initial cleanability of the finished samples, and the protein residue determination was useful for determining the effect of repeated cleaning. Data on the removal of milk soil suggest that stainless steel should be purchased based on measures of surface defects rather than finish type. Surface defects, as determined using a surface roughness gauge, produced a correlation of 0.82 with spore counts. Data also indicated that biofilm was more difficult to remove than milk-based soil. PMID:11510656

  10. Geometric Algorithms for Cleanability in Manufacturing

    OpenAIRE

    Yasui, Yusuke

    2011-01-01

    This thesis describes geometric algorithms to check the cleanability of a design during the manufacturing process. The automotive industry needs a computational tool to determine how to clean their products due to the trend of miniaturization and increased geometric complexity of mechanical parts. A newly emerging concept in a product design, Design-for-Cleanability, necessitates algorithms to help designers to design parts that are easy to clean during the manufacturing process. In this thes...

  11. HEPA air filter (image)

    Science.gov (United States)

    ... pet dander and other irritating allergens from the air. Along with other methods to reduce allergens, such ... controlling the amount of allergens circulating in the air. HEPA filters can be found in most air ...

  12. Experimental Investigation of In Situ Cleanable or Regenerative Filters for High Level Radioactive Waste Tanks

    International Nuclear Information System (INIS)

    The Westinghouse Savannah River Company, located at the Savannah River Site (SRS) in Aiken, South Carolina, is currently testing two types of filter media for application as in situ regenerable/cleanable filters on high-level radioactive liquid waste tanks. Each of the 1.3 million-gallon tanks is equipped with an exhaust ventilation system to provide tank ventilation and to maintain the tank contents at approximately 1-in. water gauge vacuum to prevent the release of radioactive material to the environment. These systems are equipped with conventional, disposable, glass-fiber, High Efficiency Particulate Air (HEPA) filters that require frequent removal, replacement, and disposal. The need for routine replacements is often caused by accelerated filter loading due to the moist operating environment, which structurally weakens the filter media. This is not only costly, but subjects site personnel to radiation exposure and possible contamination. The types of filter media tested, as part of a National Energy Technology Laboratory procurement, were sintered metal and monolith ceramic. The media were subjected to a hostile environment to simulate conditions that challenge the tank ventilation systems. The environment promoted rapid filter plugging to maximize the number of filter loading/cleaning cycles that would occur in a specified period of time. The filters were challenged using non-radioactive, simulated high level waste materials and atmospheric dust, as these materials are most responsible for filter pluggage in the field. The filters were cleaned/regenerated in situ using an aqueous solution of dilute (10% volume) nitric acid. The study found that both filter media were insensitive to high humidity or moisture conditions and were easily cleaned in situ. The filters regenerated to approximately clean filter status even after numerous plugging and cleaning cycles. The filters were leak tested using poly alpha olefin aerosol at the beginning, middle, and end of the

  13. HEPA filter encapsulation

    Science.gov (United States)

    Gates-Anderson, Dianne D.; Kidd, Scott D.; Bowers, John S.; Attebery, Ronald W.

    2003-01-01

    A low viscosity resin is delivered into a spent HEPA filter or other waste. The resin is introduced into the filter or other waste using a vacuum to assist in the mass transfer of the resin through the filter media or other waste.

  14. HEPA filter monitoring program

    Science.gov (United States)

    Kirchner, K. N.; Johnson, C. M.; Aiken, W. F.; Lucerna, J. J.; Barnett, R. L.; Jensen, R. T.

    1986-07-01

    The testing and replacement of HEPA filters, widely used in the nuclear industry to purify process air, are costly and labor-intensive. Current methods of testing filter performance, such as differential pressure measurement and scanning air monitoring, allow determination of overall filter performance but preclude detection of incipient filter failure such as small holes in the filters. Using current technology, a continual in-situ monitoring system was designed which provides three major improvements over current methods of filter testing and replacement. The improvements include: cost savings by reducing the number of intact filters which are currently being replaced unnecessarily; more accurate and quantitative measurement of filter performance; and reduced personnel exposure to a radioactive environment by automatically performing most testing operations.

  15. Ceramic HEPA Filter Program

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, M A; Bergman, W; Haslam, J; Brown, E P; Sawyer, S; Beaulieu, R; Althouse, P; Meike, A

    2012-04-30

    Potential benefits of ceramic filters in nuclear facilities: (1) Short term benefit for DOE, NRC, and industry - (a) CalPoly HTTU provides unique testing capability to answer questions for DOE - High temperature testing of materials, components, filter, (b) Several DNFSB correspondences and presentations by DNFSB members have highlighted the need for HEPA filter R and D - DNFSB Recommendation 2009-2 highlighted a nuclear facility response to an evaluation basis earthquake followed by a fire (aka shake-n-bake) and CalPoly has capability for a shake-n-bake test; (2) Intermediate term benefit for DOE and industry - (a) Filtration for specialty applications, e.g., explosive applications at Nevada, (b) Spin-off technologies applicable to other commercial industries; and (3) Long term benefit for DOE, NRC, and industry - (a) Across industry, strong desire for better performance filter, (b) Engineering solution to safety problem will improve facility safety and decrease dependence on associated support systems, (c) Large potential life-cycle cost savings, and (d) Facilitates development and deployment of LLNL process innovations to allow continuous ventilation system operation during a fire.

  16. FULL SCALE REGENERABLE HEPA FILTER DESIGN USING SINTERED METAL FILTER ELEMENTS

    International Nuclear Information System (INIS)

    A Department of Energy funded contract involved the development of porous metal as a HEPA filter, and the subsequent design of a full-scale regenerable HEPA filtration system (RHFS). This RHFS could replace the glass fiber HEPA filters currently being used on the high level waste (HLW) tank ventilation system with a system that would be moisture tolerant, durable, and cleanable in place. The origins of the contract are a 1996 investigation at the Savannah River Technology Center (SRTC) regarding the use of porous metal as a HEPA filter material. This contract was divided into Phases I, IIA and IIB. Phase I of the contract evaluated simple filter cylinders in a simulated High Level Waste (HLW) environment and the ability to clean and regenerate the filter media after fouling. Upon the successful completion of Phase I, Phase IIA was conducted, which included lab scale prototype testing and design of a full-scale system. The work completed under Phase IIA included development of a full-scale system design, development of a filter media meeting the HEPA filtration efficiency that would also be regenerable using prescribed cleaning procedures, and the testing of a single element system prototype at Savannah River. All contract objectives were met. The filter media selected was a nickel material already under development at Mott, which met the HEPA filtration efficiency standard. The Mott nickel media met and exceeded the HEPA requirement, providing 99.99% removal against a requirement of 99.97%. Double open-ended elements of this media were provided to the Savannah River Test Center for HLW simulation testing in the single element prototype filter. These elements performed well and further demonstrated the practicality of a metallic media regenerable HEPA filter system. An evaluation of the manufacturing method on many elements demonstrated the reproducibility to meet the HEPA filtration requirement. The full-scale design of the Mott RHFS incorporated several important

  17. Survey of HEPA filter experience

    International Nuclear Information System (INIS)

    A survey of high efficiency particulate air (HEPA) filter applications and experience at Department of Energy (DOE) sites was conducted to provide an overview of the reasons and magnitude of HEPA filter changeouts and failures. Results indicated that approximately 58% of the filters surveyed were changed out in the three year study period, and some 18% of all filters were changed out more than once. Most changeouts (63%) were due to the existence of a high pressure drop across the filter, indicative of filter plugging. Other reasons for changeout included leak-test failure (15%), preventive maintenance service life limit (13%), suspected damage (5%) and radiation buildup (4%). Filter failures occurred with approximately 12% of all installed filters. Of these failures, most (64%) occurred for unknown or unreported reasons. Handling or installation damage accounted for an additional 19% of reported failures. Media ruptures, filter-frame failures and seal failures each accounted for approximately 5 to 6% of the reported failures

  18. Conditioning materials with biomacromolecules: composition of the adlayer and influence on cleanability.

    Science.gov (United States)

    Touré, Yetioman; Genet, Michel J; Dupont-Gillain, Christine C; Sindic, Marianne; Rouxhet, Paul G

    2014-10-15

    The influence of substrate hydrophobicity and biomacromolecules (dextran, bovine serum albumin - BSA) adsorption on the cleanability of surfaces soiled by spraying aqueous suspensions of quartz particles (10-30μm size), then dried, was investigated using glass and polystyrene as substrates. The cleanability was evaluated using radial flow cell (RFC). The surface composition was determined by X-ray photoelectron spectroscopy (XPS). The interpretation of XPS data allowed the complexity due to the ubiquitous presence of organic contaminants to be coped with, and the surface composition to be expressed in terms of both the amount of adlayer and the mass concentration of adlayer constituents. When soiled with a suspension of particles in water, glass was much less cleanable than polystyrene, which was attributed to its much lower water contact angle, in agreement with previous observations on starch soil. Dextran was easily desorbed and did not affect the cleanability. The presence of BSA at the interface strongly improved the cleanability of glass while the contact angle did not change appreciably. In contrast, soiling polystyrene with quartz particles suspended in a BSA solution instead of water did not change markedly the cleanability, while the contact angle was much lower and the aggregates of soiling particles were more flat. These observations are explained by the major role of capillary forces developed upon drying, which influence the closeness of the contact between the soiling particles and the substrate and, thereby, the adherence of particles. The capillary forces are proportional to the liquid surface tension and depend in a more complex way on contact angles of the particles and of the substrate. The dependence of cleanability on capillary forces, and in particular on the liquid surface tension, is predominant as compared with its dependence on the size and shape of the soiling aggregates, which influence the efficiency of shear forces exerted by the

  19. Preliminary field evaluation of high efficiency steel filters

    International Nuclear Information System (INIS)

    The authors have conducted an evaluation of two high efficiency steel filters in the exhaust of an uranium oxide grit blaster at the Y-12 Plant in Oak Ridge Tennessee. The filters were installed in a specially designed filter housing with a reverse air-pulse cleaning system for automatically cleaning the filters in-place. Previous tests conducted on the same filters and housing at LLNL under controlled conditions using Arizona road dust showed good cleanability with reverse air pulses. Two high efficiency steel filters, containing 64 pleated cartridge elements housed in the standard 2' x 2' x l' HEPA frame, were evaluated in the filter test housing using a 1,000 cfm slip stream containing a high concentration of depleted uranium oxide dust. One filter had the pleated cartridges manufactured to the authors specifications by the Pall Corporation and the other by Memtec Corporation. Test results showed both filters had a rapid increase in pressure drop with time, and reverse air pulses could not decrease the pressure drop. The authors suspected moisture accumulation in the filters was the problem since there were heavy rains during the evaluations, and the pressure drop of the Memtec filter decreased dramatically after passing clean, dry air through the filter and after the filter sat idle for one week. Subsequent laboratory tests on a single filter cartridge confirmed that water accumulation in the filter was responsible for the increase in filter pressure drop and the inability to lower the pressure drop by reverse air pulses. No effort was made to identify the source of the water accumulation and correct the problem because the available funds were exhausted

  20. Preliminary field evaluation of high efficiency steel filters

    International Nuclear Information System (INIS)

    We have conducted an evaluation of two high efficiency steel filters in the exhaust of an uranium oxide grit blaster at the Y-12 Plant in Oak Ridge Tennessee. The filters were installed in a specially designed filter housing with a reverse air-pulse cleaning system for automatically cleaning the filters in-place. Previous tests conducted on the same filters and housing at LLNL under controlled conditions using Arizona road dust showed good cleanability with reverse air pulses. Two high efficiency steel filters, containing 64 pleated cartridge elements housed in the standard 2' x 2' x 1' HEPA frame, were evaluated in the filter test housing using a 1,000 cfm slip stream containing a high concentration of depleted uranium oxide dust. One filter had the pleated cartridges manufactured to our specifications by the Pall Corporation and the other by Memtec Corporation. Test results showed both filters had a rapid increase in pressure drop with time, and reverse air pulses could not decrease the pressure drop. We suspected moisture accumulation in the filters was the problem since there were heavy rains during the evaluations, and the pressure drop of the Memtec filter decreased dramatically after passing clean, dry air through the filter and after the filter sat idle for one week. Subsequent laboratory tests on a single filter cartridge confirmed that water accumulation in the filter was responsible for the increase in filter pressure drop and the inability to lower the pressure drop by reverse air pulses. No effort was made to identify the source of the water accumulation and correct the problem because the available funds were exhausted

  1. Preliminary field evaluation of high efficiency steel filters

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; Larsen, G.; Lopez, R. [Lawrence Livermore National Laboratory, CA (United States)] [and others

    1995-02-01

    We have conducted an evaluation of two high efficiency steel filters in the exhaust of an uranium oxide grit blaster at the Y-12 Plant in Oak Ridge Tennessee. The filters were installed in a specially designed filter housing with a reverse air-pulse cleaning system for automatically cleaning the filters in-place. Previous tests conducted on the same filters and housing at LLNL under controlled conditions using Arizona road dust showed good cleanability with reverse air pulses. Two high efficiency steel filters, containing 64 pleated cartridge elements housed in the standard 2` x 2` x 1` HEPA frame, were evaluated in the filter test housing using a 1,000 cfm slip stream containing a high concentration of depleted uranium oxide dust. One filter had the pleated cartridges manufactured to our specifications by the Pall Corporation and the other by Memtec Corporation. Test results showed both filters had a rapid increase in pressure drop with time, and reverse air pulses could not decrease the pressure drop. We suspected moisture accumulation in the filters was the problem since there were heavy rains during the evaluations, and the pressure drop of the Memtec filter decreased dramatically after passing clean, dry air through the filter and after the filter sat idle for one week. Subsequent laboratory tests on a single filter cartridge confirmed that water accumulation in the filter was responsible for the increase in filter pressure drop and the inability to lower the pressure drop by reverse air pulses. No effort was made to identify the source of the water accumulation and correct the problem because the available funds were exhausted.

  2. Utilization of profilometry, SEM, AFM and contact angle measurements in describing surfaces of plastic floor coverings and explaining their cleanability

    Science.gov (United States)

    Kuisma, R.; Pesonen-Leinonen, E.; Redsven, I.; Kymäläinen, H.-R.; Saarikoski, I.; Sjöberg, A.-M.; Hautala, M.

    2005-06-01

    The tendency to soil and cleanability of ten commercial plastic floor coverings: eight vinyl (PVC) floor coverings, one vinyl composite tile and one plastic composite tile, were examined. Floor coverings were soiled with inorganic, organic and biological soil. The cleanability was measured both by bioluminescence of ATP (adenosine triphosphate) and colorimetrically. The surface topography was studied by AFM, SEM and with a profilometer. From the 2D- and 3D-profilometric measurements several characteristic parameters of the surface profiles were extracted. The tendency to soil and cleanability were compared with the characteristics of the surface. A weak correlation was found between roughness and soilability but no correlation between roughness and cleanability. Roughness had no correlation with contact angle.

  3. Strategies for Burr Minimization and Cleanability in Aerospace and Automotive Manufacturing

    OpenAIRE

    Avila, Miguel C.; Gardner, Joel D.; Reich-Weiser, Corinne; Vijayaraghavan, Athulan; Dornfeld, David

    2006-01-01

    The quality of machined components in the aerospace and automotive industries has become increasingly critical in the past years because of greater complexity of the workpieces, miniaturization, usage of new composite materials, and tighter tolerances. This trend has put continual pressure not only on improvements in machining operations, but also on the optimization of the cleanability of parts. The paper reviews recent work done in these areas at the University of California-Berkele...

  4. Evaluation of HEPA filter service life

    International Nuclear Information System (INIS)

    Rocky Flats Environmental Technology Site (RFETS), has approximately 10,000 High Efficiency Particulate Air (HEPA) Filters installed in a variety of filter plenums. These ventilation/filtration plenum systems are used to control the release of airborne particulate contaminates to the environment during normal operations and potential accidents. This report summarizes the results of destructive and non-destructive tests on HEPA filters obtained from a wide variety of ages and service conditions. These tests were performed to determine an acceptable service life criteria for HEPA filters used at Rocky Flats Environmental Technology Site (RFETS). A total of 140 filters of various ages (1972 to 1996) and service history (new, aged unused, used) were tested. For the purpose of this report, filter age from manufacture date/initial test date to the current sample date was used, as opposed to the actual time a filter was installed in an operating system

  5. Realization of commercial high strength HEPA filters

    International Nuclear Information System (INIS)

    HEPA-filter media though having excellent particle removal efficiencies, remain characterized as rather brittle, fragile and weak materials. As a result, undesired structural damage followed by significant losses in filtration efficiency can easily occur in handling, transport, and even normal operation of filter units. In recent years extensive investigations into the structural limits of HEPA filters in dry air and under extended exposure to high humidity airflow have been carried out. In the course of this work the failure modes and the underlying failure mechanisms were thoroughly studied. On the basis of the information obtained, considerable improvements in the structural strength of HEPA filters could be achieved. As verified by removal efficiency tests, differential pressures up to 56kPa in dry air and 15kPa after extended operation under fog conditions were proven to be sustainable without mechanical damage to the filter medium. In cooperation with three major European filter manufacturers the know-how gained has been transferred into practical application through development of commercially available high-strength filter units. Three new KWU (Siemens-Kraftwerksunion) nuclear power plants in Germany have already been fully equipped with HEPA filters of this improved design. The German licensing authorities are now considering modifications of their requirement specifications to reflect the increased strength of the new filter units

  6. HEPA filter fire (and subsequent unfiltered release)

    International Nuclear Information System (INIS)

    This document supports the development and presentation of the following accident scenario in the TWRS Final Safety Analysis Report: HEPA Filter Failure - Exposure to High Temperature or Pressure. The calculations needed to quantify the risk associated with this accident scenario are included within

  7. In-place HEPA filter penetration test

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; Wilson, K.; Elliott, J. [Lawrence Livermore National Lab., CA (United States)] [and others

    1997-08-01

    We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in-place penetration test is practical. 14 refs., 14 figs., 3 tabs.

  8. HEPA filter fire (and subsequent unfiltered release)

    Energy Technology Data Exchange (ETDEWEB)

    Powers, T.B.

    1996-09-27

    This document supports the development and presentation of the following accident scenario in the TWRS Final Safety Analysis Report: HEPA Filter Failure - Exposure to High Temperature or Pressure. The calculations needed to quantify the risk associated with this accident scenario are included within.

  9. Factors affecting the wettability of different surface materials with vegetable oil at high temperatures and its relation to cleanability

    DEFF Research Database (Denmark)

    Ashokkumar, Saranya; Adler-Nissen, Jens; Møller, Per

    2012-01-01

    The main aim of the work was to investigate the wettability of different surface materials with vegetable oil (olive oil) over the temperature range of 25–200°C to understand the differences in cleanability of different surfaces exposed to high temperatures in food processes. The different surface...... different levels of roughness. The cosine of the contact angle of olive oil on different surface materials rises linearly with increasing temperature. Among the materials analyzed, polymers (PTFE, silicone) gave the lowest cosθ values. Studies of the effect of roughness and surface flaws on wettability...... contact angle and cleanability. In addition to surface wettability with oil many other factors such as roughness and surface defects play an essential role in determining their cleanability....

  10. Degradation of HEPA filters exposed to DMSO

    International Nuclear Information System (INIS)

    Dimethyl sulfoxide (DMSO) sprays are being used to remove the high explosive (HE) from nuclear weapons in the process of their dismantlement. A boxed 50 cfm HEPA filter with an integral prefilter was exposed to DMSO vapor and aerosols that were generated by a spray nozzle to simulate conditions expected in the HE dissolution operation. After 198 hours of operation, the pressure drop of the filter had increased from 1.15 inches to 2.85 inches, and the efficiency for 0.3 μm dioctyl sebacate (DOS) aerosols decreased from 99.992% to 98.6%. Most of the DMSO aerosols had collected as a liquid pool inside the boxed HEPA. The liquid was blown out of the filter exit with 100 cfm air flow at the end of the test. Since the filter still met the minimum allowed efficiency of 99.97% after 166 hours of exposure, we recommend replacing the filter every 160 hours of operation or sooner if the pressure drop increases by 50%. Examination of the filter showed that visible cracks appeared at the joints of the wooden frame and a portion of the sealant had pulled away from the frame. Since all of the DMSO will be trapped in the first HEPA filter, the second HEPA filter should not suffer from DMSO degradation. Thus the combined efficiency for the first filter (98.6%) and the second filter (99.97%) is 99.99996% for 0.3μm particles. If the first filter is replaced prior to its degradation, each of the filters will have 99.97% efficiency, and the combined efficiency will be 99.999991%. The collection efficiency for DMSO/HE aerosols will be much higher because the particle size is much greater

  11. Degradation of HEPA filters exposed to DMSO

    International Nuclear Information System (INIS)

    Dimethyl sulfoxide (DMSO) sprays are being used to remove the high explosive (HE) from nuclear weapons in the process of their dismantlement. A boxed 50 cmf HEPA filter with an integral prefilter was exposed to DMSO vapor and aerosols that were generated by a spray nozzle to simulate conditions expected in the HE dissolution operation. After 198 hours of operation, the pressure drop of the filter had increased form 1.15 inches to 2,85 inches, and the efficiency for 0.3 μm dioctyl sebacate (DOS) aerosols decreased form 99.992% to 98.6%. Most of the DMSO aerosols had collected as a liquid pool inside the boxed HEPA. The liquid was blown out of the filter exit with 100 cmf air flow at the end of the test. Since the filter still met the minimum allowed efficiency of 99.97% after 166 hours of exposure, we recommend replacing the filter every 160 hours of operation or sooner if the pressure drop increases by 50%. Examination of the filter showed that visible cracks appeared at the joints of the wooden frame and a portion of the sealant had pulled away from the frame. Since all of the DMSO will be trapped in the first HEPA filter, the second HEPA filter should not suffer from DMSO degradation. Thus the combined efficiency for the first filter (98.6%) and the second filter (99.97%) is 99.99996% for 0.3 μm particles. If the first filter is replaced prior to its degradation, each of the filters will have 99.97% efficiency, and the combined efficiency will be 99.999991%. The collection efficiency for DMSO/HE aerosols will be much higher because the particle size is much greater

  12. Degradation of HEPA filters exposed to DMSO

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; Wilson, K.; Larsen, G. [Lawrence Livermore National Laboratory, CA (United States)] [and others

    1995-02-01

    Dimethyl sulfoxide (DMSO) sprays are being used to remove the high explosive (HE) from nuclear weapons in the process of their dismantlement. A boxed 50 cmf HEPA filter with an integral prefilter was exposed to DMSO vapor and aerosols that were generated by a spray nozzle to simulate conditions expected in the HE dissolution operation. After 198 hours of operation, the pressure drop of the filter had increased form 1.15 inches to 2,85 inches, and the efficiency for 0.3 {mu}m dioctyl sebacate (DOS) aerosols decreased form 99.992% to 98.6%. Most of the DMSO aerosols had collected as a liquid pool inside the boxed HEPA. The liquid was blown out of the filter exit with 100 cmf air flow at the end of the test. Since the filter still met the minimum allowed efficiency of 99.97% after 166 hours of exposure, we recommend replacing the filter every 160 hours of operation or sooner if the pressure drop increases by 50%. Examination of the filter showed that visible cracks appeared at the joints of the wooden frame and a portion of the sealant had pulled away from the frame. Since all of the DMSO will be trapped in the first HEPA filter, the second HEPA filter should not suffer from DMSO degradation. Thus the combined efficiency for the first filter (98.6%) and the second filter (99.97%) is 99.99996% for 0.3 {mu}m particles. If the first filter is replaced prior to its degradation, each of the filters will have 99.97% efficiency, and the combined efficiency will be 99.999991%. The collection efficiency for DMSO/HE aerosols will be much higher because the particle size is much greater.

  13. HEPA/Vaccine Plan for Indoor Anthrax Remediation

    OpenAIRE

    Lawrence M Wein; Liu, Yifan; Leighton, Terrance J.

    2005-01-01

    We developed a mathematical model to compare 2 indoor remediation strategies in the aftermath of an outdoor release of 1.5 kg of anthrax spores in lower Manhattan. The 2 strategies are the fumigation approach used after the 2001 postal anthrax attack and a HEPA/vaccine plan, which relies on HEPA vacuuming, HEPA air cleaners, and vaccination of reoccupants. The HEPA/vaccine approach leads to few anthrax cases among reoccupants if applied to all but the most heavily contaminated buildings, and ...

  14. Contextualizing Hepatocyte Functionality of Cryopreserved HepaRG Cell Cultures.

    Science.gov (United States)

    Jackson, Jonathan P; Li, Linhou; Chamberlain, Erica D; Wang, Hongbing; Ferguson, Stephen S

    2016-09-01

    Over the last decade HepaRG cells have emerged as a promising alternative to primary human hepatocytes (PHH) and have been featured in over 300 research publications. Most of these reports employed freshly differentiated HepaRG cells that require time-consuming culture (∼28 days) for full differentiation. Recently, a cryopreserved, predifferentiated format of HepaRG cells (termed here "cryo-HepaRG") has emerged as a new model that improves global availability and experimental flexibility; however, it is largely unknown whether HepaRG cells in this format fully retain their hepatic characteristics. Therefore, we systematically investigated the hepatocyte functionality of cryo-HepaRG cultures in context with the range of interindividual variation observed with PHH in both sandwich-culture and suspension formats. These evaluations uncovered a novel adaptation period for the cryo-HepaRG format and demonstrated the impact of extracellular matrix on cryo-HepaRG functionality. Pharmacologically important drug-metabolizing alleles were genotyped in HepaRG cells and poor metabolizer alleles for CYP2D6, CYP2C9, and CYP3A5 were identified and consistent with higher frequency alleles found in individuals of Caucasian decent. We observed liver enzyme inducibility with aryl hydrocarbon receptor, constitutive androstane receptor (CAR), and pregnane X receptor activators comparable to that of sandwich-cultured PHH. Finally, we show for the first time that cryo-HepaRG supports proper CAR cytosolic sequestration and translocation to hepatocyte nuclei in response to phenobarbital treatment. Taken together, these data reveal important considerations for the use of this cell model and demonstrate that cryo-HepaRG are suitable for metabolism and toxicology screening.

  15. Steel

    International Nuclear Information System (INIS)

    Composition of age hardening steel, % : Fe - (12.0-12.4) Cr - (2-2.7) Ni (0.5-0.6) Ti - (1.0-1.2) Mn - (0.03 - 0.04) C having high values of magnetoelastic internal friction and mechanical properties as well as an ability to operate under the conditions of alternating loadings are proposed. Damping properties of the steel permit to improve labour conditions. Data for the above steel on internal friction, impact strength and tensile properties are given

  16. Aerosol penetration inside HEPA filtration media

    International Nuclear Information System (INIS)

    Attempts made to modelize changes in high-efficiency particulate air (HEPA) filter pressure drop as a function of such parameters as the amount of aerosol collected, which also take account of filtering medium characteristics, those of the filtered aerosol and the filtration velocity, have always been limited by a lack of knowledge of the distribution of particles within the medium. For the last few years, a method, developed over 25 years ago to study the distribution of Radon daughters within filter media made of cellulose fibers, has been reused and applied to radioactive and fluorescent aerosols penetration studies. This method enables determination of aerosol distribution on the surface and inside the filter medium by peeling away successive layers using an adhesive tape and measuring the specific amounts removed each time. Knowledge of aerosol penetration within the filter has revealed that, for a give aerosol, particle distribution inside the filter rapidly decreased exponentially and that fixation on the filter's front surface rapidly superseded penetration inside the medium. The deposit profiles thus measured have made it possible to propose a model for determining the rate of filter pressure drop increase that closely agrees with experimental results

  17. HEPA Filter Performance under Adverse Conditions

    International Nuclear Information System (INIS)

    This study involved challenging nuclear grade high-efficiency particulate air (HEPA) filters under a variety of conditions that can arise in Department of Energy (DOE) applications such as: low or high RH, controlled and uncontrolled challenge, and filters with physically damaged media or seals (i.e., leaks). Reported findings correlate filter function as measured by traditional differential pressure techniques in comparison with simultaneous instrumental determination of up and down stream PM concentrations. Additionally, emission rates and failure signatures will be discussed for filters that have either failed or exceeded their usable lifetime. Significant findings from this effort include the use of thermocouples up and down stream of the filter housing to detect the presence of moisture. Also demonstrated in the moisture challenge series of tests is the effect of repeated wetting of the filter. This produces a phenomenon referred to as transient failure before the tensile strength of the media weakens to the point of physical failure. An evaluation of the effect of particle size distribution of the challenge aerosol on loading capacity of filters is also included. Results for soot and two size distributions of KCl are reported. Loading capacities for filters ranged from approximately 70 g of soot to nearly 900 g for the larger particle size distribution of KCl. (authors)

  18. Experience with HEPA filters at United States nuclear installations

    International Nuclear Information System (INIS)

    Part 50 of Title 10 of the United States Code of Federal Regulations requires that a number of atmosphere cleanup systems be included in the design of commercial nuclear power plants to be licensed in the United States. These filtering systems are to contain high efficiency particulate air (HEPA) filters for removal of radioactive particulate matter generated during normal and accident conditions. Recommendations for the design, testing and maintenance of the filtering systems and HEPA filter components are contained in a number of United States Nuclear Regulatory Commission documents and industry standards. This paper will discuss this published guidance available to designers of filtering systems and the plant operators of U.S. commercial nuclear power plants. The paper will also present a survey of published reports of experience with HEPA filters, failures and possible causes for the failures, and other abnormal occurrences pertaining to HEPA filters installed in U.S. nuclear power installations. A discussion will be included of U.S. practices for qualification of HEPA filters before installation, and verification of continued performance capability at scheduled intervals during operation

  19. Determination of HEPA Filter Efficiency With Diocthyl Pthalate Aerosol

    International Nuclear Information System (INIS)

    Ultrafine aerosol filtration by HEPA (High Efficiency Particulate Air) filter has been determinated experimentally, based on the measurement of monodisperse Diocthyl Pthalate (DOP) aerosol concentration before and after passing the test filter. Using this technique, filter efficiency can be determined as a function of aerosol diameter with range from 0.017 to 0.747 um. The average efficiencies for Whatman -41 ; Whatman -42 and Whatman GF/A filters were 56.14 %; 95,74 %; and 99.65 % respectively. Gelman A Fiber Glass and Whatman membrane filter have fulfilled criterion as HEPA filter according to standard of IAEA, because of their minimum effiency of 99.90 %

  20. Scanning electron microscopy of ULPA and HEPA filtering papers

    International Nuclear Information System (INIS)

    The behavior of newly developed ULPA and HEPA filtering papers has been examined in an abnormal condition due to overheating up to 400 degree C. A noteworth failure in mechanical resistance has been observed, whereas efficiency was scarcely affected. Scanning electron microscopy showed that observed anticipated failures were accompanied with ruptures of the glass microfibers of the papers

  1. ALTERNATE HIGH EFFICIENCY PARTICULATE AIR (HEPA) FILTRATION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Bruce Bishop; Robert Goldsmith; Karsten Nielsen; Phillip Paquette

    2002-08-16

    In Phase IIA of this project, CeraMem has further developed and scaled up ceramic HEPA filters that are appropriate for use on filtration of vent gas from HLW tanks at DOE sites around the country. This work included procuring recrystallized SiC monoliths, developing membrane and cement materials, and defining a manufacturing process for the production of prototype full sizes HEPA filters. CeraMem has demonstrated that prototype full size filters can be manufactured by producing 9 full size filters that passed DOP aerosol testing at the Oak Ridge Filter Test Facility. One of these filters was supplied to the Savannah River Technical Center (SRTC) for process tests using simulated HLW tank waste. SRTC has reported that the filter was regenerable (with some increase in pressure drop) and that the filter retained its HEPA retention capability. CeraMem has also developed a Regenerable HEPA Filter System (RHFS) design and acceptance test plan that was reviewed by DOE personnel. The design and acceptance test plan form the basis of the system proposal for follow-on work in Phase IIB of this project.

  2. ALTERNATE HIGH EFFICIENCY PARTICULATE AIR (HEPA) FILTRATION SYSTEM

    International Nuclear Information System (INIS)

    In Phase IIA of this project, CeraMem has further developed and scaled up ceramic HEPA filters that are appropriate for use on filtration of vent gas from HLW tanks at DOE sites around the country. This work included procuring recrystallized SiC monoliths, developing membrane and cement materials, and defining a manufacturing process for the production of prototype full sizes HEPA filters. CeraMem has demonstrated that prototype full size filters can be manufactured by producing 9 full size filters that passed DOP aerosol testing at the Oak Ridge Filter Test Facility. One of these filters was supplied to the Savannah River Technical Center (SRTC) for process tests using simulated HLW tank waste. SRTC has reported that the filter was regenerable (with some increase in pressure drop) and that the filter retained its HEPA retention capability. CeraMem has also developed a Regenerable HEPA Filter System (RHFS) design and acceptance test plan that was reviewed by DOE personnel. The design and acceptance test plan form the basis of the system proposal for follow-on work in Phase IIB of this project

  3. A review of DOE HEPA filter component test activities

    Energy Technology Data Exchange (ETDEWEB)

    Slawski, J.W.; Bresson, J.F. [Informatics Corp., Inc., Albuquerque, NM (United States); Scripsick, R.C. [Los Alamos National Lab., NM (United States)

    1997-08-01

    All HEPA filters purchased for installation in DOE nuclear facilities are required to be tested at a Filter Test Facility (FTF) prior to installation. The number of HEPA filters purchased by DOE has been reduced so much that the Hanford FTF was closed. From Fiscal Year (FY) 1992 to 1994, funding was not provided to the FTF Technical Support Group (TSG) at the Los Alamos National Laboratory. As a consequence, Round Robin Tests (RRTs), performed twice each year by the FTFs to assess constituency of test results among the FTFs, were not performed in FY 1992 and FY 1993. The Annual Reports of FTF test activities were not prepared for FY 1992 - 1995. Technical support provided to the FTFs was minimal. There is talk of closing a second FTF, and ongoing discussions as to whether DOE will continue to fund operation of the FTFs. In FY 1994, DOE Defense Programs commenced funding the TSG. RRT data for FY 1994 and 1995 have been entered into the database; the FY 1994 RRT report has been issued; and the FY 1995 RRT report is in progress. Data from semiannual reports have been retrieved and entered into the database. Standards related to HEPA filter test and procurement activities are now scheduled for issuance by FY 1996. Continuation of these activities depends on whether DOE will continue to support the HEPA filter test program. The history and activities of the FTFs and the TSG at Los Alamos have been reported at previous Air Cleaning Conferences. Data from the FY 1991 Annual Report of FTF activities was presented at the 1992 Air Cleaning Conference. Preparation of the Annual Reports was temporarily suspended in 1992. However, all of the FTF Semiannual report data have been retrieved and entered into the data base. This paper focuses primarily on the results of HEPA filter tests conducted by FTFs during FY 1992 - FY 1995, and the possible effects of the DOE program uncertainties on the quality of HEPA filters for installation at the DOE sites. 15 refs., 13 tabs.

  4. Overhead robot system for remote HEPA filter replacement

    International Nuclear Information System (INIS)

    A high-efficiency particulate air (HEPA) filter system for facility exhaust air filtraction of radioactive particles has been designed that utilizes a modified industrial gantry robot to remotely replace filter elements. The system filtration design capacity can be readily changed by increasing or decreasing the number of plenums, which only affects the cell length and robot bridge travel. The parallel flow plenum design incorporates remote HEPA filter housings, which are commercially available. Filter removal and replacement is accomplished with the robot under sequenced program control. A custom-designed robot control console, which interfaces with the standard gantry robot power center controller, minimizes operator training. Critical sequence steps are operator verified, using closed-circuit television (CCTV), before proceeding to the next programmed stop point. The robot can be operated in a teleoperator mode to perform unstructured maintenance tasks, such as replacing filter housing components and cell lights

  5. The effects of temperature on HEPA filter media

    International Nuclear Information System (INIS)

    This paper presents the results from a series of experiments to study the changes in the physical properties of HEPA filter media after exposure to elevated temperatures. Data are presented for papers heated in the range 120-500 degrees C. The observed changes in strength and paper stiffness are explained in terms of alterations to the binder due to thermal degradation. The information generated has clarified a particular failure mode associated with a small number of filter inserts at elevated temperatures

  6. Performance of HEPA filters under hot dynamic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Frankum, D.P.; Costigan, G. [AEA Technology, Oxfordshire (United Kingdom)

    1995-02-01

    Accidents in nuclear facilities involving fires may have implications upon the ventilation systems where high efficiency particulate air (HEPA) filters are used to minimise the airborne release of radioactive or toxic particles. The Filter Development Section at Harwell Laboratory has been investigating the effect of temperature on the performance of HEPA filters under hot dynamic conditions[{sub 1}] for a number of years. The test rig is capable of delivering air flows of 10001/s (at ambient conditions) at temperatures up to 500{degrees}C, where measurements of the penetration and pressure drop across the filter are obtained. This paper reports the experiments on different constructions of HEPA filters; rectangular and circular. The filters were tested at an air temperature of 200{degrees}C for up to 48 hours at the rated airflow to assess their performance. The penetration measurements for rectangular filters were observed to be below 0.021% after prolonged operation. In a number of cases, holes appeared along the pleat creases of circular filters although the penetration remained below 1%. The sealing gasket for these filters was noted to deform with temperature, permitting a leakage path. A prototype high strength circular filter was evaluated at temperatures of up to 400{degrees}C with a penetration less than 0.65%.

  7. Closure of 324 Facility potential HEPA filter failure unreviewed safety questions

    International Nuclear Information System (INIS)

    This document summarizes the activities which occurred to resolve an Unreviewed Safety Question (USQ) for the 324 Facility [Waste Technology Engineering Laboratory] involving Potential HEPA Filter Breach. The facility ventilation system had the capacity to fail the HEPA filters during accident conditions which would totally plug the filters. The ventilation system fans were modified which lowered fan operating parameters and prevented HEPA filter failures which might occur during accident conditions

  8. Testing HEPA filter response to high flow velocity and overpressure

    International Nuclear Information System (INIS)

    In cooperation with the Los Alamos National Laboratory (LANL) HEPA filters presently on the market and modified versions were tested using the LANL blowdown facility. The filter response during the test was documented on high speed films which indicated, among other information, the load when first failure occurred and the failure mode. Differential pressure through the filter and velocity were measured with variable reluctance pressure transducers and an oscilloscope recorder. New HEPA filters show first failures already at differential pressures between some 4 kPa and 17 kPa. The better results are obtained with conventionally pleated filter paper packs sealed in a wooden frame with a polyurethane material. However, these filters cannot be used under accident conditions. Metal frame filters considered as potential filters for accident situations showed only poor resistance against overpressures. The weakest point in such filters proved to be the attachment of the filter pack in the metal frame, which limited the loadability to about 10 kPa. As soon as proper attachment is assured, the integrity of the filter pack limits the admissible differential pressure. Through some modifications of wood frame filters, physical integrity was improved to a failure pressure of 24 kPa. During operation, the filter elements are loaded with dust. Dust loading up to 1000 Pa pressure drop at rated flow, which was simulated with polystyrene latex aerosols, was found to reduce the mechanical stability by up to 40%. Pressure drop characteristics of HEPA filters influence the occurrence of high differential pressures and high mechanical loads. Pressure drops (δp) of unloaded and preloaded filters were investigated up to high flow velocities (v). Measured data can be presented in the form of δp=av+bv2, where a and b are constants. Theory, in contrast, predicts a linear relationship. The deviation is due to deformations of the pleated filter paper pack with increasing flow velocity and

  9. Behavior of HEPA filters under high humidity airflows

    International Nuclear Information System (INIS)

    To help determine and improve the safety margins of High Efficiency Particulate Air (HEPA) filter units in nuclear facilities under possible accident conditions, the structural limits and failure mechanisms of filter in high-humidity airflows were established and the fundamental physical phenomena underlying filter failure or malfunction in humid air were identified. Empirical models for increases in filter pressure drop with time in terms of the relevant airstream parameters were also developed. The weaknesses of currently employed humidity countermeasures used in filter protection are discussed and fundamental explanations for reported filter failures in normal service are given. (orig./DG)

  10. Development of acid-resistant HEPA filter components

    International Nuclear Information System (INIS)

    Laboratory and in-service tests of various HEPA filter media and separators were conducted to establish their relative resistances to HNO3-HF vapors. Filter medium of glass fiber with Nomex additive and aluminum separators with an epoxy-vinyl coating have performed quite well in the acid environment in the laboratory, and in prototype-filters placed in service in a plenum at Rocky Flats. Proprietary filters with new design and/or components were also tested in service with generally good results

  11. Preliminary studies to determine the shelf life of HEPA filters

    International Nuclear Information System (INIS)

    We have completed a preliminary study using filter media tests and filter qualification tests to investigate the effect of shelf-life on HEPA filter performance. Our media studies showed that the tensile strength decreased with age, but the data were not sufficient to establish a shelf-life. Thermogravimetric analyses demonstrated that one manufacturer had media with low tensile strength due to insufficient binder. The filter qualification tests (heated air and overpressure) conducted on different aged filters showed that filter age is not the primary factor affecting filter performance; materials and the construction design have a greater effect. An unexpected finding of our study was that sub-standard HEPA filters have been installed in DOE facilities despite existing regulations and filter qualification tests. We found that the filter with low tensile strength failed the overpressure test. The same filter had passed the heated air test, but left the filter so structurally weak, it was prone to blow-out. We recommend that DOE initiate a filter qualification program to prevent this occurrence

  12. Improved HEPA Filter Technology for Flexible and Rigid Containment Barriers

    Energy Technology Data Exchange (ETDEWEB)

    P. A. Pinson

    1998-07-01

    Safety and reliability in glovebox operations can be significantly improved and waste packaging efficiencies can be increased by inserting flexible, lightweight, high capacity HEPA filters into the walls of plastic sheet barriers. This HEPA filter/barrier technology can be adapted to a wide variety of applications: disposable waste bags, protective environmental barriers for electronic equipment, single or multiple use glovebag assemblies, flexible glovebox wall elements, and room partitions. These reliable and inexpensive filtered barriers have many uses in fields such as radioactive waste processing, HVAC filter changeout, vapor or grit blasting, asbestos cleanup, pharmaceutical, medical, biological, and electronic equipment containment. The applications can result in significant cost savings, improved operational reliability and safety, and total waste volume reduction. This technology was developed at the Argonne National Laboratory-West (ANL-W) in 1993 and has been used at ANL-W since then at the TRU Waste Characterization Chamber Gloveboxes. Another 1998 AGS Conference paper titled "TRU Waste Characterization Gloveboxes", presented by Mr. David Duncan of ANL-W, describes these boxes.

  13. Multiple HEPA filter test methods, January--December 1976

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, B.; Kyle, T.; Osetek, D.

    1977-06-01

    The testing of tandem high-efficiency particulate air (HEPA) filter systems is of prime importance for the measurement of accurate overall system protection factors. A procedure, based on the use of an intra-cavity laser particle spectrometer, has been developed for measuring protection factors in the 10/sup 8/ range. A laboratory scale model of a filter system was constructed and initially tested to determine individual HEPA filter characteristics with regard to size and state (liquid or solid) of several test aerosols. Based on these laboratory measurements, in-situ testing has been successfully conducted on a number of single and tandem filter installations within the Los Alamos Scientific Laboratory as well as on extraordinary large single systems at Rocky Flats. For the purpose of recovery and for simplified solid waste disposal, or prefiltering purposes, two versions of an inhomogeneous electric field air cleaner have been devised and are undergoing testing. Initial experience with one of the systems, which relies on an electrostatic spraying phenomenon, indicates performance efficiency of greater than 99.9% for flow velocities commonly used in air cleaning systems. Among the effluents associated with nuclear fuel reprocessing is /sup 129/I. An intra-cavity laser detection system is under development which shows promise of being able to detect mixing ratios of one part in 10/sup 7/, I/sub 2/ in air.

  14. Preliminary studies to determine the shelf life of HEPA filters

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, H.; Fretthold, J.K.; Rainer, F. [Lawrence Livermore National Laboratory, CA (United States)] [and others

    1995-02-01

    We have completed a preliminary study using filter media tests and filter qualification tests to investigate the effect of shelf-life on HEPA filter performance. Our media studies showed that the tensile strength decreased with age, but the data were not sufficient to establish a shelf-life. Thermogravimetric analyses demonstrated that one manufacturer had media with low tensile strength due to insufficient binder. The filter qualification tests (heated air and overpressure) conducted on different aged filters showed that filter age is not the primary factor affecting filter performance; materials and the construction design have a greater effect. An unexpected finding of our study was that sub-standard HEPA filters have been installed in DOE facilities despite existing regulations and filter qualification tests. We found that the filter with low tensile strength failed the overpressure test. The same filter had passed the heated air test, but left the filter so structurally weak, it was prone to blow-out. We recommend that DOE initiate a filter qualification program to prevent this occurrence.

  15. HEPA Filter Disposal Write-Up 10/19/16

    Energy Technology Data Exchange (ETDEWEB)

    Loll, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-10-20

    Process knowledge (PK) collection on HEPA filters, is handled via the same process as other waste streams at LLNL. The Field technician or Characterization point of contact creates an information gathering document (IGD) in the IGD database, with input provided from the generator, and submits it for electronic approval. This document is essentially a waste generation profile, detailing the physical, chemical as well as radiological characteristics, and hazards, of a waste stream. It will typically contain a general, but sometimes detailed, description of the work processes which generated the waste. It will contain PK as well as radiological, and industrial hygiene analytical swipe results, and any other analytical or other supporting knowledge related to characterization. The IGD goes through an electronic approval process to formalize the characterization and to ensure the waste has an appropriate disposal path. The waste generator is responsible for providing initial process knowledge information, and approves the IGD before it routed to chemical and radiological waste characterization professionals. This is the standard characterization process for LLNL generated HEPA Filters.

  16. Thermal treatment for radioactive HEPA filter media generated from nuclear facilities

    International Nuclear Information System (INIS)

    Many radioactive HEPA filter wastes are generated from the high radioactive facilities in operation, improvement and repair, and under decommissioning. Spent filter wastes of about 1,500 drums have been stored in the waste storage facility of the Korea Atomic Energy Research Institute (KAERI) since its operation. In the future, a lot of HEPA filters in high radioactivity will be occurred from pyroprocessing which is treatment facility for used nuclear fuel. Therefore, the technology development for the radioactive HEPA filter treatment is necessary for effective management and safe disposal for HEPA filter wastes. The thermal treatment has been known as one of the most effective technologies for volume reduction and recycling of metallic radioactive wastes. In this study, the thermal treatment for radioactive HEPA filter media was conducted for the volume reduction. The volatility and leachability for heavy metals and radionuclides in radioactive HEPA filter media were analyzed to investigate the volatilization during thermal treatment and stability after thermal treatment for safe disposal, respectively. The knowledge gained from this study will aid in the development of thermal treatment for HEPA filter media

  17. Potential for Hepa filter damage from water spray systems in filter plenums

    International Nuclear Information System (INIS)

    The water spray systems in high efficiency particulate air (HEPA) filter plenums that are used in nearly all Department of Energy (DOE) facilities for protection against fire was designed under the assumption that the HEPA filters would not be damaged by the water sprays. The most likely scenario for filter damage involves filter plugging by the water spray, followed by the fan blowing out the filter medium. A number of controlled laboratory tests that were previously conducted in the late 1980s are reviewed in this paper to provide a technical basis for the potential HEPA filter damage by the water spray system in HEPA filter plenums. In addition to the laboratory tests, the scenario for HEPA filter damage during fires has also occurred in the field. Afire in a four-stage, HEPA filter plenum at Rocky Flats in 1980 caused the first three stages of HEPA filters to blow out of their housing and the fourth stage to severely bow. Details of this recently declassified fire are presented in this paper. Although these previous findings suggest serious potential problems exist with the current water spray system in filter plenum , additional studies are required to confirm unequivocally that DOE's critical facilities are at risk

  18. Behavior of HEPA filter systems under accident conditions

    International Nuclear Information System (INIS)

    With respect to the behavior of HEPA filters under high humidity conditions, emphasis was placed on the study of the differential pressure increase. Under fog conditions, the differential pressure of dust loaded filters increased within minutes, up to values sufficient to damage normal commercial filters units. The investigation into the failure mechanisms was completed with the development of an equation to calculate filter medium tensile stresses for two of the three most important modes of failure. Initial work was begun toward the development of a computer code to model transient fluiddynamic and thermodynamic conditions in complex air cleaning systems. Further investigation into the transmission of weak shock waves in air-cleaning system ductwork were carried out in branches of ducts with square cross-sections and with variable cross-sections. (orig./DG)

  19. In-service ageing effects on HEPA filters

    International Nuclear Information System (INIS)

    HEPA filters with in-plant lives of up to ten years have been obtained from both nuclear and non-nuclear facilities within the United Kingdom and have been examined in detail to identify whether in-service deterioration has taken place. Filters with radioactive contamination levels of up to 100 μCi α and 1 mCi βγ have been care-fully disassembled and the casing, spacers, gaskets, and seals examined. Paper samples from each disassembled filter have been subjected to an extensive range of tests including tensile strength, flexibility, particle penetration, burst strength and water repellency measurements. The results of this work indicate reductions in paper strength properties and serious corrosion of aluminium spacers leading to their adhesion to the filter paper. (author)

  20. Method for HEPA filter leak scanning with differentiating aerosol detector

    Energy Technology Data Exchange (ETDEWEB)

    Kovach, B.J.; Banks, E.M.; Wikoff, W.O. [NUCON International, Inc., Columbus, OH (United States)

    1997-08-01

    While scanning HEPA filters for leaks with {open_quotes}Off the Shelf{close_quote} aerosol detection equipment, the operator`s scanning speed is limited by the time constant and threshold sensitivity of the detector. This is based on detection of the aerosol density, where the maximum signal is achieved when the scanning probe resides over the pinhole longer than several detector time-constants. Since the differential value of the changing signal can be determined by observing only the first small fraction of the rising signal, using a differentiating amplifier will speed up the locating process. The other advantage of differentiation is that slow signal drift or zero offset will not interfere with the process of locating the leak, since they are not detected. A scanning hand-probe attachable to any NUCON{reg_sign} Aerosol Detector displaying the combination of both aerosol density and differentiated signal was designed. 3 refs., 1 fig.

  1. Investigation and deactivation of B Plant HEPA filters

    International Nuclear Information System (INIS)

    This paper describes the integrated approach used to manage environmental, safety, and health considerations related to the B Plant canyon exhaust air filters at the US Department of Energy (DOE) Hanford Site. The narrative illustrates the development and implementation of integrated safety management as applied to a facility and its systems undergoing deactivation. During their lifetime, the high efficiency particulate air (HEPA) filters prevented the release of significant quantities of radioactive materials into the air. As the material in B Plant AVESF accumulated on the filters, it created an unusual situation. Over long periods of time, the radiation dose from the filter loading, combined with aging and chemical exposure actually degrade those filters which were intended to protect against any release to the environment

  2. Flow resistance of HEPA filters in supersaturated airstreams

    International Nuclear Information System (INIS)

    A loss of coolant accident or fire suppression with water sprays would release free moisture into the air within the containment building of a nuclear reactor. The resulting high air humidity could be expected to unfavorably affect the behavior of the HEPA filters in the facility air cleaning systems. Still to be found in the literature are instances of moisture related deterioration in filter performance during less serious incidents, and even during normal operations. One phenomenon which contributes to filter failure, and which also causes air-cleaning system malfunction characterized by drastically reduced flow rates, is the increase in filter differential pressure resulting from supersaturated airflow. In order to better evaluate the performance and the reliability of filters exposed to fog, a study of the factors which influence filter pressure drop was carried out in tests of clean and dust loaded full scale HEPA-filter units. Investigated were the effects of several airstream parameters and such filter characteristics as manufacturer, design, pack geometry, extent and type of dust loading, as well as pleat orientation to the airflow. A discontinuous gravimetric method employing full-size filter units as sampling filters was successfully implemented to determine the average liquid moisture content of the airstream with an uncertainty of ≤10%. The dust loading in filters removed from service and the liquid moisture content of the air proved to most adversely affect the rate and extent of the pressure drop increase. Reductions in the susceptibility of clean filters to pressure drop increases can be obtained by changes in filter geometry, design or orientation to the airflow that enhance the drainage of water from the filter medium. However, the predominance of the adverse influence of dust loading appears to be able to counteract the effectiveness of the improvements studied

  3. Criteria for calculating the efficiency of HEPA filters during and after design basis accidents

    International Nuclear Information System (INIS)

    We have reviewed the literature on the performance of high efficiency particulate air (HEPA) filters under normal and abnormal conditions to establish criteria for calculating the efficiency of HEPA filters in a DOE nonreactor nuclear facility during and after a Design Basis Accident (DBA). The literature review included the performance of new filters and parameters that may cause deterioration in the filter performance such as filter age, radiation, corrosive chemicals, seismic and rough handling, high temperature, moisture, particle clogging, high air flow and pressure pulses. The deterioration of the filter efficiency depends on the exposure parameters; in severe exposure conditions the filter will be structurally damaged and have a residual efficiency of 0%. Despite the many studies on HEPA filter performance under adverse conditions, there are large gaps and limitations in the data that introduce significant error in the estimates of HEPA filter efficiencies under DBA conditions. Because of this limitation, conservative values of filter efficiency were chosen when there was insufficient data

  4. Particle Removal Efficiency of the Portable HEPA Air Cleaner in a Simulated Hospital Ward

    DEFF Research Database (Denmark)

    Qian, Hua; Li, Yuguo; Sun, Hequan;

    2010-01-01

    Use of a HEPA (high efficiency particulate air) filter in a room is believed to assist in reducing the risk of transmission of infectious diseases through removing the particles or large droplets to which pathogens may be attached. Use of a portable HEPA filter(s) in hospital wards is hypothesized...... of beds in an isolation ward is insufficient. An experiment was conducted in a full scale experimental ward with a dimension of 6.7 m × 6 m × 2.7 m and 6 beds to test these hypotheses for a portable HEPA filter. The removal efficiency for different size particles was measured at different locations...... filter (for particle removal only) is from 2.7 to 5.6 ACH in the ward. The strong supply air jet from the portable HEPA filter interacted with the room airflow pattern and became dominate, introducing global airflow mixing in the room. Background noise levels were also measured and noise level...

  5. Evaluation of the Hepa Wash® treatment in pigs with acute liver failure

    OpenAIRE

    Al-Chalabi, Ahmed; Matevossian, Edouard; v. Thaden, Anne-K.; Luppa, Peter; Neiss, Albrecht; Schuster, Tibor; Yang, Zejian; Schreiber, Catherine; Schimmel, Patrick; Nairz, Ewald; Perren, Aurel; Radermacher, Peter; Huber, Wolfgang; Schmid, Roland M.; Kreymann, Bernhard

    2013-01-01

    Background Mortality of patients with acute liver failure (ALF) is still unacceptably high. Available liver support systems are still of limited success at improving survival. A new type of albumin dialysis, the Hepa Wash® system, was newly introduced. We evaluated the new liver support system as well as the Molecular Adsorbent Recycling System (MARS) in an ischemic porcine model of ALF. Methods In the first study animals were randomly allocated to control (n=5) and Hepa Wash (n=6) groups. In...

  6. Evaluation of the Hepa Wash® treatment in pigs with acute liver failure

    OpenAIRE

    Al-Chalabi, Ahmed; Matevossian, Edouard; v. Thaden, Anne-K.; Luppa, Peter; Neiss, Albrecht; Schuster, Tibor; Yang, Zejian; Schreiber, Catherine; Schimmel, Patrick; Nairz, Ewald; Radermacher, Peter; Huber, Wolfgang; Schmid, Roland M.; Kreymann, Bernhard; Perren, Aurel

    2013-01-01

    BACKGROUND Mortality of patients with acute liver failure (ALF) is still unacceptably high. Available liver support systems are still of limited success at improving survival. A new type of albumin dialysis, the Hepa Wash® system, was newly introduced. We evaluated the new liver support system as well as the Molecular Adsorbent Recycling System (MARS) in an ischemic porcine model of ALF. METHODS In the first study animals were randomly allocated to control (n=5) and Hepa Wash (n=6...

  7. Safety evaluation for packaging (onsite) for the Pacific Northwest National Laboratory HEPA filter box

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, J.C.

    1998-07-15

    This safety evaluation for packaging (SEP) evaluates and documents the safe onsite transport of eight high-efficiency particulate air (HEPA) filters in the Pacific Northwest National Laboratory HEPA Filter Box from the 300 Area of the Hanford Site to the Central Waste Complex and on to burial in the 200 West Area. Use of this SEP is authorized for 1 year from the date of release.

  8. The high efficiency steel filters for nuclear air cleaning

    International Nuclear Information System (INIS)

    We have, in cooperation with industry, developed high-efficiency filters made from sintered stainless-steel fibers for use in several air-cleaning applications in the nuclear industry. These filters were developed to overcome the failure modes in present high-efficiency particulate air (HEPA) filters. HEPA filters are made from glass paper and glue, and they may fail when they get hot or wet and when they are overpressured. In developing our steel filters, we first evaluated the commercially available stainless-steel filter media made from sintered powder and sintered fiber. The sintered-fiber media performed much better than sintered-powder media, and the best media had the smallest fiber diameter. Using the best media, we then built prototype filters for venting compressed gases and evaluated them in our automated filter tester. 12 refs., 20 figs

  9. High efficiency steel filters for nuclear air cleaning

    International Nuclear Information System (INIS)

    The authors have, in cooperation with industry, developed high-efficiency filters made from sintered stainless-steel fibers for use in several air-cleaning applications in the nuclear industry. These filters were developed to overcome the failure modes in present high-efficiently particulate air (HEPA) filters. HEPA filters are made from glass paper and glue, and they may fail when they get hot or wet and when they are overpressured. In developing steel filters, they first evaluated the commercially available stainless-steel filter media made from sintered powder and sintered fiber. The sintered-fiber media performed much better than sintered-powder media, and the best media had the smallest fiber diameter. Using the best media, prototype filters were then built for venting compressed gases and evaluated in their automated filter tester

  10. Electrospun TiO₂ nanofelt surface-decorated with Ag nanoparticles as sensitive and UV-cleanable substrate for surface enhanced Raman scattering.

    Science.gov (United States)

    Zhao, Yong; Sun, Lei; Xi, Min; Feng, Quan; Jiang, Chaoyang; Fong, Hao

    2014-04-23

    In this study, the free-standing electrospun nanofibrous mat (i.e., nanofelt) consisting of anatase-phase TiO2 nanofibers with diameters of ∼200 nm was prepared, and the nanofelt was subsequently surface-decorated with Ag nanoparticles via an electroless plating method. The sensitivity toward surface enhanced Raman scattering (SERS) and UV-cleanable property of electrospun TiO2/Ag nanofelt were then investigated. In the SERS tests, the target analyte (i.e., 4-mercaptobenzoic acid, Rhodamine 6G, and 4-aminothiophenol) was first adsorbed onto the TiO2/Ag nanofelt as the probe analyte; this was followed by the measurements of Raman intensity and SERS maps. Thereafter, the nanofelt adsorbed with target analyte was cleaned and regenerated/recovered upon UV irradiation in O2-saturated water, and the removal of target analyte was attributed to photodegradation property of anatase-phase TiO2. This study suggested that the electrospun TiO2/Ag nanofelt would be promising as SERS-active substrate with UV-cleanable property for cost-effective and reproducible SERS applications.

  11. Radioactive analysis of a spent HEPA filter using the distribution characteristics of the captured radionuclide

    International Nuclear Information System (INIS)

    To investigate the species and the distribution of the captured nuclides in a HEPA filter, it was dismantled into a metal part and a filter medium part to obtain a filter medium. From the nuclide analysis results for a filter medium part through pre-treatment of it, it was possible to obtain three kinds of typical distributions in view of the distribution of the captured nuclides in the filter medium. When considering these distribution characteristics of the captured radionuclide, the region showing the high concentration of the captured nuclides was the intake or the outlet part of the HEPA filter. On the other side, the middle part generally represented a uniform distribution below the average concentration of the captured nuclides. Therefore, in the event of taking a representative sample of a HEPA filter at the intake and the outlet part, the results of a nuclide analysis for that sample could be estimated as existing in the range from 1.0 to 1.5 times the real concentration of the nuclides captured by a filter medium. As a result, to conduct a radionuclide assessment of a spent HEPA filter without a dismantlement of it, the analysis results for a representative sample taken from both the intake and the outlet part of a spent HEPA filter could be regarded as an average value for the corresponding HEPA filter. (author)

  12. Performance limitations of HEPA filters at high temperatures

    International Nuclear Information System (INIS)

    Over the last few years a number of studies have investigated the performance of High Efficiency Particulate Air (HEPA) filters under simulated accident conditions modelling a fire or high temperature airflow. Earlier studies have concentrated on evaluating the insert performance when subjected to hot airflows at 500 degree C through the clean filter. This temperature was selected on the basis of a static oven test for flammability required by the purchasing specification. At these temperatures, the work showed that the filters could fail catastrophically. Calculations have shown that the temperature seen by main filter banks, distant from the source of a fire, would be of the order of 250 degree C. The work has now extended to an investigation of the performance of loaded, as opposed to clean filters at temperatures up to 275 degree C thereby attempting to produce a more representative model of the real fire/accident condition. The work reported here has considered three filter designs and records their performance at temperatures of up to 275 degree C for periods of up to 24 hours. The filters all have an initial pressure differential of 750 Pa produced by loading with a test dust

  13. Pilot-scale tests of HEME and HEPA dissolution process

    Energy Technology Data Exchange (ETDEWEB)

    Qureshi, Z.H.; Strege, D.K.

    1994-06-01

    A series of pilot-scale demonstration tests for the dissolution of High Efficiency Mist Eliminators (HEME`s) and High Efficiency Particulate Airfilters (HEPA) were performed on a 1/5th linear scale. These fiberglass filters are to be used in the Defense Waste Processing Facility (DWPF) to decontaminate the effluents from the off-gases generated during the feed preparation process and vitrification. When removed, these filters will be dissolved in the Decontamination Waste Treatment Tank (DWTT) using 5 wt% NaOH solution. The contaminated fiberglass is converted to an aqueous stream which will be transferred to the waste tanks. The filter metal structure will be rinsed with process water before its disposal as low-level solid waste. The pilot-scale study reported here successfully demonstrated a simple one step process using 5 wt% NaOH solution. The proposed process requires the installation of a new water spray ring with 30 nozzles. In addition to the reduced waste generated, the total process time is reduced to 48 hours only (66% saving in time). The pilot-scale tests clearly demonstrated that the dissolution process of HEMEs has two stages - chemical digestion of the filter and mechanical erosion of the digested filter. The digestion is achieved by a boiling 5 wt% caustic solutions, whereas the mechanical break down of the digested filter is successfully achieved by spraying process water on the digested filter. An alternate method of breaking down the digested filter by increased air sparging of the solution was found to be marginally successful are best. The pilot-scale tests also demonstrated that the products of dissolution are easily pumpable by a centrifugal pump.

  14. HEPA Filter Differential Pressure Fan Interlock System Functional Requirements and Technical Design Criteria

    International Nuclear Information System (INIS)

    Double-shell tanks (DSTs) and Double Contained Receiver Tanks (DCRTs) are actively ventilated, along with certain single-shell tanks (SSTs) and other RPP facilities. The exhaust air stream on a typical primary ventilation system is drawn through two stages of high-efficiency particulate air (HEPA) filtration to ensure confinement of airborne radioactive materials. Active ventilation exhaust stacks require a stack CAM interlock to detect releases from postulated accidents, and to shut down the exhaust fan when high radiation levels are detected in the stack airstream. The stack CAM interlock is credited as a mitigating control to stop continued unfiltered radiological and toxicological discharges from the stack, which may result from an accident involving failure of a HEPA filter. This document defines the initial technical design baseline for a HEPA filter AP fan interlock system

  15. HEPA filters of high structural strength for nuclear air cleaning systems

    International Nuclear Information System (INIS)

    HEPA-filter media, though having excellent particle-removal efficiencies, remain characterized as rather brittle, fragile, and weak materials. As a result, undesired structural damage, followed by significant losses in filtration efficiency, can easily occur in handling, transport, and even normal operation of filter units. In recent years, extensive investigations into the structural limits of HEPA filters in dry air and under extended exposure to high-humidity airflow have been carried out. In the course of this work, the failure modes and the underlying failure mechanisms were thoroughly studied. On the basis of the information obtained, considerable improvements in the structural strength of HEPA filters could be achieved. As verified by removal efficiency tests, differential pressures up to 56 kPA in dry air and 15 kPA after extended operation under fog conditions were proved to be sustainable without mechanical damage to the filter medium

  16. Summary of meeting on disposal of LET ampersand D HEPA filters

    International Nuclear Information System (INIS)

    This report is a compilation of correspondence between Westinghouse Idaho Nuclear Company and the US EPA over a period of time from 1988 to 1992 (most from 1991-92) regarding waste management compliance with EPA regulations. Typical subjects include: compliance with satellite accumulation requirements; usage of ''Sure Shot'' containers in place of aerosol cans; notice of upcoming recyclable battery shipments; disposition of batteries; HEPA filter leach sampling and permit impacts; functional and operation requirements for the spent filter handling system; summary of meeting on disposal of LET and D HEPA filters; solvent substitution database report; and mercury vapor light analytical testing

  17. The development of non-separation HEPA filter in nuclear field

    International Nuclear Information System (INIS)

    At present, to lower the operation cost of cleaning equipment and to reduce the solid waste amount are urgent tasks for the air cleaning system in nuclear facilities. In order to meet this demand a new type air cleaning equipment, non-separation HEPA filter (high efficiency particulate air filter), has been developed. The peculiarity of this non-separation HEPA filter, the developed status in China and abroad as well as some key issues are systematically summarized in the article. (1 ref., 5 figs., 7 tabs.)

  18. Summary of meeting on disposal of LET&D HEPA filters

    Energy Technology Data Exchange (ETDEWEB)

    1991-11-21

    This report is a compilation of correspondence between Westinghouse Idaho Nuclear Company and the US EPA over a period of time from 1988 to 1992 (most from 1991-92) regarding waste management compliance with EPA regulations. Typical subjects include: compliance with satellite accumulation requirements; usage of ``Sure Shot`` containers in place of aerosol cans; notice of upcoming recyclable battery shipments; disposition of batteries; HEPA filter leach sampling and permit impacts; functional and operation requirements for the spent filter handling system; summary of meeting on disposal of LET and D HEPA filters; solvent substitution database report; and mercury vapor light analytical testing.

  19. New procedure for testing HEPA filters: a method omitting testing at 20% rated flow

    International Nuclear Information System (INIS)

    A theoretical analysis of HEPA penetration vs. pinholes in filter media is presented. A calculation formula which shows the tendency of such changes was derived and has been demonstrated experimentally. By this formula equivalent penetration was calculated. Nomograms were used to facilitate the work. As a result, testing needs to be performed only at rated flow

  20. Alternative strategies to reduce cost and waste volume in HEPA filtration using metallic filter media - 59348

    International Nuclear Information System (INIS)

    Document available in abstract form only. Full text of publication follows: The disposal costs of contaminated HEPA and THE filter elements have been proved to be disproportionately high compared with the cost of the elements themselves. Work published elsewhere (Moore, et el 1992; Bergman et al 1997) suggests that the cost of use of traditional, panel type, glass fibre HEPA filtration trains to the DOE was, during that period, $29.5 million, based on a five year life cycle, and including installation, testing, removal and disposal life cycle costs being based on estimates dating from 1987-1990. Within that cost estimate, $300 was the value given to the filter and $4, 450 was given to the peripheral activity. Clearly, if the $4, 450 component could be reduced, tremendous saving could ensue, in addition to the reduction of the legacy burden of waste volume. This issue exists for operators in both the US and in Europe. If HEPA filters could be cleaned to a condition where they could either be re-used or decontaminated to the extent that they could be stored as a lower cost wasteform or if HEPA/THE filter elements were available without any organic content likely to give rise to flammable or explosive decomposition gases during long term storage this would also reduce the costs and monitoring necessary in storage. (author)

  1. Potential for HEPA filter damage from water spray systems in filter plenums

    International Nuclear Information System (INIS)

    The water spray systems in high efficiency particulate air (HEPA) filter plenums that are used in nearly all Department of Energy (DOE) facilities for protection against fire was designed under the assumption that the HEPA filters would not be damaged by the water sprays. The most likely scenario for filter damage involves filter plugging by the water spray, followed by the fan blowing out the filter medium. A number of controlled laboratory tests that were previously conducted in the late 1980s are reviewed in this paper to provide a technical basis for the potential HEPA filter damage by the water spray system in HEPA filter plenums. In addition to the laboratory tests, the scenario for BEPA filter damage during fires has also occurred in the field. A fire in a four-stage, BEPA filter plenum at Rocky Flats in 1980 caused the first three stages of BEPA filters to blow out of their housing and the fourth stage to severely bow. Details of this recently declassified fire are presented in this paper. Although these previous findings suggest serious potential problems exist with the current water spray system in filter plenums, additional studies are required to confirm unequivocally that DOE's critical facilities are at risk. 22 refs., 15 figs

  2. Time dependency of HEPA filter performance during loading with liquid particles

    Energy Technology Data Exchange (ETDEWEB)

    Tsunoda, Masahiko; Kitano, Kyoshiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Ikezawa, Yoshio

    1997-06-01

    The time dependency of filter performance across a high-efficiency particulate air (HEPA) filter was experimentally studied. The experimental study was carried out using a HEPA filter (203 x 203 x 150 mm) clogged with liquid particles (mosquito stick aerosol). The aerosol concentration for filter loading was 0.84 mg/m{sup 3} and the size distribution was similar to lognormal distribution (CMD=0.21 {mu}m, {sigma}=1.65). The mass loading was about 60 g/m{sup 2} when the pressure drop across the HEPA filter reached twice the initial pressure drop. The DOP particle penetrations through the HEPA filter were evaluated when relative pressure drops ({Delta}P/{Delta}P{sub 0}) were nearly 1.0, 1.3, 1.4, 1.6, 1.8 and 2.1. The most penetrating particle size (MPPS) was almost independent of the mass loading if the face velocity was constant. However, the DOP particle penetration increased remarkably with mass loading, and the tendency of increase was not affected by particle size or face velocity. (author)

  3. Software Verification and Validation Test Report for the HEPA filter Differential Pressure Fan Interlock System

    Energy Technology Data Exchange (ETDEWEB)

    ERMI, A.M.

    2000-09-05

    The HEPA Filter Differential Pressure Fan Interlock System PLC ladder logic software was tested using a Software Verification and Validation (V&V) Test Plan as required by the ''Computer Software Quality Assurance Requirements''. The purpose of his document is to report on the results of the software qualification.

  4. Potential for HEPA filter damage from water spray systems in filter plenums

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W. [Lawrence Livermore National Lab., CA (United States); Fretthold, J.K. [Rocky Flats Safe Sites of Colorado, Golden, CO (United States); Slawski, J.W. [Department of Energy, Germantown, MD (United States)

    1997-08-01

    The water spray systems in high efficiency particulate air (HEPA) filter plenums that are used in nearly all Department of Energy (DOE) facilities for protection against fire was designed under the assumption that the HEPA filters would not be damaged by the water sprays. The most likely scenario for filter damage involves filter plugging by the water spray, followed by the fan blowing out the filter medium. A number of controlled laboratory tests that were previously conducted in the late 1980s are reviewed in this paper to provide a technical basis for the potential HEPA filter damage by the water spray system in HEPA filter plenums. In addition to the laboratory tests, the scenario for BEPA filter damage during fires has also occurred in the field. A fire in a four-stage, BEPA filter plenum at Rocky Flats in 1980 caused the first three stages of BEPA filters to blow out of their housing and the fourth stage to severely bow. Details of this recently declassified fire are presented in this paper. Although these previous findings suggest serious potential problems exist with the current water spray system in filter plenums, additional studies are required to confirm unequivocally that DOE`s critical facilities are at risk. 22 refs., 15 figs.

  5. The HepaRG cell line is suitable for bioartificial liver application

    NARCIS (Netherlands)

    R. Hoekstra; G.A.A. Nibourg; T.V. van der Hoeven; M.T. Ackermans; T.B.M. Hakvoort; T.M. van Gulik; W.H. Lamers; R.P. Oude Elferink; R.A.F.M. Chamuleau

    2011-01-01

    For bioartificial liver application, cells should meet the following minimal requirements: ammonia elimination, drug metabolism and blood protein synthesis. Here we explore the suitability of HepaRG cells, a human cell line reported to differentiate into hepatocyte clusters and surrounding biliary e

  6. Exposure Assessment of Four Pharmaceutical Powders Based on Dustiness and Evaluation of Damaged HEPA Filters

    DEFF Research Database (Denmark)

    Levin, Marcus; Koponen, Ismo K.; Jensen, Keld A.

    2014-01-01

    In this study, we show the different dustiness characteristics of four molecular pharmaceutical powder candidates and evaluate the performance of HEPA filters damaged with three different pinhole sizes and exposed to dust using real industrial powders in a miniaturized EN15051 rotating drum...

  7. Performances of pleated HEPA filters as a function of relative humidity of air

    International Nuclear Information System (INIS)

    Pleated High Efficiency Particulate Air (HEPA) filters are used for maintaining the containment of radioactive substances in nuclear plants; thus, they are sensitive elements of nuclear safety. Some accidental situations, such as the emergence of a hole on a pipe with release of steam, can lead to a high increase of the air humidity. This work can overcome the lack of analytical data in the literature regarding the behaviour of pleated HEPA filters, in terms of changes in pressure drop and efficiency, in presence of humidity (unsaturated air). Experimental clogging tests have been performed on a test bench with two aerosols: non hygroscopic micron-size alumina particles and hygroscopic sub-micron sodium chloride particles. The results showed that the influence of humidity during the clogging of a HEPA filter depends on several parameters: the geometry of the filter (plane or pleated), the size distribution and hygroscopicity of the aerosol clogging and finally the interaction time between the aerosol and humid air. Measurements of efficiency of clean and clogged filters (at different degrees of clogging), performed with the normalized soda fluorescein aerosol, are also sensitive to the presence of more or less relative humidity in the air. Finally, all results helped to develop an empirical model for estimating the evolution of the pressure drop of HEPA filters; this model is applicable during the formation of the particulate cake in presence of humidity without reducing of the surface area filtration. (author)

  8. Define and Quantify the Physics of Air Flow, Pressure Drop and Aerosol Collection in Nuclear Grade HEPA Filters

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Murray E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-23

    Objective: Develop a set of peer-review and verified analytical methods to adjust HEPA filter performance to different flow rates, temperatures and altitudes. Experimental testing will measure HEPA filter flow rate, pressure drop and efficiency to verify the analytical approach. Nuclear facilities utilize HEPA (High Efficiency Particulate Air) filters to purify air flow for workspace ventilation. However, the ASME AG-1 technical standard (Code on Nuclear Air and Gas Treatment) does not adequately describe air flow measurement units for HEPA filter systems. Specifically, the AG-1 standard does not differentiate between volumetric air flow in ACFM (actual cubic feet per minute)compared to mass flow measured in SCFM (standard cubic feet per minute). More importantly, the AG-1 standard has an overall deficiency for using HEPA filter devices at different air flow rates, temperatures, and altitudes. Technical Approach: The collection efficiency and pressure drops of 18 different HEPA filters will be measured over a range of flow rates, temperatures and altitudes. The experimental results will be compared to analytical scoping calculations. Three manufacturers have allocated six HEPA filters each for this effort. The 18 filters will be tested at two different flow rates, two different temperatures and two different altitudes. The 36 total tests will be conducted at two different facilities: the ATI Test facilities (Baltimore MD) and the Los Alamos National Laboratory (Los Alamos NM). The Radiation Protection RP-SVS group at Los Alamos has an aerosol wind tunnel that was originally designed to evaluate small air samplers. In 2010, modifications were started to convert the wind tunnel for HEPA filter testing. (Extensive changes were necessary for the required aerosol generators, HEPA test fixtures, temperature control devices and measurement capabilities.) To this date, none of these modification activities have been funded through a specific DOE or NNSA program. This is

  9. Characteristics of borosilicate glass media fabricated by melting HEPA filter media with inorganic additives

    International Nuclear Information System (INIS)

    HEPA filters are widely used in the nuclear fields as a final off-gas cleaning unit. To assess the applicability of vitrification technology either to treat used filter media or to produce borosilicate glass medium for the solidification of alpha-contaminated wastes, various waste glasses of different compositions were fabricated by melting mixture of HEPA filter media and inorganic additives. Physicochemical properties such as microhardness, density, thermal expansion, and short-term leaching behavior were characterized. XRD analysis showed that amorphous glasses were formed for a wide range of mixing ratio. Leach resistances, measured by PCT-B leach tests, were superior to that of EA (Environmental Assessment) glass. Other properties were similar to those of glass media used for the vitrification of high-level radioactive wastes in foreign countries

  10. Investigation into the behaviour of HEPA filters at high temperature, air humidity, and elevated differential pressure

    International Nuclear Information System (INIS)

    Investigations into the response of full-size HEPA filters to extended operation under high humidity airflows were continued with tests of 47 commercial and 13 prototypical filter units. The parameters studied were relative air humidity or liquid moisture content, temperatures between 20 and 800C, filter loading with dust, exposure time, and filter orientation to airflow. In view of complementary investigations with samples of HEPA-filter media, a laboratory test facility was built and put into operation. Based on the establishment of the main failure mechanisms, new prototype filters, incorporating a filter medium reinforced by glass-fiber cloth and a new separator design with modified corrugations, were built and tested. (orig./DG)

  11. Particle size for greatest penetration of HEPA filters - and their true efficiency

    International Nuclear Information System (INIS)

    The particle size that most greatly penetrates a filter is a function of filter media construction, aerosol density, and air velocity. In this paper the published results of several experiments are compared with a modern filtration theory that predicts single-fiber efficiency and the particle size of maximum penetration. For high-efficiency particulate air (HEPA) filters used under design conditions this size is calculated to be 0.21 μm diam. This is in good agreement with the experimental data. The penetration at 0.21 μm is calculated to be seven times greater than at the 0.3 μm used for testing HEPA filters. Several mechanisms by which filters may have a lower efficiency in use than when tested are discussed

  12. Efficiency of standard and high capacity HEPA filters during simulated tornado and explosive pulses

    International Nuclear Information System (INIS)

    Standard HEPA (high efficiency particulate air) filters were subjected to simulated tornado transients and high capacity HEPA filters to simulated explosive shock waves to determine their filtering efficiency and particulate release characteristics during these events. Efficiencies, measured by introducing a monodispersed aerosol upstream of the test filters and collecting it on nucleopore filters downstream of the test filters proved to be as low as 98.17% during tornado transients and as low as 71% during explosive transients. Particulate released from loaded filters during tornado transients amounted to about 10 μg of polystyrene latex. For explosive transients the mass of released polystyrene particulate was on the order of 1.0 mg. (author)

  13. Feasibility study for an additional HEPA filter leaching system in NWCF

    International Nuclear Information System (INIS)

    This report documents the feasibility of installing a second high-efficiency particulate air (HEPA) filter leaching system in the New Waste Calcining Facility at the Idaho Chemical Processing Plant (ICPP). A large spent filter backlog already exists at the ICPP, and it has been uncertain whether the existing HEPA filter leaching system will have a throughput rate sufficient to work off the existing backlog in a timely manner. Three areas within the New Waste Calcining Facility (NWCF) have been identified as possible locations for a second filter leaching system. This report examines the suitability of each location, identifies modifications that would be necessary-to install a filter leaching system at each location, examines the impact of modifying each location, and discusses recent efforts to estimate filter throughput using the existing filter leaching system. Based on all available information, installation of a second filter leaching system is not recommended at the present time

  14. First Study Of HEPA Filter Prototype Performance To Control The Airborne Pollution

    International Nuclear Information System (INIS)

    This paper will report the efficiency test result of the filtration tool prototype of High Efficiency Particulate Air (HEPA filter) for low temperature, to control the airborne pollution of aerosol particle of solid and liquid. The prototype design of HEPA filter was based on the characteristic data of filter material (fibrous diameter, density, filter thickness), flow rate of air and first pressure drop. From the result of laboratory scale test, using DOP/PSL aerosol with 0,3 mum diameter and the flow rate of 3,78 m exp.3/min, was obtained filtration efficiency revolve between 89,90 and 99,94 % for the filter prototype of A, B, C, and D. the efficiency estimation of theory with filtration programme and the experiment was different amount 1 %. The value of the prototype efficiency of D filter was not far different with AAF-USA filter and its price is cheaper 30 % than the price of AAF-USA filter

  15. Performance of HEPA Filter Medium under Accidental Conditions in Nuclear Installations

    International Nuclear Information System (INIS)

    High Efficiency Particulate Air filters (HEPA Filters) are the main components in ventilation or confinement system for the retention of radioactive particles in nuclear installations. During abnormal conditions or accidents (e.g. fire accident, criticality in a nuclear fuel cycle facility and LOCA in power reactors) the resulting heat, smoke and humidity affect to a large extent the performance of HEPA filters. As a part of a research programme aims at the evaluation and improvement of the performance of HEPA filter media during abnormal conditions, the effect of elevated temperatures up to 400 degree C on the resistance of medium to penetration of water under pressure has been investigated. The test results showed that the resistance of the medium to penetration of water decreases with increase in temperature and thermal exposure time. This could be attributed to burnout of the organic binder used to improve the resistance of the medium to the penetration of water. The results also showed that at 400 degree C the resistance of the medium to the penetration of water disappeared. This was confirmed by inspection of the filter medium samples after exposure to high temperature using a scanning electron microscope. The inspection of the medium samples showed that the organic binder in the medium was deformed and finally collapsed at 400 degree C. Also, a best estimate model for the relation of filter medium resistance to water penetration under elevated temperature has been implemented. The results of this study can help in establishing a regulatory operating limit conditions (OLCs) for HEPA filter operation at high temperatures conditions in nuclear installations

  16. The application of HEPA filter units in gas streams of high dust concentrations

    International Nuclear Information System (INIS)

    High Efficiency Particulate Air Filter (HEPA) units are currently employed for cleaning air and gas streams of very low dust concentrations where their high removal efficiencies reliably protect the environment. The high dust concentrations encountered during the modification and decommissioning of nuclear facilities, in the processing of contaminated scrap, or in the incineration of radioactive waste have limited the use of HEPA filters to the role of final stage clean-up filters. Recleaning HEPA filter units in their service locations offers economic advantages compared with conventional combinations of multiple dust removal devices. Fluid dynamic techniques come into consideration for the nondetrimental recleaning of inherently fragile, glass fiber filter media. This is explained by the relatively low mechanical stress induced during the required high-intensity recleaning processes, in comparison to beating or shaking methods. In this work, recleaning via low pressure reverse flow is addressed in detail. The influence of reverse flow intensity and particle size on recleanability is studied in laboratory tests on specimens of HEPA filter media. The minimum required reverse flow intensity is determined on the basis of the residual pressure drop after recleaning. Measurements of local pressures in a single pleat and theoretically calculated flow patterns showed that airflows in conventional deep-pleat pack geometries during reverse flow recleaning are not uniformly distributed. The difference between the air velocities at the pleat inlet and the downstream end can vary by up to a factor of five at typical reverse flow intensities, decreasing the overall effectiveness of particle dislodgement from the filter medium and shortening filter unit service life. Results are presented of field investigations into the recleanability of deep-pleat filter units during actual service conditions for three different dust types. 7 refs., 12 figs., 1 tab

  17. Performance of HEPA Filter Medium under Accidental Conditions in Nuclear Installations

    International Nuclear Information System (INIS)

    High Efficiency Particulate Air filters (HEPA Filters) are the main components in ventilation or confinement system for the retention of radioactive particles in nuclear installations. During abnormal conditions or accidents (e.g. fire accident, criticality in a nuclear fuel cycle facility and LOCA in power reactors) the resulting heat, smoke and humidity affect to a large extent the performance of HEPA filters. As a part of a research programme aims at the evaluation and improvement of the performance of HEPA filter media during abnormal conditions, the effect of elevated temperatures up to 400 degree C on the resistance of medium to penetration of water under pressure has been investigated. The test results showed that the resistance of the medium to penetration of water decreases with increase in temperature and thermal exposure time. This could be attributed to burnout of the organic binder used to improve the resistance of the medium to the penetration of water. The results also showed that at 400 degree C the resistance of the medium to the penetration of water disappeared. This was confirmed by inspection of the filter medium samples after exposure to high temperature using a scanning electron microscope. The inspection of the medium samples showed that the organic binder in the medium was deformed and finally collapsed at 400 degree C. Also, a best estimate model for the relation of filter medium resistance to water penetration under elevated temperature has been implemented. The results of this study can help in establishing a regulatory operating limit conditions (OLCs) for HEPA filter operation at high temperatures conditions in nuclear installations.

  18. ASME AG-1 Section FC Qualified HEPA Filters; a Particle Loading Comparison - 13435

    Energy Technology Data Exchange (ETDEWEB)

    Stillo, Andrew [Camfil Farr, 1 North Corporate Drive, Riverdale, NJ 07457 (United States); Ricketts, Craig I. [New Mexico State University, Department of Engineering Technology and Surveying Engineering, P.O. Box 30001 MSC 3566, Las Cruces, NM 88003-8001 (United States)

    2013-07-01

    High Efficiency Particulate Air (HEPA) Filters used to protect personnel, the public and the environment from airborne radioactive materials are designed, manufactured and qualified in accordance with ASME AG-1 Code section FC (HEPA Filters) [1]. The qualification process requires that filters manufactured in accordance with this ASME AG-1 code section must meet several performance requirements. These requirements include performance specifications for resistance to airflow, aerosol penetration, resistance to rough handling, resistance to pressure (includes high humidity and water droplet exposure), resistance to heated air, spot flame resistance and a visual/dimensional inspection. None of these requirements evaluate the particle loading capacity of a HEPA filter design. Concerns, over the particle loading capacity, of the different designs included within the ASME AG-1 section FC code[1], have been voiced in the recent past. Additionally, the ability of a filter to maintain its integrity, if subjected to severe operating conditions such as elevated relative humidity, fog conditions or elevated temperature, after loading in use over long service intervals is also a major concern. Although currently qualified HEPA filter media are likely to have similar loading characteristics when evaluated independently, filter pleat geometry can have a significant impact on the in-situ particle loading capacity of filter packs. Aerosol particle characteristics, such as size and composition, may also have a significant impact on filter loading capacity. Test results comparing filter loading capacities for three different aerosol particles and three different filter pack configurations are reviewed. The information presented represents an empirical performance comparison among the filter designs tested. The results may serve as a basis for further discussion toward the possible development of a particle loading test to be included in the qualification requirements of ASME AG-1

  19. Introduction of a new generation of high-capacity HEPA filters and a comparison of their performance to HEPA filters available on the market

    International Nuclear Information System (INIS)

    A recently developed manufacturing process has resulted in a high capacity hepa filter that meets the United States Department of Energy requirements. The DIMPLE-PLEAT trademark process, using newly developed low resistance media formulation, has been successfully employed to produce a true separatorless glass microfiber filter element, SUPER-FLOW reg sign, II* in any practical depth from 1 to 12 inches. A good number of 24'' x 24'' x 11 1/2'' filters, after passing tests at the filter retest facility, have already been employed by a facility operated for the DOE. These filters are installed in a system designed for 2000 CFM per unit - a high capacity operation. In addition, these new filters are also routinely being supplied to other DOE operations. This specially formulated all glass microfiber non-woven media is unique because it offers the lowest resistance and the highest dust holding capacity of any hepa filters meeting DOE requirements for strength and thickness as per MIL-F-51079D. Application of this media to an appropriate design for circular filters similar to those employed at Harwell (U.K.) is in progress

  20. Multiple HEPA filter test methods, July 1, 1974--March 31, 1975

    International Nuclear Information System (INIS)

    A laboratory apparatus has been constructed for testing two HEPA filters in a series configuration. The apparatus consists of an instrumented wind tunnel in which the HEPA filters are mounted, and an auxiliary wind tunnel for obtaining diluted samples of the challenge aerosol upstream of the first filter. Measurements performed with a single particle aerosol spectrometer demonstrate the capability for measuring overall protection factors of greater than 2.5 x 108. The decay of penetration as a function of time in individual HEPA filters indicates no preferential size discrimination in the range of 0.1 μm to 1.0 μm; nor is there a preferential size discrimination of penetration in this same range. A theoretical feasibility study has been performed on the use of an inhomogeneous electric field/induced aerosol electric dipole interaction for potential use as an air cleaning mechanism. Numerical evaluation of a coaxial cylinder geometry indicates that the method is feasible for collection of particles down to 0.1 μm under typical airflow velocity conditions. Small modifications in the geometry may be incorporated to create an instrument capable of measuring particle size. Geometries other than coaxial cylinders are also under investigation

  1. Behavior of the polygonal HEPA filter exposed to water droplets carried by the offgas flow

    International Nuclear Information System (INIS)

    A polygonal high-efficiency particulate air (HEPA) filter element has been developed and tested with a view to cleaning the dissolver offgas from reprocessing plants. It is likewise suited to filter process offgases generated in other plants. Due to its high dew point (about 30 degree C) the dissolver offgas, before being directed into the HEPA filter, is heated with a gas heater to approx. 100 degree C so that condensation in the pipework upstream of the filter and in the filter proper is avoided. In case of failure of the heater the offgas may undergo condensation upstream of the HEPA filter until it is bypassed to a standby heater or a standby filter system. Consequently, the filter may be loaded with water droplets. therefore, experiments have been performed with a view to estimating the behavior of the polygonal filter element when exposed to condensate droplets in a real plant. According to the experiments performed so far it can be anticipated that in case of failure of the heater the amount of condensate produced until bypassing to a standby system will not damage a new or little loaded polygonal filter element. The experiments will be carried on with the goal of investigating the behavior of a heavily loaded polygonal filter element exposed to water droplets

  2. Effect of elevated temperature on the mechanical strength of HEPA filters

    International Nuclear Information System (INIS)

    The effect of elevated temperature on the mechanical strength of HEPA filters was studied in order to evaluate and improve their performance under high temperature conditions. As part of this study the mechanical strength of HEPA filter medium which is the limiting factor in terms of the filter strength was experimentally studied at elevated temperature up to 400 degree C, and thermal exposure times ranged from 2 min to 4 h. The failure pressures of HEPA filter units after long exposure to 250 degree C were also investigated. The test results show that the medium strength decreases with increase in temperature challenge and thermal exposure time due to burnout of the organic binder used to improve the strength and flexibility of the medium. The test results also show that the tensile strength of the conventional filter medium drops to about 40 % of the value at room temperature after exposure to 250 degree C for 6 h; therefore, the continuous exposure of the conventional filter medium to this temperature is critical. The average failure differential pressures of all commercial tested filters were found to lie between 9 and 18 kPa at ambient temperature and between 6 and 11 kPa after thermal challenge at 250 degree C for 100 h. It was found that swelling and capture of the ends of individual pleats has led to filter failure.3 fig., 2 tab

  3. Methods for in-place testing of HEPA and iodine filters used in nuclear power plants

    International Nuclear Information System (INIS)

    The purpose of this work was a general investigation of existing in-place test methods and to build an equipment for in-place testing of HEPA and iodine sorption filters. In this work the discussion is limited to methods used in in-place testing of HEPA and iodine sorption filters used in light-water-cooled reactor plants. Dealy systems, built for the separation of noble gases, and testing of them is not discussed in the work. Contaminants present in the air of a reactor containment can roughly be diveded into three groups: aerosols, reactive gases, and noble gases. The aerosols are filtered with HEPA (High Efficiency Particulate Air) filters. The most important reactive gases are molecular iodine and its two compounds: hydrogen iodide and methyl iodide. Of gases to be removed by the filters methyl iodide is the gas most difficult to remove especially at high relative humidities. Impregnated activated charcoal is generally used as sorption material in the iodine filters. Experience gained from the use of nuclear power plants proves that the function of high efficiency air filter systems can not be considered safe until this is proved by in-place tests. In-place tests in use are basically equal. A known test agent is injected upstream of the filter to be tested. The efficiency is calculated from air samples taken from both sides of the filter. (author)

  4. The effect of media area on the dust holding capacity of deep pleat HEPA filters

    International Nuclear Information System (INIS)

    The high potential cost of storage, treatment and disposal of radioactive wastes places a premium on the longevity of installed HEPA filters in situations in radioactive processing facilities where dust capacity is a life determining factor. Previous work investigated the dust holding capacity v pressure drop characteristics of different designs of HEPA filter and also the effect of using graded density papers. This paper records an investigation of the effect of media area variation on the dust holding capacity of the open-quotes deep-pleatclose quotes design of HEPA filter. As in the previously reported work two test dusts (carbon black and sub micron sodium chloride) in the range (0.15 - 0.4μm) were used. Media area adjustment was effected by varying the number of separators within the range 60 - 90. Results with the coarser dust allowed an optimum media area to be identified. Media areas greater or smaller than this optimum retained less dust than the optimum for the same terminal pressure drop. Conversely with the finer sodium chloride aerosol the dust holding capacity continued to increase up to the maximum area investigated. 7 refs., 4 figs

  5. Efficiency and mass loading characteristics of a typical HEPA filter media material

    International Nuclear Information System (INIS)

    The particle removal efficiency of the high-efficiency particulate air (HEPA) filter material used at the Savannah River Site was measured as a function of monodisperse particle diameter and two gas filtration velocities. the results indicate that the material meets or exceeds the minimum specified efficiency of 99.97% for all particle diameters at both normal and minimum operating flow conditions encountered at the Savannah River site. The pressure drop across the HEPA filter material used at the Savannah River site was measured as a function of particle mass loading for various aerosol size distributions. The pressure drop was found to increase linearly with the particle mass loaded onto the filters, as long as the particles were completely dry. The slope of the curve was found to be dependent on the particle diameter and velocity of the aerosol. The linear behavior between the initial pressure drop (clean filter) and the final pressure drop (loaded filter) implies that the filtration mechanism is dominated by the particle cake that rapidly forms on the front surface of the HEPA filter. This behavior is consistent with the high filtration efficiency of the material

  6. The effect of media area on the dust holding capacity of deep pleat HEPA filters

    Energy Technology Data Exchange (ETDEWEB)

    Dyment, J. [AWE, Aldermaston (United Kingdom); Loughborough, D. [AEAT Harwell, Oxford (United Kingdom)

    1997-08-01

    The high potential cost of storage, treatment and disposal of radioactive wastes places a premium on the longevity of installed HEPA filters in situations in radioactive processing facilities where dust capacity is a life determining factor. Previous work investigated the dust holding capacity v pressure drop characteristics of different designs of HEPA filter and also the effect of using graded density papers. This paper records an investigation of the effect of media area variation on the dust holding capacity of the {open_quotes}deep-pleat{close_quotes} design of HEPA filter. As in the previously reported work two test dusts (carbon black and sub micron sodium chloride) in the range (0.15 - 0.4{mu}m) were used. Media area adjustment was effected by varying the number of separators within the range 60 - 90. Results with the coarser dust allowed an optimum media area to be identified. Media areas greater or smaller than this optimum retained less dust than the optimum for the same terminal pressure drop. Conversely with the finer sodium chloride aerosol the dust holding capacity continued to increase up to the maximum area investigated. 7 refs., 4 figs.

  7. Recleaning of HEPA filters by reverse flow - evaluation of the underlying processes and the cleaning technique

    International Nuclear Information System (INIS)

    HEPA filter operation at high concentrations of fine dusts requires the periodic recleaning of the filter units in their service locations. Due to the low mechanical stress induced during the recleaning process the regenration via low pressure reverse flow is a very suitable technique. Recleanability of HEPA filter had been attained for particle diameter >0,4 μm at air velocities up to 1 m/s, but filter clogging occurred in case of smaller particles. The recleaning forces are too weak for particles <0,4 μm. With respect to the low tensile strength of HEPA filter media higher flow velocities are excluded. The analysis of reverse flow recleaning in a single pleat device showed extremly non uniform flow pattern in conventional deep-pleat pack geometries. More uniform flow conditions are attained by changing the pleat geometry. The realisation of high flow velocities at the glas fiber medium inside the filter pack requires shortening of the pleates to some 150 mm and the adaptation of the distance between filter pack and the recleaning device with respect to the nozzle diameter and the width of the filter pleats. (orig.). 44 figs., 36 refs

  8. Seismic qualification of HEPA filters by test in an actual operating condition

    International Nuclear Information System (INIS)

    Flander's Filters, Inc., has completed an analysis and test program which has resulted in a seismically prequalified high efficiency particulate air (HEPA) filter housing with the HEPA filters installed and operating during the qualification testing. The nuclear seismic qualification program was performed by Corporate Consulting and Development Company, Ltd. During the seismic qualification testing a dioctylphthalate (DOP) test was performed for the duration of the shake table test and the system performed successfully. The details of the seismic qualification test procedure, housing and filter design, and the structural performance results are presented. Comparisons are made between theoretically predicted results and test results. The preliminary test program pointed out some potential vibration problems with separator type filters due to media puncture during shaking. HEPA filters have typically been given less emphasis from a seismic qualification standpoint than the primary structure and equipment (such as fans, cooling coils, heaters, etc.) in filter trains and/or air handling units. This nuclear seismic qualification program has shown that this design for filters and housing will withstand the seismic occurrence and perform its required safety related function during and after the seismic occurrence. Conclusions resulting from this test program are presented and some recommendations and precautions are given

  9. Radioactive air emissions notice of construction for HEPA filtered vacuum radioactive air emission units

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.E.

    1997-10-27

    This notice of construction (NOC) requests a categorical approval for construction and operation of certain portable high-efficiency particulate air (HEPA) filtered vacuum radionuclide airborne emission units (HVUs). Approval of this NOC application is intended to allow operation of the HVUs without prior project-specific approval. This NOC does not request replacement or supersedence of any previous agreements/approvals by the Washington State Department of Health (WDOH) for the use of vacuums on the Hanford Site. These previous agreements/approvals include the approved NOCs for the use of EuroClean HEPA vacuums at the T Plant Complex and the Kelly Decontamination System at the Plutonium-Uranium Extraction (PUREX) Plant. Also, this NOC does not replace or supersede the agreement reached regarding the use of HEPA hand-held/shop-vacuum cleaners for routine cleanup activities conducted by the Environmental Restoration Project. Routine cleanup activities are conducted during the surveillance and maintenance of inactive waste sites (Radioactive Area Remedial Action Project) and inactive facilities. HEPA hand-held/shop-vacuum cleaners are used to clean up spot surface contamination areas found during outdoor radiological field surveys, and to clean up localized radiologically contaminated material (e.g., dust, dirt, bird droppings, animal feces, liquids, insects, spider webs, etc.). This agreement, documented in the October 12, 1994 Routine Meeting Minutes, is based on routine cleanup consisting of spot cleanup of low-level contamination provided that, in each case, the source term potential would be below 0.1 millirem per year. This application is intended to request sitewide approval for the new activities, and provide an option for any facility on the site to use this approval, within the terms of this NOC. The HVUs used in accordance with this NOC will support reduction of radiological contamination at various locations on the Hanford Site. Radiation Protection Air

  10. Volatility and leachability of heavy metals and radionuclides in thermally treated HEPA filter media generated from nuclear facilities

    International Nuclear Information System (INIS)

    Highlights: ► Thermally treated HEPA filter media was transformed into glassy bulk materials. ► Main radionuclide and heavy metal were Cs-137 and Zn. ► Cs and Zn were transformed into stable form without volatilization and leaching. ► The proposed technique is simple and energy efficient procedure. - Abstract: The purpose of the present study was to apply thermal treatments to reduce the volume of HEPA filter media and to investigate the volatility and leachability of heavy metals and radionuclides during thermal treatment. HEPA filter media were transformed to glassy bulk material by thermal treatment at 900 °C for 2 h. The most abundant heavy metal in the HEPA filter media was Zn, followed by Sr, Pb and Cr, and the main radionuclide was Cs-137. The volatility tests showed that the heavy metals and radionuclides in radioactive HEPA filter media were not volatilized during the thermal treatment. PCT tests indicated that the leachability of heavy metals and radionuclides was relatively low compared to those of other glasses. XRD results showed that Zn and Cs reacted with HEPA filter media and were transformed into crystalline willemite (ZnO·SiO2) and pollucite (Cs2OAl2O34SiO2), which are not volatile or leachable. The proposed technique for the volume reduction and transformation of radioactive HEPA filter media into glassy bulk material is a simple and energy efficient procedure without additives that can be performed at relatively low temperature compared with conventional vitrification process.

  11. Criteria for calculating the efficiency of deep-pleated HEPA filters with aluminum separators during and after design basis accidents

    International Nuclear Information System (INIS)

    The authors have reviewed the literature on the performance of high efficiency particulate air (HEPA) filters under normal and abnormal conditions to establish criteria for calculating the efficiency of HEPA filters in a DOE nonreactor nuclear facility during and after a Design Basis Accident (DBA). This study is only applicable to the standard deep-pleated HEPA filter with aluminum separators as specified in ASME N509. The literature review included the performance of new filters and parameters that may cause deterioration in the filter performance such as filter age, radiation, corrosive chemicals, seismic and rough handling, high temperature, moisture, particle clogging, high air flow and pressure pulses. The deterioration of the filter efficiency depends on the exposure parameters; in severe exposure conditions the filter will be structurally damaged and have a residual efficiency of 0%. Despite the many studies on HEPA filter performance under adverse conditions, there are large gaps and limitations in the data that introduce significant error in the estimates of HEPA filter efficiencies under DBA conditions. Because of this limitation, conservative values of filter efficiency were chosen when there was insufficient data

  12. Limits of HEPA-filter application under high-humidity conditions

    International Nuclear Information System (INIS)

    As a result of a loss-of-coolant accident in a water-cooled nuclear reactor, the HEPA filters inside the air-cleaning systems can be exposed to high relative humidity, to condensing water vapor, and even to aerosols of liquid water. The data documented in the literature on the response of HEPA filters to such challenges was judged to be inconclusive and incomplete particularly with respect to filters preloaded with dust during service operation. Therefore, an experimental program was initiated using the test facility TAIFUN, equipped with instrumentation to accurately measure relative humidity. An optical system permitted observation and documentation of the response of the downstream side of the test filter during the tests, which lasted between 6 and 250 hours. The 21 filters tested at 500C, constant volumetric air flow rate, and ambient pressure demonstrated that the differential pressure of new clean filters increased significantly only above 95% r.h., rose up to 0.5 to 2 kPa at 100% r.h. and reached values between 6 and 9 kPa during filtration of liquid-water aerosols. Extended challenge with liquid-water aerosols caused all new filters to fail structurally. The HEPA filters that were preloaded during prior service exhibited a considerably higher rate and extent of increase in differential pressure. Such filters had already failed under test at 100% r.h. The installation of a highly efficient mist eliminator did not prevent failure of the dust loaded filters. The modes and mechanisms of filter failure are discussed

  13. Design and construction of a type testing and production test facility for HEPA filters to be installed in ventilation systems of German nuclear power plants

    International Nuclear Information System (INIS)

    High-efficiency particulate air filters (HEPA filters) in nuclear plants frequently constitute part of the last barrier separating potentially contaminated areas from the environment. Their failure may cause radioactive substances to be released. The sensitivity of the filter media employed, and the problems associated with manufacturing the HEPA filters normally used in nuclear plants, result in considerable differences in the quality of commercial HEPA filters. Aging of filter components during operation may greatly reduce the loading capacity of the entire filter. A relatively large number of HEPA filters were found to be defective at the end of service life. In order to be able to guarantee the removal efficiency of HEPA filters over a sufficient length of service life and under accident conditions, quality control measures must be introduced. Type tests of the HEPA filters to be used in nuclear plants must include a number of criteria beyond the loads imposed by the rated volumetric flow rate under the usual room air conditions. These criteria have been combined in a special type test (DIN 25 414), and passing this test should be made a prerequisite for the use of HEPA filters in nuclear plants. In addition, random inspections of production HEPA filters should be carried out to allow an adequate standard of quality to be guaranteed for a long time. (orig./GL)

  14. Criteria for calculating the efficiency of deep-pleated HEPA filters with aluminum separators during and after design basis accidents

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; First, M.W.; Anderson, W.L. [Lawrence Livermore National Laboratory, CA (United States)] [and others

    1995-02-01

    We have reviewed the literature on the performance of HEPA filters under normal and abnormal conditions to establish criteria for calculating the efficiency of HEPA filters in a DOE nonreactor nuclear facility during and after a Design Basis Accident (DBA). This study is only applicable to the standard deep-pleated HEPA filter with aluminum separators as specified in ASME N509[1]. Other HEPA filter designs such as the mini-pleat and separatorless filters are not included in this study. The literature review included the performance of new filters and parameters that may cause deterioration in the filter performance such as filter age, radiation, corrosive chemicals, seismic and rough handling, high temperature, moisture, particle clogging, high air flow and pressure pulses. The deterioration of the filter efficiency depends on the exposure parameters; in severe exposure conditions the filter will be damaged and have a residual efficiency of 0%. There are large gaps and limitations in the data that introduce significant error in the estimates of HEPA filter efficiencies under DBA conditions. Because of this limitation, conservative values of filter efficiency were chosen. The estimation of the efficiency of the HEPA filters under DBA conditions involves three steps: (1) The filter pressure drop and environmental parameters are determined during and after the DBA, (2) Comparing the filter pressure drop to a set of threshold values above which the filter is damaged. There is a different threshold value for each combination of environmental parameters, and (3) Determining the filter efficiency. If the filter pressure drop is greater than the threshold value, the filter is damaged and is assigned 0% efficiency. If the pressure drop is less, then the filter is not damaged and the efficiency is determined from literature values of the efficiency at the environmental conditions.

  15. In-situ continuous scanning high efficiency particulate air (HEPA) filter monitoring system

    International Nuclear Information System (INIS)

    The testing and replacement of HEPA filters, which are widely used in the nuclear industry to purify process air before it is ventilated to the atmosphere, is a costly and labor-intensive undertaking. Current methods of testing filter performance, such as differential pressure measurement and scanning air monitoring, allow for determination of overall filter performance but preclude detection of symptoms of incipient filter failure, such as small holes in the filters themselves. Using current technology, a continual in-situ monitoring system has been designed which provides three major improvements over current methods of filter testing and replacement. This system (1) realizes a cost savings by reducing the number of intact filters which are currently being replaced unnecessarily, (2) provides a more accurate and quantitative measurement of filter performance than is currently achieved with existing testing methods, and (3) reduces personnel exposure to a radioactive environment by automatically performing most testing operations. The operation and performance of the HEPA filter monitoring system are discussed

  16. High-efficiency particulate air (HEPA) filter performance following service and radiation exposure

    International Nuclear Information System (INIS)

    Small HEPA filters were exposed to a 60Co source with a radiation strength of 3 x 107 rads per hour and then exposed to steam--air mixtures at several times filter design flow, followed by extended exposure to steam and air at reduced flow. Additional filters were exposed to air flow in a reactor confinement system and then similarly tested with steam--air mixture flows. The test data and calculated effects of filter pluggage with moisture on confinement system performance following potential reactor accidents are described. Gamma radiation exposure impaired the performance of new filters only slightly and temporarily improved performance of service aged filters. Normal confinement system service significantly impaired filter performance although not sufficiently to prevent adequate performance of the SRP confinement system following an unlikely reactor accident. Calculations based on measured filter pluggage indicate that during an accident air flow could be reduced approximately 50 percent with service-degraded HEPA filters present, or approximately 10 percent with new filters damaged by the radiation exposure. (U.S.)

  17. Preliminary studies to determine the shelf life of HEPA filters. Revision 1

    International Nuclear Information System (INIS)

    We have completed a preliminary study using filter media tests and filter qualification tests to investigate the effect of shelf-life on HEPA filter performance. Our media studies showed that the tensile strength decreased with age, but the data were not sufficient to establish a shelf-life. Thermogravimetric analyses demonstrated that one manufacturer had media with low tensile strength due to insufficient binder. The filter qualification tests (heated air and overpressure) conducted on different aged filters showed that filter age is not the primary factor affecting filter performance; materials and the construction design have a greater effect. An unexpected finding of our study was that sub-standard HEPA filters have been installed in DOE facilities despite existing regulations and filter qualification tests. We found that the filter with low tensile strength failed the overpressure test. The same filter had passed the heated air test, but left the filter so structurally weak, it was prone to blow-out. We recommend that DOE initiate a filter qualification program to prevent this occurrence

  18. Life prolongation and cost reduction of steel ladles with improving refractories and their structure; Taikabutsu zaishitsu to kozo kaizen ni yoru shuka taikabutsu no chojumyoka to kosuto teigen

    Energy Technology Data Exchange (ETDEWEB)

    Nakai, Masato; Kasahara, Hajime; Fukutani, Fujio; Imai, Hiroyuki [Nippon Steel Corp., Tokyo (Japan)

    1999-06-01

    Steel Making Plant, Hirohata Iron Works, Nippon Steel Corp. succeeded to reduce the cost of furnace materials by measures described below down to 49% compared to that in 1992. (1) For tuyre bricks, cleanability against oxygen was improved by compacting by vacuum cast forming. (2) For SL bricks, the cost was reduced by applying imported bricks and optimization of the range of use. (3) For alumina-magnesia amorphous refractories for side walls, low expansion and breaking resistance were improved by optimization of magnesia quantity and silica ultra fine powder quantity. (4) For side wall structure, improvement of tie-in between the ground part and the side wall and lining with efficient thickness were carried out. (NEDO)

  19. Investigations into the penetration and pressure drop of HEPA filter media during loading with submicron particle aerosols at high concentrations

    International Nuclear Information System (INIS)

    High Efficiency Particulate Air (HEPA) filters are typically employed in particle removal and retention within the air cleaning systems of clean rooms in the pharmaceutical, nuclear and semiconductor industries for dust concentrations of some μg/m3. Their extremely high removal efficiencies for submicron particles make them attractive candidates in complying with increasingly lower emission limits for industrial processes that involve dust concentrations of up to several g/m3. Cost-effective operation under such conditions requires the filter units to be recleanable. The recleanability of HEPA filter media depends not only on the operating conditions during the cleaning process but also on the filtration conditions during particle loading. The structure and location of the particles captured by the glass fiber matrix greatly affect the degree to which they can be subsequently dislodged and removed from the filter medium. Changes in filtration efficiency with service time for various particle diameters in the critical submicron size range, as well as the effects of filtration velocity on the increase in pressure drop, are important criteria with regard to recleaning HEPA filter units. Of special significance for the recleanability of HEPA filter media is knowledge of how operating conditions affect dust cake formation. (author)

  20. Evaluation of Alternative Control for Prevention and or Mitigation of HEPA Filter Failure Accidents at Tank Farm Facilities

    International Nuclear Information System (INIS)

    This study evaluates the adequacy and benefit of use of HEPA filter differential pressure limiting setpoints to initiate exhauster shut down as an alternative safety control for postulated accidents that might result in filtration failure and subsequent unfiltered release from Tank Farm primary tank ventilators

  1. Evaluation of genotoxicity using automated detection of γH2AX in metabolically competent HepaRG cells.

    Science.gov (United States)

    Quesnot, Nicolas; Rondel, Karine; Audebert, Marc; Martinais, Sophie; Glaise, Denise; Morel, Fabrice; Loyer, Pascal; Robin, Marie-Anne

    2016-01-01

    The in situ detection of γH2AX was recently reported to be a promising biomarker of genotoxicity. In addition, the human HepaRG hepatoma cells appear to be relevant for investigating hepatic genotoxicity since they express most of drug metabolizing enzymes and a wild type p53. The aim of this study was to determine whether the automated in situ detection of γH2AX positive HepaRG cells could be relevant for evaluation of genotoxicity after single or long-term repeated in vitro exposure compared to micronucleus assay. Metabolically competent HepaRG cells were treated daily with environmental contaminants and genotoxicity was evaluated after 1, 7 and 14 days. Using these cells, we confirmed the genotoxicity of aflatoxin B1 and benzo(a)pyrene and demonstrated that dimethylbenzanthracene, fipronil and endosulfan previously found genotoxic with comet or micronucleus assays also induced γH2AX phosphorylation. Furthermore, we showed that fluoranthene and bisphenol A induced γH2AX while no effect had been previously reported in HepG2 cells. In addition, induction of γH2AX was observed with some compounds only after 7 days, highlighting the importance of studying long-term effects of low doses of contaminants. Together, our data demonstrate that automated γH2AX detection in metabolically competent HepaRG cells is a suitable high-through put genotoxicity screening assay.

  2. Use of the HepaRG Cell Line to Assess Potential Human Hepatotoxicity of ToxCast™ Chemicals

    Science.gov (United States)

    The HepaRG cell line is a promising model system for predicting human hepatotoxicity in part because of the greater capacity to metabolize chemicals than other cell models. We hypothesized that this cell line would be a relevant model for toxicity testing of industrial chemicals....

  3. Disruption of BSEP Function in HepaRG Cells Alters Bile Acid Disposition and Is a Susceptive Factor to Drug-Induced Cholestatic Injury.

    Science.gov (United States)

    Qiu, Xi; Zhang, Yueping; Liu, Tongtong; Shen, Hong; Xiao, Yongling; Bourner, Maureen J; Pratt, Jennifer R; Thompson, David C; Marathe, Punit; Humphreys, W Griffith; Lai, Yurong

    2016-04-01

    In the present study, we characterized in vitro biosynthesis and disposition of bile acids (BAs) as well as hepatic transporter expression followed by ABCB11 (BSEP) gene knockout in HepaRG cells (HepaRG-KO cells). BSEP KO in HepaRG cells led to time-dependent BA accumulation, resulting in reduced biosynthesis of BAs and altered BA disposition. In HepaRG-KO cells, the expression of NTCP, OATP1B1, OATP2B1, BCRP, P-gp, and MRP2 were reduced, whereas MRP3 and OCT1 were up-regulated. As a result, BSEP KO altered the disposition of BAs and subsequently underwent adaptive regulations of BA synthesis and homeostasis to enable healthy growth of the cells. Although BSEP inhibitors caused no or slight increase of BAs in HepaRG wild type cells (HepaRG-WT cells), excessive intracellular accumulation of BAs was observed in HepaRG-KO cells exposed to bosentan and troglitazone, but not dipyridamole. LDH release in the medium was remarkably increased in HepaRG-KO cultures exposed to troglitazone (50 μM), suggesting drug-induced cellular injury. The results revealed that functional impairment of BSEP predisposes the cells to altered BA disposition and is a susceptive factor to drug-induced cholestatic injury. In total, BSEP inhibition might trigger the processes but is not a sole determinant of cholestatic cellular injury. As intracellular BA accumulation is determined by BSEP function and the subsequent adaptive gene regulation, assessment of intracellular BA accumulation in HepaRG-KO cells could be a useful approach to evaluate drug-induced liver injury (DILI) potentials of drugs that could disrupt other BA homeostasis pathways beyond BSEP inhibition. PMID:26910619

  4. PPAR agonists reduce steatosis in oleic acid-overloaded HepaRG cells

    International Nuclear Information System (INIS)

    Although non-alcoholic fatty liver disease (NAFLD) is currently the most common form of chronic liver disease there is no pharmacological agent approved for its treatment. Since peroxisome proliferator-activated receptors (PPARs) are closely associated with hepatic lipid metabolism, they seem to play important roles in NAFLD. However, the effects of PPAR agonists on steatosis that is a common pathology associated with NAFLD, remain largely controversial. In this study, the effects of various PPAR agonists, i.e. fenofibrate, bezafibrate, troglitazone, rosiglitazone, muraglitazar and tesaglitazar on oleic acid-induced steatotic HepaRG cells were investigated after a single 24-hour or 2-week repeat treatment. Lipid vesicles stained by Oil-Red O and triglycerides accumulation caused by oleic acid overload, were decreased, by up to 50%, while fatty acid oxidation was induced after 2-week co-treatment with PPAR agonists. The greatest effects on reduction of steatosis were obtained with the dual PPARα/γ agonist muraglitazar. Such improvement of steatosis was associated with up-regulation of genes related to fatty acid oxidation activity and down-regulation of many genes involved in lipogenesis. Moreover, modulation of expression of some nuclear receptor genes, such as FXR, LXRα and CAR, which are potent actors in the control of lipogenesis, was observed and might explain repression of de novo lipogenesis. Conclusion: Altogether, our in vitro data on steatotic HepaRG cells treated with PPAR agonists correlated well with clinical investigations, bringing a proof of concept that drug-induced reversal of steatosis in human can be evaluated in in vitro before conducting long-term and costly in vivo studies in animals and patients. - Highlights: • There is no pharmacological agent approved for the treatment of NAFLD. • This study demonstrates that PPAR agonists can reduce fatty acid-induced steatosis. • Some nuclear receptors appear to be potent actors in the control

  5. PPAR agonists reduce steatosis in oleic acid-overloaded HepaRG cells

    Energy Technology Data Exchange (ETDEWEB)

    Rogue, Alexandra [Inserm UMR 991, 35043 Rennes Cedex (France); Université de Rennes 1, Faculté des Sciences Pharmaceutiques et Biologiques, 35043 Rennes Cedex (France); Biologie Servier, Gidy (France); Anthérieu, Sébastien; Vluggens, Aurore [Inserm UMR 991, 35043 Rennes Cedex (France); Université de Rennes 1, Faculté des Sciences Pharmaceutiques et Biologiques, 35043 Rennes Cedex (France); Umbdenstock, Thierry [Technologie Servier, Orléans (France); Claude, Nancy [Institut de Recherches Servier, Courbevoie (France); Moureyre-Spire, Catherine de la; Weaver, Richard J. [Biologie Servier, Gidy (France); Guillouzo, André, E-mail: Andre.Guillouzo@univ-rennes1.fr [Inserm UMR 991, 35043 Rennes Cedex (France); Université de Rennes 1, Faculté des Sciences Pharmaceutiques et Biologiques, 35043 Rennes Cedex (France)

    2014-04-01

    Although non-alcoholic fatty liver disease (NAFLD) is currently the most common form of chronic liver disease there is no pharmacological agent approved for its treatment. Since peroxisome proliferator-activated receptors (PPARs) are closely associated with hepatic lipid metabolism, they seem to play important roles in NAFLD. However, the effects of PPAR agonists on steatosis that is a common pathology associated with NAFLD, remain largely controversial. In this study, the effects of various PPAR agonists, i.e. fenofibrate, bezafibrate, troglitazone, rosiglitazone, muraglitazar and tesaglitazar on oleic acid-induced steatotic HepaRG cells were investigated after a single 24-hour or 2-week repeat treatment. Lipid vesicles stained by Oil-Red O and triglycerides accumulation caused by oleic acid overload, were decreased, by up to 50%, while fatty acid oxidation was induced after 2-week co-treatment with PPAR agonists. The greatest effects on reduction of steatosis were obtained with the dual PPARα/γ agonist muraglitazar. Such improvement of steatosis was associated with up-regulation of genes related to fatty acid oxidation activity and down-regulation of many genes involved in lipogenesis. Moreover, modulation of expression of some nuclear receptor genes, such as FXR, LXRα and CAR, which are potent actors in the control of lipogenesis, was observed and might explain repression of de novo lipogenesis. Conclusion: Altogether, our in vitro data on steatotic HepaRG cells treated with PPAR agonists correlated well with clinical investigations, bringing a proof of concept that drug-induced reversal of steatosis in human can be evaluated in in vitro before conducting long-term and costly in vivo studies in animals and patients. - Highlights: • There is no pharmacological agent approved for the treatment of NAFLD. • This study demonstrates that PPAR agonists can reduce fatty acid-induced steatosis. • Some nuclear receptors appear to be potent actors in the control

  6. Adhesion and removal kinetics of Bacillus cereus biofilms on Ni-PTFE modified stainless steel.

    Science.gov (United States)

    Huang, Kang; McLandsborough, Lynne A; Goddard, Julie M

    2016-01-01

    Biofilm control remains a challenge to food safety. A well-studied non-fouling coating involves codeposition of polytetrafluoroethylene (PTFE) during electroless plating. This coating has been reported to reduce foulant build-up during pasteurization, but opportunities remain in demonstrating its efficacy in inhibiting biofilm formation. Herein, the initial adhesion, biofilm formation, and removal kinetics of Bacillus cereus on Ni-PTFE-modified stainless steel (SS) are characterized. Coatings lowered the surface energy of SS and reduced biofilm formation by > 2 log CFU cm(-2). Characterization of the kinetics of biofilm removal during cleaning demonstrated improved cleanability on the Ni-PTFE coated steel. There was no evidence of biofilm after cleaning by either solution on the Ni-PTFE coated steel, whereas more than 3 log and 1 log CFU cm(-2) of bacteria remained on the native steel after cleaning with water and an alkaline cleaner, respectively. This work demonstrates the potential application of Ni-PTFE non-fouling coatings on SS to improve food safety by reducing biofilm formation and improving the cleaning efficiency of food processing equipment. PMID:27020838

  7. Use of evidence in 3 local level HEPA policies in Denmark

    DEFF Research Database (Denmark)

    Jakobsen, Mette Winge; Juel Lau, Cathrine; Skovgaard, Thomas;

    2013-01-01

    Purpose: The University of Southern Denmark and the Research Centre for Prevention and Health in the Capital Region of Denmark are involved in the first work package of the REPOPA project dealing with mapping and further analyses of use of research evidence in selected health enhancing physical......, followed by interviews with key stakeholders involved in the policy making process, were carried out. The data were analyzed with the focus on the characteristics of the research knowledge used for policy making and factors influencing the use of research and other kinds of information. Findings...... local context was reported. Policy makers focus on both using and generating knowledge. However, research evidence is only used in HEPA policy making if applicable to the local setting. Many factors influence the use of research into policy making such as involvement of stakeholders, availability of...

  8. Effect of various polymeric binders on the radiation resistance of glass fiber HEPA filter media

    International Nuclear Information System (INIS)

    Glass fiber HEPA filter media bonded with various polymeric materials were exposed to several levels of radiation dosage from an electron beam source. The effects on water repellency, tensile strength, DOP filtration efficiency and organic content were noted. All media suffered degradation at the highest levels of radiation dosage (7 x 108 rads). However, at intermediate levels, radiation resistance was affected by the type of binder. Greatest resistance to radiation was exhibited by media bonded with a phenylated polysiloxane resin. Cross-linking polymers such as polystyrene and SBR displayed improvement in some properties, such as in water repellency and tensile strength, at low levels of radiation exposure (less than 2 x 108 rads), however degraded at higher levels of exposure. Filtration properties such as DOP efficiency and resistance to air flow did not appear to be greatly affected by radiolysis. (U.S.)

  9. Performance testing of HEPA filters: Progress towards a European standard procedure

    International Nuclear Information System (INIS)

    Proposals for a future European testing procedure for 'High Efficiency Particulate Air Filters (HEPA and ULPA)' are being developed by CEN (Comite Europeen de Normalisation). The new standard will be given the status of national standard in participating countries, conflicting national standards being withdrawn. The standard will comprise 5 parts covering the grouping and classification of HEPA and ULPA filters according to their efficiency, fundamental principles of testing, marking etc (in part 1). Part 2 will cover aerosol production, measurement principles, counting equipment and statistics. Parts 3-5 will cover testing flat sheet media, leak testing of filter elements and the efficiency testing of filter elements respectively. The efficiency test methods allow the use of either homogeneous monodisperse or polydisperse aerosols for the determination of particulate filtration efficiencies as a function of particle size. The particle size at which maximum penetration occurs is first determined in flat sheet media tests; tests on filter elements (constructed using the same filter medium) may be carried out using either a homogeneous monodisperse aerosol of the size at which maximum penetration occurs (MPPS) or a polydisperse aerosol whose median size is close to the MPPS. Tests with monodisperse aerosols may be conducted using condensation nucleus counting equipment; tests using polydisperse test aerosols require the use of optical sizing particle counters. When determining the efficiency of filter elements the downstream aerosol concentrations may be determined from air samples obtained using either an overall method (single point sampling after mixing) or a scan method. The scan method also allows 'local' efficiency values to be determined. 1 ref., 1 fig., 1 tab

  10. In-place testing of tandem HEPA filter stages using fluorescent aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Elder, J.C.; Kyle, T.G.; Tillery, M.I.; Ettinger, H.J.

    1980-01-01

    Fluorescent test aerosols were used in field testing of large multiple-stage HEPA filter systems. The technique excluded interference from non-fluorescent background particles known to leak into the plenum or ducting between the filters and the downstream sampling probe. This technique solved the problem of measuring extremely low concentrations of the test aerosol in the presence of background aerosol. The upstream fluorescent test aerosol was diluted with clean air and drawn into a single particle aerosol spectrometer capable of counting, sizing, and detecting fluorescence of each particle. The particle sizing function was performed on light scattered by the particle passing through the beam of a helium-cadmium laser. Concurrently the fluorescence excited by the laser illumination was detected at a longer wavelength. Since spectrometer response in the fluorescent mode was <2% of naturally occurring aerosols, background aerosols were insignificant as an interference to the downstream concentration measurement. Decontamination factors (DF) on the order of 10/sup 8/ were measured in the field studies on >9.4 m/sup 3//s (20,000 cfm) systems. Additional generator capacity and acceptably lower test aerosol to background aerosol concentraion ratios could be used to extend this capability to measure DF greater than 10/sup 8/. Dye-tagged DOP aerosols were generated either by gas-thermal or sonic nozzle generators. Experiments with the gas-thermal generator showed only 20% of fluorescence from the dye was degraded by the vaporization process. A single sonic nozzle was shown to aerosolize 0.7 to 1.0 L/h of dye-tagged DOP aerosol in the proper size range for HEPA filter testing. A multiple sonic nozzle generator is a practical consideration to provide greater capacity.

  11. Performance testing of HEPA filters: Progress towards a European standard procedure

    Energy Technology Data Exchange (ETDEWEB)

    Dyment, J.

    1997-08-01

    Proposals for a future European testing procedure for {open_quotes}High Efficiency Particulate Air Filters (HEPA and ULPA){close_quotes} are being developed by CEN (Comite Europeen de Normalisation). The new standard will be given the status of national standard in participating countries, conflicting national standards being withdrawn. The standard will comprise 5 parts covering the grouping and classification of HEPA and ULPA filters according to their efficiency, fundamental principles of testing, marking etc (in part 1). Part 2 will cover aerosol production, measurement principles, counting equipment and statistics. Parts 3-5 will cover testing flat sheet media, leak testing of filter elements and the efficiency testing of filter elements respectively. The efficiency test methods allow the use of either homogeneous monodisperse or polydisperse aerosols for the determination of particulate filtration efficiencies as a function of particle size. The particle size at which maximum penetration occurs is first determined in flat sheet media tests; tests on filter elements (constructed using the same filter medium) may be carried out using either a homogeneous monodisperse aerosol of the size at which maximum penetration occurs (MPPS) or a polydisperse aerosol whose median size is close to the MPPS. Tests with monodisperse aerosols may be conducted using condensation nucleus counting equipment; tests using polydisperse test aerosols require the use of optical sizing particle counters. When determining the efficiency of filter elements the downstream aerosol concentrations may be determined from air samples obtained using either an overall method (single point sampling after mixing) or a scan method. The scan method also allows {open_quotes}local{close_quotes} efficiency values to be determined. 1 ref., 1 fig., 1 tab.

  12. Tool steels

    DEFF Research Database (Denmark)

    Højerslev, C.

    2001-01-01

    resistance against abrasive wear and secondary carbides (if any) increase the resistance against plastic deformation. Tool steels are alloyed with carbide forming elements (Typically: vanadium, tungsten, molybdenumand chromium) furthermore some steel types contains cobalt. Addition of alloying elements...

  13. Steel Spring

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Tarnished Hebei Iron and Steel Group regains chance to shine A lthough it is too early to tell whether the steel-making sector has emerged [from its gloom, a big divide is openling between China’s large and small producers. While most of the marginal players are still reeling from a market contagion, steel titans like the Shanghai-based Baosteel

  14. Analysis of fire and smoke threat to off-gas HEPA filters in a transuranium processing plant

    International Nuclear Information System (INIS)

    The author performed an analysis of fire risk to the high-efficiency particulate air (HEPA) filters that provide ventilation containment for a transuranium processing plant at the Oak Ridge National Laboratory. A fire-safety survey by an independent fire-protection consulting company had identified the HEPA filters in the facility's off-gas containment ventilation system as being at risk from fire effects. Independently studied were the ventilation networks and flow dynamics, and typical fuel loads were analyzed. It was found that virtually no condition for fire initiation exists and that, even if a fire started, its consequences would be minimal as a result of standard shut-down procedures. Moreover, the installed fire-protection system would limit any fire and thus would further reduce smoke or heat exposure to the ventilation components. 4 references, 4 figures, 5 tables

  15. Study on DOP substitutes for leaking rate testing of HEPA filter used in nuclear air cleaning systems

    International Nuclear Information System (INIS)

    Based on an extensive investigation over available literatures concerning HEPA filter testing, PEG400, SHELL on dina oil 15 and P.a. were chosen as candidates for Dop substitutes, and on which a series of tests were conducted about their aerosol conversion rate, particle size distribution, Dop detector response and leaking rate in H EPA filter. With consideration of technical properties, safety performance and economy, homemade P.a. is finally selected as the best substitute for Dop among the three. (authors)

  16. Comparative Localization and Functional Activity of the Main Hepatobiliary Transporters in HepaRG Cells and Primary Human Hepatocytes.

    Science.gov (United States)

    Bachour-El Azzi, Pamela; Sharanek, Ahmad; Burban, Audrey; Li, Ruoya; Guével, Rémy Le; Abdel-Razzak, Ziad; Stieger, Bruno; Guguen-Guillouzo, Christiane; Guillouzo, André

    2015-05-01

    The role of hepatobiliary transporters in drug-induced liver injury remains poorly understood. Various in vivo and in vitro biological approaches are currently used for studying hepatic transporters; however, appropriate localization and functional activity of these transporters are essential for normal biliary flow and drug transport. Human hepatocytes (HHs) are considered as the most suitable in vitro cell model but erratic availability and inter-donor functional variations limit their use. In this work, we aimed to compare localization of influx and efflux transporters and their functional activity in differentiated human HepaRG hepatocytes with fresh HHs in conventional (CCHH) and sandwich (SCHH) cultures. All tested influx and efflux transporters were correctly localized to canalicular [bile salt export pump (BSEP), multidrug resistance-associated protein 2 (MRP2), multidrug resistance protein 1 (MDR1), and MDR3] or basolateral [Na(+)-taurocholate co-transporting polypeptide (NTCP) and MRP3] membrane domains and were functional in all models. Contrary to other transporters, NTCP and BSEP were less abundant and active in HepaRG cells, cellular uptake of taurocholate was 2.2- and 1.4-fold and bile excretion index 2.8- and 2.6-fold lower, than in SCHHs and CCHHs, respectively. However, when taurocholate canalicular efflux was evaluated in standard and divalent cation-free conditions in buffers or cell lysates, the difference between the three models did not exceed 9.3%. Interestingly, cell imaging showed higher bile canaliculi contraction/relaxation activity in HepaRG hepatocytes and larger bile canaliculi networks in SCHHs. Altogether, our results bring new insights in mechanisms involved in bile acids accumulation and excretion in HHs and suggest that HepaRG cells represent a suitable model for studying hepatobiliary transporters and drug-induced cholestasis. PMID:25690737

  17. Extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters by supercritical carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, J.B.

    1997-09-01

    Supercritical fluid extraction (SFE) using unmodified carbon dioxide has been explored as an alternative method for the extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters. HEPA filters provide the final stage of containment on many exhaust systems in US Department of Energy (DOE) facilities by preventing the escape of chemical and radioactive materials entrained in the exhausted air. The efficiency of the filters is tested by the manufacturer and DOE using dioctylphthalate (DOP), a substance regulated by the US Environmental Protection Agency under the Resource Conservation and Recovery Act. Therefore, the filters must be analyzed for semivolatile organics before disposal. Ninety-eight acid, base, and neutral semivolatile organics were spiked onto blank HEPA material and extracted using SFE, Soxhlet, automated Soxhlet, and sonication techniques. The SFE conditions were optimized using a Dionex SFE-703 instrument. Average recoveries for the 98 semivolatile compounds are 82.7% for Soxhlet, 74.0% for sonication, 70.2% for SFE, and 62.9% for Soxtec. Supercritical fluid extraction reduces the extraction solvent volume to 10--15 mL, a factor of 20--30 less than Soxhlet and more than 5 times less than Soxtec and sonication. Extraction times of 30--45 min are used compared to 16--18 h for Soxhlet extraction.

  18. 5-azacytidine inhibits the proliferation of bladder cancer cells via reversal of the aberrant hypermethylation of the hepaCAM gene.

    Science.gov (United States)

    Wang, Xiaorong; Chen, E; Yang, Xue; Wang, Yin; Quan, Zhen; Wu, Xiaohou; Luo, Chunli

    2016-03-01

    Hepatocyte cell adhesion molecule (hepaCAM), a tumor-suppressor gene, is rarely expressed in bladder carcinoma. However, little is known concerning the mechanisms of low hepaCAM expression in bladder cancer. Abnormal hypermethylation in the promoter plays a crucial role in cancer by silencing tumor-suppressor genes, which is catalyzed by DNA methyltransferases (DNMTs). In the present study, a total of 31 bladder cancer and 22 adjacent tissues were assessed by immunohistochemistry to detect DNMT3A/3B and hepaCAM expression. Methylation of hepaCAM was determined by methylation‑specific polymerase chain reaction (MSP). The mRNA and protein levels of DNMT3A/3B and hepaCAM were determined by RT-PCR and western blot analysis after treatment with 5-azacytidine (AZAC). Following AZAC treatment, the proliferation of bladder cancer cells was detected by CCK-8 and colony formation assays. Cell cycle distribution was examined by flow cytometry. To further evaluate the tumor‑suppressive roles of AZAC and the involved mechanisms, the anti-tumorigenicity of AZAC was tested in vivo. The expression of DNMT3A/3B protein was markedly increased in the bladder carcinoma tissues (P<0.05), and had a negative linear correlation with hepaCAM expression in the same patients according to Pearson's analysis (r=-0.7176/-0.7127, P<0.05). The MSP results indicated that the hepaCAM gene was hypermethylated in three bladder cancer cell lines. Furthermore, we found that downregulation of DNMT3A/3B expression, after treatment with AZAC, reversed the hypermethylation and expression of hepaCAM in bladder cancer cells. In addition, AZAC inhibited the proliferation of bladder cancer cells and arrested cells at the G0/G1 phase. The in vivo results showed that expression of DNMT3A/3B and hepaCAM as well as tumor growth of nude mice were markedly altered which corresponded with the in vitro results. Due to the ability to reactivate expression of hepaCAM and inhibit growth of bladder cancer cells

  19. The development of a HEPA filter with improved dust holding characteristics

    International Nuclear Information System (INIS)

    A limitation of the HEPA filters used in the extract of nuclear facilities is their relatively low capacity for captured dust. The costs associated with the disposal of a typical filter means that there are clear incentives to extend filter life. The work described in this report are the initial stages in the development of a filter which incorporates a medium which enhances its dust holding capacity. Experimental equipment was installed to enable the dust loading characteristics of candidate media to be compared with those of the glass fibre based papers currently used in filter construction. These tests involved challenging representative samples of the media with an air stream containing a controlled concentration of thermally generated sodium chloride particles. The dust loading characteristics of the media were then compared in terms of the rate of increasing in pressure differential. A number of open-quotes graded densityclose quotes papers were subsequently identified which appeared to offer significant improvements in dust holding. In the second phase of the programme deep-pleat filters (1,700 M3h-1) incorporating graded density papers were manufactured and tested. Improvements of up to 50% were observed in their capacity for the sub-micron sodium chloride test dust. Smaller differences (15%) were measured when a coarser, carbon black, challenge was used. This is attributed to the differences in the particles sizes of the two dusts

  20. Survey of HEPA filter applications and experience at Department of Energy sites

    International Nuclear Information System (INIS)

    Results indicated that approximately 58% of the filters surveyed were changed out in the 1977 to 1979 study period and some 18% of all filters were changed out more than once. Most changeouts (60%) were due to the existence of a high pressure drop across the filter, indicative of filter plugging. The next most recurrent reasons for changeout and their percentage changeouts were leak test failure (15%) and preventive maintenance service life limit (12%). An average filter service life was calculated to be 3.0 years with a 2.0-year standard deviation. The labor required for filter changeout was calculated as 1.5 manhours per filter changed. Filter failures occurred with approximately 12% of all installed filters. Most failures (60%) occurred for unknown reasons and handling or installation damage accounted for an additional 20% of all failures. Media ruptures, filter frame failures and seal failures occurred with approximately equal frequency at 5 to 6% each. Subjective responses to the questionnaire indicate problems are: need for improved acid and moisture resistant filters; filters more readily disposable as radioactive waste; improved personnel training in filter handling and installation; and need for pretreatment of air prior to HEPA filtration

  1. Plutonium and uranium emission experience in U.S. nuclear facilities using HEPA filtration

    International Nuclear Information System (INIS)

    The weekly, monthly and yearly emission experience of eleven U.S. nuclear facilities is presented, and reviewed. Each of these facilities uses HEPA filtration to control emissions, the various vent streams using from one to three such filtration systems in series. Available emission records cover from one to five vents at each facility, and cover periods ranging from two to eleven years. The majority of the facilities process plutonium, either exclusively or as mixed oxide, but a few process highly enriched uranium-235, natural uranium and/or thorium. Facilities include fuel fabrication plants, fuel reprocessing plants, and experimental facilities. The emission curves show clearly not only the normal operation of the filter systems, but also the effects of minor leaks, and of major failures, as well as the effects of retention of material in ducts and other passive parts of the filtration systems. An analysis is presented of the operation of such systems in real environments, and the non-Stokes Law behavior of very dense particles is exemplified by experiments done with a non-radoactive tracer, whose crystal is isomorphous with those of plutonium and uranium dioxides, tungsten dioxide

  2. The histone deacetylase inhibiting drug Entinostat induces lipid accumulation in differentiated HepaRG cells

    Science.gov (United States)

    Nunn, Abigail D. G.; Scopigno, Tullio; Pediconi, Natalia; Levrero, Massimo; Hagman, Henning; Kiskis, Juris; Enejder, Annika

    2016-06-01

    Dietary overload of toxic, free metabolic intermediates leads to disrupted insulin signalling and fatty liver disease. However, it was recently reported that this pathway might not be universal: depletion of histone deacetylase (HDAC) enhances insulin sensitivity alongside hepatic lipid accumulation in mice, but the mechanistic role of microscopic lipid structure in this effect remains unclear. Here we study the effect of Entinostat, a synthetic HDAC inhibitor undergoing clinical trials, on hepatic lipid metabolism in the paradigmatic HepaRG liver cell line. Specifically, we statistically quantify lipid droplet morphology at single cell level utilizing label-free microscopy, coherent anti-Stokes Raman scattering, supported by gene expression. We observe Entinostat efficiently rerouting carbohydrates and free-fatty acids into lipid droplets, upregulating lipid coat protein gene Plin4, and relocating droplets nearer to the nucleus. Our results demonstrate the power of Entinostat to promote lipid synthesis and storage, allowing reduced systemic sugar levels and sequestration of toxic metabolites within protected protein-coated droplets, suggesting a potential therapeutic strategy for diseases such as diabetes and metabolic syndrome.

  3. The development of a HEPA filter with improved dust holding characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Dyment, J.; Hamblin, C.

    1995-02-01

    A limitation of the HEPA filters used in the extract of nuclear facilities is their relatively low capacity for captured dust. The costs associated with the disposal of a typical filter means that there are clear incentives to extend filter life. The work described in this report are the initial stages in the development of a filter which incorporates a medium which enhances its dust holding capacity. Experimental equipment was installed to enable the dust loading characteristics of candidate media to be compared with those of the glass fibre based papers currently used in filter construction. These tests involved challenging representative samples of the media with an air stream containing a controlled concentration of thermally generated sodium chloride particles. The dust loading characteristics of the media were then compared in terms of the rate of increasing in pressure differential. A number of {open_quotes}graded density{close_quotes} papers were subsequently identified which appeared to offer significant improvements in dust holding. In the second phase of the programme deep-pleat filters (1,700 M{sup 3}h{sup {minus}1}) incorporating graded density papers were manufactured and tested. Improvements of up to 50% were observed in their capacity for the sub-micron sodium chloride test dust. Smaller differences (15%) were measured when a coarser, carbon black, challenge was used. This is attributed to the differences in the particles sizes of the two dusts.

  4. Reduction in MRSA environmental contamination with a portable HEPA-filtration unit.

    Science.gov (United States)

    Boswell, T C; Fox, P C

    2006-05-01

    There is renewed interest in the hospital environment as a potentially important factor for cross-infection with methicillin-resistant Staphylococcus aureus (MRSA) and other nosocomial pathogens. The aim of this study was to evaluate the effectiveness of a portable high-efficiency particulate air (HEPA)-filtration unit (IQAir Cleanroom H13, Incen AG, Goldach, Switzerland) at reducing MRSA environmental surface contamination within a clinical setting. The MRSA contamination rate on horizontal surfaces was assessed with agar settle plates in ward side-rooms of three patients who were heavy MRSA dispersers. Contamination rates were measured at different air filtration rates (60-235 m(3)/h) and compared with no air filtration using Poisson regression. Without air filtration, between 80% and 100% of settle plates were positive for MRSA, with the mean number of MRSA colony-forming units (cfu)/10-h exposure/plate ranging from 4.1 to 27.7. Air filtration at a rate of 140 m(3)/h (one patient) and 235 m(3)/h (two patients), resulted in a highly significant decrease in contamination rates compared with no air filtration (adjusted rate ratios 0.037, 0.099 and 0.248, respectively; P contamination within patient isolation rooms, and this may prove to be a useful addition to existing MRSA infection control measures.

  5. Aging assessment of nuclear air-treatment system HEPA filters and adsorbers

    International Nuclear Information System (INIS)

    A Phase I aging assessment of high-efficiency particulate air (HEPA) filters and activated carbon gas adsorption units (adsorbers) was performed by the Pacific Northwest Laboratory (PNL) as part of the US Nuclear Regulatory Commission's (NRC) Nuclear Plant Aging Research (NPAR) Program. Information concerning design features; failure experience; aging mechanisms, effects, and stressors; and surveillance and monitoring methods for these key air-treatment system components was compiled. Over 1100 failures, or 12 percent of the filter installations, were reported as part of a Department of Energy (DOE) survey. Investigators from other national laboratories have suggested that aging effects could have contributed to over 80 percent of these failures. Tensile strength tests on aged filter media specimens indicated a decrease in strength. Filter aging mechanisms range from those associated with particle loading to reactions that alter properties of sealants and gaskets. Low radioiodine decontamination factors associated with the Three Mile Island (TMI) accident were attributed to the premature aging of the carbon in the adsorbers. Mechanisms that can lead to impaired adsorber performance include oxidation as well as the loss of potentially available active sites as a result of the adsorption of pollutants. Stressors include heat, moisture, radiation, and airborne particles and contaminants

  6. Steel Planning

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    China releases a new plan for the iron and steel industry centered on industrial upgrades The new 12th Five-Year Plan (2011-15) for China’s iron and steel industry, recently released on the website of the Ministry of Industry and Information

  7. ANALYSIS OF VAPORS FROM METHYLENE CHLORIDE EXTRACTS OF NUCLEAR GRADE HEPA FILTER FIBERGLASS SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    FRYE JM; ANASTOS HL; GUTIERREZ FC

    2012-06-07

    While several organic compounds were detected in the vapor samples used in the reenactment of the preparation of mounts from the extracts of nuclear grade high-efficiency particulate air filter fiberglass samples, the most significant species present in the samples were methylene chloride, phenol, phenol-d6, and 2-fluorophenol. These species were all known to be present in the extracts, but were expected to have evaporated during the preparation of the mounts, as the mounts appeared to be dry before any vapor was collected. These species were present at the following percentages of their respective occupational exposure limits: methylene chloride, 2%; phenol, 0.4%; and phenol-d6, 0.6%. However, there is no established limit for 2-fluorophenol. Several other compounds were detected at low levels for which, as in the case of 2-fluorophenol, there are no established permissible exposure limits. These compounds include 2-chlorophenol; N-nitroso-1-propanamine; 2-fluoro-1,1{prime}-biphenyl; 1,2-dihydroacenaphthylene; 2,5-cyclohexadiene-1,4-dione,2,6-bis(1,1-dimethylethyl); trimethyl oxirane; n-propylpropanamine; 2-(Propylamino)ethanol; 4-methoxy-1-butene; 6-methyl-5-hepten-2-one; and 3,4-dimethylpyridine. Some of these were among those added as surrogates or spike standards as part ofthe Advanced Technologies and Laboratories International, Inc. preparation ofthe extract of the HEPA filter media and are indicated as such in the data tables in Section 2, Results; other compounds found were not previously known to be present. The main inorganic species detected (sulfate, sodium, and sulfur) are also consistent with species added in the preparation of the methylene chloride extract of the high-efficiency particulate air sample.

  8. Investigation of HEPA filters subjected to tornado pressure pulses. Initial structural testing

    International Nuclear Information System (INIS)

    Initial results from a program to determine response of 610- x 610-mm (24- x 24-in.) HEPA filters to tornado-induced pressure transients are described. Filters were structurally tested by subjecting them to 20.7-kPa (3-psi) pressure differentials at pressurization rates from 6.9 kPa/s (1 psi/s) to 34.5 kPa/s (5 psi/s). Two sizes of filters were used in the tests: 149 mm (57/8 in.) thick and 292 mm (111/2 in.) thick. The 149-mm (57/8 in.-) thick filters failed catastrophically at 20.7-kPa (3-psi) pressure differentials. Pressure drop across the filters, not pressurization rate, appears to be the primary cause of failure. The 292-mm- (111/2-in.) thick filters were also tested with the above pressurization rates. These units failed by breakage of the folded downstream ends of the fiber mat. Of four 292-mm- (111/2-in.-) thick filters tested, a 20.7-kPa (3-psi) pressure differential produced failure at the lowest and highest pressurization rates, but not at two intermediate rates. Additional tests will be required to determine a possible relationship between structural failure and pressurization rate. Flow-resistance data were also obtained for the 610- x 610-mm (24- x 24-in.) filters. Other activities described concern construction of small-scale particulate-loading and pressure-testing devices. These devices will be used to test 203- x 203-mm (8- x 8-in.) filters so that methods of testing and instrumentation requirements can be established for the full-scale tests. Progress is also reported on the data acquisition systems, the laser instrumentation system, and the construction of a building over the facility test section

  9. Mathematical models for changes in HEPA filter pressure drop caused by high air humidity

    International Nuclear Information System (INIS)

    Possible high air humidities resulting from an accident in a nuclear installation threaten the integrity of high-efficiency particulate air (HEPA) filter units in the facility air cleaning systems. Field surveys indicate that filter units continue to be exposed to adverse humidities in routine service despite the development of moisture countermeasures. One of the detrimental consequences of exposure to high air humidity is an increase in filter pressure drop (Δp). Reported failures due to a tearing of the filter medium partly result from elevated structural loadings imposed by Δp increases. The extent to which filter Δp varies with airstream conditions can be used to help calculate safety margins for filter units during normal and upset operations as well as during postulated accidents involving high air humidity. Studies of humidity-related changes in pressure drop were carried out to help explain structural failures in routine service and to obtain the empirical data needed to numerically model flow dynamics in air cleaning systems under accident conditions. Tests were performed on full-scale filter units under fog conditions and on samples of filter media at humidities up to 99% RH. Test results show that typical changes in Δp can be mathematically modeled by a number of time functions having coefficients that can only be determined empirically. Regression analysis is used to establish the coefficients for specific filter units and dust loadings tested under the operating conditions of interest. Comparison of measured and calculated increases in pressure drop for clean filter units under fog conditions show that good agreement can be obtained with coefficients determined as relatively simple functions of the airstream velocity and liquid water content

  10. The case for improved HEPA-filter mechanical performance standards revisited

    International Nuclear Information System (INIS)

    Under benign operating conditions, High Efficiency Particulate Air (HEPA) filter units serve as reliable and relatively economical components in the air cleaning systems of nuclear facilities worldwide. Despite more than four decades of filter-unit evaluation and improvements, however, the material strength characteristics of the glass fiber filter medium continue to ultimately limit filter functional reliability. In worst-case scenarios involving fire suppression, loss-of-coolant accidents (LOCA's), or exposure to shock waves or tornado induced flows, rupture of the filter medium of units meeting current qualification standards cannot be entirely ruled out. Even under so-called normal conditions of operation, instances of filter failure reported in the literature leave open questions of filter-unit reliability. Though developments of filter units with improved burst strengths have been pursued outside the United States, support for efforts in this country has been comparatively minimal. This despite user requests for filters with greater moisture resistance, for example. Or the fact that conventional filter designs result in not only the least robust component to be found in a nuclear air cleaning system, but also the one most sensitive to the adverse effects of conditions deviating from those of normal operation. Filter qualification-test specifications of current codes, standards, and regulatory guidelines in the United States are based primarily upon research performed in a 30-year period beginning in the 1950's. They do not seem to reflect the benefits of the more significant developments and understanding of filter failure modes and mechanisms achieved since that time. One overseas design, based on such knowledge, has proven reliability under adverse operating conditions involving combined and serial challenges. Its widespread use, however, has faltered on a lack of consensus in upgrading filter performance standards. 34 refs., 2 figs., 3 tabs

  11. Differential toxicity of heterocyclic aromatic amines and their mixture in metabolically competent HepaRG cells

    International Nuclear Information System (INIS)

    Human exposure to heterocyclic aromatic amines (HAA) usually occurs through mixtures rather than individual compounds. However, the toxic effects and related mechanisms of co-exposure to HAA in humans remain unknown. We compared the effects of two of the most common HAA, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), individually or in combination, in the metabolically competent human hepatoma HepaRG cells. Various endpoints were measured including cytotoxicity, apoptosis, oxidative stress and DNA damage by the comet assay. Moreover, the effects of PhIP and/or MeIQx on mRNA expression and activities of enzymes involved in their activation and detoxification pathways were evaluated. After a 24 h treatment, PhIP and MeIQx, individually and in combination, exerted differential effects on apoptosis, oxidative stress, DNA damage and cytochrome P450 (CYP) activities. Only PhIP induced DNA damage. It was also a stronger inducer of CYP1A1 and CYP1B1 expression and activity than MeIQx. In contrast, only MeIQx exposure resulted in a significant induction of CYP1A2 activity. The combination of PhIP with MeIQx induced an oxidative stress and showed synergistic effects on apoptosis. However, PhIP-induced genotoxicity was abolished by a co-exposure with MeIQx. Such an inhibitory effect could be explained by a significant decrease in CYP1A2 activity which is responsible for PhIP genotoxicity. Our findings highlight the need to investigate interactions between HAA when assessing risks for human health and provide new insights in the mechanisms of interaction between PhIP and MeIQx.

  12. The case for improved HEPA-filter mechanical performance standards revisited

    Energy Technology Data Exchange (ETDEWEB)

    Ricketts, C.I.; Smith, P.R. [New Mexico State Univ., Las Cruces, NM (United States)

    1997-08-01

    Under benign operating conditions, High Efficiency Particulate Air (HEPA) filter units serve as reliable and relatively economical components in the air cleaning systems of nuclear facilities worldwide. Despite more than four decades of filter-unit evaluation and improvements, however, the material strength characteristics of the glass fiber filter medium continue to ultimately limit filter functional reliability. In worst-case scenarios involving fire suppression, loss-of-coolant accidents (LOCA`s), or exposure to shock waves or tornado induced flows, rupture of the filter medium of units meeting current qualification standards cannot be entirely ruled out. Even under so-called normal conditions of operation, instances of filter failure reported in the literature leave open questions of filter-unit reliability. Though developments of filter units with improved burst strengths have been pursued outside the United States, support for efforts in this country has been comparatively minimal. This despite user requests for filters with greater moisture resistance, for example. Or the fact that conventional filter designs result in not only the least robust component to be found in a nuclear air cleaning system, but also the one most sensitive to the adverse effects of conditions deviating from those of normal operation. Filter qualification-test specifications of current codes, standards, and regulatory guidelines in the United States are based primarily upon research performed in a 30-year period beginning in the 1950`s. They do not seem to reflect the benefits of the more significant developments and understanding of filter failure modes and mechanisms achieved since that time. One overseas design, based on such knowledge, has proven reliability under adverse operating conditions involving combined and serial challenges. Its widespread use, however, has faltered on a lack of consensus in upgrading filter performance standards. 34 refs., 2 figs., 3 tabs.

  13. Resistance of HEPA filter separator materials to humid air--hydrogen fluoride--fluorine environments

    International Nuclear Information System (INIS)

    The U. S. Energy Research and Development Administration (ERDA) is interested in the development of a high-efficiency particulate air (HEPA) filter that is resistant to such corrosive reagents as hydrogen fluoride (HF) and fluorine (F2) in air environments of normal relative humidity (about 50% RH). Several types of separator materials are used in the fabrication of commercial filters. The basic types of separator materials are asbestos, Kraft paper, plastic, and aluminum. At the request of the ERDA Division of Operational Safety, the different types of separator materials have been evaluated for their resistance to corrosive attack by HF and F2. The separator materials were dynamically tested in the 4-stage multiunit tester located in the Oak Ridge Gaseous Diffusion Plant laboratories. This is the system previously used in the evaluation of the Herty Foundation filter paper samples. Concurrent with the testing of filter media for its resistance to HF and F2, another component of the completed filter, the separator, was tested. All samples were exposed to a constant air flow (50% RH) of 32 liters/min, at 1000F, containing 900 ppM HF and 300 ppM F2. Exposure periods varied from 2 to 1000 h; however, the longer exposures were made only on the stronger candidates. Test results show the plastic and aluminum separator materials to be superior to the other types in resistance to HF and F2. The asbestos separators disintegrated after a relatively short exposure time; the Kraft paper types were the next weakest. The Clear Plastic S was the best performer of the plastics tested

  14. Interactions between hepatitis B virus and aflatoxin B(1): effects on p53 induction in HepaRG cells.

    Science.gov (United States)

    Lereau, Myriam; Gouas, Doriane; Villar, Stéphanie; Besaratinia, Ahmad; Hautefeuille, Agnès; Berthillon, Pascale; Martel-Planche, Ghislaine; Nogueira da Costa, André; Ortiz-Cuaran, Sandra; Hantz, Olivier; Pfeifer, Gerd P; Hainaut, Pierre; Chemin, Isabelle

    2012-03-01

    Infection by hepatitis B virus (HBV) and dietary exposure to aflatoxin B(1) (AFB(1)) are the main risk factors for the development of chronic liver disease and hepatocellular carcinoma (HCC). How these factors cooperate is still largely unknown. AFB(1) activation leads to DNA adduction and mutagenesis, with a specific mutation at codon 249 in TP53 (p.R249S). So far, only limited studies have addressed the effects of AFB(1) on HBV replication. We have analysed the effects of both risk factors on p53 induction during HBV infection in HepaRG, a cell line with hepatocyte-like morphology that metabolizes AFB(1) and supports HBV infection. Exposure to AFB(1) up to 5 µM induced a downregulation of HBV replication after 48 h, as measured by a decrease in viral antigens in the culture medium (HBsAg, HBeAg and large envelope protein) and in intracellular levels of HBV transcripts, DNA and HBsAg. Conversely, HBV infection did not significantly modify AFB(1)-DNA adduct formation or repair as assessed by immunodot-blot assay, and the induction of p53 in response to AFB(1) was similar in infected and non-infected HepaRG cells. Overall, our results suggest that AFB(1) exposure decreases HBV replication, whereas DNA damage by AFB(1) and subsequent p53 induction is not affected by the presence of the virus. Thus, in HepaRG cell line, AFB(1) and HBV do not cooperate to increase DNA damage by AFB(1). Further studies on the effects of both factors in a context of chronicity are needed to better understand synergistic effects. PMID:22113009

  15. In Vivo Evaluation of a New Embolic Spherical Particle (HepaSphere) in a Kidney Animal Model

    International Nuclear Information System (INIS)

    HepaSphere is a new spherical embolic material developed in a dry state that absorbs fluids and adapts to the vessel wall, leaving no space between the particle and the arterial wall. The aim of this study was to elucidate the final in vivo size, deformation, final location, and main properties of the particles when reconstituted with two different contrast media (Iodixanol and Ioxaglate) in an animal model. Two sizes of 'dry-state' particles (50-100 and 150-200 μm) were reconstituted using both ionic and nonionic contrast media. The mixture was used to partly embolize both kidneys in an animal model (14 pigs). The animals were sacrificed 4 weeks after the procedure and the samples processed. The final size of the particles was 230.2 ± 62.5 μm for the 50- to 100-μm dry-state particles and 314.4 ± 71 μm for the 150- to 200-μm dry-state particles. When the contrast medium (ionic versus nonionic) used for the reconstitution was studied to compare (Student's t-test) the final size of the particles, no differences were found (p > 0.05). The mean in vivo deformation for HepaSphere was 17.1% ± 12.3%. No differences (p > 0.05) were found in the deformation of the particle regarding the dry-state size or the contrast medium (Mann-Whitney test). We conclude that HepaSphere is stable, occludes perfectly, and morphologically adapts to the vessel lumen of the arteries embolized. There is no recanalization of the arteries 4 weeks after embolization. Its final in vivo size is predictable and the particle has the same properties in terms of size and deformation with the two different contrast media (Iodixanol and Ioxaglate)

  16. Effects of Rutaecarpine on Hydrogen Peroxide-Induced Apoptosis in Murine Hepa-1c1c7 Cells

    OpenAIRE

    Lee, Sung-Jin; Ahn, Hyunjin; Nam, Kung-Woo; Kim, Kyeong Ho; Mar, Woongchon

    2012-01-01

    The aim of this study was to investigate the inhibitory effects of rutaecarpine on DNA strand breaks and apoptosis induced by hydrogen peroxide (H2O2) in murine Hepa-1c1c7 cells. Oxidative DNA damage was estimated by nuclear condensation assessment, fluorescence-activated cell sorting analysis, and Comet assay. Rutaecarpine inhibited cell death induced by 500 μM H2O2, as assessed by 4',6-diamidino-2-phenylindole (DAPI) staining. Treatment with rutaecarpine reduced the number of DNA strand bre...

  17. Alloyed steel

    International Nuclear Information System (INIS)

    The composition and properties are listed of alloyed steel for use in the manufacture of steam generators, collectors, spacers, emergency tanks, and other components of nuclear power plants. The steel consists of 0.08 to 0.11% w.w. C, 0.6 to 1.4% w.w. Mn, 0.35 to 0.6% w.w. Mo, 0.02 to 0.07% w.w. Al, 0.17 to 0.37% w.w. Si, 1.7 to 2.7% w.w. Ni, 0.03 to 0.07% w.w. V, 0.005 to 0.012% w.w. N, and the rest is Fe. The said steel showed a sufficiently low transition temperature between brittle and tough structures, a greater depth of hardenability, and better weldability than similar steels. (B.S.)

  18. Steel welding.

    OpenAIRE

    Kučera, Marek

    2011-01-01

    Topic of the thesis concerns the problem of steel welding. The aim was to give acomprehensive overview on the topic, describe the known methods, advantages and disadvantages of welding technology. The introductory part is focused on introducing the basics of the process required to produce high-quality connections. Chapter three offers an overview of known and used welding methods with thein brief description of the method. The next chapter describes steel as material suitable for welding....

  19. Experimental study of plane and pleated HEPA filters clogged by particles simulating a combustion aerosol

    International Nuclear Information System (INIS)

    In nuclear facilities, airborne particles are the vector of most of the radiological contamination. For this reason, pleated HEPA filters are one of the containment devices which are actively studied by the IRSN (Institut de Radioprotection et de Surete Nucleaire) to ensure the safety of nuclear exploitation. To avoid contamination of the environment, the understanding of the behavior of the filters especially in accidental situation has to be as exhaustive as possible. The most probable accident and the most penalizing for the containment devices is fire which leads to a massive soot particle production. In this case, the clogging of the filters is a problematic which has to be taken into account. Up to now, an empirical correlation has been developed to predict the pressure drop increase. The empirical nature of this correlation doesn't allow its use in ail situations. A phenomenological understanding and model of the clogging is then necessary. The following PhD work aims to reduce the pressure drop evolution to physical observations for each step of the clogging in order to model it on the most physical basis as possible. To do so, the study has been divided in two parts. The first one focusing on the behavior of flat filter by measuring the penetration of particles inside the medium and the porosity of the deposit formed on its surface. In the second part a small scale experiment based on a single pleat has been developed. Accumulation of the particles inside the pleat has been directly observed, deformation of the pleat as well as airflow in the pleat (using a PIV method) has been measured. During these experiments, pressure drop has been monitored and the measured parameters have been linked to the pressure drop evolution. Finality is to build a simple analytical model to predict the pressure drop evolution of the filters as a function of the deposited mass, the aerosol characteristics and the ventilation conditions. The main perspective opened by these

  20. Reliability and Validity of the SE-HEPA: Examining Physical Activity- and Healthy Eating-Specific Self-Efficacy among a Sample of Preadolescents

    Science.gov (United States)

    Steele, Michael M.; Burns, Leonard G.; Whitaker, Brandi N.

    2013-01-01

    Objective. The purpose of this study was to examine the psychometric properties of the self-efficacy for healthy eating and physical activity measure (SE-HEPA) for preadolescents. Method. The reliability of the measure was examined to determine if the internal consistency of the measure was adequate (i.e., [alpha]s greater than 0.70). Next, in an…

  1. The Effect of Hyperthermia on DNA in Mouse HepA Cells-An Analysis with Computer and Observation with EM

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A computer analysis system, automated imaging cytometry (AIC), flow cytometry (FCM) and EM, were used to study the relationship of apoptosis and the change of DNA in mouse HepA cells subjected to hyperthermia. Our results showed that pyknotic rate in the 44 ℃ group was significantly increased (P<0. 01 ) when compared with that in the 37 ℃ group, both the diploid rate and aneuploid rate in the 44 ℃ group were significantly decreased (P< 0. 01 ) when compared with that in the 37 ℃ group. The pyknotic rate determined by ALC was in conformity with the apoptotic index (AI) determined by FCM. Under EM, ultrastructures of HapA ells appeared typical apoptosis changes in the 44 ℃ group. We are led to conclude that (1) when the temperature is 42 ℃ or 44 ℃ for 2 h, it did not promote the necrosis of HepA cells; (2) when the temperature is 42 ℃ for 2 h, it did not obviously induce the apoptosis of HepA cells, and the 44 ℃ for 2 h obviously induced the apoptosis of HepA cells; (3) AIC method can be used as an aid for the measurement of apoptotic index. Further study is needed to established it as a novel, simple and convenient method for determining the apoptosis.

  2. Automated detection of hepatotoxic compounds in human hepatocytes using HepaRG cells and image-based analysis of mitochondrial dysfunction with JC-1 dye

    International Nuclear Information System (INIS)

    In this study, our goal was to develop an efficient in situ test adapted to screen hepatotoxicity of various chemicals, a process which remains challenging during the early phase of drug development. The test was based on functional human hepatocytes using the HepaRG cell line, and automation of quantitative fluorescence microscopy coupled with automated imaging analysis. Differentiated HepaRG cells express most of the specific liver functions at levels close to those found in primary human hepatocytes, including detoxifying enzymes and drug transporters. A triparametric analysis was first used to evaluate hepatocyte purity and differentiation status, mainly detoxication capacity of cells before toxicity testing. We demonstrated that culturing HepaRG cells at high density maintained high hepatocyte purity and differentiation level. Moreover, evidence was found that isolating hepatocytes from 2-week-old confluent cultures limited variations associated with an ageing process occurring over time in confluent cells. Then, we designed a toxicity test based on detection of early mitochondrial depolarisation associated with permeability transition (MPT) pore opening, using JC-1 as a metachromatic fluorescent dye. Maximal dye dimerization that would have been strongly hampered by efficient efflux due to the active, multidrug-resistant (MDR) pump was overcome by coupling JC-1 with the MDR inhibitor verapamil. Specificity of this test was demonstrated and its usefulness appeared directly dependent on conditions supporting hepatic cell competence. This new hepatotoxicity test adapted to automated, image-based detection should be useful to evaluate the early MPT event common to cell apoptosis and necrosis and simultaneously to detect involvement of the multidrug resistant pump with target drugs in a human hepatocyte environment. - Highlights: → We define conditions to preserve differentiation of selective pure HepaRG hepatocyte cultures. → In these conditions, CYPs

  3. Hegelian Steel

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    2015-01-01

    Even in our globalized world the notion of national economies remain incredibly strong, just as a considerable part of the literature on transnational governance and globalization continue to rely on a zero-sum perspective concerning the relationship between the national and the transnational. De...... of the European steel industry....

  4. Phase I characterization of the HEPA (High Efficiency Particulate Air) filter media used in the airborne activity confinement system at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Novick, V.J.; Higgins, P.J. (Argonne National Lab., IL (USA))

    1989-01-01

    The purpose of this report was to characterize the HEPA filter media material. This work consisted of two major tasks. First, the pressure drop characteristics of the HEPA filter material were measured as a function of the aerosol mass loading. Particle size effects were studied by using three different particle size distributions to load the filter material. The second task was to determine the filtration efficiency spectrum for solid particles as a function of particle diameter. The filtration efficiency was measured at two different media velocities, one corresponding to the equivalent flow rate under normal operating conditions, the other corresponding to the minimum equivalent flow rate expected through the filter compartments. These tests were conducted at the Argonne National Laboratory between September 1988 and February 1989. 20 refs., 31 figs., 10 tabs.

  5. Evaluation of HEPA vacuum cleaning and dry steam cleaning in reducing levels of polycyclic aromatic hydrocarbons and house dust mite allergens in carpets

    OpenAIRE

    Yu, Chang Ho; Yiin, Lih-Ming; Fan, Zhi-hua (Tina); Rhoads, George G.

    2008-01-01

    Dry steam cleaning, which has gained recent attention as an effective method to reduce house dust mite (HDM) allergen concentration and loading in carpets, was evaluated in this study for its efficacy in lowering levels of polycyclic aromatic hydrocarbons (PAHs) as well as HDM allergens. Fifty urban homes with wail-to-wall carpets, mostly low-income and with known lead contamination, were studied in 2003 and 2004. Two carpet-cleaning interventions were compared: Repeated HEPA (High Efficiency...

  6. Recovery of plutonium from HEPA filters by Ce(IV)-promoted dissolution of PuO2 and recycle of the cerium promoter

    International Nuclear Information System (INIS)

    The experimental studies carried out included (1) the electrolytic production of Ce(IV) from Ce(III), (2) the leaching of refractory PuO2 from HEPA filter materials with maintenance of Ce(IV) concentrations by anodic oxidation during leaching, and (3) evaluation of methods for contacting the HEPA solids with the leaching solution and for separating the solid residue from the leaching liquor. Anodic oxidation of Ce(III) was accomplished with an electric current efficiency of about 85% at current densities of 0.04 to 0.4 A/dm2 at a platinum anode. Refractory PuO2 was dissolved by a 4.0 M HNO3 - 0.1 M Ce(IV) solution in 1.5 h at 1000C using stirred-contact leaching of the solids or by recirculating the leachant through a packed column of the solids. Cerium (IV) concentrations were maintained continuously by anodic oxidation throughout leaching. Dissolution times up to 10 h were required unless the HEPA media were oxidized initially in air at 3000C to destroy carbonaceous species which consumed Ce(IV) more rapidly than it could be regenerated by anodic oxidation. Leaching solids in packed columns avoided the relatively difficult liquid-solids separation by centrifugation which was required after stirred-contact leaching; however, the solids handling difficulties associated with charging and discharging of the packed columns in a remote environment remain a significant design obstacle. A chemical flowsheet is proposed for the recovery of actinides from HEPA filters. A 4 M HNO3 - 0.1 M Ce(IV) nitrate solution is used as the leachant and the Ce(III) is recycled to the leaching operation using bidentate solvent extraction

  7. The In Situ Test of HEPA Filter in Cleanroom%洁净室高效过滤器的在位检测

    Institute of Scientific and Technical Information of China (English)

    赵厚猛

    2012-01-01

    对洁净室高效过滤器在位检测做了简单的介绍,对旧车间高效过滤器进行在位检测提供了指导意见。%The introduction to in situ test of HEPA filter in cleanroom was made, Providing guidance to such test in old workshop.

  8. Recovery of plutonium from HEPA filters by Ce(IV): promoted dissolution of PuO2 and recycle of the cerium promoter

    International Nuclear Information System (INIS)

    Studies carried out in this investigation included (1) electrolytic production of Ce(IV) from Ce(III), (2) leaching of refractory PuO2 from HEPA filters with maintenance of Ce(IV) by anodic oxidation during leaching, and (3) evaluation of methods for contacting the HEPA solids with the leaching solution and for separating the solid residue from the leaching liquor. Anodic oxidation of Ce(III) was accomplished with an electric current efficiency of about 85% at current densities of 0.04 to 0.4 A/dm2 at Pt anode. Refractory PuO2 was dissolved by a 4.0 M HNO3 - 0.1 M Ce(IV) solution in 1.5 h at 1000C using stirred-contact leaching of the solids or by recirculating the leachant through a packed column of the solids. Cerium(IV) concentrations were maintained continuously by anodic oxidation throughout leaching. Dissolution times up to 10 h were required unless the HEPA media were oxidized initially in air at 3000C to destroy carbonaceous species which consumed Ce(IV) more rapidly than it could be regenerated be anodic oxidation. Leaching solids in packed columns avoided the relatively difficult liquid-solids separation by centrifugation which was required after stirred-contact leaching; however, the solids handling difficulties remain. A flowsheet is proposed for the recovery of actinides from HEPA filters. A 4 M HNO3 - 0.1 M Ce(IV) nitrate solution is used as the leachant and the Ce(III) is recycled to the leaching operation using bidentate solvent extraction

  9. The synthetic retinoid AGN 193109 but not retinoic acid elevates CYP1A1 levels in mouse embryos and Hepa-1c1c7 cells.

    Science.gov (United States)

    Soprano, D R; Gambone, C J; Sheikh, S N; Gabriel, J L; Chandraratna, R A; Soprano, K J; Kochhar, D M

    2001-07-15

    The synthetic retinoid AGN 193109 is a potent pan retinoic acid receptor (RAR) antagonist. Treatment of pregnant mice with a single oral 1 mg/kg dose of this antagonist on day 8 postcoitum results in severe craniofacial (median cleft face or frontonasal deficiency) and eye malformations in virtually all exposed fetuses. Using differential display analysis, we have determined that CYP1A1 mRNA levels are elevated in mouse embryos 6 h following treatment with AGN 193109. Similarly, an elevation in CYP1A1 mRNA levels, protein levels, and aryl hydrocarbon hydoxylase activity occurs in Hepa-1c1c7 cells, with the maximal elevation observed when the cells were treated with 10(-5) M AGN 193109 for 4 to 8 h. Elevation in CYP1A1 mRNA levels in mouse embryos and Hepa-1c1c7 cells does not occur upon treatment with the natural retinoid, all-trans-retinoic acid. Finally, elevation in CYP1A1 mRNA levels was not observed when mutant Hepa-1c1c7 cells, which are defective in either the aryl hydrocarbon receptor (AhR) or aryl hydrocarbon receptor nuclear translocator (ARNT), were treated with AGN 193109. This suggests that the AhR/ARNT pathway and not the RAR/RXR pathway is mediating the elevation of CYP1A1 mRNA levels by AGN 193109, at least in the Hepa-1c1c7 cells. This is the first example of a retinoid that displays the abililty to regulate both the RAR/RXR and AhR/ARNT transcriptional regulatory pathways.

  10. Fire tests to evaluate the potential fire threat and its effects on HEPA filter integrity in cell ventilation at the Oak Ridge National Laboratory, Building 7920

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, H.K.; Staggs, K.J.; Doughty, S.M. [Oak Ridge National Lab., TN (United States)

    1992-12-01

    As a result of a DOE (Tiger Team) Technical Safety Appraisal (November 1990) of the Radiochemical Engineering Development Center (REDC), ORNL Building 7920, a number of fire protection concerns were identified. The primary concern was the perceived loss of ventilation system containment due to the thermal destruction and/or breaching of the prefilters and/or high-efficiency particulate air filters (HEPA `s) and the resultant radioactive release to the external environment. The following report describes the results of an extensive fire test program performed by the Fire Research Discipline (FRD) of the Special Projects Division of Lawrence Livermore National Lab (LLNL) and funded by ORNL to address these concerns. Full scale mock-ups of a REDC hot cell tank pit, adjacent cubicle pit, and associated ventilation system were constructed at LLNL and 13 fire experiments were conducted to specifically answer the questions raised by the Tiger Team. Our primary test plan was to characterize the burning of a catastrophic solvent spill (kerosene) of 40 liters and its effect on the containment ventilation system prefilters and HEPA filters. In conjunction with ORNL and Lockwood Greene we developed a test matrix that assessed the fire performance of the prefilters and HEPA filters; evaluated the fire response of the fiber reinforced plastic (FRP) epoxy ventilation duct work; the response and effectiveness of the fire protection system, the effect of fire in a cubicle on the vessel off-gas (VOG) elbow, and other fire safety questions.

  11. Walking in the high-rise city: a Health Enhancement and Pedometer-determined Ambulatory (HEPA program in Hong Kong

    Directory of Open Access Journals (Sweden)

    Leung AYM

    2014-08-01

    Full Text Available Angela YM Leung,1,2 Mike KT Cheung,3 Michael A Tse,4 Wai Chuen Shum,5 BJ Lancaster,1,6 Cindy LK Lam7 1School of Nursing, 2Research Centre on Heart, Brain, Hormone and Healthy Aging, Li Ka Shing Faculty of Medicine, University of Hong Kong, 3Centre on Research and Advocacy, Hong Kong Society for Rehabilitation, 4Institute of Human Performance, University of Hong Kong, 5Sheng Kung Hui Holy Carpenter Church Social Services, Hong Kong Special Administrative Region, People’s Republic of China; 6School of Nursing, Vanderbilt University, Nashville, TN, USA; 7Department of Family Medicine and Primary Care, University of Hong Kong, Hong Kong Special Administrative Region, People’s Republic of China Abstract: Due to the lack of good infrastructure in the public estates, many older adults in urban areas are sedentary. The Health Enhancement and Pedometer-Determined Ambulatory (HEPA program was developed to assist older adults with diabetes and/or hypertension to acquire walking exercise habits and to build social support, while engaged in regular physical activity. This study aimed to describe the HEPA program and to report changes in participants’ walking capacity and body strength after 10-week walking sessions. A pre- and postintervention design was used. Pedometers were used to measure the number of steps taken per day before and after the 10-week intervention. Upper and lower body strength, lower body flexibility, and quality of life were assessed. A total of 205 older adults completed the program and all health assessments. After the 10-week intervention, the average number of steps per day increased by 36%, from 6,591 to 8,934. Lower body strength, upper body strength, and aerobic fitness increased significantly after 10 weeks, along with improvement in the 12-item Short Form Health Survey (SF™-12 physical and mental health component summary scores. A social support network was built in the neighborhood, and the local environment was

  12. L-选择素与小鼠肝癌细胞Hepa1-6淋巴道转移的关系%Correlation between L-selectin and lymphatic metastasis potential of mice hepa1-6 cells

    Institute of Scientific and Technical Information of China (English)

    刘芯宇; 张嘉宁

    2013-01-01

    目的 研究L-选择素(L-selectin)与其配体甘露糖受体(mannose receptor,MR)间相互作用与小鼠肝癌细胞Hepa1-6淋巴道转移潜能相关性.方法 构建含有L-selectin的重组载体pcDNA3.1,转染小鼠肝癌细胞 Hepa1-6,筛选稳定表达L-selectin的细胞株.采用免疫组化、RT-PCR、流式细胞、体外黏附试验技术研究小鼠肝癌细胞Hepa1-6中L-selectin的表达及其与肿瘤细胞淋巴道转移潜能的相关性.结果 1重组质粒为目的基因L-selectin.2 Hepa1-6细胞表面有L-selectin表达,阳性率20.2%.3流式细胞仪检测结果表明Hepa1-6细胞表达L-selectin为19.9%.4体外黏附试验结果表明,不具有转移特性的Hepa1-6表达L-selectin后可发生淋巴道转移,L-selectin能与MR结合(P<0.001),介导Hepa1-6的淋巴道转移.结论 Hepa1-6表达目的基因L-selectin后具有淋巴道转移潜能,并能与MR在体外结合,介导肿瘤细胞的淋巴道转移.%Objective To study the correlation between L-selectin and its ligand mannose receptor with mice hepatoma cells Hepal-6 lymphatic metastatic potential. Methods The recombinant plasmids pcDNA3. 1 containing L-selectin was constructed, and transfected mouse liver tumor Hepal-6 cells. The cell strains with a stable expression of L-selectin were screened. Immunochemistry,flow cytometric analysis, RT-PCR and other procedures, in addition to in vitro adhesion assays were performed, to verify the expression of L-selectin on the surface of Hepal -6 cells, and the interactions between L-selectin and tumor cells lymphatic metastasis potential was studied. Results The target gene of recombinant plasmid was L-selectin. L-selectin was expressed on Hepal-6 cell' s surface with the positive rate of 20. 2% . By flow cytometric analysis,the positive expression rate of L-selectin in Hepal-6 cells was 19. 9% . In vitro adhesion assays indicated that this protein was able to bind specifically to MR(P < 0.001) ,and further confirmed that Hepal-6 cells

  13. 3-Nitrobenzanthrone and 3-aminobenzanthrone induce DNA damage and cell signalling in Hepa1c1c7 cells

    Energy Technology Data Exchange (ETDEWEB)

    Landvik, N.E. [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway); Arlt, V.M.; Nagy, E. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Brookes Lawley Building, Sutton, Surrey SM2 5NG (United Kingdom); Solhaug, A. [Section for Toxicology, Department of Feed and Food Safety, National Veterinary Institute Pb 750 Sentrum, N-0106 Oslo (Norway); Tekpli, X. [EA SeRAIC, Equipe labellisee Ligue contre le Cancer, IFR 140, Universite de Rennes 1, Rennes (France); Schmeiser, H.H. [Research Group Genetic Alteration in Carcinogenesis, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Refsnes, M. [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway); Phillips, D.H. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Brookes Lawley Building, Sutton, Surrey SM2 5NG (United Kingdom); Lagadic-Gossmann, D. [EA SeRAIC, Equipe labellisee Ligue contre le Cancer, IFR 140, Universite de Rennes 1, Rennes (France); Holme, J.A., E-mail: jorn.holme@fhi.no [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway)

    2010-02-03

    3-Nitrobenzanthrone (3-NBA) is a mutagenic and carcinogenic environmental pollutant found in diesel exhaust and urban air pollution. In the present work we have characterised the effects of 3-NBA and its metabolite 3-aminobenzanthrone (3-ABA) on cell death and cytokine release in mouse hepatoma Hepa1c1c7 cells. These effects were related to induced DNA damage and changes in cell signalling pathways. 3-NBA resulted in cell death and caused most DNA damage as judged by the amount of DNA adducts ({sup 32}P-postlabelling assay), single strand (ss)DNA breaks and oxidative DNA lesions (comet assay) detected. An increased phosphorylation of H2AX, chk1, chk2 and partly ATM was observed using flow cytometry and/or Western blotting. Both compounds increased phosphorylation of p53 and MAPKs (ERK, p38 and JNK). However, only 3-NBA caused an accumulation of p53 in the nucleus and a translocation of Bax to the mitochondria. The p53 inhibitor pifithrin-alpha inhibited 3-NBA-induced apoptosis, indicating that cell death was a result of the triggering of DNA signalling pathways. The highest phosphorylation of Akt and degradation of I{kappa}B-{alpha} (suggesting activation of NF-{kappa}B) were also seen after treatment with 3-NBA. In contrast 3-ABA increased IL-6 release, but caused little or no toxicity. Cytokine release was inhibited by PD98059 and curcumin, suggesting that ERK and NF-{kappa}B play a role in this process. In conclusion, 3-NBA seems to have a higher potency to induce DNA damage compatible with its cytotoxic effects, while 3-ABA seems to have a greater effect on the immune system.

  14. Ultrahigh carbon steels, Damascus steels, and superplasticity

    Energy Technology Data Exchange (ETDEWEB)

    Sherby, O.D. [Stanford Univ., CA (United States). Dept. of Materials Science and Engineering; Wadsworth, J. [Lawrence Livermore National Lab., CA (United States)

    1997-04-01

    The processing properties of ultrahigh carbon steels (UHCSs) have been studied at Stanford University over the past twenty years. These studies have shown that such steels (1 to 2.1% C) can be made superplastic at elevated temperature and can have remarkable mechanical properties at room temperature. It was the investigation of these UHCSs that eventually brought us to study the myths, magic, and metallurgy of ancient Damascus steels, which in fact, were also ultrahigh carbon steels. These steels were made in India as castings, known as wootz, possibly as far back as the time of Alexander the Great. The best swords are believed to have been forged in Persia from Indian wootz. This paper centers on recent work on superplastic UHCSs and on their relation to Damascus steels. 32 refs., 6 figs.

  15. Reinforcing the Steel Sector

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    By pushing forward mergers between steel-makers, China gears up to consolidate the large but fragmented industryIn a government effort to consolidate the crowded steel industry and position it for fierce global competition, the state-

  16. Differences in TCDD-elicited gene expression profiles in human HepG2, mouse Hepa1c1c7 and rat H4IIE hepatoma cells

    Directory of Open Access Journals (Sweden)

    Burgoon Lyle D

    2011-04-01

    Full Text Available Abstract Background 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD is an environmental contaminant that elicits a broad spectrum of toxic effects in a species-specific manner. Current risk assessment practices routinely extrapolate results from in vivo and in vitro rodent models to assess human risk. In order to further investigate the species-specific responses elicited by TCDD, temporal gene expression responses in human HepG2, mouse Hepa1c1c7 and rat H4IIE cells were compared. Results Microarray analysis identified a core set of conserved gene expression responses across species consistent with the role of AhR in mediating adaptive metabolic responses. However, significant species-specific as well as species-divergent responses were identified. Computational analysis of the regulatory regions of species-specific and -divergent responses suggests that dioxin response elements (DREs are involved. These results are consistent with in vivo rat vs. mouse species-specific differential gene expression, and more comprehensive comparative DRE searches. Conclusions Comparative analysis of human HepG2, mouse Hepa1c1c7 and rat H4IIE TCDD-elicited gene expression responses is consistent with in vivo rat-mouse comparative gene expression studies, and more comprehensive comparative DRE searches, suggesting that AhR-mediated gene expression is species-specific.

  17. Experimental relationship between the specific resistance of a HEPA [High Efficiency Particulate Air] filter and particle diameters of different aerosol materials

    International Nuclear Information System (INIS)

    The increase in pressure drop across a HEPA filter has been measured as a function of the particle mass loading using two materials with different particle morphologies. The HEPA filter media chosen, is identical to the filter media used in the Airborne Activity Confinement System (AACS) on the Savannah River Reactors. The velocity through the test filter media was the same as the velocity through the AACS media, under normal operating flow conditions. Sodium Chloride challenge particles were generated using an atomizer, resulting in regularly shaped crystalline forms. Ammonium chloride aerosols were formed from the gas phase reaction of HCl and NH4OH vapors resulting in irregular agglomerates. In both cases, the generation conditions were adjusted to provide several different particle size distributions. For each particle size distribution, the mass of material loaded per unit area of filter per unit pressure drop for a given filtration velocity (1/Specific resistance) was measured. Theoretical considerations in the most widely accepted filter cake model predict that the mass per unit area and per unit pressure drop should increase with the particle density times the particle diameter squared. However, these test results indicate that the increase in the mass loaded per unit area per unit pressure drop, for both materials, can be better described by plotting the specific resistance divided by the particle density as an inverse function of the particle density times the particle diameter squared. 9 refs., 7 figs

  18. Metabolomics analysis of the toxicity pathways of triphenyl phosphate in HepaRG cells and comparison to oxidative stress mechanisms caused by acetaminophen.

    Science.gov (United States)

    Van den Eede, Nele; Cuykx, Matthias; Rodrigues, Robim M; Laukens, Kris; Neels, Hugo; Covaci, Adrian; Vanhaecke, Tamara

    2015-12-01

    Since the publication of REACH guidelines, the need for in vitro tools for toxicity testing has increased. We present here the development of a hepatotoxicity testing tool using human HepaRG cell cultures and metabolomics. HepaRG cells were exposed to either 4mM acetaminophen (APAP) as reference toxicant for oxidative stress or 50 μM triphenyl phosphate (TPHP) as toxicant with unknown toxicity pathways (TPs). After 72 h exposure, cells were subjected to quenching and liquid-liquid extraction which resulted in a polar and an apolar fraction. Analysis of fractions was performed by ultrahigh performance liquid chromatography-high resolution tandem mass spectrometry (UHPLC-QTOF-MS). Significantly up or down regulated metabolites were selected by univariate statistics prior to identification. In order to obtain robust and specific TP biomarkers, the experiment was also repeated using a different culture medium composition to assess which metabolites show consistent changes. Potential biomarkers belonging to different TPs were found for APAP and TPHP. For APAP, the biomarkers were related to a decrease in unsaturated phospholipids, and for TPHP to an accumulation of phosphoglycerolipids and increase of palmitoyl lysophosphatidylcholine. This first proof-of-concept opens new perspectives for the analysis of other (reference) toxicants with different TPs and it can be used to expand the in vitro tool for hepatotoxicity screening of various compounds.

  19. The steel scrap age.

    Science.gov (United States)

    Pauliuk, Stefan; Milford, Rachel L; Müller, Daniel B; Allwood, Julian M

    2013-04-01

    Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age.

  20. Weldability of Stainless Steels

    International Nuclear Information System (INIS)

    It gives an outline of metallographic properties of welding zone of stainless steels, generation and mechanisms of welding crack and decreasing of corrosion resistance of welding zone. It consists of seven chapters such as introduction, some kinds of stainless steels and properties, metallographic properties of welding zone, weld crack, toughness of welding zone, corrosion resistance and summary. The solidification modes of stainless steels, each solidification mode on the cross section of Fe-Cr-Ni alloy phase diagram, each solidification mode of weld stainless steels metal by electron beam welding, segregation state of alloy elements at each solidification mode, Schaeffler diagram, Delong diagram, effects of (P + S) mass content in % and Cr/Ni equivalent on solidification cracking of weld stainless steels metal, solidification crack susceptibility of weld high purity stainless steels metal, effects of trace impurity elements on solidification crack susceptibility of weld high purity stainless steels metal, ductile fracture susceptibility of weld austenitic stainless steels metal, effects of H2 and ferrite content on generation of crack of weld 25Cr-5N duplex stainless steels, effects of O and N content on toughness of weld SUS 447J1 metals, effect of ferrite content on aging toughness of weld austenitic stainless steel metal, corrosion morphology of welding zone of stainless steels, generation mechanism of knife line attack phenomenon, and corrosion potential of some kinds of metals in seawater at room temperature are illustrated. (S.Y.)

  1. In vivo – in vitro toxicogenomic comparison of TCDD-elicited gene expression in Hepa1c1c7 mouse hepatoma cells and C57BL/6 hepatic tissue

    Directory of Open Access Journals (Sweden)

    Boverhof Darrell R

    2006-04-01

    Full Text Available Abstract Background In vitro systems have inherent limitations in their ability to model whole organism gene responses, which must be identified and appropriately considered when developing predictive biomarkers of in vivo toxicity. Systematic comparison of in vitro and in vivo temporal gene expression profiles were conducted to assess the ability of Hepa1c1c7 mouse hepatoma cells to model hepatic responses in C57BL/6 mice following treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD. Results Gene expression analysis and functional gene annotation indicate that Hepa1c1c7 cells appropriately modeled the induction of xenobiotic metabolism genes in vivo. However, responses associated with cell cycle progression and proliferation were unique to Hepa1c1c7 cells, consistent with the cell cycle arrest effects of TCDD on rapidly dividing cells. In contrast, lipid metabolism and immune responses, representative of whole organism effects in vivo, were not replicated in Hepa1c1c7 cells. Conclusion These results identified inherent differences in TCDD-mediated gene expression responses between these models and highlighted the limitations of in vitro systems in modeling whole organism responses, and additionally identified potential predictive biomarkers of toxicity.

  2. 生物安全实验室效率检漏型高效空气过滤装置的研制%Development of HEPA Filter Unit with Efficiency Leak Detection for Bio-safety Laboratory

    Institute of Scientific and Technical Information of China (English)

    张宗兴; 赵明; 衣颖; 祁建城

    2013-01-01

    目的:研制一种可安装在生物安全实验室内的效率检漏型排风高效过滤装置,可实现对高效空气过滤器的原位检漏和消毒.方法:依据高效空气过滤器效率法检测和气体消毒要求,进行高效空气过滤装置的结构设计.结果:该高效空气过滤装置,可采用效率法对高效过滤器进行原位检漏,并可对过滤器进行原位气体消毒及验证消毒效果,满足相关标准要求.结论:该装置适用于生物安全实验室的污染空气排放处置,可满足我国生物安全实验室建设的需要.%Objective To develop an exhaust HEPA filter unit installed in the laboratory that has the functions of in-situ leak detection and sterilization of HEPA filter.Methods The structure composition of the unit was designed according to the requirement of efficiency test and gas sterilization of HEPA filter.Results The HEPA filter unit which met relevant standard requirements had the functions of in-situ leak detection using efficiency test,sterilization and validating the effect of sterilization of HEPA filter.Conclusion The unit which is applicable to decontamination of contaminated air emissions of bio-safety laboratory can meet the needs of construction of bio-safety laboratory in China.

  3. Activation of the sonic hedgehog signaling pathway occurs in the CD133 positive cells of mouse liver cancer Hepa 1–6 cells

    Directory of Open Access Journals (Sweden)

    Jeng KS

    2013-08-01

    Full Text Available Kuo-Shyang Jeng,1 I-Shyan Sheen,2 Wen-Juei Jeng,2 Ming-Che Yu,3 Hsin-I Hsiau,3 Fang-Yu Chang,3 Hsin-Hua Tsai31Department of Surgery, Far Eastern Memorial Hospital, Taipei, 2Department of Hepato-Gastroenterology, Chang Gung Memorial Hospital, Linkou Medical Center, Chang Gung University, 3Department of Medical Research, Far Eastern Memorial Hospital, Taipei, Taiwan, Republic of ChinaBackground: The important role of cancer stem cells in carcinogenesis has been emphasized in research. CD133+ cells have been mentioned as liver cancer stem cells in hepatocellular carcinoma (HCC. Some researchers have proposed that the sonic hedgehog (Shh pathway contributes to hepatocarcinogenesis and that the pathway activation occurs mainly in cancer stem cells. We investigated whether the activation of the Shh pathway occurs in CD133+ cells from liver cancer.Materials and methods: We used magnetic sorting to isolate CD133+ cells from mouse cancer Hepa 1–6 cells. To examine the clonogenicity, cell culture and soft agar colony formation assay were performed between CD133+ and CD133- cells. To study the activation of the Shh pathway, we examined the mRNA expressions of Shh, patched homolog 1 (Ptch-1, glioma-associated oncogene homolog 1 (Gli-1, and smoothened homolog (Smoh by real-time polymerase chain reaction of both CD133+ and CD133- cells.Results: The number (mean ± standard deviation of colonies of CD133+ cells and CD133- cells was 1,031.0 ± 104.7 and 119.7 ± 17.6 respectively. This difference was statistically significant (P < 0.001. Their clonogenicity was 13.7% ± 1.4% and 1.6% ± 0.2% respectively with a statistically significant difference found (P < 0.001. CD133+ cells and CD133– cells were found to have statistically significant differences in Shh mRNA and Smoh mRNA (P = 0.005 and P = 0.043 respectively.Conclusion: CD133+ Hepa 1–6 cells have a significantly higher colony proliferation and clonogenicity. The Shh pathway is activated in these

  4. Modern Steel Framed Schools.

    Science.gov (United States)

    American Inst. of Steel Construction, Inc., New York, NY.

    In view of the cost of structural framing for school buildings, ten steel-framed schools are examined to review the economical advantages of steel for school construction. These schools do not resemble each other in size, shape, arrangement or unit cost; some are original in concept and architecture, and others are conservative. Cost and…

  5. Clean Production of Steel and Refractories in China's Steel Industry

    Institute of Scientific and Technical Information of China (English)

    SU Tiansen

    2002-01-01

    The paper describes the importance of clean production of steel and the relationships amongst sustaining development of steel industry, environment protection and the role of refractories in the clean production of steel. The main achievements and main shortcomings in the clean production of China' s steel industry have been reviewed together with the introduction of the policy supporting system and the future development of clean production in China' s steel industry.

  6. Nuclear transmutation in steels

    Science.gov (United States)

    Belozerova, A. R.; Shimanskii, G. A.; Belozerov, S. V.

    2009-05-01

    The investigations of the effects of nuclear transmutation in steels that are widely used in nuclear power and research reactors and in steels that are planned for the application in thermonuclear fusion plants, which are employed under the conditions of a prolonged action of neutron irradiation with different spectra, made it possible to study the effects of changes in the isotopic and chemical composition on the tendency of changes in the structural stability of these steels. For the computations of nuclear transmutation in steels, we used a program complex we have previously developed on the basis of algorithms for constructing branched block-type diagrams of nuclide transformations and for locally and globally optimizing these diagrams with the purpose of minimizing systematic errors in the calculation of nuclear transmutation. The dependences obtained were applied onto a Schaeffler diagram for steels used for structural elements of reactors. For the irradiation in fission reactors, we observed only a weak influence of the effects of nuclear transmutation in steels on their structural stability. On the contrary, in the case of irradiation with fusion neutrons, a strong influence of the effects of nuclear transmutation in steels on their structural stability has been noted.

  7. Fatigue of stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Solin, J. (VTT Technical Research Centre of Finland, Espoo (Finland))

    2010-05-15

    The 2009b update of ASME III introduces a new set of fatigue design curves. The new curve for austenitic stainless steels is exactly matching with the one endorsed in 2007 by the US NRC for new designs only. This has a notable effect in usage factor calculation at strain amplitudes below 0.5 %. However, experimental results clearly demonstrate that a new air curve would not be needed for the studied stainless steel grades. Our current results suggest arguments for use of stabilized stainless steels in NPP piping components, where high cycle fatigue (epsilon{sub a}<=0.5%) is a concern. (orig.)

  8. Glass Stronger than Steel

    Science.gov (United States)

    Yarris, Lynn

    2011-03-28

    A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of steel or any other known material, has been developed and tested by a collaboration of researchers from Berkeley Lab and Caltech.

  9. Life after Steel

    Science.gov (United States)

    Mangan, Katherine

    2013-01-01

    Bobby Curran grew up in a working-class neighborhood in Baltimore, finished high school, and followed his grandfather's steel-toed bootprints straight to Sparrows Point, a 3,000-acre sprawl of industry on the Chesapeake Bay. College was not part of the plan. A gritty but well-paying job at the RG Steel plant was Mr. Curran's ticket to a secure…

  10. Articles comprising ferritic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Rakowski, James M.

    2016-06-28

    An article of manufacture comprises a ferritic stainless steel that includes a near-surface region depleted of silicon relative to a remainder of the ferritic stainless steel. The article has a reduced tendency to form an electrically resistive silica layer including silicon derived from the steel when the article is subjected to high temperature oxidizing conditions. The ferritic stainless steel is selected from the group comprising AISI Type 430 stainless steel, AISI Type 439 stainless steel, AISI Type 441 stainless steel, AISI Type 444 stainless steel, and E-BRITE.RTM. alloy, also known as UNS 44627 stainless steel. In certain embodiments, the article of manufacture is a fuel cell interconnect for a solid oxide fuel cell.

  11. Profiles in garbage: Steel cans

    Energy Technology Data Exchange (ETDEWEB)

    Miller, C. [Environmental Industry Associations, Washington, DC (United States)

    1998-02-01

    Steel mills are the largest market for steel cans. Integrated mills use the basic oxygen process to manufacture tinplate, appliances, car bodies, and steel framing. Electric arc furnaces use 100% scrap to produce steel shapes such as railroad ties and bridge spans. Electric arc furnaces are more geographically diverse and tend to have smaller capacities than basic oxygen furnaces. Detinners remove the tin from steel cans for resale to tin using industries. With less tin use in steel cans, the importance of the detinning market has declined substantially. Foundries use scrap as a raw material in making castings and molds for industrial users.

  12. The Effect of Aromatic Hydrocarbon Receptor on the Phenotype of the Hepa 1c1c7 Murine Hepatoma Cells in the Absence of Dioxin

    Directory of Open Access Journals (Sweden)

    Feng Wang

    2007-01-01

    Full Text Available The aromatic hydrocarbon receptor (AhR mediates biological responses to certain exogenous ligands, such as the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, and has also been demonstrated to modulate the cell cycle and differentiated state of several cell lines independently of exogenous ligands. In this study, we used DNA micorarray analysis to elucidate the profile of genes responsive to the expression of unliganded AhR by re-introducing AhR into an AhR-deficient mouse derivative (c19 of the mouse hepatoma cell line Hepa1c1c7. 22 gene products were up-regulated and 8 were down-regulated two-fold or more in c19 cells infected with a retroviral vector expressing mouse AhR. Surprisingly, expression of genes involved in cell proliferation or differentiation were not affected by introduction of AhR. AhR also did not restore expression of the albumin gene in c19 cells. Introduction of AhR into c12, a similar AhRdefective mouse hepatoma cell line, also did not restore albumin expression, and furthermore, did not lead to changes in cellular morphology or cell cycle parameters. These observations fail to support the notion that unliganded AhR regulates proliferation and differentiation of liver-derived cells.

  13. 3-Nitrofluoranthene (3-NF) but not 3-aminofluoranthene (3-AF) elicits apoptosis as well as programmed necrosis in Hepa1c1c7 cells

    International Nuclear Information System (INIS)

    In this study, we show that the environmental pollutant, 3-nitrofluoranthene (3-NF) but not its amine form, 3-aminofluoranthene (3-AF), induces apoptosis as well as regulated necrosis with necroptotic features in Hepa1c1c7 cells. Upon exposure to 3-NF, both typical apoptotic and necrotic cells were observed. A large number of the cells exhibited a characteristic partial nuclear chromatin condensation. Cycloheximide completely attenuated 3-NF-induced cell death. Activation of caspase-8, -9, and -3 were observed. Moreover, Z-VAD-FMK decreased the apoptotic cells, whereas the number of propidium iodide (PI)-positive cells with partial chromatin condensation was reduced by Nec-1, an inhibitor of receptor interacting protein (RIP-1). Cyp1a1, but not nitric oxide synthase (NOS), appears to be involved in activation of 3-NF to reactive metabolites. Increase in the number as well as size of lysosomes, myelinosomes, and activation of autophagy were also observed. 3-NF induced phosphorylation of ERK1/2, JNK and p38 MAPKs. Interestingly, while inhibitors of ERK1/2 and JNK reduced apoptotic as well as necrotic cell death, the p38 inhibitor, SB202190 reduced only the necrotic cell death. Taken together, 3-NF elicits both apoptosis and a caspase-independent programmed cell death (PCD) with autophagic characteristics. Conversely, with 3-AF, no apparent cytotoxic effects besides a reduction in cell proliferation was observed

  14. Clean steels for fusion

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, D.S.

    1995-03-01

    Fusion energy production has an inherent advantage over fission: a fuel supply with reduced long term radioactivity. One of the leading candidate materials for structural applications in a fusion reactor is a tungsten stabilized 9% chromium Martensitic steel. This alloy class is being considered because it offers the opportunity to maintain that advantage in the reactor structure as well as provide good high temperature strength and radiation induced swelling and embrittlement resistance. However, calculations indicate that to obtain acceptable radioactivity levels within 500 years after service, clean steel will be required because the niobium impurity levels must be kept below about 2 appm and nickel, molybdenum, nitrogen, copper, and aluminum must be intentionally restricted. International efforts are addressing the problems of clean steel production. Recently, a 5,000 kg heat was vacuum induction melted in Japan using high purity commercial raw materials giving niobium levels less than 0.7 appm. This paper reviews the need for reduced long term radioactivity, defines the advantageous properties of the tungsten stabilized Martensitic steel class, and describes the international efforts to produce acceptable clean steels.

  15. Thermochemical surface engineering of steels

    OpenAIRE

    2015-01-01

    Thermochemical Surface Engineering of Steels provides a comprehensive scientific overview of the principles and different techniques involved in thermochemical surface engineering, including thermodynamics, kinetics principles, process technologies and techniques for enhanced performance of steels

  16. Thermochemical surface engineering of steels

    DEFF Research Database (Denmark)

    Thermochemical Surface Engineering of Steels provides a comprehensive scientific overview of the principles and different techniques involved in thermochemical surface engineering, including thermodynamics, kinetics principles, process technologies and techniques for enhanced performance of steels...

  17. Continuous steel production and apparatus

    Science.gov (United States)

    Peaslee, Kent D.; Peter, Jorg J.; Robertson, David G. C.; Thomas, Brian G.; Zhang, Lifeng

    2009-11-17

    A process for continuous refining of steel via multiple distinct reaction vessels for melting, oxidation, reduction, and refining for delivery of steel continuously to, for example, a tundish of a continuous caster system, and associated apparatus.

  18. Fatigue damage of steel components

    DEFF Research Database (Denmark)

    Fæster, Søren; Zhang, Xiaodan; Huang, Xiaoxu;

    2014-01-01

    Railway rails and the inner ring in roller bearings in wind turbines are both experiencing steel-to-steel contact in small areas with huge loads resulting in extremely high stresses in the base materials......Railway rails and the inner ring in roller bearings in wind turbines are both experiencing steel-to-steel contact in small areas with huge loads resulting in extremely high stresses in the base materials...

  19. A-3 steel work completed

    Science.gov (United States)

    2009-01-01

    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  20. Microbial-Influenced Corrosion of Corten Steel Compared with Carbon Steel and Stainless Steel in Oily Wastewater by Pseudomonas aeruginosa

    Science.gov (United States)

    Mansouri, Hamidreza; Alavi, Seyed Abolhasan; Fotovat, Meysam

    2015-07-01

    The microbial corrosion behavior of three important steels (carbon steel, stainless steel, and Corten steel) was investigated in semi petroleum medium. This work was done in modified nutrient broth (2 g nutrient broth in 1 L oily wastewater) in the presence of Pseudomonas aeruginosa and mixed culture (as a biotic media) and an abiotic medium for 2 weeks. The behavior of corrosion was analyzed by spectrophotometric and electrochemical methods and at the end was confirmed by scanning electron microscopy. The results show that the degree of corrosion of Corten steel in mixed culture, unlike carbon steel and stainless steel, is less than P. aeruginosa inoculated medium because some bacteria affect Corten steel less than other steels. According to the experiments, carbon steel had less resistance than Corten steel and stainless steel. Furthermore, biofilm inhibits separated particles of those steels to spread to the medium; in other words, particles get trapped between biofilm and steel.

  1. Effects of KLF14 gene overexpression on insulin resistance in hepa1-6 hepatoma carcinoma cell%KLF14基因过表达对改善Hepa1-6小鼠肝癌细胞胰岛素抵抗的作用

    Institute of Scientific and Technical Information of China (English)

    代继桓; 李伶; 杨刚毅; 任艳; 贾彦军; 罗小河; 冉文侠; 曾梦

    2015-01-01

    Objective To investigate the role of KLF14 overexpression on insulin resistance in Hepa1-6 cell.Methods The tissue distribution of KLF14 in healthy C57/6J mice was detected by real-time quantitative PCR(RT-PCR).Expression vector for pIRES2-EGFP-KLF14 gene was constructed and transfected into Hepa1-6 cell.The mRNA level of KLF14 was determined by RT-QPCR;KLF14 and p-AKT protein levels were measured by Western blot.Results The recombinant plasmid pIRES2-EGFP-KLF14 was constructed successfully.In transfected hepa1-6 cell,KLF14 mRNA and protein were significantly higher than those of control and blank cells after 48 h(P<0.01).The KLF14 gene was ubiquitously in mice.The relative mRNA expression level of KLF14 from high to low in order was heart,muscle,liver,fat, intestine,kidney,brain,lung,stomach,speech and epididymis.After treated with serum intervention,there was no significant difference be-tween normal and patient groups without transfection;whereas the p-AKT expression in the patient group with transfection was significantly in-creased compared with that in normal group.In insulin-stimulated conditions,the p-AKT expression was inhibited after treated with PI3K in-hibitor LY294002 regardless of transfection or not.Conclusions There is an extensive expression of KLF14 in various tissues of C57BL/6J mice,indicating that KLF14 might play a role in maintaining normal physiological function;KLF14 gene overexpression could promote the ac-tivation of AKT,and its effects in increasing insulin sensitivity in diabetics is more distinct than normal people.%目的:探讨KLF14基因过表达对小鼠肝癌细胞Hepa1-6胰岛素抵抗的影响。方法实时荧光定量PCR(RT-QPCR)检测KLF14基因mRNA在健康C57BL/6J小鼠各组织的表达分布情况;构建小鼠KLF14基因重组真核表达质粒pIRES2-EGFP-KLF14并转染Hepa1-6细胞,RT-PCR法检测KLF14基因mRNA的表达;Western印迹检测KLF14及p-AKT蛋白水平的

  2. KLF14基因过表达对改善Hepa1-6小鼠肝癌细胞胰岛素抵抗的作用%Effects of KLF14 gene overexpression on insulin resistance in hepa1-6 hepatoma carcinoma cell

    Institute of Scientific and Technical Information of China (English)

    代继桓; 李伶; 杨刚毅; 任艳; 贾彦军; 罗小河; 冉文侠; 曾梦

    2015-01-01

    Objective To investigate the role of KLF14 overexpression on insulin resistance in Hepa1-6 cell.Methods The tissue distribution of KLF14 in healthy C57/6J mice was detected by real-time quantitative PCR(RT-PCR).Expression vector for pIRES2-EGFP-KLF14 gene was constructed and transfected into Hepa1-6 cell.The mRNA level of KLF14 was determined by RT-QPCR;KLF14 and p-AKT protein levels were measured by Western blot.Results The recombinant plasmid pIRES2-EGFP-KLF14 was constructed successfully.In transfected hepa1-6 cell,KLF14 mRNA and protein were significantly higher than those of control and blank cells after 48 h(P<0.01).The KLF14 gene was ubiquitously in mice.The relative mRNA expression level of KLF14 from high to low in order was heart,muscle,liver,fat, intestine,kidney,brain,lung,stomach,speech and epididymis.After treated with serum intervention,there was no significant difference be-tween normal and patient groups without transfection;whereas the p-AKT expression in the patient group with transfection was significantly in-creased compared with that in normal group.In insulin-stimulated conditions,the p-AKT expression was inhibited after treated with PI3K in-hibitor LY294002 regardless of transfection or not.Conclusions There is an extensive expression of KLF14 in various tissues of C57BL/6J mice,indicating that KLF14 might play a role in maintaining normal physiological function;KLF14 gene overexpression could promote the ac-tivation of AKT,and its effects in increasing insulin sensitivity in diabetics is more distinct than normal people.%目的:探讨KLF14基因过表达对小鼠肝癌细胞Hepa1-6胰岛素抵抗的影响。方法实时荧光定量PCR(RT-QPCR)检测KLF14基因mRNA在健康C57BL/6J小鼠各组织的表达分布情况;构建小鼠KLF14基因重组真核表达质粒pIRES2-EGFP-KLF14并转染Hepa1-6细胞,RT-PCR法检测KLF14基因mRNA的表达;Western印迹检测KLF14及p-AKT蛋白水平的

  3. Thermomechanical treatment of steel

    International Nuclear Information System (INIS)

    Thermomechanical treatment is defined as a process in which a forming operation is carried out in the course of a treatment in order to improve the mechanical properties of a material. Several thermomechanical processes for the treatment of steel are described. (WBU)

  4. Japan steel mill perspective

    Energy Technology Data Exchange (ETDEWEB)

    Murase, K. [Kobe Steel Ltd., Tokyo (Japan)

    2004-07-01

    The international and Japan's steel industry, the coking coal market, and Japan's expectations from Canada's coal industry are discussed. Japan's steel mills are operating at full capacity. Crude steel production for the first half of 2004 was 55.8 million tons. The steel mills are profitable, but costs are high, and there are difficulties with procuring raw materials. Japan is trying to enhance the quality of coke, in order to achieve higher productivity in the production of pig iron. Economic growth is rising disproportionately in the BRICs (Brazil, Russia, India, and China), with a large increase in coking coal demand from China. On the supply side, there are several projects underway in Australia and Canada to increase production. These include new developments by Elk Valley Coal Corporation, Grande Cache Coal, Western Canadian Coal, and Northern Energy and Mining in Canada. The Elga Mine in the far eastern part of Russia is under development. But the market is expected to remain tight for some time. Japan envisions Canadian coal producers will provide a stable coal supply, expansion of production and infrastructure capabilities, and stabilization of price. 16 slides/overheads are included.

  5. Interactions of endosulfan and methoxychlor involving CYP3A4 and CYP2B6 in human HepaRG cells.

    Science.gov (United States)

    Savary, Camille C; Jossé, Rozenn; Bruyère, Arnaud; Guillet, Fabrice; Robin, Marie-Anne; Guillouzo, André

    2014-08-01

    Humans are usually exposed to several pesticides simultaneously; consequently, combined actions between pesticides themselves or between pesticides and other chemicals need to be addressed in the risk assessment. Many pesticides are efficient activators of pregnane X receptor (PXR) and/or constitutive androstane receptor (CAR), two major nuclear receptors that are also activated by other substrates. In the present work, we searched for interactions between endosulfan and methoxychlor, two organochlorine pesticides whose major routes of metabolism involve CAR- and PXR-regulated CYP3A4 and CYP2B6, and whose mechanisms of action in humans remain poorly understood. For this purpose, HepaRG cells were treated with both pesticides separately or in mixture for 24 hours or 2 weeks at concentrations relevant to human exposure levels. In combination they exerted synergistic cytotoxic effects. Whatever the duration of treatment, both compounds increased CYP3A4 and CYP2B6 mRNA levels while differently affecting their corresponding activities. Endosulfan exerted a direct reversible inhibition of CYP3A4 activity that was confirmed in human liver microsomes. By contrast, methoxychlor induced this activity. The effects of the mixture on CYP3A4 activity were equal to the sum of those of each individual compound, suggesting an additive effect of each pesticide. Despite CYP2B6 activity being unchanged and increased with endosulfan and methoxychlor, respectively, no change was observed with their mixture, supporting an antagonistic effect. Altogether, our data suggest that CAR and PXR activators endosulfan and methoxychlor can interact together and with other exogenous substrates in human hepatocytes. Their effects on CYP3A4 and CYP2B6 activities could have important consequences if extrapolated to the in vivo situation.

  6. 1-Nitropyrene (1-NP) induces apoptosis and apparently a non-apoptotic programmed cell death (paraptosis) in Hepa1c1c7 cells

    International Nuclear Information System (INIS)

    Mechanistic studies of nitro-PAHs (polycyclic aromatic hydrocarbons) of interest might help elucidate which chemical characteristics are most important in eliciting toxic effects. 1-Nitropyrene (1-NP) is the predominant nitrated PAH emitted in diesel exhaust. 1-NP-exposed Hepa1c1c7 cells exhibited marked changes in cellular morphology, decreased proliferation and different forms of cell death. A dramatic increase in cytoplasmic vacuolization was observed already after 6 h of exposure and the cells started to round up at 12 h. The rate of cell proliferation was markedly reduced at 24 h and apoptotic as well as propidium iodide (PI)-positive cells appeared. Electron microscopic examination revealed that the vacuolization was partly due to mitochondria swelling. The caspase inhibitor Z-VAD-FMK inhibited only the apoptotic cell death and Nec-1 (an inhibitor of necroptosis) exhibited no inhibitory effects on either cell death or vacuolization. In contrast, cycloheximide markedly reduced both the number of apoptotic and PI-positive cells as well as the cytoplasmic vacuolization, suggesting that 1-NP induced paraptotic cell death. All the MAPKs; ERK1/2, p38 and JNK, appear to be involved in the death process since marked activation was observed upon 1-NP exposure, and their inhibitors partly reduced the induced cell death. The ERK1/2 inhibitor PD 98057 completely blocked the induced vacuolization, whereas the other MAPKs inhibitors only had minor effects on this process. These findings suggest that 1-NP may cause apoptosis and paraptosis. In contrast, the corresponding amine (1-aminopyrene) elicited only minor apoptotic and necrotic cell death, and cells with characteristics typical of paraptosis were absent

  7. Methoxychlor suppresses the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible CYP1A1 expression in murine Hepa-1c1c7 cells.

    Science.gov (United States)

    Han, Eun Hee; Jeong, Tae Cheon; Jeong, Hye Gwang

    2007-08-01

    Methoxychlor (MXC) is a pesticide that was developed as a replacement for dichlorodiphenyltrichloroethane (DDT). The influence of MXC on CYP1A1 expression or the functions of mouse hepatoma Hepa-1clc7 remain unclear. Cultured Hepa-1c1c7 cells were treated with MXC with or without 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to assess the role of MXC on CYP1A1 expression. MXC alone did not affect CYP1A1-specific 7-ethoxyresorufin O-deethylase (EROD) activity. In contrast, TCDD-inducible EROD activities were markedly reduced upon concomitant treatment with TCDD and MXC in a concentration-dependent manner. Treatment with ICI 182.780, an estrogen-receptor antagonist, did not affect the suppressive effects of MXC on TCDD-inducible EROD activity. TCDD-inducible CYP1A1 mRNA levels were markedly suppressed upon treatment with TCDD and MXC, and this is consistent with their effects on EROD activity. A transient transfection assay using dioxin-response element (DRE)-linked luciferase and an electrophoretic mobility shift assay revealed that MXC reduced the transformation of the aryl hydrocarbons (Ah) receptor to a form capable of specifically binding to the DRE sequence in the promoter region of the CYP1A1 gene. These results suggest that the downregulation of CYP1A1 gene expression by MXC in Hepa-1c1c7 cells might be an antagonism of the DRE binding potential of the nuclear Ah receptor but is not mediated through the estradiol receptor.

  8. Dual-color fluorescence imaging to monitor CYP3A4 and CYP3A7 expression in human hepatic carcinoma HepG2 and HepaRG cells.

    Directory of Open Access Journals (Sweden)

    Saori Tsuji

    Full Text Available Human adult hepatocytes expressing CYP3A4, a major cytochrome P450 enzyme, are required for cell-based assays to evaluate the potential risk of drug-drug interactions caused by transcriptional induction of P450 enzymes in early-phase drug discovery and development. However, CYP3A7 is preferentially expressed in premature hepatoblasts and major hepatic carcinoma cell lines. The human hepatocellular carcinoma cell line HepaRG possesses a high self-renewal capacity and can differentiate into hepatic cells similar to human adult hepatocytes in vitro. Transgenic HepaRG cells, in which the expression of fluorescent reporters is regulated by 35 kb regulatory elements of CYP3A4, have a distinct advantage over human hepatocytes isolated by collagenase perfusion, which are unstable in culture. Thus, we created transgenic HepaRG and HepG2 cells by replacing the protein-coding regions of human CYP3A4 and CYP3A7 with enhanced green fluorescent protein (EGFP and DsRed reporters, respectively, in a bacterial artificial chromosome vector that included whole regulatory elements. The intensity of DsRed fluorescence was initially high during the proliferation of transgenic HepaRG cells. However, most EGFP-positive cells were derived from those in which DsRed fluorescence was extinguished. Comparative analyses in these transgenic clones showed that changes in the total fluorescence intensity of EGFP reflected fold changes in the mRNA level of endogenous CYP3A4. Moreover, CYP3A4 induction was monitored by the increase in EGFP fluorescence. Thus, this assay provides a real-time evaluation system for quality assurance of hepatic differentiation into CYP3A4-expressing cells, unfavourable CYP3A4 induction, and fluorescence-activated cell sorting-mediated enrichment of CYP3A4-expressing hepatocytes based on the total fluorescence intensities of fluorescent reporters, without the need for many time-consuming steps.

  9. History of ultrahigh carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Wadsworth, J.; Sherby, O.D.

    1997-06-20

    The history and development of ultrahigh carbon steels (i.e., steels containing between 1 and 2.l percent C and now known as UHCS) are described. The early use of steel compositions containing carbon contents above the eutectoid level is found in ancient weapons from around the world. For example, both Damascus and Japanese sword steels are hypereutectoid steels. Their manufacture and processing is of interest in understanding the role of carbon content in the development of modern steels. Although sporadic examples of UHCS compositions are found in steels examined in the early part of this century, it was not until the mid-1970s that the modern study began. This study had its origin in the development of superplastic behavior in steels and the recognition that increasing the carbon content was of importance in developing that property. The compositions that were optimal for superplasticity involved the development of steels that contained higher carbon contents than conventional modern steels. It was discovered, however, that the room temperature properties of these compositions were of interest in their own right. Following this discovery, a period of intense work began on understanding their manufacture, processing, and properties for both superplastic forming and room temperature applications. The development of superplastic cast irons and iron carbides, as well as those of laminated composites containing UHCS, was an important part of this history.

  10. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  11. Steels and welding nuclear

    International Nuclear Information System (INIS)

    This ENEA Data-Base regards mechanical properties, chemical composition and heat treatments of nuclear pressure vessel materials: type A533-B, A302-B, A508 steel plates and forgings, submerged arc welds and HAZ before and after nuclear irradiation. Irradiation experiments were generally performed in high flux material test reactors. Data were collected from international available literature about water nuclear reactors pressure vessel materials embrittlement

  12. Contaminated Mexican steel incident

    International Nuclear Information System (INIS)

    This report documents the circumstances contributing to the inadvertent melting of cobalt 60 (Co-60) contaminated scrap metal in two Mexican steel foundries and the subsequent distribution of contaminated steel products into the United States. The report addresses mainly those actions taken by US Federal and state agencies to protect the US population from radiation risks associated with the incident. Mexico had much more serious radiation exposure and contamination problems to manage. The United States Government maintained a standing offer to provide technical and medical assistance to the Mexican Government. The report covers the tracing of the source to its origin, response actions to recover radioactive steel in the United States, and return of the contaminated materials to Mexico. The incident resulted in significant radiation exposures within Mexico, but no known significant exposure within the United States. Response to the incident required the combined efforts of the Nuclear Regulatory Commission (NRC), Department of Energy, Department of Transportation, Department of State, and US Customs Service (Department of Treasury) personnel at the Federal level and representatives of all 50 State Radiation Control Programs and, in some instances, local and county government personnel. The response also required a diplomatic interface with the Mexican Government and cooperation of numerous commercial establishments and members of the general public. The report describes the factual information associated with the event and may serve as information for subsequent recommendations and actions by the NRC. 8 figures

  13. Stainless Steel Permeability

    Energy Technology Data Exchange (ETDEWEB)

    Buchenauer, Dean A. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Karnesky, Richard A. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States)

    2015-09-01

    An understanding of the behavior of hydrogen isotopes in materials is critical to predicting tritium transport in structural metals (at high pressure), estimating tritium losses during production (fission environment), and predicting in-vessel inventory for future fusion devices (plasma driven permeation). Current models often assume equilibrium diffusivity and solubility for a class of materials (e.g. stainless steels or aluminum alloys), neglecting trapping effects or, at best, considering a single population of trapping sites. Permeation and trapping studies of the particular castings and forgings enable greater confidence and reduced margins in the models. For FY15, we have continued our investigation of the role of ferrite in permeation for steels of interest to GTS, through measurements of the duplex steel 2507. We also initiated an investigation of the permeability in work hardened materials, to follow up on earlier observations of unusual permeability in a particular region of 304L forgings. Samples were prepared and characterized for ferrite content and coated with palladium to prevent oxidation. Issues with the poor reproducibility of measurements at low permeability were overcome, although the techniques in use are tedious. Funding through TPBAR and GTS were secured for a research grade quadrupole mass spectrometer (QMS) and replacement turbo pumps, which should improve the fidelity and throughput of measurements in FY16.

  14. PHOSPHORUS REMOVAL USING STEEL SLAG

    Institute of Scientific and Technical Information of China (English)

    Y.Z. Lan; S. Zhang; J.K. Wang; R. W. Smith

    2006-01-01

    Steel slag is a byproduct produced in large amounts in the steel-making process. It is an important resource that can be effectively utilized. An experiment was described in which steel slag was tested as an adsorbent for the removal of phosphorus from waste water. Phosphorus removal depended on the amount of steel slag added, the pH value, the contact time, and the initial concentration. Under laboratory conditions when the added slag was 7.5g/L, the contact time 2h, and the pH value was equivalent to 6.5, over 99% of the phosphorus was removed; the experimental data on steel slag adsorption of phosphorus in the water fitted the Freundlich isotherm model. Steel slag was found to be very effective in adsorbing phosphorus.

  15. Fracture Mechanisms in Steel Castings

    Directory of Open Access Journals (Sweden)

    Z. Stradomski

    2013-07-01

    Full Text Available The investigations were inspired with the problem of cracking of steel castings during the production process. A single mechanism of decohesion - the intergranular one - occurs in the case of hot cracking, while a variety of structural factors is decisive for hot cracking initiation, depending on chemical composition of the cast steel. The low-carbon and low-alloyed steel castings crack due to the presence of the type II sulphides, the cause of cracking of the high-carbon tool cast steels is the net of secondary cementite and/or ledeburite precipitated along the boundaries of solidified grains. Also the brittle phosphor and carbide eutectics precipitated in the final stage solidification are responsible for cracking of castings made of Hadfield steel. The examination of mechanical properties at 1050°C revealed low or very low strength of high-carbon cast steels.

  16. Strip casting of stainless steels

    OpenAIRE

    Raabe, D.

    1997-01-01

    FLAT PRODUCTS OF STAINLESS STEELS ARE CONVENTIONALLY MANUFACTURED BY CONTINUOUS CASTING, HOT ROLLING, HOT BAND ANNEALING, PICKLING, COLD ROLLING AND RECRYSTALLISATION. IN THE LAST YEARS STRIP CASTING HAS INCREASINGLY ATTRACTED ATTENTION. IT OFFERS THREE IMPROVEMENTS IN COMPARISON TO THE CONVENTIONAL METHOD.1.) IT ALLOWS TO CAST STEEL SHEETS WITH THE SAME THICKNESS AND WIDTH AS THOSE PRODUCED BY HOT ROLLING. THIS MEANS THAT THE HOT ROLLING PROCESSIS BYPASSED. 2.) THE STRIP CAST STEEL REVEALS A...

  17. Output Model of Steel Plant

    Institute of Scientific and Technical Information of China (English)

    ZHANG Long-qiang; TIAN Nai-yuan; ZHANG Jin; XU An-jun

    2008-01-01

    Based on the requirement of compactivity, continuity, and high efficiency, and taking full advantage of cushion capability of flexible parts such as external refining in new generation steel plant, an output model of steel plant was established in terms of matching between BOF and caster. Using this model, the BOF nominal capacity is selected, the caster output and equipment amount are computed, and then the steel plant output is computed.

  18. Synthesis of thermit noncorrodible steels

    OpenAIRE

    Жигуц, Юрій Юрійович

    2013-01-01

    The present paper the basic solutions to the problem of obtaining cavitation-resistant steels examined the use of thermite steels, the benefits of combining thermite steels with metallotermic methods of getting is showed. The advantages of metallotermic synthesis methods include: autonomy of processes, independence of energy sources, simplicity of equipment, high-performance process and easy transition from experimental research to industrial production. The need to developed the technology o...

  19. Mechanics in Steels through Microscopy

    OpenAIRE

    Tirumalasetty, G.K.

    2013-01-01

    The goal of the study consolidated in this thesis is to understand the mechanics in steels using microscopy. In particular, the mechanical response of Transformation Induced Plasticity (TRIP) steels is correlated with their microstructures. Chapter 1 introduces the current state of the art of TRIP steels, highlighting the importance of microstructure - mechanical properties - applications relationships. In Chapter 2 the material properties and material processing are described into more detai...

  20. Tough Year Ahead for Steel

    Institute of Scientific and Technical Information of China (English)

    REN WEI

    2006-01-01

    @@ The steel industry, a top beneficiary of the country's sizzling economic growth, is this year likely to see only a meager profit or even report losses, according to a report by the National Development and Reform Commission. Mounting demand for steel in real estate construction and auto making during the past years resulted in an investment craze into the sector, and has caused a glut on the market. Average steel prices fell by a third last year, though domestic steel makers still managed to post a profit of 127.4 billion yuan (US$15.9 billion) on aggregate.

  1. Milled Die Steel Surface Roughness Correlation with Steel Sheet Friction

    DEFF Research Database (Denmark)

    Berglund, J.; Brown, C.A.; Rosén, B.-G.;

    2010-01-01

    This work investigates correlations between the surface topography ofmilled steel dies and friction with steel sheet. Several die surfaces were prepared by milling. Friction was measured in bending under tension testing. Linear regression coefficients (R2) between the friction and texture...

  2. Cleanable sintered metal filters in hot off-gas systems

    International Nuclear Information System (INIS)

    Filters with sintered metal elements, arranged as tube bundles with backflush air cleaning, are the equivalent of bag filters for high-temperature, harsh environments. They are virtually the only alternative for high-temperature off-gas systems where a renewable, highly efficient particle trap is required. Tests were conducted which show that the sintered metal elements installed in a filter system provide effective powder collection in high-temperature atmospheres over thousands of cleaning cycles. Such a sintered metal filter system is now installed on the experimental defense waste calciner at the Savannah River Laboratory. The experimental results included in this paper were used as the basis for its design

  3. Steels for nuclear power. I

    International Nuclear Information System (INIS)

    The principles are listed of nuclear reactor operation and the reactors are classified by neutron energy, fuel and moderator designs, purpose and type of moderator. The trend and the development of light-water reactor applications are described. The fundamental operating parameters of the WWER type reactors are indicated. The effect is discussed of neutron radiation on reactor structural materials. The characteristics are described of steel corrosion due to the contact of the steel with steam or sodium in the primary coolant circuit. The reasons for stress corrosion are given and the effects of radiation on corrosion are listed. The requirements and criteria are given for the choice of low-alloy steel for the manufacture of pressure vessels, volume compensators, steam generators, cooling conduits and containment. A survey is given of most frequently used steels for pressure vessels and of the mechanical and structural properties thereof. The basic requirements for the properties of steel used in the primary coolant circuit are as follows: sufficient strength in operating temperature, toughness, good weldability, resistance to corrosion and low brittleness following neutron irradiation. The materials are listed used for the components of light-water and breeder reactors. The production of corrosion-resistant steels is discussed with a view to raw materials, technology, steel-making processes, melting processes, induction furnace steel-making, and to selected special problems of the chemical composition of steels. The effects are mainly discussed of lead, bismuth and tin as well as of some other elements on hot working of high-alloy steels and on their structure. The problems of corrosion-resistant steel welding and of pressure vessel cladding are summed up. Also discussed is the question of the concept and safeguards of the safety of nuclear installation operation and a list is presented of most commonly used nondestructive materials testing methods. The current

  4. Niobium in rail steels

    International Nuclear Information System (INIS)

    The strengthening capacity of niobium in high carbon steels is governed by the carbon content, soaking conditions prior to rolling and the finish rolling temperature. Yield and tensile strengths may be increased by up to 70-100 MPa (10-15 k.s.i.) in C-Mn-Cr rails with niobium additions of about 0.03 percent. The strengthening mechanism appears to be precipitation hardening of niobium carbonitride in the pro-eutectoid ferrite and ferrite lamellae in pearlite. In addition, ductility improvements may be effected through the austenite grain refining action of niobium in hot rolling leading to a reduction in pearlite colony size

  5. Steel designers' handbook

    CERN Document Server

    Gorenc, Branko; Tinyou, Ron

    2012-01-01

    The Revised 7th Edition of Steel Designers' Handbook is an invaluable tool for all practising structural, civil and mechanical engineers as well as engineering students at university and TAFE in Australia and New Zealand. It has been prepared in response to changes in the design Standard AS 4100, the structural Design Actions Standards, AS /ANZ 1170, other processing Standards such as welding and coatings, updated research as well as feedback from users. This edition is based on Australian Standard (AS) 4100: 1998 and subsequent amendments. The worked numerical examples in the book have been e

  6. Mechanics in Steels through Microscopy

    NARCIS (Netherlands)

    Tirumalasetty, G.K.

    2013-01-01

    The goal of the study consolidated in this thesis is to understand the mechanics in steels using microscopy. In particular, the mechanical response of Transformation Induced Plasticity (TRIP) steels is correlated with their microstructures. Chapter 1 introduces the current state of the art of TRIP s

  7. The industrial ecology of steel

    Energy Technology Data Exchange (ETDEWEB)

    Considine, Timothy J.; Jablonowski, Christopher; Considine, Donita M.M.; Rao, Prasad G.

    2001-03-26

    This study performs an integrated assessment of new technology adoption in the steel industry. New coke, iron, and steel production technologies are discussed, and their economic and environmental characteristics are compared. Based upon detailed plant level data on cost and physical input-output relations by process, this study develops a simple mathematical optimization model of steel process choice. This model is then expanded to a life cycle context, accounting for environmental emissions generated during the production and transportation of energy and material inputs into steelmaking. This life-cycle optimization model provides a basis for evaluating the environmental impacts of existing and new iron and steel technologies. Five different plant configurations are examined, from conventional integrated steel production to completely scrap-based operations. Two cost criteria are used to evaluate technology choice: private and social cost, with the latter including the environmental damages associated with emissions. While scrap-based technologies clearly generate lower emissions in mass terms, their emissions of sulfur dioxide and nitrogen oxides are significantly higher. Using conventional damage cost estimates reported in the literature suggests that the social costs associated with scrap-based steel production are slightly higher than with integrated steel production. This suggests that adopting a life-cycle viewpoint can substantially affect environmental assessment of new technologies. Finally, this study also examines the impacts of carbon taxes on steel production costs and technology choice.

  8. Challanges in Steel Science & Technology

    OpenAIRE

    Prahl, Ulrich; Santofimia, María Jesús; Yardley, Vicky; Gautier, Elisabeth; Tasan, Cem; Hedström, Peter; San Martín, David; PETROV Roumen; Jiménez, José A.; Almagro Bello, Juan F.; Gutiérrez, Isabel; Casellas, Daniel; Kerscher, Eberhard; Sabirov, IIchat; García, Ignacio

    2014-01-01

    Ponencias de WorkShop Advanced Steels 2014. Challenges in Steel Science & Technology. Celebrado en la central del CSIC, c/Serrano, 17, del 18 y 10 de septiembre de 2014.Organizado por: CENIM-CSIC, ASCO Industries (Fr), ASM Spain Chapter (Es), CTM (Es).

  9. Steels from materials science to structural engineering

    CERN Document Server

    Sha, Wei

    2013-01-01

    Steels and computer-based modelling are fast growing fields in materials science as well as structural engineering, demonstrated by the large amount of recent literature. Steels: From Materials Science to Structural Engineering combines steels research and model development, including the application of modelling techniques in steels.  The latest research includes structural engineering modelling, and novel, prototype alloy steels such as heat-resistant steel, nitride-strengthened ferritic/martensitic steel and low nickel maraging steel.  Researchers studying steels will find the topics vital to their work.  Materials experts will be able to learn about steels used in structural engineering as well as modelling and apply this increasingly important technique in their steel materials research and development. 

  10. Dual phase bainitic linepipe steels

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, D.; Yakubtsov, I.; Zhang, R. [Queen' s Univ., Kingston, ON (Canada). Dept. of Mechanical and Materials Engineering; Poruks, P. [Atomic Energy of Canada Ltd., Chalk River, ON (Canada); Turi, T. [Stelco Lake Erie, Nanticoke, ON (Canada); Emadi, D.; Essadiqi, E. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Materials Technology Lab

    2005-07-01

    Over the past 50 years, the strength of commercial linepipe steel has increased at a steady rate of about 70 MPa per decade due to advances in steelmaking, plate processing and microstructural design. API X100 grade steel, which has a yield strength of 690 MPa, is currently available, and X120 steels are under development. The microstructure of linepipe steels has evolved from predominantly polygonal ferrite to fine bainite. For the X120 steels, lower bainite-, tempered lath martensite- and dual phase microstructures are being examined. This study obtained the microstructures of ultrafine bainite with dispersed particles of the carbon-rich martensite-austenite (M-A) phase. The objective was to obtain a matrix of mostly intragranularly-nucleated bainitic ferrite containing a high volume fraction of dispersed M-A particles. The mechanical properties of bainitic linepipe steels were also examined. Basic studies of phase transformations and mechanical properties in these steels established significant relationships between processing schedule and the evolution of microstructure, and between final microstructure and mechanical properties. The optimal combination of strength and toughness properties was obtained with a microstructure consisting of a matrix of intragranularly-nucleated bainite and small dispersed particles of martensite. This microstructure was described as being a dual phase acicular ferrite (AF) with M-A. The window of steel composition and processing parameters which give the dual phase AF-M-A microstructure was determined in an experimental study on 15 mm thick plate. The minimum strength and toughness properties for Grade 621 (X90) linepipe steel can be achieved by either a lean steel composition with extreme processing parameters, or by a higher alloy composition with a more industrially realistic processing schedule. This study also proposed how this approach can be extended to obtain high strength linepipe grades. 15 refs., 9 tabs., 10 figs.

  11. Nanoprecipitation in bearing steels

    Energy Technology Data Exchange (ETDEWEB)

    Barrow, A.T.W. [SKF University Technology Centre, Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ (United Kingdom); Rivera-Diaz-del-Castillo, P.E.J., E-mail: pejr2@cam.ac.uk [SKF University Technology Centre, Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ (United Kingdom)

    2011-11-15

    {theta}-phase is the main hardening species in bearing steels and appears in both martensitically and bainitically hardened microstructures. This work presents a survey of the microstrucural features accompanying nanoprecipitation in bearing steels. Nanoprecipitate structures formed in 1C-1.5Cr wt.% with additions of Cr, Mn, Mo, Si and Ni are studied. The work is combined with thermodynamic calculations and neural networks to predict the expected matrix composition, and whether this will transform martensitically or bainitically. Martensite tetragonality, composition and the amount of retained austenite are related to hardness and the type of nanoprecipitate structures in martensitic grades. The {theta}-phase volume fraction, the duration of the bainite to austenite transformation and the amount of retained austenite are related to hardness and a detailed quantitative description of the precipitate nanostructures. Such description includes compositional studies using energy-dispersive spectroscopy, which shows that nanoprecipitate formation takes place under paraequilibrium. Special attention is devoted to a novel two-step bainite tempering process which shows maximum hardness; we prove that this is the most effective process for incorporating solute into the precipitates, which are finer than those resulting from one-step banitic transformation processes.

  12. Influence of the steel scrap classes on the liquid steel output molten in electric steel processes

    Directory of Open Access Journals (Sweden)

    K. Janiszewski

    2012-12-01

    Full Text Available Purpose: This is why we have analysed in the paper, using statistical analysing methods, the influence of use in the electric arc furnace charges of steel scrap of different qualities on the index of liquid steel output from a melt.Design/methodology/approach: The used research methodology consists in analytical simulation of variations in mass of liquid steel obtained from melts differing in steel scrap content in the metallic charge and statistical analyses of industrial results acquired from the corresponding process documentation (so called melt cards.Findings: Basing on the analytical and statistical analyses carried out we have determine resulting variations in the liquid steel per melt ratios depending on the content of steel scrap in the metallic charge.Research limitations/implications: The research results obtained can be utilized in each steelmaking facility, which employs the Electric Steelmaking process, in order to “design” the metallic charge compositions, having in view the quality and economic aspects.Practical implications: The research results presented in the paper can be used for steel production of high purity steels.Originality/value: The results presented in this paper are directed to the steelmakers employing the Electric Steelmaking process and constitute the authors’ original study.

  13. Improving the toughness of ultrahigh strength steel

    Energy Technology Data Exchange (ETDEWEB)

    Soto, Koji

    2002-08-15

    The ideal structural steel combines high strength with high fracture toughness. This dissertation discusses the toughening mechanism of the Fe/Co/Ni/Cr/Mo/C steel, AerMet 100, which has the highest toughness/strength combination among all commercial ultrahigh strength steels. The possibility of improving the toughness of this steel was examined by considering several relevant factors.

  14. High-strength, low-alloy steels.

    Science.gov (United States)

    Rashid, M S

    1980-05-23

    High-strength, low-alloy (HSLA) steels have nearly the same composition as plain carbon steels. However, they are up to twice as strong and their greater load-bearing capacity allows engineering use in lighter sections. Their high strength is derived from a combination of grain refinement; precipitation strengthening due to minor additions of vanadium, niobium, or titanium; and modifications of manufacturing processes, such as controlled rolling and controlled cooling of otherwise essentially plain carbon steel. HSLA steels are less formable than lower strength steels, but dualphase steels, which evolved from HSLA steels, have ferrite-martensite microstructures and better formability than HSLA steels of similar strength. This improved formability has substantially increased the utilization potential of high-strength steels in the manufacture of complex components. This article reviews the development of HSLA and dual-phase steels and discusses the effects of variations in microstructure and chemistry on their mechanical properties. PMID:17772810

  15. Cold-formed steel design

    CERN Document Server

    Yu, Wei-Wen

    2010-01-01

    The definitive text in the field, thoroughly updated and expanded Hailed by professionals around the world as the definitive text on the subject, Cold-Formed Steel Design is an indispensable resource for all who design for and work with cold-formed steel. No other book provides such exhaustive coverage of both the theory and practice of cold-formed steel construction. Updated and expanded to reflect all the important developments that have occurred in the field over the past decade, this Fourth Edition of the classic text provides you with more of the detailed, up-to-the-minute techni

  16. Modelling fracture in ferritic steel

    CERN Document Server

    Smith, G

    2002-01-01

    Results from mathematical models and computer simulations of fracture in polycrystalline steels are presented for a range of temperatures. The proportions of intergranular and intragranular failure predicted are compared with experimental results for brittle fracture, ductile fracture and in the transition region. Interactive software to create two-dimensional polycrystalline models, which allow a range of physical to be varied independently, is described. The results include those for model materials chosen to match steels used by the power generation industry. The models simulate segregation and cavitation effects in steel and fracture of weldments and their associated heat-affected zones.

  17. Stainless steel denitriding with slag

    International Nuclear Information System (INIS)

    Calculation and experimental methods were used to investigate the process of titanium nitride formation when alloying chromium nickel stainless steels with titanium. At common concentrations of titanium and nitrogen, titanium nitrides were observed to be precipitated from the melt into slag in amounts of 0.1% and more. The laboratory study of the slag influence of the process of steel refining from titanium nitrides showed that the slag containing calcium, aluminium and magnesium oxides is favourable to the denitriding of steel. In addition, the possibility of direct transition of dissolved nitrogen from the metal into the slag is revealed. 7 refs., 1 fig., 2 tabs

  18. Stainless steel display evaluation

    Science.gov (United States)

    Hopper, Darrel G.; Meyer, Frederick M.; Longo, Sam J.; Trissell, Terry L.

    2007-04-01

    Active matrix organic light emitting diode (AMOLED) technology is one candidate to become a low power alternative in some applications to the currently dominant, active matrix liquid crystal display (AMLCD), technology. Furthermore, fabrication of the AMOLED on stainless steel (SS) foil rather than the traditional glass substrate, while presenting a set of severe technical challenges, opens up the potential for displays that are both lighter and less breakable. Also, transition to an SS foil substrate may enable rollable displays - large when used but small for stowage within gear already worn or carried or installed. Research has been initiated on AMOLED/SS technology and the first 320 x 240 color pixel 4-in. demonstration device has been evaluated in the AFRL Display Test and Evaluation Laboratory. Results of this evaluation are reported along with a research roadmap.

  19. Review on Cold-Formed Steel Connections

    OpenAIRE

    Yeong Huei Lee; Cher Siang Tan; Shahrin Mohammad; Mahmood Md. Tahir; Poi Ngian Shek

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connection...

  20. Some peculiarities of corrosion of wheel steel

    OpenAIRE

    Alexander SHRAMKO; Alfred KOZLOWSKY; Elena BELAJA; Yuriy PROIDAK; Pinchuk, Sofia; Gubenko, Svetlana

    2009-01-01

    Corrosion mechanism and rate of different chemical composition and structural condition of wheel steel were investigated. It was shown that “white layers”, variation in grain size and banding of wheel steel structure results in corrosion rate. Microstructure of steel from different elements of railway wheels after operation with corrosion was investigated. Wheel steel with addition of vanadium corroded more quickly than steel without vanadium. Non-metallic inclusions are the centre of corrosi...

  1. Effects of changes in steel industry concentration

    OpenAIRE

    Bobenič, T.; A. Bobenič Hintošová; Hliboká, L.; I. Vasková

    2015-01-01

    The paper on a basis of completed mergers and acquisitions within global steel industry presents changes in steel industry concentration and analyzes its effects on world trade with steel products and on prices of input materials as well as of output products. The analyses performed for the 1990 - 2012 period revealed that increased concentration in global steel industry did not lead to more intensive world trade with steel products; however it is connected with increase of finished products ...

  2. CHANGES IN DISTRIBUTION OF STEEL PRODUCTS

    OpenAIRE

    Beata Œlusarczyk

    2009-01-01

    Steel industry is one of the most globalized branch, globalization has had the influence on iron ore supply, steel production and distribution as well. In last years, steel products distribution process has changed significantly, because of rising competitiveness due to common world market influence and main global players actions. The paper presents changes in steel products distribution in Poland focusing on main steel producers activity in distribution as well as distributors response on n...

  3. 2169 steel waveform experiments.

    Energy Technology Data Exchange (ETDEWEB)

    Furnish, Michael David; Alexander, C. Scott; Reinhart, William Dodd; Brown, Justin L.

    2012-11-01

    In support of LLNL efforts to develop multiscale models of a variety of materials, we have performed a set of eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn, balance predominantly Fe). These experiments provided carefully controlled shock, reshock and release velocimetry data, with initial shock stresses ranging from 10 to 50 GPa (particle velocities from 0.25 to 1.05 km/s). Both windowed and free-surface measurements were included in this experiment set to increase the utility of the data set, as were samples ranging in thickness from 1 to 5 mm. Target physical phenomena included the elastic/plastic transition (Hugoniot elastic limit), the Hugoniot, any phase transition phenomena, and the release path (windowed and free-surface). The Hugoniot was found to be nearly linear, with no indications of the Fe phase transition. Releases were non-hysteretic, and relatively consistent between 3- and 5-mmthick samples (the 3 mm samples giving slightly lower wavespeeds on release). Reshock tests with explosively welded impactors produced clean results; those with glue bonds showed transient releases prior to the arrival of the reshock, reducing their usefulness for deriving strength information. The free-surface samples, which were steps on a single piece of steel, showed lower wavespeeds for thin (1 mm) samples than for thicker (2 or 4 mm) samples. A configuration used for the last three shots allows release information to be determined from these free surface samples. The sample strength appears to increase with stress from ~1 GPa to ~ 3 GPa over this range, consistent with other recent work but about 40% above the Steinberg model.

  4. Corrosion of Steels in Steel Reinforced Concrete in Cassava Juice

    Science.gov (United States)

    Oluwadare, G. O.; Agbaje, O.

    The corrosion of two types of construction steels, ST60Mn and RST37-2♦, in a low cyanide concentration environment (cassava juice) and embedded in concrete had been studied. The ST60 Mn was found to be more corrosion resistant in both ordinary water and the cassava juice environment. The cyanide in cassava juice does not attack the steel but it provides an environment of lower pH around the steel in the concrete which leads to breakdown of the passivating film provided by hydroxyl ions from cement. Other factors such as the curing time of the concrete also affect the corrosion rates of the steel in the concrete. The corrosion rate of the steel directly exposed to cassava juice i.e., steel not embedded in concrete is about twice that in concrete. Long exposure of concrete structure to cassava processing effluent might result in deterioration of such structures. Careful attention should therefore be paid to disposal of cassava processing effluents, especially in a country like Nigeria where such processing is now on the increase.

  5. Mechanical Behaviour and Microstructural Characterization of Carbon Steel Samples from Three Selected Steel Rolling Plants

    OpenAIRE

    P. O. Atanda; Abioye, A. A.; A. O. Iyiola

    2015-01-01

    The research investigated the mechanical behavior of samples of steel rods obtained from three selected Steel Rolling Companies in South Western part of Nigeria. This was done by carrying out some mechanical tests such as tensile, impact and hardness as well as microstructural examination.Four sets of 16 mm steel rod samples were collected from Tiger steel industries, Phoenix steel and Oxil steel Industies, all located in South West Nigeria, The chemical composition was carried out using a...

  6. Hydrogen embrittlement of structural steels.

    Energy Technology Data Exchange (ETDEWEB)

    Somerday, Brian P.

    2010-06-01

    Carbon-manganese steels are candidates for the structural materials in hydrogen gas pipelines, however it is well known that these steels are susceptible to hydrogen embrittlement. Decades of research and industrial experience have established that hydrogen embrittlement compromises the structural integrity of steel components. This experience has also helped identify the failure modes that can operate in hydrogen containment structures. As a result, there are tangible ideas for managing hydrogen embrittement in steels and quantifying safety margins for steel hydrogen containment structures. For example, fatigue crack growth aided by hydrogen embrittlement is a key failure mode for steel hydrogen containment structures subjected to pressure cycling. Applying appropriate structural integrity models coupled with measurement of relevant material properties allows quantification of safety margins against fatigue crack growth in hydrogen containment structures. Furthermore, application of these structural integrity models is aided by the development of micromechanics models, which provide important insights such as the hydrogen distribution near defects in steel structures. The principal objective of this project is to enable application of structural integrity models to steel hydrogen pipelines. The new American Society of Mechanical Engineers (ASME) B31.12 design code for hydrogen pipelines includes a fracture mechanics-based design option, which requires material property inputs such as the threshold for rapid cracking and fatigue crack growth rate under cyclic loading. Thus, one focus of this project is to measure the rapid-cracking thresholds and fatigue crack growth rates of line pipe steels in high-pressure hydrogen gas. These properties must be measured for the base materials but more importantly for the welds, which are likely to be most vulnerable to hydrogen embrittlement. The measured properties can be evaluated by predicting the performance of the pipeline

  7. MICROALLOYED STEELS FOR THE AUTOMOTIVE INDUSTRY

    Directory of Open Access Journals (Sweden)

    Debanshu Bhattacharya

    2014-12-01

    Full Text Available Two major drivers for the use of newer steels in the automotive industry are fuel efficiency and increased safety performance. Fuel efficiency is mainly a function of weight of steel parts, which in turn, is controlled by gauge and design. Safety is determined by the energy absorbing capacity of the steel used to make the part. All of these factors are incentives for the U.S. automakers to use both Highly Formable and Advanced High Strength Steels (AHSS to replace the conventional steels used to manufacture automotive parts in the past. AHSS is a general term used to describe various families of steels. The most common AHSS is the dual-phase steel that consists of a ferrite-martensite microstructure. These steels are characterized by high strength, good ductility, low tensile to yield strength ratio and high bake hardenability. Another class of AHSS is the complex-phase or multi-phase steel which has a complex microstructure consisting of various phase constituents and a high yield to tensile strength ratio. Transformation Induced Plasticity (TRIP steels is another class of AHSS steels finding interest among the U.S. automakers. These steels consist of a ferrite-bainite microstructure with significant amount of retained austenite phase and show the highest combination of strength and elongation, so far, among the AHSS in use. High level of energy absorbing capacity combined with a sustained level of high n value up to the limit of uniform elongation as well as high bake hardenability make these steels particularly attractive for safety critical parts and parts needing complex forming. A relatively new class of AHSS is the Quenching and Partitioning (Q&P steels. These steels seem to offer higher ductility than the dual-phase steels of similar strengths or similar ductility as the TRIP steels at higher strengths. Finally, martensitic steels with very high strengths are also in use for certain parts. The most recent initiative in the area of AHSS

  8. Weld bonding of stainless steel

    DEFF Research Database (Denmark)

    Santos, I. O.; Zhang, Wenqi; Goncalves, V.M.;

    2004-01-01

    This paper presents a comprehensive theoretical and experimental investigation of the weld bonding process with the purpose of evaluating its relative performance in case of joining stainless steel parts, against alternative solutions based on structural adhesives or conventional spot-welding. Th......This paper presents a comprehensive theoretical and experimental investigation of the weld bonding process with the purpose of evaluating its relative performance in case of joining stainless steel parts, against alternative solutions based on structural adhesives or conventional spot...

  9. Chinese steel: limits to growth

    Energy Technology Data Exchange (ETDEWEB)

    Hites, B. [World Steel Dynamics, Englewood Cliffs, NJ (US)

    2004-07-01

    Twenty one slides/overheads outline the opinion of World Steel Dynamics (WSD) on the future of China's steel industry. Until recently WSD likened this to a Greyhound bus, experiencing massive expansion and gaining momentum. Now constraints have emerged and a new analogy is being used, of a freight train - with slower growth, from 2005-2010 of 5-7% per annum. Ten reasons are identified for this slower growth.

  10. Streamlining Iron and Steel Production

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Eliminating unproductive iron and steel facilities is vital to environmental protection and sustainable development of this industry The Chinese Government is once again shutting down unproductive plants in tune with its green policy and the march toward sustainable development.This time it’s the iron and steel industry to feel the brunt of the Chinese Government’s stringent measures. The deafening buzz of factory floors have

  11. Atmospheric corrosion of mild steel

    OpenAIRE

    Morcillo, M.; de la Fuente, D.; I. Díaz; Cano, H.

    2011-01-01

    The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a) the morphology of steel c...

  12. Fatigue Strength of Weathering Steel

    OpenAIRE

    Kunz, Ludvík; Lukáš, Petr; Klusák, Jan

    2012-01-01

    Fatigue behaviour of Atmofix 52 steel (comparable to COR-TENâ steel) exposed to atmospheric corrosion for 20 years was investigated. S-N curves for load symmetrical cycling and cycling with stress ratio R = 0 were determined on specimens detracted from a failed transmission tower. The data were compared with those on material without a rust layer. The fracture surfaces and, in particular, the sites of fatigue crack initiation were analyzed. Substantial decrease of fatigue life and fatigue lim...

  13. Fatigue properties of weathering steel

    OpenAIRE

    Zavadilová, Petra

    2012-01-01

    This work deals with the influence of atmospheric corrosion on high-cycle fatigue properties of a weathering steel ATMOFIX B. New experimental data on fatigue strength of a steel exposed for 20 years to an atmospheric corrosion were compared to those characterizing the base material. Reduction of the fatigue lifetime of the exposed material compared with the base material was predicted on the basic of fractographic examination of fracture surfaces and the influence of surface notches on fatig...

  14. Fatique behaviour of electrical steel

    Directory of Open Access Journals (Sweden)

    Bode B.

    2014-06-01

    Full Text Available Electrical steel comes into focus with the development of electrically powered cars. In contrast to electrical motors used stationarily (e.g. conveyer belt drives in industrial applications, electrical steel in a car engine is subjected to cyclic loading due to vibrations caused by the imbalance of the rotor and start and stop driving events. For a safe and reliable design of an electrical motor the fatigue behaviour of electrical steel needs to be analysed. To minimize eddy current losses, a rotor consists of several hundred electrical steel sheets with a typical thickness of less than 1 mm. Due to optimal electrical and magnetic properties a very coarse microstructure of electrical steel is required. Only one to three grains are distributed along sheet thickness. Regarding the grain size and sheet thickness the material behaviour is governed by the reaction of single grains and grain-grain-interaction to external cyclic loading. Fatigue experiments with a load ratio of R = 0.005 and R = 0.1 were carried out. They give a very flat S-N-curve where the fatigue limit is close to the yield strength of this electrical steel. Crack initiation is observed at surface roughness and areas of stress concentration resulting from manufacturing processes.

  15. Properties of hot rolled steels for enamelling

    International Nuclear Information System (INIS)

    The results of an investigation of the structure and properties of experimental produced hot rolled steels suitable for enamelling are presented in the paper. Hot rolled steels for enamelling represent a special group of the steels for conventional enamelling. Their quality has to be adapted to the method and conditions of enamelling. Therefore, these steels should meet some specific requirements. In addition to usual investigation of the chemical composition and mechanical properties, microstructure and quality of the steel surface also were investigated. The basic aim was to examine steels capability for enamelling, i. e. steels resistance to the fish scales phenomena, by trial enamelling, as well as quality of the steel - enamel contact surface, to evaluate the binding. Also, the changes of the mechanical properties, especially the yield point, during thermal treatment, as a very specific requirement, were investigated, by simplified method. Good results were obtained confirming the steels capability for enamelling. (Original)

  16. THE STRUCTURAL ANALYSIS OF STEEL SILOS WITH CYLINDRICAL-WALL BEARING AND PROFILE-STEEL BEARING

    Directory of Open Access Journals (Sweden)

    Zhengjun Tang

    2015-04-01

    Full Text Available The silos are widely used in bulk material in many fields such as agriculture, mining, chemical, electric power storage, etc. Thin metal cylindrical silo shells are vulnerable to buckling failure caused by the compressive wall friction force. In this paper, the structural analysis of two types of steel silo with cylindrical-wall bearing and profile-steel bearing is implemented by Abaqus finite element analysis. The results indicate that under the same loading conditions, steel silos with profile-steel bearing and cylindrical-Wall bearing have similar values in Mises stress, but the steel silo with profile-steel bearing has a smaller radial displacement and a better capability of buckling resistance. Meanwhile, the total steel volumes reduced 8.0% comparing to the steel silo with cylindrical-wall bearing. Therefore, steel soil with profile-steel bearing not only has a less steel volumes but also a good stability.

  17. Review on Cold-Formed Steel Connections

    Directory of Open Access Journals (Sweden)

    Yeong Huei Lee

    2014-01-01

    Full Text Available The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed.

  18. Review on cold-formed steel connections.

    Science.gov (United States)

    Lee, Yeong Huei; Tan, Cher Siang; Mohammad, Shahrin; Tahir, Mahmood Md; Shek, Poi Ngian

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448

  19. Carbon Segregation of Bearing Steel Concasting Billet

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The formation mechanism of “white band” and central carbon segregation of high-carbon Cr bearing steel concasting billets are discussed in this paper. The maximum oxygen content in the steel produced by concasting process was 13x10-6 with an average oxygen content of 9.3x 10-6.Comparison of metallurgical quality and fatigue property between the concasting steel (CC) andingot casting steel (IC) showed that the carbon segregation (C/C0) in former steel was 0.92~1.10and its fatigue life was equal to that of the latter steel.

  20. Review on Cold-Formed Steel Connections

    Science.gov (United States)

    Tan, Cher Siang; Mohammad, Shahrin; Md Tahir, Mahmood; Shek, Poi Ngian

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448

  1. Microbial corrosion of stainless steel.

    Science.gov (United States)

    Ibars, J R; Moreno, D A; Ranninger, C

    1992-11-01

    Stainless steel, developed because of their greater resistance to corrosion in different aggressive environments, have proved to be affected, however, by various processes and types of corrosion. Some of these types of corrosion, mainly pitting, is activated and developed in the presence of microorganisms, which acting in an isolated or symbiotic way, according to their adaptation to the environment, create a favorable situation for the corrosion of these steel. The microorganisms that are involved, mainly bacteria of both the aerobic and anaerobic type, modify the environment where the stainless steel is found, creating crevices, differential aeration zones or a more aggressive environment with the presence of metabolites. In these circumstances, a local break of the passive and passivating layer is produced, which is proper to these types of steel and impedes the repassivation that is more favorable to corrosion. In the study and research of these types of microbiologically influenced corrosion are found electrochemical techniques, since corrosion is fundamentally an electrochemical process, and microbiological techniques for the identification, culture, and evaluation of the microorganisms involved in the process, as well as in the laboratory or field study of microorganism-metal pairs. Microstructural characterization studies of stainless steel have also been considered important, since it is known that the microstructure of steel can substantially modify their behavior when faced with corrosion. As for surface analysis studies, it is known that corrosion is a process that is generated on and progresses from the surface. The ways of dealing with microbiologically influenced corrosion must necessarily include biocides, which are not always usable or successful, the design of industrial equipment or components that do not favor the adherence of microorganisms, using microstructures in steel less sensitive to corrosion, or protecting the materials. PMID:1492953

  2. Kinetics of borided gear steels

    Indian Academy of Sciences (India)

    Ibrahim Gunes

    2013-06-01

    In this study, the case properties and diffusion kinetics of GS18NiMoCr36 (GS18), GS22NiMoCr56 (GS22) and GS32NiCrMo6.4 (GS32) gear steels borided in Ekabor-II powder were investigated by conducting a series of experiments at temperatures of 1123, 1173 and 1223 K for 2, 4 and 6 h. The boride layer was characterized by optical microscopy, X-ray diffraction technique and microVickers hardness tester. X-ray diffraction analysis of boride layers on the surface of the steels revealed the existence of FeB, Fe2B, CrB and Cr2B compounds. The thickness of the boride layer increases by increasing boriding time and temperature for all steels. The hardness of the boride compounds formed on the surface of the steels GS18, GS22 and GS32 ranged from 1624 to 1905 HV0,05, 1702 to 1948 HV0,05, and 1745 to 2034 HV0,05 respectively, whereas Vickers hardness values of the untreated steels GS18, GS22 and GS32 were 335 HV0,05, 358 HV0,05 and 411 HV0,05, respectively. The activation energies (Q) of borided steels were 228.644 kJ/mol for GS18, 280.609 kJ/mol for GS22 and 294.359 kJ/mol for GS32. The growth kinetics of the boride layers forming on the GS18, GS22 and GS32 steels and the thickness of boride layers were also investigated.

  3. Towards Responsible Steel: Preliminary Insights

    Directory of Open Access Journals (Sweden)

    Suzanne Benn

    2014-03-01

    Full Text Available This paper examines the structures and processes underpinning the attempt of the Australian steel industry to establish a certification scheme for Responsible Steel. We take it as a case example of how collective action and collaboration along a supply chain has the potential to be a win-win situation for the environment and for the competitiveness of an industry sector. The paper identifies the drivers that have prompted key stakeholders from all major sectors of the Australian steel product life cycle from mining through steel manufacturing, processing, product fabrication, use and re-use, and recycling to collaborate in the establishment of the Steel Stewardship Forum (SSF, the structure established to lead the development of the certification scheme. The development of this initiative is indicative of the wider shift to sustainability-related certification schemes as a means of garnering legitimacy and market advantage and provides detailed insights into both the drivers for and the challenges associated with such initiatives. Findings from the paper contribute to our understanding of the shift to sustainable supply chains as it is interpreted through institutional and institutional entrepreneurship theory.

  4. Steel erected at A-3 Test Stand

    Science.gov (United States)

    2008-01-01

    Workers erect the first fabricated steel girders to arrive at the A-3 Test Stand at Stennis Space Center. Steel work began at the construction site Oct. 29 and is scheduled to continue into next spring.

  5. Effect of Geobacter sulfurreducens on the microbial corrosion of mild steel, ferritic and austenitic stainless steels

    OpenAIRE

    Mehanna, Maha; Basséguy, Régine; Délia, Marie-Line; Bergel, Alain

    2009-01-01

    The influence of Geobacter sulfurreducens was tested on the anaerobic corrosion of four different steels: mild steel 1145, ferritic steel 403 and austenitic steels 304L and 316L. Within a few hours, the presence of cells induced a free potential (Eoc) ennoblement around +0.3 V on 1145 mild steel, 403 ferritic steel and 304L austenitic steels and slightly less on 316L. The kinetics of Eoc ennoblement depended on the amount of bacteria in the inoculum, but the final potential value depended ess...

  6. Heat treatment of supermartensitic steels

    International Nuclear Information System (INIS)

    Low carbon supermartensitic 13% Cr steels with 4-6%Ni and 0-2.5%Mo additives have been developed from type AISI 420 steels for applications in the oil industry. They offer significantly better weldability, improved general corrosion resistance, particularly in carbon dioxide environments, and some grades exhibit improved resistance to sulphide stress corrosion cracking. In this paper results of detailed investigations on a 13Cr-6Ni-2,5Mo-Ti steel after quenching and double tempering are presented. Microstructural studies were carried out using optical microscopy, transmission electron microscopy and X-ray diffractometry. The results prove the formation of austenite during tempering at both 690 and 620 oC is accompanied by intensive precipitation of Fe2Mo Laves phase particles. (author)

  7. Corrosion of carbon steel welds

    International Nuclear Information System (INIS)

    This report assesses the factors which cause preferential attack to occur in carbon steel fusion welds. It was concluded that the main factors were: the inclusion content of the weld metal, the potential of the weld metal being less noble than that of the parent, and the presence of low-temperature transformation products in the heat-affected zone of the weld. These factors should be minimized or eliminated as appropriate so that the corrosion allowances determined for carbon steel waste drums is also adequate for the welds. An experimental/theoretical approach is recommended to evaluate the relative corrosion resistance of welds prepared from BS 4360 grade 43A steel to that of the parent material. (author)

  8. Optimum design of steel structures

    CERN Document Server

    Farkas, József

    2013-01-01

    This book helps designers and manufacturers to select and develop the most suitable and competitive steel structures, which are safe, fit for production and economic. An optimum design system is used to find the best characteristics of structural models, which guarantee the fulfilment of design and fabrication requirements and minimize the cost function. Realistic numerical models are used as main components of industrial steel structures. Chapter 1 containts some experiences with the optimum design of steel structures Chapter 2 treats some newer mathematical optimization methods. Chapter 3 gives formulae for fabrication times and costs. Chapters 4 deals with beams and columns. Summarizes the Eurocode rules for design. Chapter 5 deals with the design of tubular trusses. Chapter 6 gives the design of frame structures and fire-resistant design rules for a frame. In Chapters 7 some minimum cost design problems of stiffened and cellular plates and shells are worked out for cases of different stiffenings and loads...

  9. Nonmetallic inclusions in HSLA steel weldments

    OpenAIRE

    Douglas, Brent A.

    1989-01-01

    Approved for public release; distribution is unlimited The U.S. Navy is currently funding a program for certification of HSLA steels to replace the HY series of high strength steels for structural fabrication. Integral to this program is the certification of welding consumables for use with these steels. The size, distribution and composition of nonmetallic inclusions in HSLA steel weld metal has been shown to play a key role in the final strength and toughness of the deposited weld. Th...

  10. Optimising steel hub location in Thailand

    OpenAIRE

    Sakaradhorn Boontaveeyuwat

    2012-01-01

    The optimal location of a steel hub in Thailand was analysed by applying aspecific research methodology designed to evaluate locations near the seaports. The growth of Thailand’s steel industry has become a centre of attention in the last decade, resulting in substantial efforts to form a distribution service centre to minimise the logistic costs associated with handling large steel flows in the future. The main analysis of the steel hublocation focused on areas situated near Laem Cha Bang, M...

  11. DP 600 steel research of dynamic testing

    OpenAIRE

    M. Mihaliková; Német, M.; Girman, V.

    2015-01-01

    Dynamic tensile testing of sheet steels is becoming more important due to the need for more optimized vehicle crashworthiness analysis in the automotive industry. For generating data in dynamic conditions, was using different assay techniques. DP (dual phase) steel is suitable for large complicated shape such as fenders, doors, bumpers and roofs. For experiments was used two testing method servo hydraulic and single bar method. Experiments were realized on steel grade DP 600. Steel were perfo...

  12. Microstructural Development during Welding of TRIP steels

    OpenAIRE

    Amirthalingam, M.

    2010-01-01

    The Advanced High Strength Steels (AHSS) are promising solutions for the production of lighter automobiles which reduce fuel consumption and increase passenger safety by improving crash-worthiness. Transformation Induced Plasticity Steel (TRIP) are part of the advanced high strength steels which offers a high strength and toughness combination with excellent uniform elongation. However, the higher alloying content of these steel limits their weldability and the thermal cycle of a welding proc...

  13. Sulfide stress cracking of pipeline steels

    International Nuclear Information System (INIS)

    The problem of the sulfide stress corrosion cracking of pipeline steels and their welded joints have been presented for pipeline steels. Results of hydrogen sulfide stress cracking inhibitors and corrosion inhibitors of three types protective actions on pipeline steels of two grades petroleum range of products are given. (author)

  14. Microstructural Development during Welding of TRIP steels

    NARCIS (Netherlands)

    Amirthalingam, M.

    2010-01-01

    The Advanced High Strength Steels (AHSS) are promising solutions for the production of lighter automobiles which reduce fuel consumption and increase passenger safety by improving crash-worthiness. Transformation Induced Plasticity Steel (TRIP) are part of the advanced high strength steels which off

  15. Clean Production of Steel and Refractories in China′s Steel Industry

    Institute of Scientific and Technical Information of China (English)

    SUTiansen

    2002-01-01

    The paper describes the importance of clean production of steel and the relationships amongst sustaining development of steel industry,environment protection and the role of refractories in the clean production of steel. The main achievements and main shortcomings in the clean production of China′s steel industry have been reviewed together with the introduction of the policy supporting system and the future development of clean production in China′s steel industry.

  16. Maraging steel - highest strength steels with simple heat treatment for difficult application purposes

    International Nuclear Information System (INIS)

    The lecture concerns the composition of the 18% NiCoMo (maraging) steels, the conversion behaviour and influence of various alloy elements, thermal treatment and its influence on the change of dimension behaviour; comparison of the thermal treatment of maraging steels with tempering steels, influence of trace elements and the way of melting on the mechanical properties, advantages and disadvantages of this group of steel, introduction of newer high-strength maraging steels, their composition and mechanical properties. (orig.)

  17. Compresibility and sinterability of HCx PM steel diluted with stainless steels

    OpenAIRE

    Gordo Elena; Khattab Nermein Hamid; Ruiz-Navas Elisa María

    2003-01-01

    HCx powder metallurgy steel contains in its composition high contents of Cr and C, and significant quantities of alloy elements typical of tool steels (Mo, V, W), to provide the corrosion resistance of stainless steel with wear resistance of tool steels. HCx appears to be a suitable material for applications in aggressive environments, as valve seat inserts in automotive engines. However, this steel presents a low compressibility leading to high production costs. In this work, some results ca...

  18. Prediction of quenched and tempered steel and cast steel properties

    Directory of Open Access Journals (Sweden)

    B. Smoljan

    2011-12-01

    Full Text Available Purpose: The influence of processing parameters, such as pouring temperature and cooling rate during the casting, as well as application of hot working and pre-heat treatment, on strength and toughness of quenched and tempered steel was investigated.Design/methodology/approach: Strength and toughness were presented by yield strength and Charpy-V notch toughness, respectively. Experimental procedure of material properties optimization was done using the 25-2 factor experiment.Findings: It was found out that yield strength is insensitive on differences between applied manufacturing processes, but by application of hot working and with appropriate pouring temperature the Charpy-V notch toughness is increased. Also, Charpy-V notch toughness is increased by interactive effect of the appropriate cooling rate during the casting and application of hot working.Research limitations/implications: The research was focused mainly on Charpy-V notch toughness of carbon and low alloyed heat treatable steels.Practical implications: The established algorithms can be used for prediction of tensile strength, yield strength and Charpy-V notch toughness in heat treating practice.Originality/value: Original relation for prediction of quenched and tempered steel and cast steel Charpy-V notch toughness are developed.

  19. Ethanol extract of Zingiber officinale Rose induces cell apoptosis and inhibits cell proliferation in mice with HepA liver cancer.%生姜醇提物诱导荷瘤鼠HepA细胞凋亡的研究

    Institute of Scientific and Technical Information of China (English)

    刘辉; 袁健; 李勇; 王玉

    2011-01-01

    目的 探讨生姜醇提物对荷瘤鼠HepA细胞生长及凋亡的影响.方法 建立荷瘤(HepA肝癌细胞)鼠动物模型,以生姜醇提物40 g/kg(高剂量)、10 g/kg(低剂量)灌胃给药20 d,测量荷瘤鼠生存时间及肿瘤重量变化,计算各组生命延长率及抑瘤率;采用TUNEL法检测组织凋亡指数(AI),观察生姜醇提物对荷瘤鼠体征及凋亡的影响.结果 生姜醇提物能明显抑制肿瘤的生长,延长半数死亡时间,给药组生命延长率达到30%~60%,高剂量组抑瘤率为32.4%;生姜醇提物可诱导荷瘤细胞凋亡,凋亡指数与对照组比较差异有显著性(P<0.01).结论 生姜醇提物可抑制荷瘤鼠肝癌细胞的生长,促进细胞凋亡.%Objective To evaluate the cell proliferation and apoptosis induced by ethanol extract of Zingiber officinale Rose in mice with HepA liver cancer. Methods The transplanted tumor model was established with subcutaneous injection of HepA cell in mice. Seventy mice were randomly divided into 7 groups. Ethanol extract of Zingiber officinale Rose lavage in 40 mg/kg ( high dose ) or 10 mg/kg ( low dose ) was performed in mice for 20 days. The sival and tumor inhibition rate were measured. Meanwhile, tumor apoptosis index assessed using TUNEL. Results Significant prolongation of sival was observed in all groups of( P <0. 05 ). Tumor inhibition rate was 32.4% in mice with high dose ethanol extract of Zingiber officinale Rose. Furthermore, significant increase of apoptosis index was revealed in test groups ( P < 0. 05 ). Conclusion Ethanol extract of Zingiber officinale Rose induces cell apoptosis and inhibits cell proliferation.

  20. Preformed posterior stainless steel crowns: an update.

    Science.gov (United States)

    Croll, T P

    1999-02-01

    For almost 50 years, dentists have used stainless steel crowns for primary and permanent posterior teeth. No other type of restoration offers the convenience, low cost, durability, and reliability of such crowns when interim full-coronal coverage is required. Preformed stainless steel crowns have improved over the years. Better luting cements have been developed and different methods of crown manipulation have evolved. This article reviews stainless steel crown procedures for primary and permanent posterior teeth. Step-by-step placement of a primary molar stainless steel crown is documented and permanent molar stainless steel crown restoration is described. A method for repairing a worn-through crown also is reviewed.

  1. Advanced sheet steels for automotive applications

    Science.gov (United States)

    Fekete, James R.; Strugala, Donald C.; Yao, Zhicong

    1992-01-01

    Vacuum degassing has recently been used by sheet steel producers to improve their products' ductility and strength. Carbon contents can be reduced by an order of magnitude to less than 0.0030 wt.%. Through careful alloying and processing, a range of new steel products has been developed for the automotive industry. These products include interstitial-free, deep-drawing-quality steels; formable, high-strength, interstitial-free steels; and bake-hardenable steels. This article summarizes the chemistry and processing needed to produce these products.

  2. Imaging molten steel flow profiles

    Science.gov (United States)

    Binns, R.; Lyons, A. R. A.; Peyton, A. J.; Pritchard, W. D. N.

    2001-08-01

    Control of delivery of molten steel in continuous casting is critical in order to ensure stability of the meniscus and satisfactory mould flow patterns, which in turn are determinants of cleanness and surface quality of steel. Considerable effort has been expended over the last ten years on optimizing the design of the metal delivery system, particularly the pouring nozzle, in order to allow the consistent production of high quality steel at a high throughput. This paper looks forward to possible systems that are capable of tomographically imaging the distribution of molten steel flows in these applications. The paper will concentrate on the feasibility of using electromagnetic methods. The paper will present some initial results; an overview of the applied image reconstruction process will also be included. The paper will conclude with a discussion of possible future developments, such as the use of a tomographic or multi-frequency approach, future research on the reconstruction image procedures and the potential for visualization and flow measurement. There is a need for further research in this area and some priority areas for future work will be suggested.

  3. Ultrasonic determination of steel structures

    International Nuclear Information System (INIS)

    In the research project 'Determination of steel structures by means of ultrasound' methods are developed for the non-destructive structure characterization with scattered ultrasound. Measurements were made at about 200 steel samples with frequencies between 5 and 20 Mc/sec. In the range of 0,05 <= d/lambda <= 0,5 (d=mean grain size, lambda = wavelength of the ultrasound pulse) known theories can be applied for the quantitative grain size determination and with an accuracy of +-15% the results agree with the metallographically measured values. The best method for this is the combination of two measurements with two different frequencies. Advantages are given by the measurement of the multiple scattering which is leading to the scattering coefficient and to the grain size with one measurement only and without assumptions concerning other parameters of ultrasound propagation. A structure characterization concerning the homogeneity inside the material is possible, too, because of the time (i.e. sound path-)-dependent scattering measurement. It is able to control the structure of monophasic steels with grain sizes between ASTM 1 and ASTM 11. Today problems unsolved are the martensitic steels, the multiphasic structures

  4. Study on cementitious properties of steel slag

    Directory of Open Access Journals (Sweden)

    Zhu G.

    2013-01-01

    Full Text Available The converter steel slag chemical and mineral components in China’s main steel plants have been analysed in the present paper. The electronic microscope, energy spectrum analysis, X-ray diffraction analysis confirmed the main mineral compositions in the converter slag. Converter slag of different components were grounded to obtain a powder with specific surface area over 400m2/kg, making them to take place some part of the cement in the concrete as the admixture and carry out the standard tests. The results indicate that the converter slag can be used as cementitious materials for construction. Furthermore, physical mechanic and durability tests on the concrete that certain amount of cement be substituted by converter steel slag powder from different steel plants are carried out, the results show that the concrete with partial substitution of steel slag powder has the advantages of higher later period strength, better frost resistance, good wear resistance and lower hydration heat, etc. This study can be used as the technical basis for “Steel Slag Powder Used For Cement And Concrete”, “Steel Slag Portland Cement”, “Low Heat Portland Steel Slag Cement”, “Steel Slag Road Cement” in China, as well as a driving force to the works of steel slag utilization with high-value addition, circular economy, energy conservation and discharge reduction in the iron and steel industry.

  5. Corrosion behavior of 2205 duplex stainless steel.

    Science.gov (United States)

    Platt, J A; Guzman, A; Zuccari, A; Thornburg, D W; Rhodes, B F; Oshida, Y; Moore, B K

    1997-07-01

    The corrosion of 2205 duplex stainless steel was compared with that of AISI type 316L stainless steel. The 2205 stainless steel is a potential orthodontic bracket material with low nickel content (4 to 6 wt%), whereas the 316L stainless steel (nickel content: 10 to 14 wt%) is a currently used bracket material. Both stainless steels were subjected to electrochemical and immersion (crevice) corrosion tests in 37 degrees C, 0.9 wt% sodium chloride solution. Electrochemical testing indicates that 2205 has a longer passivation range than 316L. The corrosion rate of 2205 was 0.416 MPY (milli-inch per year), whereas 316L exhibited 0.647 MPY. When 2205 was coupled to 316L with equal surface area ratio, the corrosion rate of 2205 reduced to 0.260 MPY, indicating that 316L stainless steel behaved like a sacrificial anode. When 316L is coupled with NiTi, TMA, or stainless steel arch wire and was subjected to the immersion corrosion test, it was found that 316L suffered from crevice corrosion. On the other hand, 2205 stainless steel did not show any localized crevice corrosion, although the surface of 2205 was covered with corrosion products, formed when coupled to NiTi and stainless steel wires. This study indicates that considering corrosion resistance, 2205 duplex stainless steel is an improved alternative to 316L for orthodontic bracket fabrication when used in conjunction with titanium, its alloys, or stainless steel arch wires. PMID:9228844

  6. Erosion behaviour of hydro turbine steels

    Indian Academy of Sciences (India)

    Akhilesh K Chauhan; D B Goel; Satya Prakash

    2008-04-01

    The martensitic stainless steel (termed as 13/4) is currently being used for fabrication of underwater parts in hydroelectric projects. There are, however, several maintenance problems associated with the use of this steel. A nitronic steel (termed as 21–4–N) has been developed as an alternative with the specific aim of overcoming these problems. A comparative study has been made on the erosion behaviour of 13/4 and 21–4–N steels by means of solid particle impingement using gas jet. The eroded surfaces after erosion tests were analysed by scanning electron microscopy. It is observed that the 21–4–N nitronic steel possesses better resistance to erosion in comparison to 13/4 martensitic stainless steel. The austenitic matrix of the nitronic steel possesses high hardness, high tensile toughness and work hardening ability, which results in higher erosion resistance.

  7. Mechanical characteristics of fused cast basalt tube encased in steel pipe for protecting steel surface

    Institute of Scientific and Technical Information of China (English)

    Jee-Seok WANG; Jong-Do KIM; Hee-Jong YOON

    2009-01-01

    Because of the various excellent characteristics of cast basalt materials, such as, anti-corrosion, anti-wearing, good hardness, high chemical stability, of which steel may not possess, the steel-basalt composite pipes are used in severe environments for compensating the defects of steel. The limit of bending moment with which steel-basalt composite pipe may safely endure was calculated and the limit curvature of the composite pipe in the safe range was presented. The application temperature of steel-basalt pipe was examined due to a different coefficient among basalt, mortar and mild steel.

  8. Comparative Structural Strength Research of Hardened Carbon Steel and Hot-Rolled Alloy Steel

    Science.gov (United States)

    Bogomolov, A. V.; Zhakupov, A. N.; Kanayev, A. T.; Sikach, I. A.; Tugumov, K. K.

    2016-08-01

    Experiments on quantitative evaluation of fatigue strength showed that St5ps and St5sp carbon steels with A400 strength class can be fully applied for erection of constructions and buildings having cyclical loads during operation. Study of corrosion resistance of hardened carbon steel in comparison with hot-rolled alloy steel consists in difference in structures and hence, difference in intensity of electric and chemical processes featuring presence of steel in concrete. Structure of St5sp steel with A400 strength class in surface area has significantly less corrosion rate than ferritic-perlitic structure of 35GS steel with A400 strength class.

  9. The comparison of frictional resistance in titanium, self-ligating stainless steel, and stainless steel brackets using stainless steel and TMA archwires: An in vitro study

    OpenAIRE

    Syed Altaf Khalid; Vadivel Kumar; Prithviraj Jayaram

    2012-01-01

    Aim: The aim of the study was to compare the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and titanium molybdenum alloy (TMA) archwires. Materials and Methods: We compared the frictional resistance in 0.018 slot and 0.022 slot of the three brackets - titanium, self-ligating stainless steel, and conventional stainless steel - using stainless steel archwires and TMA archwires. An in vitro study of simulated ca...

  10. Bimetallic layered castings alloy steel – carbon cast steel

    Directory of Open Access Journals (Sweden)

    T. Wróbel

    2011-01-01

    Full Text Available In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast processso-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer. The bearing part of bimetallic layered casting is typical foundry material i.e. ferritic-pearlitic carbon cast steel, whereas working part (layer is plate of austenitic alloy steel sort X10CrNi 18-8. The ratio of thickness between bearing and working part is 8:1. The quality of the bimetallic layered castings was evaluated on the basis of ultrasonic NDT (non-destructive testing, structure and macro- and microhardness researches.

  11. Prediction of quenched and tempered steel and cast steel properties

    OpenAIRE

    B. Smoljan; D. Iljkić; H. Novak

    2011-01-01

    Purpose: The influence of processing parameters, such as pouring temperature and cooling rate during the casting, as well as application of hot working and pre-heat treatment, on strength and toughness of quenched and tempered steel was investigated.Design/methodology/approach: Strength and toughness were presented by yield strength and Charpy-V notch toughness, respectively. Experimental procedure of material properties optimization was done using the 25-2 factor experiment.Findings: It was ...

  12. Cleanliness of Alloying Structural Steel

    Institute of Scientific and Technical Information of China (English)

    YU Hui-xiang; WANG Xin-hua; ZHANG Jing; LI Hai-bo; WANG Wan-jun

    2011-01-01

    Alloying structural steel used for mechanical structures has a high requirement for cleanliness because its failures are greatly affected by non-metallic inclusions and total oxygen content in steel.It has been reported by some steelmaking plants to have some problems in controlling total oxygen content and inclusions during alloying structural steel production.For this purpose,cleanliness control in 0.2C-0.3Si-0.6Mn-1Cr-0.2Mo steel was investigated.Firstly,low melting temperature zone(≤1873 K) of CaO-Al2O3-MgO system and formation condition of low melting temperature inclusions were investigated through thermodynamic equilibrium calculation.On this basis,industrial tests were carried out.Through sampling at different stages,transformation of oxide inclusions and change of total oxygen content in steel were studied.The results show that:in order to form CaO-Al2O3-MgO system inclusions with low melting temperature,mass percent of Al2O3,MgO and CaO in inclusions should be controlled from 37.6% to 70.8%,0 to 17.4% and 25.5% to 60.6%;For the condition of 1873 K and 0.05%(mass percent) dissolved aluminum in steel,the activities of dissolved oxygen,magnesium and calcium should be controlled as 0.298×10-4-2×10-4,0.1×10-5-40×10-5 and 0.8×10-8-180×10-8 respectively.With secondary refining proceeding,average total oxygen content and inclusion amount decrease,the type of most inclusions changes from Al2O3 after tapping to Al2O3-MgO after top slag is formed during ladle furnace refining and finally to CaO-Al2O3-MgO after RH treatment.In the final products,average total oxygen content was 12.7×10-6 and most inclusions were in spherical shape with size less than 5 μm.

  13. Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)

    Science.gov (United States)

    Aslani, Farhad; Nejadi, Shami

    2012-09-01

    Steel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths (τ (app)) and slip coefficient (β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle (ϕ). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers

  14. Steel Safeguards and the Welfare of U.S. Steel Firms and Downstream Consumers of Steel: A Shareholder Wealth Perspective

    OpenAIRE

    Liebman, Benjamin H.; Kasaundra M. Tomlin

    2006-01-01

    This paper analyzes the steel safeguards implemented and subsequently removed during 2001-2003. Our results reveal that for shareholders of U.S. steel companies, safeguards generated positive “abnormal” returns of approximately 6%; and the cancellation of the safeguards resulted in wealth gains of about 5%. Steel shareholders experienced negative abnormal returns of -5% in response to the WTO ruling that the U.S. violated WTO law. The results here are consistent with the neoclassical view tha...

  15. A mortality study among mild steel and stainless steel welders.

    Science.gov (United States)

    Moulin, J J; Wild, P; Haguenoer, J M; Faucon, D; De Gaudemaris, R; Mur, J M; Mereau, M; Gary, Y; Toamain, J P; Birembaut, Y

    1993-03-01

    A mortality study was carried out in conjunction with the European mortality study among welders coordinated by the International Agency for Research on Cancer (IARC). The study was aimed at assessing risks for lung cancer in relation to exposure to asbestos, welding fumes containing chromium and nickel, and tobacco smoke. The study included a cohort of 2721 welders and an internal comparison group of 6683 manual workers employed in 13 factories in France. The mortality of the two cohorts was studied from 1975 to 1988 by the historical prospective method. Job histories of welders were traced including welding processes used, metals welded, and proportion of worktime spent in welding. Data on smoking habits were collected from medical records. The observed number of deaths were compared with those expected (standardised mortality ratio (SMR)) based on national rates with adjustments for age, sex, and calendar time. The smoking habits of 87% of the whole study population were known. The distribution of welders and controls according to smoking was not statistically different. The overall mortality was slightly higher for welders (SMR = 1.02, 95% confidence interval (95% CI) 0.89-1.18) than for controls (SMR = 0.91, 95% CI 0.84-0.99). For lung cancer, the SMR was 1.24 (95% CI 0.75-1.94) for welders, whereas the corresponding value was lower for controls (SMR = 0.94, 95% CI 0.68-1.26). The SMR for lung cancer was 1.59 among non-shipyard mild steel welders (95% CI 0.73-3.02). This contrasted with the results for all stainless steel welders (SMR = 0.92, 95% CI 0.19-2.69), and for stainless steel welders predominantly exposed to chromium VI (SMR = 1.03, 95% CI 0.12-3.71). Moreover, SMRs for lung cancer for mild steel welders tended to increase with duration of exposure and time since first exposure, leading to significant excesses for duration > or = 20 years and latency > or = 20 years. Such a pattern was not found for stainless steel welders.

  16. Niobium in engineering bar steels

    International Nuclear Information System (INIS)

    The use of niobium as a microalloying addition to hot rolled and cold finished bars offers many opportunities to achieve enhanced mechanical properties in a very cost effective manner. By the addition of niobium (sometimes in combination with vanadium) to selected carbon steel grades, it is possible to produce hot rolled bars with minimum yield strengths up to 689 MPa (100 ksi) and cold finished bars with yield strengths up to 1035 MPa (150 ksi). These high-strength-low-alloy bars have a myriad of applications particularly for automotive parts such as shafts, stabilizer bars, tie rods, piston rods, fasteners such as U-bolts, brackets, and various transmission parts. Of particular value has been the specification of Nb-microalloyed steels for such hot forgings as connecting rods and caps, and weld yokes a situation which has permitted elimination of post-forging heat treatment (quenching and tempering). Significant reductions in cost and energy consumption have been realized

  17. Steel Industry Energy Bandwidth Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2004-10-01

    ITP conducted a study on energy use and potential savings, or "bandwidth" study, in major steelmaking processes. Intended to provide a realistic estimate of the potential amount of energy that can be saved in an industrial process, the "bandwidth" refers to the difference between the amount of energy that would be consumed in a process using commercially available technology versus the minimum amount of energy needed to achieve those same results based on the 2nd law of thermodynamics. The Steel Industry Energy Bandwidth Study (PDF 133 KB) also estimates steel industry energy use in the year 2010, and uses that value as a basis for comparison against the minimum requirements. This energy savings opportunity for 2010 will aid focus on longer term R&D.

  18. Fatigue Strength of Weathering Steel

    Directory of Open Access Journals (Sweden)

    Ludvík KUNZ

    2012-03-01

    Full Text Available Fatigue behaviour of Atmofix 52 steel (comparable to COR-TENâ steel exposed to atmospheric corrosion for 20 years was investigated. S-N curves for load symmetrical cycling and cycling with stress ratio R = 0 were determined on specimens detracted from a failed transmission tower. The data were compared with those on material without a rust layer. The fracture surfaces and, in particular, the sites of fatigue crack initiation were analyzed. Substantial decrease of fatigue life and fatigue limit due to corrosion exposition was found. Based on observation of surface layer with corrosion products and on fractographic analysis of failed specimens conclusions on fatigue damage mechanism were drawn. No grain boundary corrosion, which can be responsible for fatigue crack initiation, was observed. Initiation of fatigue cracks was related to surface roughness and took place exclusively on corrosion dimples.DOI: http://dx.doi.org/10.5755/j01.ms.18.1.1335

  19. Steel Industry Marginal Opportunity Analysis

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2005-09-01

    The Steel Industry Marginal Opportunity Analysis (PDF 347 KB) identifies opportunities for developing advanced technologies and estimates both the necessary funding and the potential payoff. This analysis determines what portion of the energy bandwidth can be captured through the adoption of state-of-the-art technology and practices. R&D opportunities for addressing the remainder of the bandwidth are characterized and plotted on a marginal opportunity curve.

  20. Benchmarking in Mobarakeh Steel Company

    Directory of Open Access Journals (Sweden)

    Sasan Ghasemi

    2008-05-01

    Full Text Available Benchmarking is considered as one of the most effective ways of improving performance incompanies. Although benchmarking in business organizations is a relatively new concept and practice, ithas rapidly gained acceptance worldwide. This paper introduces the benchmarking project conducted in Esfahan’s Mobarakeh Steel Company, as the first systematic benchmarking project conducted in Iran. It aimsto share the process deployed for the benchmarking project in this company and illustrate how the projectsystematic implementation led to succes.

  1. Ultra high strength in steel.

    Directory of Open Access Journals (Sweden)

    V. R. Parameswaran

    1962-07-01

    Full Text Available Very high strength levels in steel, not obtained by conventional methods of hardening by quenching and low temperature tempering, are obtained by mew hardening techniques involving the thermal-mechanical treatment of metastable austenite.The earlier attempts on such hardening techniques and the development of new processes such as 'Ausforming' investigated in the Ford Motor Company Research Laboratories and ''Maraging'' developed and patented by the International Nickel Company (MondLimited, are briefly reviewed here.

  2. Nano-composite stainless steel

    Science.gov (United States)

    Dehoff, Ryan R.; Blue, Craig A.; Peter, William H.; Chen, Wei; Aprigliano, Louis F.

    2015-07-14

    A composite stainless steel composition is composed essentially of, in terms of wt. % ranges: 25 to 28 Cr; 11 to 13 Ni; 7 to 8 W; 3.5 to 4 Mo; 3 to 3.5 B; 2 to 2.5 Mn; 1 to 1.5 Si; 0.3 to 1.7 C; up to 2 O; balance Fe. The composition has an austenitic matrix phase and a particulate, crystalline dispersed phase.

  3. Atmospheric corrosion of mild steel

    OpenAIRE

    Morcillo, Manuel; Fuente, Daniel de la; Díaz Ocaña, Iván; Cano, Heidis

    2011-01-01

    The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a) the morpholog...

  4. Metadynamic recrystallization in C steels

    Indian Academy of Sciences (India)

    A R Morgridge

    2002-08-01

    Metadynamic recrystallization has been investigated in three plain carbon steels (ENIA, EN2 and EN24) through the use of hot interrupted compression tests on a wedge plastometer. Holding time was 0.5 s between passes. Strain rates of 0.05 and 0.12/s and small strain increments of 3, 5 and 7% were employed. Test temperatures were varied between 800 and 1100°C. Various incremental and continuous stress strain curves were highlighted at different temperatures and strain rates for 3 steels, ENIA, EN2 and EN24, resulting in varying flow stresses and strains. Highest peak stress was 180 MPa for EN24 at peak strain of 0.25 and 900°C, with a strain rate 0.12/s. Peak strain values for all steels at 1100°C was 0.133 at a strain rate of 0.05/s and 0.15 at a strain rate of 0.12/s. Strain accumulation resulted in dynamic and metadynamic recrystallization with refinement to about 15 m for dynamic and 22 m for metadynamic recrystallization. Fractional softening, , decreased from 0.27 to 0.12 as recrystallization times in metadynamic recrystallization increased from 0.9 s to 1.5 s at 1100°C. Time for 50% metadynamic recrystallization was also reduced as temperature increased. For ENIA, a drop from 10000 s to 20 s, as temperature increased from 800 to 1100 °C was observed. For EN24 and EN2 steels, a drop from 4000 s to 6 s for similar temperature rise was observed. Metadynamic recrystallization (at strains higher than critical strain) is observed to be a strong function of strain rate and a very weak function of temperature and strain. It significantly refined the austenite grain size prior to transformation.

  5. Microstructural degradation of bearing steels

    OpenAIRE

    Solano Alvarez, Wilberth

    2015-01-01

    The aim of the work presented in this thesis is to clarify one of the most fundamental aspects of fatigue damage in bearings steels through critical experiments, in particular whether damage in the form of cracks precedes hard ?white-etching matter" formation, which is carbon supersaturated nanoscaled ferrite. Heat treatments have been designed to create four different crack types and distributions: scarce martensite plate cracks, fine grain boundary cracks, abundant martensite plate cracks, ...

  6. Austenitic Oxide Dispersion Strengthened Steels : A Review

    Directory of Open Access Journals (Sweden)

    Lavanya Raman

    2016-06-01

    Full Text Available Materials play an important role in the fast breeder reactors.  Materials used in cladding tube and fuel pins should have better creep and void swelling resistance. To overcome these difficulties, a new class of material known as oxide dispersion strengthened (ODS steels are used. There are two groups of ODS steels, the ferritic and the austenitic ODS steels based on the matrix. The present paper reviews the current status of research in austenitic ODS steels. The interaction of dislocations with finely dispersed incoherent, hard particles that governs the strength and high temperature properties of ODS materials is briefly reviewed. The synthesis route adopted for these ODS steels, which is mostly through powder metallurgy route is also discussed. The role of various oxides such as Y2O3, ZrO2and TiO2and the clusters formed in these ODS steels on the mechanical properties and void swelling characteristics is also discussed.

  7. Strengthening of nitrogen-containing maraging steels

    Energy Technology Data Exchange (ETDEWEB)

    Kaputkina, L.M.; Prokoshkina, V.G.; Uluntsev, D.Yu. [Moskovskij Inst. Stali i Splavov, Moscow (Russian Federation)

    1999-07-01

    The austenitic and austenitic-martensitic aging 15Cr(5-10)Ni2CuMoV(Nb)Ti-N - based steels were elaborated and investigated. These steels combine advantages of austenitic and martensitic steels and allow wide variety of phase compositions and mechanical properties. For nitrogen-containing austenitic and austenitic-martensitic steels it is possible to achieve, due to stress-induced martensitic transformation and thermomechanical treatment optimization, the strength level of martensitic-austenitic steels in a combination with high plasticity and fracture toughness inherent in pure austenitic structures. At the same time corrosion resistance of these steels in low-aggressive media is preserved and wear resistance increases as twice. (orig.)

  8. Fracture behavior of various welded steels

    International Nuclear Information System (INIS)

    In this study, P295GH (17Mn4) pressure vessel steel and AISI 304 stainless steel were joined by using ER 309L electrodes. Welded specimens were fatigued by four point bending experiments. Cracks occurred on the stainless steel side of the weldment during the fatigue tests. Finite element (FE) analyses were conducted by fixing 2-D precracked model for welded 17Mn4 pressure vessel steel and AISI 304 stainless steel by using ER 309L electrodes. True stress and true strain values of the AISI 304, 17Mn4 steels and ER 309L electrodes were determined by tensile tests. Stress analyses were conducted after entering the linear and nonlinear properties of the materials into software manually. Eventually, fracture mechanics analyses were conducted for the model, and J integral fracture toughness values of the crack on the weldment were calculated.

  9. Utilization of structural steel in buildings.

    Science.gov (United States)

    Moynihan, Muiris C; Allwood, Julian M

    2014-08-01

    Over one-quarter of steel produced annually is used in the construction of buildings. Making this steel causes carbon dioxide emissions, which climate change experts recommend be reduced by half in the next 37 years. One option to achieve this is to design and build more efficiently, still delivering the same service from buildings but using less steel to do so. To estimate how much steel could be saved from this option, 23 steel-framed building designs are studied, sourced from leading UK engineering firms. The utilization of each beam is found and buildings are analysed to find patterns. The results for over 10 000 beams show that average utilization is below 50% of their capacity. The primary reason for this low value is 'rationalization'-providing extra material to reduce labour costs. By designing for minimum material rather than minimum cost, steel use in buildings could be drastically reduced, leading to an equivalent reduction in 'embodied' carbon emissions.

  10. Fracture behavior of various welded steels

    Energy Technology Data Exchange (ETDEWEB)

    Ozdemir, Tevfik Ertugrul; Cetinel, Hakan [Celal Bayar Univ., Manisa (Turkey). Dept. of Mechanical Engineering; Uyulgan, Bahadir [Dokuz Eyluel Univ., Izmir (Turkey). Dept. of Metallurgical and Materials Engineering

    2016-02-01

    In this study, P295GH (17Mn4) pressure vessel steel and AISI 304 stainless steel were joined by using ER 309L electrodes. Welded specimens were fatigued by four point bending experiments. Cracks occurred on the stainless steel side of the weldment during the fatigue tests. Finite element (FE) analyses were conducted by fixing 2-D precracked model for welded 17Mn4 pressure vessel steel and AISI 304 stainless steel by using ER 309L electrodes. True stress and true strain values of the AISI 304, 17Mn4 steels and ER 309L electrodes were determined by tensile tests. Stress analyses were conducted after entering the linear and nonlinear properties of the materials into software manually. Eventually, fracture mechanics analyses were conducted for the model, and J integral fracture toughness values of the crack on the weldment were calculated.

  11. Development and outlook of Chinese steel industry

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The fast development of Chinese steel industry has drawn great attention from the world.Market n eeding and technical development are the main driving forces for the rapid development of Chinese steel industry. Based on the discussing of the reasons of its rapid development, the present paper further analyzed the main problems and distance towards the advanced level of international steel industry. It bring forward that Chinese steel industry should enhance the research and development on new generation steel materials and production process to ensure its sustainable development. Through populating the key technologies of syntheses energy saving and water saving to realize the main equipments self-making and establish a new recyclable steel production process.

  12. Microstructures in laser welded high strength steels

    Science.gov (United States)

    Rizzi, P.; Bellingeri, S.; Massimino, F.; Baldissin, D.; Battezzati, L.

    2009-01-01

    In this work, the effect of laser welding on the microstructure was studied for three Advanced High Strength Steels: transformation induced plasticity steel (TRIP), dual phase steel (DP) and martensitic steel. Two sheets of the same steel were laser welded and a microstructural study was performed by optical microscopy, scanning electron microscopy and X-ray diffraction. For all samples the welded zone was constituted by martensite and the heat affected zone shows a continuous change in microstructure depending on temperatures reached and on the different cooling rates. The change in mechanical properties in the welded area was followed by Vickers micro-hardness measurements. Quasi binary phase diagrams were calculated and, according to position of T0 lines, it was deduced that austenite is the primary phase forming during rapid solidification for all steels.

  13. Microstructures in laser welded high strength steels

    International Nuclear Information System (INIS)

    In this work, the effect of laser welding on the microstructure was studied for three Advanced High Strength Steels: transformation induced plasticity steel (TRIP), dual phase steel (DP) and martensitic steel. Two sheets of the same steel were laser welded and a microstructural study was performed by optical microscopy, scanning electron microscopy and X-ray diffraction. For all samples the welded zone was constituted by martensite and the heat affected zone shows a continuous change in microstructure depending on temperatures reached and on the different cooling rates. The change in mechanical properties in the welded area was followed by Vickers micro-hardness measurements. Quasi binary phase diagrams were calculated and, according to position of T0 lines, it was deduced that austenite is the primary phase forming during rapid solidification for all steels.

  14. Plain carbon steel bipolar plates for PEMFC

    Institute of Scientific and Technical Information of China (English)

    WANG Jianli; SUN Juncai; TIAN Rujin; XU Jing

    2006-01-01

    Bipolar plates are a multifunctional component of PEMFC. Comparing with the machined graphite and stainless steels, the plain carbon steel is a very cheap commercial metal material. In this paper, the possibility of applying the plain carbon steels in the bipolar plate for PEMFC was exploited. In order to improve the corrosion resistance of the low carbon steel in the PEMFCs' environments,two surface modification processes was developed and then the electrochemical performances and interfacial contact resistance (ICR) of the surface modified plate of plain carbon steel were investigated. The results show that the surface modified steel plates have good corrosion resistance and relatively low contact resistance, and it may be a candidate material as bipolar plate of PEMFC.

  15. Large deformation structural performance of double skin composite construction using British Steel's 'Bi-Steel'

    OpenAIRE

    McKinley, B.

    1999-01-01

    Double skin composite construction consists of two relatively thin steel plates with the space between filled with, usually, normal weight concrete. The transfer of shear between the steel and concrete is possible through the use of steel shear connectors that are welded to the steel plates. A study of previously published information revealed that the areas to market double skin composite construction would be submerged tube tunneling and floating offshore structures, particularly those used...

  16. Buckling of steel and composite steel and concrete columns in case of fire

    OpenAIRE

    Correia, Antonio M.; Rodrigues, João Paulo C.

    2010-01-01

    Bare steel columns are known to have a very low fire resistance. The high thermal conductivity and the sudden decrease of the steel yield stress and Young Modulus in function of the temperature are responsible for this behaviour. The purpose of this study is to compare different modes of failure of building steel columns. The buckling of the columns is strongly influenced by the contact with other elements such as brick walls. Three types of situations were compared: steel columns...

  17. Did US Safeguard Protection on Steel Affect Market Power of European Steel Producers?

    OpenAIRE

    Hylke VANDENBUSSCHE; Zarnic, Ziga

    2006-01-01

    This paper empirically investigates the effects of US safeguard protection on steel imports in 2002 on the mark-ups of EU steel producers. We identify a large panel of European steel producers between 1995 and 2004 affected by the safeguards. Using the Roeger method, our results show that US safeguards significantly reduced EU firms?mark-ups. Single-product EU steel firms suffered relatively more from the protection than multi-product firms. Controlling for firm heterogeneity, these results a...

  18. Regularity of Structural Superplasticity of Hypoeutectoid Steel

    Institute of Scientific and Technical Information of China (English)

    YANG Yun-lin; WEN Jiu-ba

    2005-01-01

    The curve of the relation between fracture elongation and temperature for unltrafine grained low alloy hypoeutectoid steels generally shows that three peaks occur at temperatures just below Ac1, between Ac1 and Ac3, and just above Ac3, When these steels are subjected to superplastic tensile test at different temperatures, the value of the last one is the lowest and the other two peaks are different one from another depending on components, microstructures and deformation conditions of the steels.

  19. Powder metallurgically produced high nitrogen steels

    Energy Technology Data Exchange (ETDEWEB)

    Liimatainen, J. [Rauma Materials Technology, Tampere (Finland)

    1999-07-01

    Nitrogen alloying of steel is a modern way of improving technical and manufacturing characteristics of stainless, high temperature and wear resistant steels. Powder metallurgy (P/M) enables nitrogen alloying in the melt during alloying or in the solid state for gas atomized powder. Especially the nitrogen alloying in the solid state provides several benefits in enhancing steel properties by nitrogen alloying. This paper describes methods of nitrogen alloying in P/M materials and shows examples of improved material properties. (orig.)

  20. Super High Strength Steel for automotive applications

    OpenAIRE

    CONFENTE, Mario; SCHNEIDER, Emmanuel; BOMONT, Olivier; LESCALIER, Christophe; BOMONT-ARZUR, Anne

    2008-01-01

    Intensive weight savings and out-sizing programs are developed in automotive industry and lead to increase the mechanical properties of the material of the automotive parts. ArcelorMittal has developed specific steel grades known as Super High Strength Steels which are designed for both high ductility and toughness and fatigue resistance. This paper investigates machinability for a drilling operation using an experimental methodology. One of the materials is a new low bainitic steel grade. Ex...

  1. Dissimilar Welding of Titanium Alloys to Steels

    OpenAIRE

    Gao, Yefei; TSUMURA, Takuya; NAKATA, Kazuhiro

    2012-01-01

    This review summarizes the dissimilar welding of titanium alloys to steels over a period of ten recent years, involving the welding processes which are used for the dissimilar welding of titanium alloys to steels, the mechanical properties of the joints and the discussion for the forming mechanism of the interface. Reducing the formation of brittle intermetallic compound (IMC) is a key requirement in the dissimilar welding of titanium alloys to steels, because the strength of the welding join...

  2. Kocel Steel Foundry Grand Opening Ceremony

    Institute of Scientific and Technical Information of China (English)

    TIAN Shi-jiang

    2006-01-01

    @@ On May 9, 2006 the Grand Opening ceremony of Kocel Steel Foundry Co., Ltd. was held in the National Economic and Technological Development Zone in Yinchuan City, Ningxia, China. Kocel Steel Foundry Co.,Ltd. is a large scale enterprise producing steel castings and it is jointly established by Ningxia Kocel Group,Changcheng Suzaki Machine & Foundry Co., Ltd. and Voestalpine Giesserei Linz GmbH, Austria.

  3. Spectral Data Processing for Steel Industry

    OpenAIRE

    Bisot, Clémence

    2015-01-01

    For steel industry, knowing and understanding characteristics of a steel strip surface at every steps of the production process is a key element to control final product quality. Today as the quality requirements increase this task gets more and more important. The surface of new steel grades with complex chemical compositions has behaviors especially hard to master. For those grades in particular, surface control is critical and difficult. One of the promising technics to assess the problem ...

  4. Experimental studies of Steel Corrugated Constructions

    Directory of Open Access Journals (Sweden)

    Lazarev Yuriy

    2016-01-01

    Full Text Available The purpose of this particular article is to assess existing calculations of steel corrugated constructions. Steel Corrugated Construction is a perspective type of constructions, which is exhibiting numerous advantages in comparison with one that currently applied in automobile and railroad networks (reinforced concrete water-throughput pipes, reinforced concrete frame bridges. The evaluation of experimental data on models of constructions of this particular type has been carried out in order to improve calculations of Steel Corrugated Constructions.

  5. Sustainability assessment and standardisation : steel buildings

    OpenAIRE

    Andrade, Joana B.; Bragança, L.

    2012-01-01

    This paper aims at evaluating in what extent are the existing sustainability assessment methodologies capable of truly reward the benefits of steel-intensive buildings in comparison with other building construction solutions. This evaluation consists in describing the more common sustainability assessment methodologies from the steel construction point of view and in comparing existing assessments to steel buildings. The pros and cons of each will also be pointed out, in order ...

  6. Prevention methods against hydrogen degradation of steel

    OpenAIRE

    J. Ćwiek

    2010-01-01

    Purpose: of this paper is presentation of mechanisms and forms of hydrogen degradation in steel along with pointing out methods for hydrogen degradation prevention.Design/methodology/approach: Hydrogen degradation of steel is a form of environmentally assisted failure which is caused by the action of hydrogen often in combination with residual or applied stress resulting in reduction of plasticity, load bearing capacity of a component, and cracking.Findings: The sources of hydrogen in steel w...

  7. The heat treatment of Fermanal cast steel

    OpenAIRE

    F. Binczyk; A. Smoliński; J. Szymszal

    2007-01-01

    The study discloses the results of microstructural examinations, testing of magnetic properties and hardness measurements as cast and after heat treatment conducted on the Fermanal cast steel. A characteristic feature of this cast steel is its density lower by about 10% than the density of carbon cast steel [4]. It has been proved that the factor deciding about the composition of microstructure (fraction of ferrite and austenite) is the content of aluminium. The matrix totally austenitic is p...

  8. Behaviour of high strength steel moment joints

    OpenAIRE

    Girão Coelho, A.M.; Bijlaard, F.S.K.

    2010-01-01

    The design of joints to European standard EN 1993 within the semi-continuous/partially restrained philosophy is restricted to steel grades up to S460. With the recent development of high performance steels, the need for these restrictions should be revisited. The semicontinuous joint modelling can be adopted as long as the joint develops rotation capacity and behaves ductile. The research summarized in this paper focuses on moment joints with components made from high strength steel S460, S69...

  9. Hot workability of duplex stainless steels

    OpenAIRE

    Martin, Guilhem

    2011-01-01

    The Duplex Stainless Steels (DSS) are defined as a family of stainless steels consisting of a two-phase microstructure involving δ-ferrite and γ-austenite. Exceptional combinations of strength and toughness together with good corrosion resistance under critical working conditions designate DSS a suitable alternative to conventional austenitic stainless steels. Unfortunately, the relatively poor hot workability of these alloys makes the industrial processing of flat products particularly criti...

  10. RATIONAL STEEL CORRUGATED PROFILE DESIGN

    Directory of Open Access Journals (Sweden)

    V. V. Kachurenko

    2015-08-01

    Full Text Available Purpose. The work sets forth the search results of new, more efficient design solutions for metal silos, namely, the analysis of existing types of profiles cross-section in a steel wall of such silo and development of less material-intensive section of corrugated profile.Methodology. To achieve the set goal there were researched the existing types of capacitive structure profiles and their strain-stress state under the load. The analysis was performed on the results of computational experiments. The prototype object was mathematical computer models. The calculations were made using the finite-element method. For computational experiment there was used the design-computing system Structure CAD for Windows. Findings. In this work there were obtained the data allowing to assess work of the profiles and to find more effective type of cross-section in terms of its material consumption. In the process of joint study of the authors a new type of profile for capacitive structures was developed; it has higher utilization efficiency and the attachment point of individual steel sheets with this type of profile. Both solutions are easy to install, reliable in operation and can be manufactured in the conditions of modern industrial production using standard equipment, materials and components. Originality. A new type of corrugated profile cross-section for steel silo walls was proposed; it has higher load carrying capacity and rigidity and allows reducing the metal thickness without changing the structure carrying capacity that results in material consumption reduction of the whole structure.For this and similar types of profiles there was designed and proposed the attachment point of individual corrugated sheets screwed with extending flange, which enables the unit connection in case of small size corrugations, where the distance is not sufficient to accommodate the bolt cap between the individual corrugations. Practical value.Application of the proposed

  11. The Structure and Mechanical Properties of Bridge Steel Weldings With Glass-Steel Liners

    Science.gov (United States)

    Muzalev, V. N.; Semukhin, B. S.; Danilov, V. I.

    2016-04-01

    A new technology is developed for welding multi-span bridge constructions. The mechanical properties and structure of the low-carbon bridge steel welds have been studied. The welding parameters and application of steel-glass liners provide for long-term service of steel constructions in conformity with the welding industry specifications.

  12. Auburn Steel Company radioactive contamination incident

    International Nuclear Information System (INIS)

    On February 21, 1983, workers at the Auburn Steel Company, Auburn, New York discovered that about 120 tons of steel poured that day had become contaminated with 60Co. In addition to the steel, the air cleaning system and portions of the mill used in casting the steel were contaminated. Approximately 25 curies of 60Co were involved. Decontamination and disposal of the contamination cost in excess of $2,200,000. This report details the discovery of the contamination, decontamination of the plant and disposal of the contamination

  13. Laser Welding of High Strength Steels

    OpenAIRE

    Guo, Wei

    2016-01-01

    S960 and S700 are two types of high strength low alloy steels (minimum yield strengths at 960 MPa and 700 MPa, respectively) developed recently by Tata Steel. These steels are typically used in heavy lifting equipment. This research examines the feasibility and characteristics of single pass autogenous laser welding (ALW), multi-pass ultra-narrow gap laser welding (NGLW) of 8 mm thick S960 and 13 mm thick S700 high strength low alloy (HSLA) steels and compared the characteristics of the welds...

  14. Progress of Production Technology of Clean Steel in Baosteel

    Institute of Scientific and Technical Information of China (English)

    CuiJian

    2005-01-01

    The progress in control technology of carbon, nitrogen, total oxygen, phosphorus, and stdphur as well as inclusions in steel is discussed at Baosteel. The purity obtained in IF steel and pipeline steel is introduced.

  15. Steel Policy: The Good, the Bad, and the Ugly

    OpenAIRE

    Gary Clyde Hufbauer; Ben Goodrich

    2003-01-01

    While the US steel industry has been in distress for decades, the "steel crisis" of 1999-2001 was particularly acute. More than 30 steel producing and steel processing firms fell into bankruptcy between 1997 and 2001, and most of the failures occurred after President Bush took office. During his presidential campaign, Bush promised steelworkers that he would not neglect them. As the crisis worsened, the steel industry and the United Steel Workers of America (USWA) pressed the Bush administrat...

  16. Local buckling strength of steel foam sandwich panels

    OpenAIRE

    Szyniszewski, S; Schafer, BW; Smith, BH; Arwade, SR; Hajjar, JF

    2012-01-01

    The objective of this paper is to provide and verify a new design method for the in-plane compressive strength of steel sandwich panels comprised of steel face sheets and foamed steel cores. Foamed steel, literally steel with internal voids, provides enhanced bending rigidity, exceptional energy dissipation, and the potential to mitigate local instability. In this work, Winters effective width expression is generalized to the case of steel foam sandwich panels. The generalization requires mod...

  17. Effect of Geobacter sulfurreducens on the microbial corrosion of mild steel, ferritic and austenitic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Mehanna, Maha [Laboratoire de Genie Chimique, CNRS - Universite de Toulouse, 5 rue Paulin Talabot, BP1301, 31029 Toulouse (France)], E-mail: mum34@psu.edu; Basseguy, Regine; Delia, Marie-Line; Bergel, Alain [Laboratoire de Genie Chimique, CNRS - Universite de Toulouse, 5 rue Paulin Talabot, BP1301, 31029 Toulouse (France)

    2009-11-15

    The influence of Geobacter sulfurreducens was tested on the anaerobic corrosion of four different steels: mild steel 1145, ferritic steel 403 and austenitic steels 304L and 316L. Within a few hours, the presence of cells induced a free potential (E{sub oc}) ennoblement around +0.3 V on 1145 mild steel, 403 ferritic steel and 304L austenitic steels and slightly less on 316L. The kinetics of E{sub oc} ennoblement depended on the amount of bacteria in the inoculum, but the final potential value depended essentially on the nature of the material. This effect was due to the capacity of G. sulfurreducens to create a direct cathodic reaction on steel surfaces, extracting the electrons directly from material. The presence of bacterial cells modified the corrosion features of mild steel and ferritic steel, so that corrosion attacks were gathered in determined zones of the surface. Local corrosion was significantly enhanced on ferritic steel. Potential ennoblement was not sufficient to induce corrosion on austenitic steels. In contrast G. sulfurreducens delayed the occurrence of pitting on 304L steel because of its capability to oxidize acetate at high potential values. The electrochemical behaviour of 304L steel was not affected by the concentration of soluble electron donor (acetate, 1-10 mM) or the amount of planktonic cells; it was directly linked to the biofilm coverage. After polarization pitting curves had been recorded, microscopic observations showed that pits propagated only in the surface zones where cell settlement was the densest. The study evidenced that Geobacter sulfurreducens can control the electrochemical behaviour of steels in complex ways that can lead to severe corrosion. As Geobacteraceae are ubiquitous species in sediments and soils they should now be considered as possible crucial actors in the microbial corrosion of buried equipment.

  18. Effect of Geobacter sulfurreducens on the microbial corrosion of mild steel, ferritic and austenitic stainless steels

    International Nuclear Information System (INIS)

    The influence of Geobacter sulfurreducens was tested on the anaerobic corrosion of four different steels: mild steel 1145, ferritic steel 403 and austenitic steels 304L and 316L. Within a few hours, the presence of cells induced a free potential (Eoc) ennoblement around +0.3 V on 1145 mild steel, 403 ferritic steel and 304L austenitic steels and slightly less on 316L. The kinetics of Eoc ennoblement depended on the amount of bacteria in the inoculum, but the final potential value depended essentially on the nature of the material. This effect was due to the capacity of G. sulfurreducens to create a direct cathodic reaction on steel surfaces, extracting the electrons directly from material. The presence of bacterial cells modified the corrosion features of mild steel and ferritic steel, so that corrosion attacks were gathered in determined zones of the surface. Local corrosion was significantly enhanced on ferritic steel. Potential ennoblement was not sufficient to induce corrosion on austenitic steels. In contrast G. sulfurreducens delayed the occurrence of pitting on 304L steel because of its capability to oxidize acetate at high potential values. The electrochemical behaviour of 304L steel was not affected by the concentration of soluble electron donor (acetate, 1-10 mM) or the amount of planktonic cells; it was directly linked to the biofilm coverage. After polarization pitting curves had been recorded, microscopic observations showed that pits propagated only in the surface zones where cell settlement was the densest. The study evidenced that Geobacter sulfurreducens can control the electrochemical behaviour of steels in complex ways that can lead to severe corrosion. As Geobacteraceae are ubiquitous species in sediments and soils they should now be considered as possible crucial actors in the microbial corrosion of buried equipment.

  19. Camel Milk Modulates the Expression of Aryl Hydrocarbon Receptor-Regulated Genes, Cyp1a1, Nqo1, and Gsta1, in Murine hepatoma Hepa 1c1c7 Cells

    Directory of Open Access Journals (Sweden)

    Hesham M. Korashy

    2012-01-01

    Full Text Available There is a traditional belief in the Middle East that camel milk may aid in prevention and treatment of numerous cases of cancer yet, the exact mechanism was not investigated. Therefore, we examined the ability of camel milk to modulate the expression of a well-known cancer-activating gene, Cytochrome P450 1a1 (Cyp1a1, and cancer-protective genes, NAD(PH:quinone oxidoreductase 1 (Nqo1 and glutathione S-transferase a1 (Gsta1, in murine hepatoma Hepa 1c1c7 cell line. Our results showed that camel milk significantly inhibited the induction of Cyp1a1 gene expression by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, the most potent Cyp1a1 inducer and known carcinogenic chemical, at mRNA, protein, and activity levels in a concentration-dependent manner. In addition, camel milk significantly decreased the xenobiotic responsive element (XRE-dependent luciferase activity, suggesting a transcriptional mechanism is involved. Furthermore, this inhibitory effect of camel milk was associated with a proportional increase in heme oxygenase 1. On the other hand, camel milk significantly induced Nqo1 and Gsta1 mRNA expression level in a concentration-dependent fashion. The RNA synthesis inhibitor, actinomycin D, completely blocked the induction of Nqo1 mRNA by camel milk suggesting the requirement of de novo RNA synthesis through a transcriptional mechanism. In conclusion, camel milk modulates the expression of Cyp1a1, Nqo1, and Gsta1 at the transcriptional and posttranscriptional levels.

  20. Soy isoflavones increase quinone reductase in hepa-1c1c7 cells via estrogen receptor beta and nuclear factor erythroid 2-related factor 2 binding to the antioxidant response element.

    Science.gov (United States)

    Froyen, Erik B; Steinberg, Francene M

    2011-09-01

    Soy protein and isoflavones (genistein and daidzein) have been demonstrated to increase quinone reductase (QR) activity, protein, and mRNA in animal and cell culture models. However, their mechanism of action has not been completely characterized. Additionally, it has not been determined if equol, a daidzein metabolite, can modulate QR activity and expression. Estrogen receptor beta (ERβ) is thought to be involved in stimulating QR gene transcription by anti-estrogens and phytoestrogens, along with nuclear factor erythroid 2-related factor 2 (Nrf2). This study tested the hypothesis that genistein, daidzein and equol increase quinone reductase activity, protein and mRNA via ERβ and Nrf2 binding to the QR antioxidant response element (ARE). QR expression and activity were determined using TaqMan polymerase chain reaction, protein immunoblots and activity assays. Molecular events were investigated using luciferase reporter gene assays and chromatin immunoprecipitation (ChIP). Hepa-1c1c7 cells were treated with control [0.1% (v:v) dimethyl sulfoxide (DMSO)]; 1 μmol/L β-naphthoflavone (positive control); 5 μmol/L resveratrol (ChIP positive control for ERβ binding) and 1, 5 and 25 μmol/L genistein, daidzein or equol. Treatment durations were 1 h (ChIP), 24 h (mRNA and luciferase assays) and 24 and 48 h (protein and activity). Genistein, daidzein and equol increased QR activity, protein and mRNA, with daidzein and equol having more of an impact at physiologic concentrations (1 and 5 μmol/L) compared to genistein. Furthermore, the study results demonstrate that genistein, daidzein and equol interact with the QR ARE and that daidzein and equol act via both ERβ and Nrf2 binding strongly to the QR ARE.

  1. Effect of weld on design of steel moment-resisting connection reinforced with steel plates

    Institute of Scientific and Technical Information of China (English)

    CHEN Peng; LI Yong

    2005-01-01

    The foreign experimental and FEM research of steel moment-resisting connection reinforced with steel plates are introduced. The effect of weld on the connection design is studied in two ways including weld detail and geometrical detail of steel plates contrast to the reference drawing of connection design in China. The research shows that the weld plays an important role in the design of connections. The welds connecting reinforced plates and beam/ column flange and the plate geometry have direct influence on the performance of the connections reinforced with plates. The study is helpful to the application of design of steel moment-resisting connection with steel plates.

  2. Experimental investigation of axially loaded steel fiber reinforced high strength concrete-filled steel tube columns

    Institute of Scientific and Technical Information of China (English)

    卢亦焱; 李娜; 李杉; 梁鸿骏

    2015-01-01

    An experimental study on the compressive behavior of steel fiber reinforced concrete-filled steel tube columns is presented. Specimens were tested to investigate the effects of the concrete strength, the thickness of steel tube and the steel fiber volume fraction on the ultimate strength and the ductility. The experimental results indicate that the addition of steel fibers in concrete can significantly improve the ductility and the energy dissipation capacity of the concrete-filled steel tube columns and delay the local buckling of the steel tube, but has no obvious effect on the failure mode. It has also been found that the addition of steel fibers is a more effective method than using thicker steel tube in enhancing the ductility, and more advantageous in the case of higher strength concrete. An analytical model to estimate the load capacity is proposed for steel tube columns filled with both plain concrete and steel fiber reinforced concrete. The predicted results are in good agreement with the experimental ones obtained in this work and literatures.

  3. Evaluation of Steel Cleanliness in a Steel Deoxidized Using Al

    Science.gov (United States)

    Castro-Cedeño, Edgar-Ivan; Herrera-Trejo, Martín; Castro-Román, Manuel; Castro-Uresti, Fabián; López-Cornejo, Monserrat

    2016-06-01

    The effect of magnesium in the aluminum used as a deoxidizer on the cleanliness of steel was studied throughout a steelmaking route for the production of thin slabs. Two deoxidizers with different Mg contents were used. The Mg content of a "typical" deoxidizer was ~0.5 wt pct Mg, whereas that for an alternative deoxidizer was ~2 wt pct Mg. The inclusion population at different stages of the steelmaking process was characterized in terms of chemical composition, number, and size distribution. The inclusion modification path shows that the solid Al2O3 and Al2O3-MgO inclusions formed in the early stage of the steel ladle treatment are modified into Al2O3-MgO-CaO liquid and MgO-Al2O3-liquid inclusions. Although some slight differences were observed in the ladle furnace samples, the chemical composition of inclusions was similar in the samples taken at the mold of the continuous casting, regardless of the deoxidizer used. Gumbel, generalized extreme value (GEV), and generalized Pareto (GP) distributions were used for the description of the size distribution. The GEV and GP distributions resulted in proper distributions to describe the evolution of size distribution throughout the steelmaking process. Furthermore, no statistically significant differences between inclusion size distributions resulting from the use of either deoxidizer were found.

  4. [Initial stages of steel biocorrosion].

    Science.gov (United States)

    Zhigletsova, S K; Rodin, V B; Kobelev, V S; Aleksandrova, N V; Rasulova, G E; Kholodenko, V P

    2000-01-01

    Initial stages of corrosion of mild steel induced by Klebsiela rhinoscleromatis BO2 were studied in various media. The effect of the microorganism was detected 8-10 h after inoculation. The number of viable cells were virtually unchanged within one month in all media, but the corrosive activity of the strain decreased. The corrosive activity of microorganisms can be determined by spectrophotometry even only after incubation for 24 h. At a low level of organic substrate, even strong colonization with microorganisms does not inevitably result in a significant damage to metals.

  5. Luders bands in RPV Steel

    OpenAIRE

    Johnson, D H

    2013-01-01

    The R6 procedure is used for the prevention and prediction of crack behaviour and other defects in the reactor pressure vessel(RPV). The RPV material is an upper-bainitic, low alloy steel structure, which deforms inhomogeneously when yielding. The current codes that are used to design and calculate the fracture, within an RPV, assume that the material yields continuously as the size of the L¨uders strain is less than 2%. However, the work of Wenman et al[1] has shown that the inclusion of a L...

  6. A recycling process for dezincing steel scrap

    Energy Technology Data Exchange (ETDEWEB)

    Dudek, F.J.; Daniels, E.J. [Argonne National Lab., IL (United States); Morgan, W.A.; Kellner, A.W.; Harrison, J. [Metal Recovery Industries, Inc., Hamilton, ON (Canada)

    1992-08-01

    In response to the several-fold increase in consumption of galvanized steel in the last decade and the problems associated with refurnacing larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is electrowon as dendritic powder. The process is effective for zinc, lead, aluminum, and cadmium removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 1,000 tons of mostly baled scrap. A pilot plant to continuously treat loose scrap is under construction. Use of degalvanized steel scrap decreases raw materials and environmental compliance costs to steel- and iron-makers, may enable integrated steel producers to recycle furnace dusts to the sinter plant, and may enable EAF production of flat products without use of DRI or pig iron. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap.

  7. A recycling process for dezincing steel scrap

    Energy Technology Data Exchange (ETDEWEB)

    Dudek, F.J.; Daniels, E.J. (Argonne National Lab., IL (United States)); Morgan, W.A.; Kellner, A.W.; Harrison, J. (Metal Recovery Industries, Inc., Hamilton, ON (Canada))

    1992-01-01

    In response to the several-fold increase in consumption of galvanized steel in the last decade and the problems associated with refurnacing larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is electrowon as dendritic powder. The process is effective for zinc, lead, aluminum, and cadmium removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 1,000 tons of mostly baled scrap. A pilot plant to continuously treat loose scrap is under construction. Use of degalvanized steel scrap decreases raw materials and environmental compliance costs to steel- and iron-makers, may enable integrated steel producers to recycle furnace dusts to the sinter plant, and may enable EAF production of flat products without use of DRI or pig iron. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap.

  8. Bauxite Based Bricks for Steel Ladle

    Institute of Scientific and Technical Information of China (English)

    Yu Lingyan; Peng Xigao

    2011-01-01

    @@ 1.Scope This standard specifies the classification,technical requirements,test methods,inspection rules,packing,marking,transportation,storage,and quality certificate of bauxite based bricks for steel ladle linings.This standard is applicable to bauxite based bricks for working layer of steel ladle.

  9. Sprayformed Hot Work Steels for Rapid Tooling

    Institute of Scientific and Technical Information of China (English)

    Yunfeng Yang; Simo-Pekka Hannula

    2003-01-01

    The present work compares microstructures of hot work steels made by different processes, that is, by sprayforming,by casting, and a commercially supplied H13 steel. Material benefits are recognized by sprayforming hot working tools such as die inserts fo

  10. 49 CFR 192.55 - Steel pipe.

    Science.gov (United States)

    2010-10-01

    ... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is qualified for use under this part if: (1) It was manufactured in accordance with a listed specification; (2... Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS...

  11. Purification of post-consumer steel crap

    NARCIS (Netherlands)

    Rem, P.C.; Van den Broeck, F.; Bakker, M.C.M.

    2012-01-01

    Post-consumer steel scrap is often hand picked for contaminants such as copper to meet specifications of steelmakers. If the hand sorting capacity exceeds 20 tons scrap/h the efficiency generally becomes problematic, leaving 50% of the copper contaminants in the steel product. In response, new techn

  12. Optimising steel hub location in Thailand

    Directory of Open Access Journals (Sweden)

    Sakaradhorn Boontaveeyuwat

    2012-11-01

    Full Text Available The optimal location of a steel hub in Thailand was analysed by applying aspecific research methodology designed to evaluate locations near the seaports. The growth of Thailand’s steel industry has become a centre of attention in the last decade, resulting in substantial efforts to form a distribution service centre to minimise the logistic costs associated with handling large steel flows in the future. The main analysis of the steel hublocation focused on areas situated near Laem Cha Bang, Map Ta Phut and Prachuab ports since these top three ports are considered important in terms of their steel throughput in Thailand. The transport costs associated with the shipment and inland transport together with port tariffs were calculated for the proposed scenarios of steel hub establishment andthese were compared with the existing situation without steel hub. The findings showed that a steel hub located near Laem Cha Bang port was the optimal option involving a saving of 9.4% on the total system costs incurred under the existing situation.

  13. Steel plate reinforcement of orthotropic bridge decks

    NARCIS (Netherlands)

    Teixeira de Freitas, S.

    2012-01-01

    The PhD research is focused on the reinforcement of fatigue cracked orthotropic steel bridge decks (OBD) by adding a second steel plate to the existing deck. The main idea is to stiffen the existing deck plate, which will reduce the stresses at the fatigue sensitive details and extend the fatigue li

  14. Steel Sheet Pile Walls in Soft Soil

    NARCIS (Netherlands)

    Kort, D.A.

    2002-01-01

    For almost a century, steel sheet pile walls are applied worldwide as earth retaining structures for excavations and quay walls. Within the framework of the development of European structural codes for Civil Engineering works, the Eurocodes, Eurocode 3 Part 5 for design of steel sheet pile walls was

  15. Development of structural steels for nuclear application

    International Nuclear Information System (INIS)

    To established the bases of nuclear structural material technologies, this study was focused on the localization and improvement of nuclear structural steels, the production of material property data, and technology developments for integrity evaluation. The important test and analysis technologies for material integrity assessment were developed, and the materials properties of the pressure vessel steels were evaluated systematically on the basis of those technologies, they are microstructural characteristics, tensile and indentation deformation properties, impact properties, and static and dynamic fracture toughness, fatigue and corrosion fatigue etc. Irradiation tests in the research reactors were prepared or completed to obtain the mechanical properties of irradiated materials. The improvement of low alloy steel was also attempted through the comparative study on the manufacturing processes, computer assisted alloy and process design, and application of the inter critical heat treatment. On the other hand, type 304 stainless steels for reactor internals were developed and tested successfully. High strength type 316LN stainless steels for reactor internals were developed and the microstructural characteristics, corrosion resistance, mechanical properties at high temperatures, low cycle fatigue property etc. were tested and analyzed in the view point of the effect of nitrogen. Type 347 stainless steels with high corrosion resistance and toughness for pipings and tubes and low-activated Cr-Mn steels were also developed and their basic properties were evaluated. Finally, the martensitic stainless steels for turbine blade were developed and tests. (author). 242 refs., 100 tabs., 304 figs

  16. Behaviour of high strength steel moment joints

    NARCIS (Netherlands)

    Girão Coelho, A.M.; Bijlaard, F.S.K.

    2010-01-01

    The design of joints to European standard EN 1993 within the semi-continuous/partially restrained philosophy is restricted to steel grades up to S460. With the recent development of high performance steels, the need for these restrictions should be revisited. The semicontinuous joint modelling can b

  17. A survey on decentralized steel industries

    Directory of Open Access Journals (Sweden)

    Mostafa Jafari

    2011-01-01

    Full Text Available During the past three decades there have been tremendous efforts on building steel factories on economic scales. The primary question is to find an economic scale for such plants which could also meet domestic demand. In this paper, we perform an empirical survey to find out whether building small steel factories are more suitable or setting up giant steel industries to meet regional demands. The results indicate that in many countries, building small steel plants based on the recent advances of technologies not only reduces the total cost of steel production but also it could significantly reduce the unnecessary transportation cost, providing cheaper labor, etc. This would lead to better competition which would increase the productivity.

  18. Corrosion of steels in sour gas environments

    International Nuclear Information System (INIS)

    This report presents a study on the effects of sour gas environments on steels. Emphasis is placed on alloys commonly used in the heavy water, sour gas and refining industries. In addition, 'high strength, low alloy' steels, known as 'oil country tubular goods', are included. Reference is made to the effects of hydrogen sulphide environments on austenitic steels and on certain specialty steels. Theories of hydrogen-related cracking mechanisms are outlined with emphasis placed on sulphide stress cracking and hydrogen induced cracking in carbon and low alloy steels. Methods of controlling sulphide stress cracking and hydrogen induced cracking are addressed separately. Case histories from the heavy water, refining, and sour gas industries are used to illustrate operating experience and failure mechanisms. Finally, recommendations, based largely on the author's industrial experience, are made with respect to quality assurance and inspection requirements for sour service components. Only published literature was surveyed. Abstracts were made of all references, reviewing the major sources in detail

  19. Design and Preparation of Steel Slag SMA

    Institute of Scientific and Technical Information of China (English)

    WU Shao-peng; YANG Wen-feng; XUE Yong-jie; LIN Zhen-hua

    2003-01-01

    On the basis of the characteristics of high rigidity and excellent friction resistance,a new kind of steel slag SMA (stone matrix asphalt) concrete was designed and prepared.The main processes include aggregate gradation,performance analysis of steel slag before and after aging,preparation methods and properties test of steel slag SMA.The experimental results indicate that the index of steel slag's activation is less than 1 percent,the dynamic stability is 5699 times/mm,and both the residual stability and ratio of frozen splitting strength are more than 80 percent;the friction factor and structure depth are 67.1% and 0.7mm respectively.These results show the steel slag SMA is superior to the common asphalt concrete and SMA that uses common aggregate.

  20. Hydrogen embrittlement in power plant steels

    Indian Academy of Sciences (India)

    R K Dayal; N Parvathavarthini

    2003-06-01

    In power plants, several major components such as steam generator tubes, boilers, steam/water pipe lines, water box of condensers and the other auxiliary components like bolts, nuts, screws fasteners and supporting assemblies are commonly fabricated from plain carbon steels, as well as low and high alloy steels. These components often fail catastrophically due to hydrogen embrittlement. A brief overview of our current understanding of the phenomenon of such hydrogen damage in steels is presented in this paper. Case histories of failures of steel components due to hydrogen embrittlement, which are reported in literature, are briefly discussed. A phenomenological assessment of overall process of hydrogen embrittlement and classification of the various damage modes are summarized. Influence of several physical and metallurgical variables on the susceptibility of steels to hydrogen embrittlement, mechanisms of hydrogen embrittlement and current approaches to combat this problem are also presented.

  1. Austenitic stainless steels with cryogenic resistance

    International Nuclear Information System (INIS)

    The most used austenitic stainless steels are alloyed with chromium and nickel and have a reduced carbon content, usually lower than 0.1 % what ensures corresponding properties for processing by plastic deformation at welding, corrosion resistance in aggressive environment and toughness at low temperatures. Steels of this kind alloyed with manganese are also used to reduce the nickel content. By alloying with manganese which is a gammageneous element one ensures the stability of austenites. Being cheaper these steels may be used extensively for components and equipment used in cryogenics field. The best results were obtained with steels of second group, AMnNi, in which the designed chemical composition was achieved, i.e. the partial replacement of nickel by manganese ensured the toughness at cryogenic temperatures. If these steels are supplementary alloyed, their strength properties may increase to the detriment of plasticity and toughness, although the cryogenic character is preserved

  2. Aerosol filtration with steel fiber filters

    Science.gov (United States)

    Bergman, W.; Wilson, K.; Larsen, G.; Lopez, R.

    1993-04-01

    An experimental study has been conducted of aerosol penetration through a new high efficiency steel fiber filter and filter media that was developed in cooperation with Pall Corporation. Previous studies have shown that sintered steel fiber media have significant improvements in higher filter efficiency and lower pressure drop than the previous steel filter technology based on sintered powder metal media. In the present study, measurements were made of the penetration of dioctyl sebacate (DOS) aerosols through flat sheet samples, pleated cartridge filters, and a 1000 cfm filter having 64 cartridges housed in a 2 x 2 x 1 ft. frame. The steel fiber media used in our study consists of 2 micron diameter stainless steel (316 L) fibers sintered together into sheets.

  3. Interaction between stainless steel and plutonium metal

    Energy Technology Data Exchange (ETDEWEB)

    Dunwoody, John T [Los Alamos National Laboratory; Mason, Richard E [Los Alamos National Laboratory; Freibert, Franz J [Los Alamos National Laboratory; Willson, Stephen P [Los Alamos National Laboratory; Veirs, Douglas K [Los Alamos National Laboratory; Worl, Laura A [Los Alamos National Laboratory; Archuleta, Alonso [Los Alamos National Laboratory; Conger, Donald J [Los Alamos National Laboratory

    2010-01-01

    Long-term storage of excess plutonium is of great concern in the U.S. as well as abroad. The current accepted configuration involves intimate contact between the stored material and an iron-bearing container such as stainless steel. While many safety scenario studies have been conducted and used in the acceptance of stainless steel containers, little information is available on the physical interaction at elevated temperatures between certain forms of stored material and the container itself. The bulk of the safety studies has focused on the ability of a package to keep the primary stainless steel containment below the plutonium-iron eutectic temperature of approximately 410 C. However, the interactions of plutonium metal with stainless steel have been of continuing interest. This paper reports on a scoping study investigating the interaction between stainless steel and plutonium metal in a pseudo diffusion couple at temperatures above the eutectic melt-point.

  4. An understanding of HSLA-65 plate steels

    Science.gov (United States)

    Sampath, K.

    2006-02-01

    HSLA-65 plate steels can be produced using one of five plate manufacturing techniques: normalizing, controlled rolling (CR), controlled rolling followed by accelerated cooling (CR-AC), direct quenching and tempering (DQT), or conventional quenching and tempering (Q&T). The HSLA-65 steels are characterized by low carbon content and low alloy content, and they exhibit a low carbon equivalent that allows improved plate weldability. These characteristics in turn (a) provide the steel plate with a refined microstructure that ensures high strength and toughness; (b) eliminate or substantially reduce the need for preheating during welding; (c) resist susceptibility to hydrogen-assisted cracking (HAC) in the weld heat affected zone (HAZ) when fusion (arc) welded using low heat-input conditions; and (d) depending on section thickness, facilitate high heat-input welding (about 2 kJ/mm) without significant loss of strength or toughness in the HAZ. However, application of this plate manufacturing process and of these controls produces significant differences in the metallurgical structure and range of mechanical properties of the HSLA-65 plate steels both among themselves and versus conventional higher strength steel (HSS) plates. For example, among the HSLA-65 plate steels, those produced by Q&T exhibit minimal variability in mechanical properties, especially in thicker plates. Besides variability in mechanical properties depending on plate thickness, the CR and CR-AC plate steels exhibit a relatively higher yield strength to ultimate tensile strength (YS/UTS) ratio than do DQT and Q&T steels. Such differences in processing and properties of HSLA-65 plate steels could potentially affect the selection and control of various secondary fabrication practices, including arc welding. Consequently, fabricators must exercise extreme caution when transferring allowable limits of certified secondary fabrication practices from one type of HSLA-65 plate steel to another, even for the

  5. Graphitization in CK 45 Steel

    Institute of Scientific and Technical Information of China (English)

    A.R.Kiani-Rashid

    2009-01-01

    The purpose of this study was to determine the influence of heat treatment cycle on graphite phase formation on CK 45 steel. The presence of well distributed graphite in the matrix is responsible for the good mechanical and thermal properties of this kind of alloy. Such properties include excellent wear resistance, higher resistance to thermal shock, and higher resistance to oxidation at high temperature. A number of specimens were made up of appropriate design to provide the experimental materials. The transformation phase to a free carbon microstructure during graphitization under different conditions was then examined for the most successful experimental steels. Austenitising temperature of 920℃ ahd the following isothermal heat treatment of 750℃ at different holding times were used. Microstructures were examined by OM (optical microscopy) and SEM (scanning electron microscopy). Furthermore, it was found that isothermal transformation at 750℃for different soaking times produced a typical microstructure. Also, the amount of graphite increased with increasing isothermal heat treatment time. Heat treatment leading to supersaturation of iron with carbon was described and some of the consequences of the supersaturation were presented. Finally, the formation of the thermodynamically stable state of the graphite taken from the supersaturated solid solution was discussed.

  6. Atmospheric corrosion of mild steel

    Directory of Open Access Journals (Sweden)

    Morcillo, M.

    2011-10-01

    Full Text Available The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a the morphology of steel corrosion products and corrosion product layers; and b long-term atmospheric corrosion ( > 10 years.

    La corrosión atmosférica del acero suave es un tema de gran amplitud que ha sido tratado por muchos autores en numerosas regiones del mundo. Este artículo de compilación incorpora publicaciones relevantes sobre esta temática, en particular sobre la naturaleza de los productos de corrosión atmosférica, mecanismos y cinética de los procesos de corrosión atmosférica, prestando una atención especial a dos aspectos sobre los que la información publicada ha sido menos abundante: a morfología de los productos de corrosión del acero y capas de productos de corrosión, y b corrosión atmosférica a larga duración (> 10 años.

  7. Automated Steel Cleanliness Analysis Tool (ASCAT)

    International Nuclear Information System (INIS)

    The objective of this study was to develop the Automated Steel Cleanliness Analysis Tool (ASCATTM) to permit steelmakers to evaluate the quality of the steel through the analysis of individual inclusions. By characterizing individual inclusions, determinations can be made as to the cleanliness of the steel. Understanding the complicating effects of inclusions in the steelmaking process and on the resulting properties of steel allows the steel producer to increase throughput, better control the process, reduce remelts, and improve the quality of the product. The ASCAT (Figure 1) is a steel-smart inclusion analysis tool developed around a customized next-generation computer controlled scanning electron microscopy (NG-CCSEM) hardware platform that permits acquisition of inclusion size and composition data at a rate never before possible in SEM-based instruments. With built-in customized ''intelligent'' software, the inclusion data is automatically sorted into clusters representing different inclusion types to define the characteristics of a particular heat (Figure 2). The ASCAT represents an innovative new tool for the collection of statistically meaningful data on inclusions, and provides a means of understanding the complicated effects of inclusions in the steel making process and on the resulting properties of steel. Research conducted by RJLG with AISI (American Iron and Steel Institute) and SMA (Steel Manufactures of America) members indicates that the ASCAT has application in high-grade bar, sheet, plate, tin products, pipes, SBQ, tire cord, welding rod, and specialty steels and alloys where control of inclusions, whether natural or engineered, are crucial to their specification for a given end-use. Example applications include castability of calcium treated steel; interstitial free (IF) degasser grade slag conditioning practice; tundish clogging and erosion minimization; degasser circulation and optimization; quality assessment/steel cleanliness; slab, billet

  8. Automated Steel Cleanliness Analysis Tool (ASCAT)

    Energy Technology Data Exchange (ETDEWEB)

    Gary Casuccio (RJ Lee Group); Michael Potter (RJ Lee Group); Fred Schwerer (RJ Lee Group); Dr. Richard J. Fruehan (Carnegie Mellon University); Dr. Scott Story (US Steel)

    2005-12-30

    The objective of this study was to develop the Automated Steel Cleanliness Analysis Tool (ASCATTM) to permit steelmakers to evaluate the quality of the steel through the analysis of individual inclusions. By characterizing individual inclusions, determinations can be made as to the cleanliness of the steel. Understanding the complicating effects of inclusions in the steelmaking process and on the resulting properties of steel allows the steel producer to increase throughput, better control the process, reduce remelts, and improve the quality of the product. The ASCAT (Figure 1) is a steel-smart inclusion analysis tool developed around a customized next-generation computer controlled scanning electron microscopy (NG-CCSEM) hardware platform that permits acquisition of inclusion size and composition data at a rate never before possible in SEM-based instruments. With built-in customized ''intelligent'' software, the inclusion data is automatically sorted into clusters representing different inclusion types to define the characteristics of a particular heat (Figure 2). The ASCAT represents an innovative new tool for the collection of statistically meaningful data on inclusions, and provides a means of understanding the complicated effects of inclusions in the steel making process and on the resulting properties of steel. Research conducted by RJLG with AISI (American Iron and Steel Institute) and SMA (Steel Manufactures of America) members indicates that the ASCAT has application in high-grade bar, sheet, plate, tin products, pipes, SBQ, tire cord, welding rod, and specialty steels and alloys where control of inclusions, whether natural or engineered, are crucial to their specification for a given end-use. Example applications include castability of calcium treated steel; interstitial free (IF) degasser grade slag conditioning practice; tundish clogging and erosion minimization; degasser circulation and optimization; quality assessment/steel

  9. 29 CFR 1926.757 - Open web steel joists.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Open web steel joists. 1926.757 Section 1926.757 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.757 Open web steel joists. (a) General. (1) Except as provided in paragraph (a)(2) of this section, where steel joists are...

  10. A Survey of Mathematical Programming Applications in Integrated Steel Plants

    OpenAIRE

    Goutam Dutta; Robert Fourer

    2001-01-01

    Mathematical programming techniques were used in the steel industry as early as 1958, and many applications of optimization in steel production have been reported since then. In this survey, we summarize published applications in the largest steel plants by type, including national steel planning, product-mix optimization, blending, scheduling, set covering, and cutting stock.

  11. Duplex stainless steels for osteosynthesis devices.

    Science.gov (United States)

    Cigada, A; Rondelli, G; Vicentini, B; Giacomazzi, M; Roos, A

    1989-09-01

    The austenitic stainless steels used today for the manufacture of osteosynthesis devices are sensitive to crevice corrosion. In this study the corrosion properties of some duplex stainless steels were evaluated and compared to traditional austenitic stainless steels. According to our results the following ranking was established: 23Cr-4Ni less than AISI 316L less than ASTM F138 less than 22Cr-5Ni-3Mo less than 27Cr-31Ni-3.5Mo less than 25Cr-7Ni-4Mo-N. In particular the results showed that the high-performance 25Cr-7Ni-4Mo-N duplex stainless steel, with high molybdenum and nitrogen contents, can be considered not susceptible to crevice corrosion in the human body. The duplex stainless steels have also better mechanical properties at the same degree of cold working compared with austenitic stainless steels. Hence the 25Cr-7Ni-4Mo-N duplex stainless steel can be considered a convenient substitute of ASTM F138 for orthopedic and osteosynthesis devices. PMID:2777835

  12. Preparation of precursor for stainless steel foam

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xiang-yang; LI Shan-ni; LI Jie; LIU Ye-xiang

    2008-01-01

    The effects of polyurethane sponge pretreatment and slurry compositions on the slurry loading in precursor were discussed, and the,performances of stainless steel foams prepared from precursors with different slurry loadings and different particle sizes of the stainless steel powder were also investigated. The experimental results show that the pretreatment of sponge with alkaline solution is effective to reduce the jam of cells in precursor and ensure the slurry to uniformly distribute in sponge, and it is also an effective method for increasing the slurry loading in precursor; the mass fraction of additive A and solid content in slurry greatly affect the slurry loading in precursor, when they are kept in 9%-13% and 52%-75%, respectively, the stainless steel foam may hold excellent 3D open-cell network structure and uniform muscles; the particle size of the stainless steel powder and the slurry loading in precursor have great effects on the bending strength, apparent density and open porosity of stainless steel foam; when the stainless steel powder with particle size of 44 tan and slurry loading of 0.5 g/cm3 in precursor are used, a stainless steel foam can be obtained, which has open porosity of 81.2%, bending strength of about 51.76 MPa and apparent density of about 1.0 g/cm3.

  13. The heat treatment of Fermanal cast steel

    Directory of Open Access Journals (Sweden)

    F. Binczyk

    2007-12-01

    Full Text Available The study discloses the results of microstructural examinations, testing of magnetic properties and hardness measurements as cast and after heat treatment conducted on the Fermanal cast steel. A characteristic feature of this cast steel is its density lower by about 10% than the density of carbon cast steel [4]. It has been proved that the factor deciding about the composition of microstructure (fraction of ferrite and austenite is the content of aluminium. The matrix totally austenitic is present in cast steel containing from 0,8 to 0,9% C, from 22 to 24% Mn, and from 4,5 to 5,5% Al. The magnetic properties examined on samples of the Fermanal cast steel were determined by spectroscopy of the Mössbauer effect with isotope 57Fe. The magnetic properties represented by a mean value of the hyperfine magnetic field Bhf and relative magnetic permeability were determined. It has been stated that the level of magnetic properties of the Fermanal cast steel depends on the content of ferrite. The effect of the parameters of solutioning and ageing on the cast steel microstructure and hardness after modification with additions of B, Ti and Nb was investigated.

  14. Hydrogen degradation of high-strength steels

    Directory of Open Access Journals (Sweden)

    J. Ćwiek

    2009-12-01

    Full Text Available Purpose: of this paper is to evaluate susceptibility of high-strength steels and welded joints to hydrogen degradation and to establish applicable mechanism of their hydrogen embrittlement and hydrogen delayed cracking.Design/methodology/approach: High-strength quenched and tempered steel grade S690Q and its welded joints have been used. Structural low-alloy steel 34CrAlNi7-10 with various plasma nitrided layers was evaluated. Susceptibility to hydrogen embrittlement of steel, welded joints, and nitrided layers was evaluated using monotonically increasing load. Slow strain rate test (SSRT was carried out in hydrogen generating environments. Susceptibility to hydrogen delayed cracking was evaluated under constant load in artificial sea water. Fractographic examinations with the use of a scanning electron microscope (SEM were performed to establish suitable mechanism of hydrogen-enhanced cracking.Findings: Tested high-strength steel and its welded joints are susceptible to hydrogen embrittlement when evaluated with the use of SSRT. The loss of plasticity is higher for welded joints then for the base metal. Tested steel and welded joints reveal high resistance to hydrogen degradation under constant load. Plasma nitrided layers are effective barriers for hydrogen entry into structural steel.Research limitations/implications: There has been no possibility to perform direct observations of exact mechanism of hydrogen-assisted cracking so far. Further research should be taken to reveal the exact mechanism of increased plasticity of a nitrided layer with absorbed hydrogen.Practical implications: Tested steel and its welded joints could be safely utilized within elastic range of stress in hydrogen generating environments, and constructions under cathodic protection provided that overprotection does not take place.Originality/value: Hydrogen-Enhanced Localized Plasticity (HELP model is a more applicable mechanism of hydrogen degradation than the others

  15. Recycling galvanized steel: Operating experience and benefits

    Energy Technology Data Exchange (ETDEWEB)

    Dudek, F.J.; Daniels, E.J. [Argonne National Lab., IL (United States); Morgan, W.A. [Metal Recovery Industries, Inc., East Chicago, IN (United States)

    1993-08-01

    In response to the increase in consumption of galvanized steel for automobiles in the last decade and the problems associated with remelting larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is recovered electrolytically as dendritic powder. The dezinced ferrous scrap is rinsed and used directly. The process is effective for zinc, lead, and aluminum removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 900 tonnes of mostly baled scrap. A pilot plant to continuously treat loose scrap, with a design capacity of 48,000 tonnes annually, has been in operation in East Chicago, Indiana since early in 1993. The first 450 t of scrap degalvanized in the pilot plant have residual zinc below 0.01% and sodium dragout below 0.01%. Use of degalvanized steel scrap decreases raw materials, environmental compliance, and opportunity costs to steel- and iron-makers. Availability of clean degalvanized scrap may enable integrated steel producers to recycle furnace dusts to the sinter plant and EAF shops to produce flat products without use of high quality scrap alternatives such as DRI, pig iron, or iron carbide. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap. The quantities of zinc available by the year 2000 from prompt and obsolete automotive scrap win approach 25% of zinc consumed in the major automotive production centers of the world. Zinc recycling from galvanized steel scrap, either before or after scrap melting, will have to be implemented.

  16. Comparative studies of HEPA filter leak test with a photometer and a particle counter%光度计与计数器测试方法在高效过滤器检漏测试中的对比研究

    Institute of Scientific and Technical Information of China (English)

    高龙; 冯昕

    2015-01-01

    HEPA filter leak test methods can be divided into photometer method and optical particle counter method.Due to different measurement principles,professionals think there exist different leak test results about this two methods.Obtains the test results for local filtration efficiency of HEPA filter with this two methods by test.For the same leak point,the local penetration test results are almost the same,no matter whether a photometer or a optical particle counter is used.Analyses the reasons for deviation.%高效空气过滤器扫描检漏方法分为光度计法和粒子计数器法。由于测试原理不同,专业人员一直认为两种测试方法对于泄漏的判断存在差异。通过试验得到了两种测试方法对高效过滤器局部过滤效率的检测结果:对于相同漏点,用两种方法测试得到的局部过滤效率基本一致。分析了测试结果偏差产生的原因。

  17. 76 FR 15299 - Certain Hot-Rolled Carbon Steel Flat Products From India: Preliminary Rescission of...

    Science.gov (United States)

    2011-03-21

    ...), or both, added to stabilize carbon and nitrogen elements. HSLA steels are recognized as steels with...) steels, and the substrate for motor lamination steels. IF steels are recognized as low carbon steels with... FR 74682 (December 1, 2010). On January 3, 2011, we received from United States Steel Corporation,...

  18. Resistance Spot Welding of dissimilar Steels

    OpenAIRE

    Ladislav Kolařík; Miroslav Sahul; Marie Kolaříková; Martin Sahul; Milan Turňa; Michal Felix

    2012-01-01

    This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA). Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to e...

  19. Resistance Spot Welding of dissimilar Steels

    Directory of Open Access Journals (Sweden)

    Ladislav Kolařík

    2012-01-01

    Full Text Available This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA. Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to evaluate the quality of the resistance spot welds. The results confirm the applicability of DeltaSpot welding for this combination of materials.

  20. Dynamic characteristics of automotive steel sheets

    Directory of Open Access Journals (Sweden)

    M. Mihaliková

    2016-10-01

    Full Text Available The aim of this experimental research was to perform an analysis of deformation characteristics on two different types of steel: IF steel, and micro-alloyed steel were used automotive industry. For that purpose changes of properties of these materials were carried out by static 10-3 · s-1 and dynamic 103 · s-1 strain rate assess its plastic properties. Vickers micro hardness test was carried out by the static and dynamic loading condition and describes different hardness distribution. The higher strain hardening of materials was obtained too that was confirmed by distribution of dislocations.

  1. Radiation-induced sensitisation of stainless steels

    International Nuclear Information System (INIS)

    The book contains the proceedings of a symposium on radiation-induced sensitization of stainless steels, which took place at Berkeley, United Kingdom, 1986. The purpose of the symposium was to examine the mechanism leading to inter-granular corrosion of 20%Cr/25% Ni/Nb stainless steel cladding of AGR fuel following irradiation. Nine papers are presented, of which three are theoretical, two papers are based upon corrosion studies of 20%Cr/25%Ni/Nb steel, and the remaining are concerned with compositional redistribution and its measurement. (U.K.)

  2. Recycle of radiologically contaminated austenitic stainless steels

    International Nuclear Information System (INIS)

    The United States Department of Energy owns large quantities of radiologically contaminated austenitic stainless steel which could by recycled for reuse if appropriate release standards were in place. Unfortunately, current policy places the formulation of a release standard for USA industry years, if not decades, away. The Westinghouse Savannah River Company, Idaho National Engineering Laboratory and various university and industrial partners are participating in initiative to recycle previously contaminated austenitic stainless steels into containers for the storage and disposal of radioactive wastes. This paper describes laboratory scale experiments which demonstrated the decontamination and remelt of stainless steel which had been contaminated with radionuclides

  3. Titanium Content Control for Bearing Steel

    Institute of Scientific and Technical Information of China (English)

    WU Wei; LIU Yue; LIU Liu; XUE Zheng-liang

    2008-01-01

    On the basis of the thermodynamic analysis and fundamental study in the laboratory,the equilibrium of the Ti-Al-O system was investigated.The results showed that the equilibrium titanium content in the steel increased with the increase in the soluble aluminum content in the steel and the TiO2 content in the slag.Although the slag basicity decreased and Al2O3 content in the slag increased,the titanium content increased.Based on these results,the BOF smelting process of low titanium bearing steel was put forward.

  4. Quenching simulation of steel grinding balls

    Energy Technology Data Exchange (ETDEWEB)

    Zapata-Hernandez, O.; Reyes, L. A.; Camurri, C.; Carrasco, C.; Garza-Monte-de-Oca, F.; Colas, R.

    2015-07-01

    The phase transformations of high carbon steel during quenching and equalizing were modelled using commercial computer packages based on the finite element method and the kinetic transformation of steel. The model was used to predict the temperature and microstructural changes taking place within balls of two different sizes that are used for grinding mineral ores. A good correlation between the temperatures measured by inserted thermocouples and those predicted by the model was obtained after modifying the thermal conductivity of the steel within the temperature domain at which mixed phases are present. The phase transformations predicted were confirmed by metallographic analyses. (Author)

  5. Tribocorrosion wear of austenitic and martensitic steels

    Directory of Open Access Journals (Sweden)

    G. Rozing

    2016-07-01

    Full Text Available This paper explores the impact of tribocorrosion wear caused by an aggressive acidic media. Tests were conducted on samples made of stainless steel AISI 316L, 304L and 440C. Austenitic steels were tested in their nitrided state and martensitic in quenched and tempered and then induction hardened state. Electrochemical corrosion resistance testing and analysis of the microstructure and hardness in the cross section was carried out on samples of selected steels. To test the possibility of applying surface modification of selected materials in conditions of use, tests were conducted on samples/parts in a worm press for final pressing.

  6. The optical metallography of some maraging steels

    International Nuclear Information System (INIS)

    The structural features of maraging steels, including those that impose limitations on strength and toughness, are briefly reviewed. Phase relationships in the iron-nickel matrix system are introduced which, in conjunction with alloy composition and heat treatment, allow the interpretation of microstructure. Details are presented of methods for revealing the microstructure of maraging steels; the prior austenite grain size following a variety of heat treatments is of special interest since excessive grain size can lead to poor ductility. These methods are illustrated with micrographs of the microstructures of MAR 350 and MAR 400 steels in the cast, solution-treated, aged and cold-worked states

  7. The stretch zone of automotive steel sheets

    Indian Academy of Sciences (India)

    Ľ Ambriško; L Pešek

    2014-04-01

    The paper deals with an experimental determination of the stretch zone dimensions in the notch tip in thin steel sheets. The stretch zone dimensions depend on steel grade, on the rolling direction as well as on the loading rate. Stretch zones were observed and measured on three steel grades. Fracture area and stretch zones were analysed by SEM. Stable crack growth was monitored by videoextensometry techniques on CT (Compact Tension) specimens. Specimens were loaded under two loading rates by eccentric tension, whereby the deformation in the notch surrounding area was recorded using a non-contact measurement–videoextensometry technique. Linear relation between the stretch zone dimensions was determined.

  8. Niobium in steels and alloys

    International Nuclear Information System (INIS)

    Data are presented on the reserves and processing of niobium raw materials followed by brief review of the current status and long-range trends in the commercial usage of niobium and its compounds. A survey is made of the physical properties of niobium and its chemical reactions with elements of direct concern in the manufacture of ferroalloys, quality steels and other products. Niobium minerals and ores, along with common ore processing practices are described briefly. Attention is paid to Brazilian niobium ores, and to the Araxa deposit specifically. Some emphasis has been given to methods of processing lean niobium ores not easily amenable to simple concentration. A systematic review is presented of the techniques used in the production of niobium ferroalloys. (E.G.)

  9. CHARACTERIZATION OF NEW TOOL STEEL FOR ALUMINUM EXTRUSION DIES

    OpenAIRE

    José Britti Bacalhau; Fernanda Moreno Rodrigues; Rafael Agnelli Mesquita

    2014-01-01

    Aluminum extrusion dies are an important segment of application on industrial tools steels, which are manufactured in steels based on AISI H13 steel. The main properties of steels applied to extrusion dies are: wear resistance, impact resistance and tempering resistance. The present work discusses the characteristics of a newly developed hot work steel to be used on aluminum extrusion dies. The effects of Cr and Mo contents with respect to tempering resistance and the Al addition ...

  10. Experience with ferrosilicoaluminum alloy during deoxidation of steel

    OpenAIRE

    Mekhtiyev, A.; Akhmetov, A.; V. Yudakova; Bulatbayev, F.

    2016-01-01

    The article describes the process of deoxidation quiet and low-alloyed steel alloy ferrosilicoaluminum complex in comparison the existing, and with steel deoxidation technology with conventional alloys - ferrosilicon and secondary aluminum. A comparative analysis of quality steel, non-metallic inclusions metallographic studies and studies of the mechanical properties of the resulting steel was done. On a large array of experimental steel proved cost-effectiveness and feasibility of ferrosilic...

  11. Do steel prices move together? : a cointegration test

    OpenAIRE

    Qian, Ying

    1990-01-01

    Lack of international comparability in crude steel prices presents a problem in constructing an econometric model of the global steel market. The commonly used measures of crude steel prices are the weighted average of the prices of steel products and the index of the weighted average of prices based on a certain year. But in the context of constructing an econometric model of the global steel market, these measures are not comparable internationally. If the various product prices are cointeg...

  12. Project B: Improved Liquid Steel Feed For Slab Casters

    Energy Technology Data Exchange (ETDEWEB)

    Brent S. Isaacson; Mike Slepian; Thomas Richter

    1998-10-01

    This report describes the completion of the development of an electromagnetic valve to control liquid steel flow for improved liquid steel feeding for slab casters. Achievements result from a joint research effort between Westinghouse Science and Technology Center, North American Refractories and U.S. Steel. This effort is part of the American Iron and Steel Institute's (AISI) Advanced Process Control Program, a collaboration between the U.S. Department of Energy (DOE) and fifteen North American steel makers.

  13. Review on research and application of stainless steel reinforced concrete

    OpenAIRE

    Gu Li; Meng Xian Hong

    2016-01-01

    For ordinary reinforced under corrosion environment corrosion problems and analysis the main factors affecting ordinary steel corrosion, proposed stainless steel bar rust and corrosion resistance advantages, introduce the related properties of the stainless steel reinforced, combined with the research status of domestic and international stainless steel bar, put forward the research and engineering application of stainless steel rebar for the related problems and direction, the prospects and ...

  14. Microstructural characterization in dissimilar friction stir welding between 304 stainless steel and st37 steel

    Energy Technology Data Exchange (ETDEWEB)

    Jafarzadegan, M. [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Feng, A.H. [State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Abdollah-zadeh, A., E-mail: zadeh@modares.ac.ir [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); Saeid, T. [Advanced Materials Research Center, Sahand University of Technology, P.O. Box: 51335-1996, Tabriz (Iran, Islamic Republic of); Shen, J. [State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Assadi, H. [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of)

    2012-12-15

    In the present study, 3 mm-thick plates of 304 stainless steel and st37 steel were welded together by friction stir welding at a welding speed of 50 mm/min and tool rotational speed of 400 and 800 rpm. X-ray diffraction test was carried out to study the phases which might be formed in the welds. Metallographic examinations, and tensile and microhardness tests were used to analyze the microstructure and mechanical properties of the joint. Four different zones were found in the weld area except the base metals. In the stir zone of the 304 stainless steel, a refined grain structure with some features of dynamic recrystallization was evidenced. A thermomechanically-affected zone was characterized on the 304 steel side with features of dynamic recovery. In the other side of the stir zone, the hot deformation of the st37 steel in the austenite region produced small austenite grains and these grains transformed to fine ferrite and pearlite and some products of displacive transformations such as Widmanstatten ferrite and martensite by cooling the material after friction stir welding. The heat-affected zone in the st37 steel side showed partially and fully refined microstructures like fusion welding processes. The recrystallization in the 304 steel and the transformations in the st37 steel enhanced the hardness of the weld area and therefore, improved the tensile properties of the joint. - Highlights: Black-Right-Pointing-Pointer FSW produced sound welds between st37 low carbon steel and 304 stainless steel. Black-Right-Pointing-Pointer The SZ of the st37 steel contained some products of allotropic transformation. Black-Right-Pointing-Pointer The material in the SZ of the 304 steel showed features of dynamic recrystallization. Black-Right-Pointing-Pointer The finer microstructure in the SZ increased the hardness and tensile strength.

  15. THE STRUCTURAL ANALYSIS OF STEEL SILOS WITH CYLINDRICAL-WALL BEARING AND PROFILE-STEEL BEARING

    OpenAIRE

    Zhengjun Tang; Daibiao Zhou; Chenwei Peng; Wenping Wu

    2015-01-01

    The silos are widely used in bulk material in many fields such as agriculture, mining, chemical, electric power storage, etc. Thin metal cylindrical silo shells are vulnerable to buckling failure caused by the compressive wall friction force. In this paper, the structural analysis of two types of steel silo with cylindrical-wall bearing and profile-steel bearing is implemented by Abaqus finite element analysis. The results indicate that under the same loading conditions, steel silos with prof...

  16. FEM Simulation of Bending Formability for Laminate Steel/Resin/Steel Lightweight Composite Sheet

    Institute of Scientific and Technical Information of China (English)

    Guancheng Ll; Yonglin KANG

    2003-01-01

    The ANSYS simulation software was used to analyze the bending formability of laminate steel/resin/steel lightweight composite sheet. The skin steel at external side produces relative slipping-off change during the bending due to its composite structure. The internal stress strain states, materials effect tools parameters and intermediate layer resin of lightweight sheet on slipping-off change were analyzed. The spring back and shear stress state after bending have also been discussed.

  17. Hydrogen gas embrittlement of stainless steels mainly austenitic steels. Volumes 1 and 2

    International Nuclear Information System (INIS)

    Steel behavior in regard to hydrogen is examined especially austenitic steels. Gamma steels are studied particularly the series 300 with various stabilities and gamma steels with improved elasticity limit for intermetallic phase precipitation and nitrogen additions. A two-phase structure γ + α' is also studied. All the samples are tested for mechanical behavior in gaseous hydrogen. Influence of metallurgical effects and of testing conditions on hydrogen embrittlement are evidenced. Microstructure resulting from mechanical or heat treatments, dislocation motion during plastic deformation and influence of deformation rate are studied in detail

  18. Numerical Analysis of Composite Steel Concrete Structural Shear Walls with Steel Encased Profiles

    Directory of Open Access Journals (Sweden)

    Daniel Dan

    2009-01-01

    Full Text Available The use of common reinforced concrete shear walls in high rise buildings is sometimes limited because of the large amount of reinforcement localized at the end of the element. A good alternative in avoiding this disadvantage is to use composite steel concrete structural shear walls with steel encased profiles. This solution used for high rise buildings, offers to designers lateral stiffness, shear capacity and high bending resisting moment of structural walls. The encasement of the steel shapes in concrete is applied also for the following purposes: flexural stiffening and strengthening of compression elements; fire protection; potentially easier repairs after moderate damage; economy with respect both to material and construction. Until now in the national and international literature poor information about nonlinear behaviour of composite steel concrete structural shear walls with steel encased profiles is available. A theoretical and experimental program related to the behaviour of steel concrete structural shear walls with steel encased profiles is developed at “Politehnica” University of Timişoara. The program refers to six different elements, which differ by the shape of the steel encased profile and also by the arrangement of steel shapes on the cross section of the element. In order to calibrate the elements for experimental study some numerical analysis were made. The paper presents the results of numerical analysis with details of stress distribution, crack distribution, structural stiffness at various loads, and load bearing capacity of the elements.

  19. Lightweight Steel Solutions for Automotive Industry

    Science.gov (United States)

    Lee, Hong Woo; Kim, Gyosung; Park, Sung Ho

    2010-06-01

    Recently, improvement in fuel efficiency and safety has become the biggest issue in worldwide automotive industry. Although the regulation of environment and safety has been tightened up more and more, the majority of vehicle bodies are still manufactured from stamped steel components. This means that the optimized steel solutions enable to demonstrate its ability to reduce body weight with high crashworthiness performance instead of expensive light weight materials such as Al, Mg and composites. To provide the innovative steel solutions for automotive industry, POSCO has developed AHSS and its application technologies, which is directly connected to EVI activities. EVI is a technical cooperation program with customer covering all stages of new car project from design to mass production. Integrated light weight solutions through new forming technologies such as TWB, hydroforming and HPF are continuously developed and provided for EVI activities. This paper will discuss the detailed status of these technologies especially light weight steel solutions based on innovative technologies.

  20. Advances in the heat treatment of steels

    Energy Technology Data Exchange (ETDEWEB)

    Morris, J.W. Jr.; Kim, J.I.; Syn, C.K.

    1978-06-01

    A number of important recent advances in the processing of steels have resulted from the sophisticated uses of heat treatment to tailor the microstructure of the steels so that desirable properties are established. These new heat treatments often involve the tempering or annealing of the steel to accompish a partial or complete reversion from martensite to austenite. The influence of these reversion heat treatments on the product microstructure and its properties may be systematically discussed in terms of the heat treating temperature in relation to the phase diagram. From this perspective, four characteristic heat treatments are defined: (1) normal tempering, (2) inter-critical tempering, (3) intercritical annealing, and (4) austenite reversion. The reactions occurring during each of these treatments are described and the nature and properties of typical product microstructures discussed, with specific reference to new commercial or laboratory steels having useful and exceptional properties.

  1. The World's Largest Steel Casting Poured Successfully

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The world's largest steel casting -- the upper beam (or the top head) for free forging oil hydraulic press with a 18,000-ton force capacity, was poured successfully by CITIC Heavy Machinery Co., Ltd. (CITICHM) on May 22, 2008. This head piece is 11.95 meters long, 3.8 meters wide, 4.59 meters high and about 520 tons in gross weight. Pouring is the most important and critical step during its manufacturing process. The production of this huge casting requires about 830 tons of refined molten steel from 10 smelting furnaces and pouring with six ladles into the mold cavity at one time, which made it currently the world's largest steel casting poured and the most one-time molten steel organized.

  2. Fatigue in Steel Structures under Random Loading

    DEFF Research Database (Denmark)

    Agerskov, Henning

    1999-01-01

    Fatigue damage accumulation in steel structures under random loading is studied. The fatigue life of welded joints has been determined both experimentally and from a fracture mechanics analysis. In the experimental part of the investigation, fatigue test series have been carried through on various...... types of welded plate test specimens and full-scale offshore tubular joints. The materials that have been used are either conventional structural steel with a yield stress of ~ 360-410 MPa or high-strength steel with a yield stress of ~ 810-1010 MPa. The fatigue tests and the fracture mechanics analyses...... test results. Both the fracture mechanics analysis and the fatigue test results indicate that Miner's rule, which is normally used in the design against fatigue in steel structures, may give results, which are unconservative, and that the validity of the results obtained from Miner's rule will depend...

  3. Clean Cast Steel Technology, Phase IV

    Energy Technology Data Exchange (ETDEWEB)

    Charles E. Bates

    2003-02-24

    The objective of the Clean Cast Steel Technology Program was to improve casting product quality by removing or minimizing oxide defects and to allow the production of higher integrity castings for high speed machining lines. Previous research has concentrated on macro-inclusions that break, chip, or crack machine tool cutters and drills and cause immediate shutdown of the machining lines. The overall goal of the project is to reduce the amount of surface macro-inclusions and improve the machinability of steel castings. Macro-inclusions and improve the machinability of steel castings. Macro-inclusions have been identified by industrial sponsors as a major barrier to improving the quality and marketability of steel castings.

  4. Overview of Steel Slag Application and Utilization

    Directory of Open Access Journals (Sweden)

    Lim J.W.

    2016-01-01

    Full Text Available Significant quantities of steel slag are generated as waste material or byproduct every day from steel industries. Slag is produced from different types of furnaces with different operating conditions. Slag contains Ferrous Oxide, Calcium Oxide, Silica etc. Physical and chemical properties of slag are affected by different methods of slag solidification such as air cooled, steam, and injection of additives. Several material characterization methods, such as X-ray Diffraction (XRD, Scanned Electron Microscopy (SEM and Inductive Coupled Plasma (ICP-OES are used to determine elemental composition in the steel slag. Therefore, slags can become one of the promising materials in various applications such as in transportation industry, construction, cement production, waste water and water treatment. The various applications of steel slag indicate that it can be reused and utilized rather than being disposed to the landfill. This paper presents a review of its applications and utilization.

  5. Stainless Steel to Titanium Bimetallic Transitions

    Energy Technology Data Exchange (ETDEWEB)

    Kaluzny, J. A. [Fermilab; Grimm, C. [Fermilab; Passarelli, D. [Fermilab

    2015-01-01

    In order to use stainless steel piping in an LCLS-II (Linac Coherent Light Source Upgrade) cryomodule, stainless steel to titanium bimetallic transitions are needed to connect the stainless steel piping to the titanium cavity helium vessel. Explosion bonded stainless steel to titanium transition pieces and bimetallic transition material samples have been tested. A sample transition tube was subjected to tests and x-ray examinations between tests. Samples of the bonded joint material were impact and tensile tested at room temperature as well as liquid helium temperature. The joint has been used successfully in horizontal tests of LCLS-II cavity helium vessels and is planned to be used in LCLS-II cryomodules. Results of material sample and transition tube tests will be presented.

  6. Effect of ultrasonic oscillations on steel rolling

    International Nuclear Information System (INIS)

    The effect of radial ultrasonic oscillations on rolling has been studied. Plates and pipes made of the St3 and 08Kh18N10T steel were rolled at 20 and at 1200 deg C. Ultrasonic waves proved to reduce pressure on the rollers by 9-14%, this eventually leading to higher efficiency of rolling. Hot rolling involving ultrasonic treatment decreased the ultrimate strength and yield point of both steels by 5-10% and increased relative elongation on account of uniform contraction. Cold ultrasound-involving rolling decreased the ultimate strength and the yield point of the St3 steel, hardly affecting those of the 08Kh18N10T steel

  7. Corrosion behavior of sensitized duplex stainless steel.

    Science.gov (United States)

    Torres, F J; Panyayong, W; Rogers, W; Velasquez-Plata, D; Oshida, Y; Moore, B K

    1998-01-01

    The present work investigates the corrosion behavior of 2205 duplex stainless steel in 0.9% NaCl solution after various heat-treatments, and compares it to that of 316L austenitic stainless steel. Both stainless steels were heat-treated at 500, 650, and 800 degrees C in air for 1 h, followed by furnace cooling. Each heat-treated sample was examined for their microstructures and Vickers micro-hardness, and subjected to the X-ray diffraction for the phase identification. Using potentiostatic polarization method, each heat-treated sample was corrosion-tested in 37 degrees C 0.9% NaCl solution to estimate its corrosion rate. It was found that simulated sensitization showed an adverse influence on both steels, indicating that corrosion rates increased by increasing the sensitization temperatures. PMID:9713683

  8. Bitter Operation in Global Steel Industry

    Institute of Scientific and Technical Information of China (English)

    Wang Sujuan

    2009-01-01

    @@ Shrinking international demand Global economy started to decline from the second half of 2008. Along with weak real estate market and dull automobile sales, steel industry fell into stagnant operation after six-year-straight rapid development.

  9. Induction surface hardening of hard coated steels

    DEFF Research Database (Denmark)

    Pantleon, Karen; Kessler, Olaf; Hoffmann, Franz;

    1999-01-01

    . The effect of induction surface hardening on the properties of the coating-substrate-systems is mainly characterized using investigations of microstructure and chemical composition as well as measurements of hardness and residual stresses in dependence on the distance from the surface. Furthermore......The deposition of hard coatings with CVD-processes is commonly used to improve the wear resistance e.g. of tool steels in forming. The advantages of CVD are undisputed (high deposition rates with simple equipment, excellent coating properties). Nevertheless, the disadvantage of the CVD......-process is the high deposition temperature, consequently the properties of steel substrates are negatively influenced. Therefore, a subsequent heat treatment of the coated steels is necessary to restore the properties of steels ready for operation. Induction surface hardening is used as a method of heat treatment...

  10. Advances in the heat treatment of steels

    International Nuclear Information System (INIS)

    A number of important recent advances in the processing of steels have resulted from the sophisticated uses of heat treatment to tailor the microstructure of the steels so that desirable properties are established. These new heat treatments often involve the tempering or annealing of the steel to accompish a partial or complete reversion from martensite to austenite. The influence of these reversion heat treatments on the product microstructure and its properties may be systematically discussed in terms of the heat treating temperature in relation to the phase diagram. From this perspective, four characteristic heat treatments are defined: (1) normal tempering, (2) inter-critical tempering, (3) intercritical annealing, and (4) austenite reversion. The reactions occurring during each of these treatments are described and the nature and properties of typical product microstructures discussed, with specific reference to new commercial or laboratory steels having useful and exceptional properties

  11. Hydrogen compatibility handbook for stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Caskey, G.R. Jr.

    1983-06-01

    This handbook compiles data on the effects of hydrogen on the mechanical properties of stainless steels and discusses this data within the context of current understanding of hydrogen compatibility of metals. All of the tabulated data derives from continuing studies of hydrogen effects on materials that have been conducted at the Savannah River Laboratory over the past fifteen years. Supplementary data from other sources are included in the discussion. Austenitic, ferritic, martensitic, and precipitation hardenable stainless steels have been studied. Damage caused by helium generated from decay of tritium is a distinctive effect that occurs in addition to the hydrogen isotopes protium and deuterium. The handbook defines the scope of our current knowledge of hydrogen effects in stainless steels and serves as a guide to selection of stainless steels for service in hydrogen.

  12. Horizontal electron beam welding for stainless steels

    International Nuclear Information System (INIS)

    Stainless steel samples have been realized by local vacuum apparatus for electron beam welding applications to reactor core shell realizations. The best welding parameters have been determined by a systematic study. The welds have been characterized by mechanical tests

  13. Localized Corrosion of Chromium Coated Steel

    NARCIS (Netherlands)

    Zhang, X.; Beentjes, P.; Mol, A.; Terryn, H.

    2006-01-01

    In this paper, we report on the studies of the local corrosion behaviour of chromium-coated ultra low carbon steel in NaCl solution using polarization, electrochemical impedance spectroscopy (EIS) and SVET.

  14. Modification of Slenderness Coefficient of Angle Steels

    Institute of Scientific and Technical Information of China (English)

    刘红燕; 李志业

    2004-01-01

    To provide information for amendment to Technical Specifications for Power Transmission Towers (SDGJ94-90), the critical loads of typical compressed angle steels was calculated. The correlation of buckling loads and slenderness of compressed angle steels was obtained with regression. A new slenderness coefficient equation was proposed based on the result of the correlation. A practical measure to ensure good result in nonlinear solution using Arch-length method is put forward.

  15. Hot ductility of continuously cast structural steels

    Energy Technology Data Exchange (ETDEWEB)

    Pytel, S.M. [Materials Science and Technology Institute, Cracow University of Technology, Cracow (Poland)

    1995-12-31

    The objective of this investigation was to explain the hot ductility of the structural steels characterized by different amount of carbon and morphology of sulfides. Two different rolling processes were simulated under computer controlled, high temperature deformation MTS system. Results of this study show that morphology of sulfides as well as temperature and amount of deformation are responsible for level of hot ductility of the steel tested. (author). 7 refs, 5 refs, 4 tabs.

  16. Rapid solidification of candidate ferritic steels

    International Nuclear Information System (INIS)

    HT-9 and 9Cr-1Mo steels were rapidly solidified by the liquid dynamic compaction process and 2-1/4Cr-1Mo steel was prepared by the ultrasonic gas atomization process. The consolidation was performed in the ferritic temperature range in order to minimize segregation. These alloys will be tested at ORNL using 1/3 CVN test specimens and the results will be compared with those for conventially processed alloys

  17. Response of steel structures to fire actions

    OpenAIRE

    Čermelj, Blaž

    2008-01-01

    The degree represents procedure of fire analysis of steel buildings with advanced methods regarding Eurocode standards. Beside fire analyse of steel construction analyse of composite plate is also introduced. Introduction consists of basiscs, procedures and idea of fire analysis of buildings. Because entire work is based on advanced fire analysis, advanced fire models and advanced calculation models were used. Fire analysis of buildings with advanced methods describes behaviour of structure i...

  18. A Duplex Stainless Steel for Chloride Environments

    Science.gov (United States)

    Sridhar, N.; Kolts, J.; Flasche, L. H.

    1985-03-01

    This paper examines the effects of microstructural changes on the corrosion, stress corrosion cracking and corrosion fatigue resistance of a duplex stainless steel to chloride environments. The microstructural changes can be precipitation of phases such as sigma and carbides, or changes in the distribution of austenite and ferrite. The former can be important in hot forming operations while the latter is important in welding. The methods of minimizing these deleterious effects can sometimes be different from those used for austenitic stainless steel.

  19. Thermal treatment of dissimilar steels' welded joints

    Science.gov (United States)

    Nikulina, A. A.; Denisova, A. S.; Gradusov, I. N.; Ryabinkina, P. A.; Rushkovets, M. V.

    2016-04-01

    In this paper combinations of chrome-nickel steel and high-carbon steel, produced by flash butt welding after heat treatment, are investigated. Light and electron microscopic studies show that the welded joints after heat treatment have a complex structure consisting of several phases as initial welded joints. A martensite structure in welded joints after thermal treatment at 300... 800 °C has been found.

  20. Deformation and Recrystallisation in Low Carbon Steels

    OpenAIRE

    Almojil, Marwan

    2010-01-01

    The annealing behaviour, including studies of recrystallisation kinetics anddevelopment of crystallographic texture, of two low carbon steels after different coldrolling reductions have been investigated using Optical Microscopy (OM), ElectronBack-Scatter Diffraction (EBSD) and Transmission Electron Microscopy (TEM).The primary recrystallisation behaviour of 20, 50, 70 and 90% cold rolled InterstitialFree (IF) and High Strength Low Alloy (HSLA) steels was studied. The HSLA wasinitially proces...

  1. Stainless chromium-nickel steels. Chapter I

    International Nuclear Information System (INIS)

    The chemical composition is tabulated of 90 chromium-nickel stainless steels and alloys given in volume %. The values are also given of the corrosion resistance of the steels and alloys. The tables show data on the surface condition or the methods of material working, types and chemical composition of the medium where corrosion resistance tests were carried out, temperature, pressure, time of tests, corrosion rates, corrosion types, and literature references. A total of 35 references is given. (J.B.)

  2. Complex steel saturation with niobium and vanadium

    International Nuclear Information System (INIS)

    Studies on determining possibility of niobium and vanadium alloying with carbides were conducted. Possibility of simultaneous saturation of carbon steels with niobium and vanadium was established. Diffusion layers coated on surfaces of 45, U8A and U10A steels under different conditions. It is shown that increase of coating density by means of alloying favours the increase of its corrosion resistance in water and aqueous solutions of salt and soda 2 times, wear resistance -1.6-5 times

  3. Laser welding of advanced high strength steels

    OpenAIRE

    Ahmed, Essam Ahmed Ali

    2011-01-01

    This research work focuses on characterization of CO2 laser beam welding (LBW) of dual phase (DP) and transformation induced plasticity (TRIP) steel sheets based on experimental, numerical simulation and statistical modeling approaches. The experimental work aimed to investigate the welding induced-microstructures, hardness, tensile properties and formability limit of laser welding butt joints of DP/DP, TRIP/TRIP and DP/TRIP steel sheets under different welding speeds. The effects of shieldin...

  4. Hybrid Laser-Arc Welding Tanks Steels

    Science.gov (United States)

    Turichin, G.; Tsibulskiy, I.; Kuznetsov, M.; Akhmetov, A.; Klimova-Korsmik, O.

    2016-04-01

    The results investigate hybrid laser-arc welding of high strength steels using design responsible metallic construction and the highest strength body of vehicles. Welds from modern high strength steels grade Hardox 400, Hardox 450, Armox 600T and AB were created. High power fiber laser LS-15 with output 15 kW and arc rectifier VDU - 1500 DC were used in the experiment. Results of the metallographic research and mechanical tests are presented.

  5. Studies of stainless steel exposed to sandblasting

    OpenAIRE

    Horodek Paweł; Eseev Marat K.; Kobets Andrey G.

    2015-01-01

    The influence of sandblasting on surface and subsurface of stainless steel is investigated using variable energy positron beam (VEP), positron annihilation spectroscopy (PAS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Samples of stainless steel were blasted using 110 μm particles of Al2O3 under different pressure and time duration. In the case of sandblasting for 90 s, the reduction of positron diffusion length depending on the applied pressure was observed. Sandb...

  6. Marine atmospheric corrosion of carbon steels

    OpenAIRE

    Morcillo, Manuel; Alcántara, Jenifer; Díaz, Iván; Chico, Belén; Simancas, Joaquín; de la Fuente, Daniel

    2015-01-01

    Basic research on marine atmospheric corrosion of carbon steels is a relatively young scientific field and there continue to be great gaps in this area of knowledge. The presence of akaganeite in the corrosion products that form on steel when it is exposed to marine atmospheres leads to a notable increase in the corrosion rate. This work addresses the following issues: (a) environmental conditions necessary for akaganeite formation; (b) characterisation of akaganeite in the corrosion products...

  7. Mix design of steel fiber reinforced concrete

    OpenAIRE

    Moreno, E.; Fernández Cánovas, M.

    1997-01-01

    Mix design of steel fiber reinforced concrete (SFRC) is concerned with achieving a workability, homogeneity, durability and strength suitable for its use. Variables defining any mix design of SFRC are commented below, as well as their influence on some properties of fresh and hardened SFRC. A special attention is paid to concrete, since it's the main use of steel fibers in Spain now, followed by paving construction.

    El objetivo de una correcta dosificación de horm...

  8. Fracture toughness properties of duplex stainless steels

    OpenAIRE

    Sieurin, Henrik

    2006-01-01

    Good toughness properties in base and weld material enable the use of duplex stainless steels (DSS) in critical applications. DSS offer high strength compared to common austenitic stainless steels. The high strength can be utilized to reduce the wall thickness and accordingly accomplish reduction of cost, welding time and transportation weight, contributing to ecological and energy savings. Although DSS have been used successfully in many applications the last decades, the full utilisation in...

  9. Advanced Ultra high Strength Bainitic Steels

    OpenAIRE

    García Caballero, Francisca; García Mateo, Carlos; Capdevila, Carlos; García de Andrés, Carlos

    2007-01-01

    The addition of about 2 wt.% of silicon to steel enables the production of a distinctive microstructure consisting of a mixture of bainitic ferrite, carbon-enriched retained austenite, and some martensite. With careful design, impressive combinations of strength and toughness have been reported for high-silicon bainitic steels. More recently, it has been demonstrated experimentally that models based on phase transformation theory can be applied successfully to the design of carbide-free baini...

  10. Phase transformations in welded supermartensitic stainless steels

    OpenAIRE

    Carrouge, Dominique

    2002-01-01

    Supermartensitic stainless steels have recently been introduced in the oil and gas industries to substitute more expensive duplex stainless steels for onshore and offshore tubing applications. Although easily joined by arc welding processes, the service life of the supermartensitic welded joint in corrosive environments relies to a large extent on the behaviour of the heat-affected zone (HAZ). The microstructure of the HAZ in these new materials has, until now, received little ...

  11. Cyclic Uniaxial Constitutive Model For Steel Reinforcement

    OpenAIRE

    Kim, Se-Hyung

    2015-01-01

    Reinforced Concrete (RC) structures are common in earthquake-prone areas. During an earthquake, the steel reinforcement is subjected to cyclic strain histories which lead to inelastic response. In the case of rare, strong earthquakes, inelastic buckling and even rupture due to low-cycle fatigue can also occur. The understanding and characterization of the performance of RC structures under earthquake hazards requires the accurate simulation of the inelastic hysteretic behavior of steel re...

  12. Strengthening of HSLA steels by cool deformation

    OpenAIRE

    a Fatehi; Calvo Muñoz, Jessica; Elwazri, A. M.; Yue, S

    2010-01-01

    In microalloyed steels, the refinement of ferrite grains together with a controlled amount of precipitation has key roles in the mechanical properties improvement. Applying small amounts of deformation, at very low hot working temperatures (i.e. coiling temperature), in the ferrite region (i.e. cool deformation) has an appreciable strengthening effect via controlling the final microstructure of the steel. One of the microstructural effects is thought to be the much finer and more uniformly...

  13. Strengthening of steels by ceramic phases

    OpenAIRE

    Feng, Yujie

    2013-01-01

    Production of ceramic reinforced thin sheet steel composites for automotive application with low density, high elastic modulus and strength is the aim of current study. Within this work, potential of various ceramic phases and possible processing routes were studied, summarized and compared through literature research. Laboratory production of TiC, TiB2 and Fe2B reinforced steel composites through conventional melting-casting route, twin roller route and powder metallurgy method were carried ...

  14. Ultrahigh Ductility, High-Carbon Martensitic Steel

    Science.gov (United States)

    Qin, Shengwei; Liu, Yu; Hao, Qingguo; Zuo, Xunwei; Rong, Yonghua; Chen, Nailu

    2016-10-01

    Based on the proposed design idea of the anti-transformation-induced plasticity effect, both the additions of the Nb element and pretreatment of the normalization process as a novel quenching-partitioning-tempering (Q-P-T) were designed for Fe-0.63C-1.52Mn-1.49Si-0.62Cr-0.036Nb hot-rolled steel. This high-carbon Q-P-T martensitic steel exhibits a tensile strength of 1890 MPa and elongation of 29 pct accompanied by the excellent product of tensile and elongation of 55 GPa pct. The origin of ultrahigh ductility for high-carbon Q-P-T martensitic steel is revealed from two aspects: one is the softening of martensitic matrix due to both the depletion of carbon in the matensitic matrix during the Q-P-T process by partitioning of carbon from supersaturated martensite to retained austenite and the reduction of the dislocation density in a martensitic matrix by dislocation absorption by retained austenite effect during deformation, which significantly enhances the deformation ability of martensitic matrix; another is the high mechanical stability of considerable carbon-enriched retained austenite, which effectively reduces the formation of brittle twin-type martensite. This work verifies the correctness of the design idea of the anti-TRIP effect and makes the third-generation advanced high-strength steels extend to the field of high-carbon steels from low- and medium-carbon steels.

  15. Microstructural studies of advanced austenitic steels

    Energy Technology Data Exchange (ETDEWEB)

    Todd, J. A.; Ren, Jyh-Ching [University of Southern California, Los Angeles, CA (USA). Dept. of Materials Science

    1989-11-15

    This report presents the first complete microstructural and analytical electron microscopy study of Alloy AX5, one of a series of advanced austenitic steels developed by Maziasz and co-workers at Oak Ridge National Laboratory, for their potential application as reheater and superheater materials in power plants that will reach the end of their design lives in the 1990's. The advanced steels are modified with carbide forming elements such as titanium, niobium and vanadium. When combined with optimized thermo-mechanical treatments, the advanced steels exhibit significantly improved creep rupture properties compared to commercially available 316 stainless steels, 17--14 Cu--Mo and 800 H steels. The importance of microstructure in controlling these improvements has been demonstrated for selected alloys, using stress relaxation testing as an accelerated test method. The microstructural features responsible for the improved creep strengths have been identified by studying the thermal aging kinetics of one of the 16Ni--14Cr advanced steels, Alloy AX5, in both the solution annealed and the solution annealed plus cold worked conditions. Time-temperature-precipitation diagrams have been developed for the temperature range 600 C to 900 C and for times from 1 h to 3000 h. 226 refs., 88 figs., 10 tabs.

  16. Stainless steel recycle FY94 progress report

    International Nuclear Information System (INIS)

    The Materials Technology Section (MTS) of the Savannah River Technology Center (SRTC) was asked to demonstrate the practicality of recycling previously contaminated stainless steel components such as reactor heat exchanger heads, process water piping and slug buckets into 208 liters (55 gallon) drums and 2.8 cubic meter (100 ft3) storage boxes. Radioactively contaminated stainless steel scrap will be sent to several industrial partners where it will be melted, decontaminated/cast into ingots, and rolled into plate and sheet and fabricated into the drums and boxes. As part of this recycle initiative, MTS was requested to demonstrate that radioactively contaminated Type 304L stainless steel could be remelted and cast to meet the applicable ASTM specification for fabrication of drums and boxes. In addition, MTS was requested to develop the technical basis of melt decontamination and establish practicality of using this approach for value added products. The findings presented in this investigation lead to the following conclusions: recycle of 18 wt% Cr-8 wt% Ni alloy can be achieved by melting Type 304 stainless steel in a air vacuum induction furnace; limited melt decontamination of the contaminated stainless steel was achieved, surface contamination was removed by standard decontamination techniques; carbon uptake in the as-cast ingots resulted from the graphite susceptor used in this experiment and is unavoidable with this furnace configuration. A new furnace optimized for melting stainless steel has been installed and is currently being tested for use in this program

  17. Steel desulphurization with synthetic slag

    Directory of Open Access Journals (Sweden)

    Heput, T.

    2007-02-01

    Full Text Available Generally speaking, sulphur is considered a harmful element for steel quality, reason why all the technological steps are being taken in order to eliminate it from the metal bath. This paper deals with the influence of the chemical composition, on the slag quantity and of the bath stirring condition upon the desulphurization process in the casting ladle by treatment with synthetic slag. The experiments were made at an open-hearth plant with the steel tapping in two ladles (the desulphurization was made with synthetic slag at one ladle while the other one was considered standard and at the electric steel plant and for the synthetic slag formation a mix was used, made, according to several receipts, of: lime (50-75%, fluorine (0-17%, bauxite (0-32% and aluminous slag (8-22%. The data were processed in the calculation programs EXCEL and MATLAB, which resulted in a series of correlations between the desulphurization degree and the chemical composition of the slag, respectively the slag quantity both for the charges bubbled with Argon and the unbubbled ones.

    En general, el azufre es considerado un elemento nocivo para la calidad del acero y, por eso, en la práctica, se toman todas las medidas de orden tecnológico para su eliminación del baño metálico. En este trabajo se analiza la influencia de la composición química, de la cantidad de escoria y del estado de agitación del baño sobre el proceso de desulfuración en la cuchara para fundir por tratamiento con escoria sintética. Los experimentos se han realizado en una acería evacuando el acero en dos ollas (en una cuchara se efectuó la desulfuración con escoria sintética y a la otra se consideró como patrón y en un acería eléctrica y para la formación de la escoria sintética se utilizó una mezcla producida según muchas recetas, formada por: cal (50-75%, fluorina (0-17%, bauxita (0-32% y escoria aluminosa (8-22%. Los datos han sido procesados en los programas de c

  18. Development and formability analysis of TRIP seamless steel tube

    Institute of Scientific and Technical Information of China (English)

    Zhang Zicheng; Zhu Fuxian

    2014-01-01

    In this paper, the production technology of transformation induced plasticity (TRIP) steel was first introduced into the steel tube manufacture field to produce the steel tubes with high strength and plasticity. The TRIP seamless steel tubes with the microstructure of ferrite, bainite, retained austenite and a little martensite were successfully fabricated using a cold-drawn steel tube with two-stage heat treatment technique and continu- ous heat treatment process, respectively. The ring tensile test and cold bend test were carried out to study the formability of the newly developed TRIP seamless steel tube. The results showed that the TRIP seamless steel tubes have a good cold formability, and they are available to be used in the tube hydroforming process. In ad- dition, the equipment of continuous heat treatment developed in the current study can be used to produce TRIP steel tube, and it may serve as an important reference for the industrial production of TRIP steel tube.

  19. Recent Progress in High Strength Low Carbon Steels

    Directory of Open Access Journals (Sweden)

    Zrník J.

    2006-01-01

    Full Text Available Advanced High Strength (AHS steels, among them especially Dual Phase (DP steels, Transformation Induced Plasticity (TRIP steels, Complex Phase (CP steels, Partially Martensite (PM steels, feature promising results in the field. Their extraordinary mechanical properties can be tailored and adjusted by alloying and processing. The introduction of steels with a microstructure consisting at least of two different components has led to the enlargement of the strength level without a deterioration of ductility. Furthermore, the development of ultra fine-grained AHS steels and their service performance are reviewed and new techniques are introduced. Various projects have been devoted to develop new materials for flat and long steel products for structural applications. The main stream line is High Strength, in order to match the weight lightening requirements that concern the whole class of load bearing structures and/or steel components and one of the most investigated topics is grain refinement.

  20. The Study on Weldability of Boron Steel and Hot-Stamped Steel by Using Laser Heat Source (Ⅲ) - Comparison on Laser Weldability of Boron Steel and Hot -Stamped Steel-

    Energy Technology Data Exchange (ETDEWEB)

    Choi, So Young; Kim, Jong Do [Korea Maritime and Ocean University, Busan (Korea, Republic of); Kim, Jong Su [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2015-01-15

    This study was conducted to compare the laser weldability of boron steel and hot-stamped steel. In general, boron steel is used in the hot-stamping process. Hot-stamping is a method for simultaneously forming and cooling boron steel in a press die after heating it to the austenitizing temperature. Hot-stamped steel has a strength of 1500 MPa or more. Thus, in this study, the laser weldability of boron steel and that of hot-stamped steel were investigated and compared. A continuous wave disk laser was used to produce butt and lap joints. In the butt welding, the critical cooling speed at which full penetration was obtained in the hot-stamped steel was lower than that of boron steel. In the lap welding, the joint widths were similar regardless of the welding speed when full penetration was obtained.

  1. Surface topography evolvement of galvanized steels in sheet metal forming

    Institute of Scientific and Technical Information of China (English)

    HOU Ying-ke; YU Zhong-qi; ZHANG Wei-gang; JIANG Hao-min; LIN Zhong-qin

    2009-01-01

    U-channel forming tests were performed to investigate the surface topography evolvement of hot-dip galvanized(GI) and galvannealed(GA) steels and the effects of die hardness on sheet metal forming(SMF). Experimental results indicate that the surface roughness values of the two galvanized steels increase with the number of forming, i.e., the surface topographies of galvanized steels are roughened in SMF. Moreover, GI steel has a better ability of damage-resistance than GA steel. The mechanisms of topography evolvement are different in the forming of GI and GA steels. Scratch is the main form of surface damage in the forming of GI steels. The severity of scratch can be decreased by increasing die hardness. GA steel results in exfoliating of the coating firstly and then severe scratching. The surface topography of galvannealed steels can be improved by increasing die hardness. However, the hardness should not be too high.

  2. Tensile-property characterization of thermally aged cast stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Michaud, W.F.; Toben, P.T.; Soppet, W.K.; Chopra, O.K. [Argonne National Lab., IL (United States)

    1994-02-01

    The effect of thermal aging on tensile properties of cast stainless steels during service in light water reactors has been evaluated. Tensile data for several experimental and commercial heats of cast stainless steels are presented. Thermal aging increases the tensile strength of these steels. The high-C Mo-bearing CF-8M steels are more susceptible to thermal aging than the Mo-free CF-3 or CF-8 steels. A procedure and correlations are presented for predicting the change in tensile flow and yield stresses and engineering stress-vs.-strain curve of cast stainless steel as a function of time and temperature of service. The tensile properties of aged cast stainless steel are estimated from known material information, i.e., chemical composition and the initial tensile strength of the steel. The correlations described in this report may be used for assessing thermal embrittlement of cast stainless steel components.

  3. Effect of cathodic protection on the state of steel reinforcement

    International Nuclear Information System (INIS)

    Damage of reinforced concrete structures is mainly caused by chloride or carbonation induced corrosion of steel. Cathodic protection is a very effective measure for corrosion control of steel in concrete, especially in chloride contaminated concrete. In this paper, effect of cathodic protection on the state of steel reinforcement is presented. Cathodic polarization of reinforcements in concrete was done under different submerged conditions. Cyclic potentiodynamic tests were used to determine the effect of cathodic protection on the behavior of the steel. Pitting appeared on the non-protected steel, but was not observed on the cathodically protected steel. microscopic photographs show that a close film exists on the protected steel, while the non-protected steel's film is loose. Investigated results have proved the effect of cathodic protection in restoring or strengthening passive film on the steel reinforcement

  4. Current Developments of Alloyed Steels for Hot Strip Roughing Mills : Characterization of High-Chromium Steel and Semi-High Speed Steel

    OpenAIRE

    LECOMTE-BECKERS, Jacqueline; Sinnaeve, Mario; Tchuindjang, Jérôme Tchoufack

    2012-01-01

    Two alloys grades for work rolls used in the roughing stand of Hot Strip Mill - high chromium steel (HCS) and semi-high-speed steel (semi-HSS), In this paper, the new semi-high-speed steel grade is studied

  5. High Mn austenitic stainless steel

    Science.gov (United States)

    Yamamoto, Yukinori [Oak Ridge, TN; Santella, Michael L [Knoxville, TN; Brady, Michael P [Oak Ridge, TN; Maziasz, Philip J [Oak Ridge, TN; Liu, Chain-tsuan [Knoxville, TN

    2010-07-13

    An austenitic stainless steel alloy includes, in weight percent: >4 to 15 Mn; 8 to 15 Ni; 14 to 16 Cr; 2.4 to 3 Al; 0.4 to 1 total of at least one of Nb and Ta; 0.05 to 0.2 C; 0.01 to 0.02 B; no more than 0.3 of combined Ti+V; up to 3 Mo; up to 3 Co; up to 1W; up to 3 Cu; up to 1 Si; up to 0.05 P; up to 1 total of at least one of Y, La, Ce, Hf, and Zr; less than 0.05 N; and base Fe, wherein the weight percent Fe is greater than the weight percent Ni, and wherein the alloy forms an external continuous scale including alumina, nanometer scale sized particles distributed throughout the microstructure, the particles including at least one of NbC and TaC, and a stable essentially single phase FCC austenitic matrix microstructure that is essentially delta-ferrite-free and essentially BCC-phase-free.

  6. Creep strength and ductility of 9 to 12% chromium steels

    DEFF Research Database (Denmark)

    Hald, John

    2004-01-01

    Steels", which covers creep data development and analysis for parent materials and welds of all ferritic creep resistant steels ranging from low alloy steels up to 12%Cr steels. The opinions stated in the paper represent the views of the author rather than the whole ECCC WG3A group.......The present paper focuses in on long-term creep properties of parent material of the new 9-12%Cr creep resistant steels, P91, E911 and P92 developed for use in advanced ultrasupercritical power plants. These steels have been at the center of activities in the ECCC Working Group 3A (WG3A) "Ferritic...

  7. Achievements of New Generation Steel Project in China

    Institute of Scientific and Technical Information of China (English)

    Weng Yuqing

    2004-01-01

    Major achievements of the national project, Fundamental Research on New Generation of Iron and Steel Materials in China (NG Steel), are reviewed in the paper. Ultrafine grained steel technology, based on deformation induced ferrite transformation (DIFT)and successive microstructure changes, is illustrated for grain refinement in both plain low carbon steel and microalloyed steel. Delayed fracture resistance of alloy structure steel can be improved through prior austenite grain refinement. It is shown by results that nano scale precipitates play an important role to grain refinement in thin slab casting and rolling (TSCR)process. Progresses on super cleanliness, high homogeneity, welding and metallurgical process simulation are also briefly introduced.

  8. Redemption of asthma pharmaceuticals among stainless steel and mild steel welders

    DEFF Research Database (Denmark)

    Kristiansen, Pernille; Jørgensen, Kristian Tore; Hansen, Johnni;

    2015-01-01

    PURPOSE: The purpose was to examine bronchial asthma according to cumulative exposure to fume particulates conferred by stainless steel and mild steel welding through a proxy of redeemed prescribed asthma pharmaceuticals. METHODS: A Danish national company-based historical cohort of 5,303 male ever...... was estimated by combining questionnaire data on welding work with a welding exposure matrix. The estimated exposure accounted for calendar time, welding intermittence, type of steel, welding methods, local exhaustion and welding in confined spaces. Hazard ratios (HRs) with 95 % confidence intervals (CIs) were...... nonsignificant increased rate of redemption of asthma medicine was observed among high-level exposed stainless steel welders in comparison with low-level exposed welders (HR 1.54, 95 % CI 0.76-3.13). This risk increase was driven by an increase risk among non-smoking stainless steel welders (HR 1.46, 95 % CI 1...

  9. Analysis of the Behaviour of Composite Steel and Steel Fiber Reinforced Concrete Slabs

    Directory of Open Access Journals (Sweden)

    Mindaugas Petkevičius

    2011-04-01

    Full Text Available There was a pending influence of steel fiber on the strength and stiffness of composite steel–concrete slabs under statical short–time load. Steel profiled sheeting and steel fiber reinforced concrete were used for specimens. Four composite slabs were made. Experimental investigations into the behaviour and influence of steel fiber reinforced concrete in composite slabs were conducted. Transverse, longitudinal, shear deformation and deflection of the slab were measured. The results indicated that the use of steel fiber in composite slabs was effective: strength was 20–24 % higher and the meanings of deflections under the action of the bending moment were 0,6MR (where MR is the bending moment at failure of the slabs and were 16–18 % lower for slabs with usual concrete. Article in Lithuanian

  10. Strengthening of HSLA steels by cool deformation

    Energy Technology Data Exchange (ETDEWEB)

    Fatehi, A., E-mail: arya.fatehi@gmail.com [Department of Mining, Metals and Materials Engineering, McGill University, 3610 University Street, Montreal, QC, H3A 2B2 (Canada); Calvo, J.; Elwazri, A.M.; Yue, S. [Department of Mining, Metals and Materials Engineering, McGill University, 3610 University Street, Montreal, QC, H3A 2B2 (Canada)

    2010-06-25

    In microalloyed steels, the refinement of ferrite grains together with a controlled amount of precipitation has key roles in the mechanical properties improvement. Applying small amounts of deformation, at very low hot working temperatures (i.e. coiling temperature), in the ferrite region (i.e. cool deformation) has an appreciable strengthening effect via controlling the final microstructure of the steel. One of the microstructural effects is thought to be the much finer and more uniformly dispersed precipitates in the steel matrix. In the present study, the effects of Nb and Cu on mechanical properties and corresponding microstructures in steels with different levels of cool deformation are investigated. The mechanical properties of the samples were determined using the shear punch test and the microstructure was examined by scanning and transmission electron microscopy. Thermodynamic simulations with FactSage were done to further analyze the precipitation possibility of different elements. It has been found that these alloying elements respond very well to cool deformation, with the strength being highest in steels containing both Nb and Cu. However, a cool deformation effect in the non-Nb and Cu bearing steel is also observed. In all cases, it was confirmed that precipitation plays a key role in the effect of cool deformation, with much of the precipitation taking place dynamically. Nevertheless, static processes also seem to have a measurable effect on room temperature properties. Even low amounts of copper (e.g. {approx}0.4 wt%) can contribute to strengthening of the steel. The Cu addition is found to affect the mechanical properties by affecting the precipitation and growth of Nb compounds.

  11. Metallurgical products of microalloy constructional steels

    Directory of Open Access Journals (Sweden)

    W. Ozgowicz

    2011-01-01

    Full Text Available Purpose: The aim of the paper is a monographic presentation, based on investigations connected with the elaboration of new kinds of microalloy steels and a technique of heat and thermo-mechanical treatment in the production of a selected group of metallurgical products.Design/methodology/approach: The influence of the chemical composition and metallurgical purity on the homogenisation of austenite was analysed, as well as thermally activated processes and phase transformations in the course of deformation and controlled cooling conditions, concerning micradditives Nb, V, Ti, B and metallurgical products.Findings: The chemical composition of the obtained constructional steels with microadditives was quoted, as well as the technological conditions of forging and rolled products required for industrial purposes.Research limitations/implications: The results of investigations concerning the structure and mechanical properties have been presented, as well as the resistance to fracture, mainly of thick plates and hand-forged and drop-forged products and also elements of sheet structures for the automotive industry, made of AHSS steels.Practical implications: The results of the author’s own investigations concerning microalloy steels indicate the actual possibility of their application in practice in many steelworks, particularly in plants producing semi products and final metallurgical products, among others in hot rolling plants and forging shops, first of all in machine building and automotive industry.Originality/value: The application of modern metallurgical technologies and metalforming has been suggested for selected metallurgical products of microalloy steels of the type HSLA with a ferrite-bainite, bainite or tempered martensite structure and also of HSS steels and UHSS steel with a wide range of mechanical properties and technological formability, which is essential in the case of products of the automotive industry.

  12. Strengthening of HSLA steels by cool deformation

    International Nuclear Information System (INIS)

    In microalloyed steels, the refinement of ferrite grains together with a controlled amount of precipitation has key roles in the mechanical properties improvement. Applying small amounts of deformation, at very low hot working temperatures (i.e. coiling temperature), in the ferrite region (i.e. cool deformation) has an appreciable strengthening effect via controlling the final microstructure of the steel. One of the microstructural effects is thought to be the much finer and more uniformly dispersed precipitates in the steel matrix. In the present study, the effects of Nb and Cu on mechanical properties and corresponding microstructures in steels with different levels of cool deformation are investigated. The mechanical properties of the samples were determined using the shear punch test and the microstructure was examined by scanning and transmission electron microscopy. Thermodynamic simulations with FactSage were done to further analyze the precipitation possibility of different elements. It has been found that these alloying elements respond very well to cool deformation, with the strength being highest in steels containing both Nb and Cu. However, a cool deformation effect in the non-Nb and Cu bearing steel is also observed. In all cases, it was confirmed that precipitation plays a key role in the effect of cool deformation, with much of the precipitation taking place dynamically. Nevertheless, static processes also seem to have a measurable effect on room temperature properties. Even low amounts of copper (e.g. ∼0.4 wt%) can contribute to strengthening of the steel. The Cu addition is found to affect the mechanical properties by affecting the precipitation and growth of Nb compounds.

  13. Mechanical properties of irradiated 9Cr-2WVTa steel

    Energy Technology Data Exchange (ETDEWEB)

    Klueh, R.L.; Alexander, D.J. [Oak Ridge National Lab., TN (United States); Rieth, M. [Forschungszentrum Karlsruhe (Germany). Inst. fuer Materialforschung II

    1998-09-01

    An Fe-9Cr-2W-0.25V-0.07Ta-0.1C (9Cr-2WVTa) steel has excellent strength and impact toughness before and after irradiation in the Fast Flux Test Facility and the High Flux Reactor (HFR). The ductile-brittle transition temperature (DBTT) increased only 32 C after 28 dpa at 365 C in FFTF, compared to a shift of {approx}60 C for a 9Cr-2WV steel--the same as the 9Cr-2WVTa steel but without tantalum. This difference occurred despite the two steels having similar tensile but without tantalum. This difference occurred despite the two steels having similar tensile properties before and after irradiation. The 9Cr-2WVTa steel has a smaller prior-austenite grain size, but otherwise microstructures are similar before irradiation and show similar changes during irradiation. The irradiation behavior of the 9Cr-2WVTa steel differs from the 9Cr-2WV steel and other similar steels in two ways: (1) the shift in DBTT of the 9Cr-2WVTa steel irradiated in FFTF does not saturate with fluence by {approx}28 dpa, whereas for the 9Cr-2WV steel and most similar steels, saturation occurs at <10 dpa, and (2) the shift in DBTT for 9Cr-2WVTa steel irradiated in FFTF and HFR increased with irradiation temperature, whereas it decreased for the 9Cr-2WV steel, as it does for most similar steels. The improved properties of the 9Cr-2WVTa steel and the differences with other steels were attributed to tantalum in solution.

  14. Expression of Mouse SCP2 Gene Adenoviral Vector Carrying Albumin Promoter in Hepa1-6 Cells%固醇携带蛋白2腺病毒载体的构建与鉴定

    Institute of Scientific and Technical Information of China (English)

    贾岩峰; 崔云峰; 崔乃强; 彭雁飞; 宁召臣; 张琚

    2012-01-01

    Objectives To construct the replication defective adenoviral vector of SCP2 gene carrying murine albumin promoter, and study the relations between SCP2 gene and the formation of cholesterol calculus. Methods The cDNA of SCP2 gene was cloned by using RT-PCR technique. The albumin promoter was linked to SCP2 gene's upstream, and the EGFP gene lied in its downstream. The plasmid pDC312-ALB-SCP2-IRES2 -EGFP was constructed by the gene recombination technique. The Admax Adenoviral Vector System was used to generate the replication defective adenoviral vectors, which were purified by CsCl method. The processes of TCID50 were applied to detect the titers of the adenoviral vectors. The RNA and protein were respectively extracted from the infected Hepal-6 cells by the adenoviral vector. The real-time quantitative PCR was employed to detect the mRNA expression levels, and the Western blotting analysis was used to measure the SCP2 protein levels. Result We constructed successfully the replication defective adenoviral vector of SCP2 gene carrying murine albumin promoter. When the mRNA levels of SCP2 gene were overexpressed, CYP7al mRNA levels were down-regulated (t=3.97,p<0.05); and the mRNA levels of HMGCR were up-regulated (t=3.23,p<0.05). Conclusions The SCP2 gene overexpression may affect cholesterol and bile acid metabolism, which could promote the formation of cholesterol calculus.%目的:构建携带白蛋白启动子SCP2 基因腺病毒载体,研究其与胆固醇结石形成的关系.方法:(1)利用RT-PCR技术克隆小鼠SCP2基因,在其上游接入白蛋白(ALB)启动子,下游连接绿色荧光报告基因(EGFP),构建穿梭质粒pDC312-ALB-SCP2-IRES2-EGFP;(2)采用Ad Max TM Adenoviru5 Vector系统包装病毒,CsCl法纯化病毒、TCID50法测定滴度;(3)重组腺病毒感染小鼠hepa-1-6细胞,实时定量PCR检测mRNA的表达;Western印迹检测SCP2蛋白表达情况;结果:成功构建携带白蛋白启动子SCP2基因腺病毒载体;当SCP2

  15. In situ 3D monitoring of corrosion on carbon steel and ferritic stainless steel embedded in cement paste

    KAUST Repository

    Itty, Pierre-Adrien

    2014-06-01

    In a X-ray microcomputed tomography study, active corrosion was induced by galvanostatically corroding steel embedded in cement paste. The results give insight into corrosion product build up, crack formation, leaching of products into the cracks and voids, and differences in morphology of corrosion attack in the case of carbon steel or stainless steel reinforcement. Carbon steel was homogeneously etched away with a homogeneous layer of corrosion products forming at the steel/cement paste interface. For ferritic stainless steel, pits were forming, concentrating the corrosion products locally, which led to more extensive damage on the cement paste cover. © 2014 Elsevier Ltd.

  16. The Synchrotron Radiation for Steel Research

    Directory of Open Access Journals (Sweden)

    Piyada Suwanpinij

    2016-01-01

    Full Text Available The synchrotron X-ray radiation is a great tool in materials characterization with several advantageous features. The high intensity allows clear interaction signals and high energy of X-ray yields higher sampling volume. The samples do not need extra preparation and the microstructure is therefore not affected. With the tunability of the X-ray energy, a large range of elements and features in the samples can be investigated by different techniques, which is a significant difference between a stand-alone X-ray tube and synchrotron X-ray. Moreover, any experimental equipment can be installed through which the synchrotron beam travels. This facilitates the so-called in situ characterization such as during heat treatment, hot deformation, chemical reaction or welding. Although steel which possesses rather high density requires very high energy X-ray for large interaction volume, lower energy is still effective for the investigation of local structure of nanoconstituents. This work picks up a couple examples employing synchrotron X-ray for the characterization of high strength steels. The first case is the quantification of precipitates in high strength low alloyed (HSLA steel by X-ray absorption spectroscopy. The other case is the in situ X-ray diffraction for phase fraction and carbon partitioning in multiphase steels such as transformation induced plasticity (TRIP steel.

  17. Development of the microalloyed constructional steels

    Directory of Open Access Journals (Sweden)

    J. Adamczyk

    2005-12-01

    Full Text Available Purpose: The aim of the paper is to present the development and the technical importance of the HSLA-typemicroalloyed constructional steels (High Strength Low Alloy in selected industry branches.Design/methodology/approach: A mechanism of the interaction of Nb, Ti, V and B microadditions introducedinto the steel on mechanical properties of selected metallurgical products with the fine-grained structure,forming under the properly selected hot-working conditions with the of (M-Nb,Ti,V; X-N,C interstitial phasesMX-type is discussed.Findings: The requirements concerning the metallurgical process, continuous casting of steel and the necessityof adjusting the hot-working conditions to the precipitation kinetics of the dispersive MX phases particles inaustenite, in the controlled rolling or thermo-mechanical treatment processes are indicated.Research limitations/implications: The continuation of investigations concerning the thermo-mechanicalrolling of automotive sheets with the multiphase structure of microalloyed steels is planned.Practical implications: The indicated data, coming also from the own research, are of practical use in relationto manufacturing the metallurgical products and machine elements of high strength and crack resistance, alsoat low temperatures.Originality/value: The results contribute to the development of rolling and forging technologies of themicroalloyed steel (HSLA elements produced using the energy-saving thermo-mechanical treatment methods.

  18. Nanostructuring steel for injection molding tools

    International Nuclear Information System (INIS)

    The production of nanostructured plastic items by injection molding with ridges down to 400 nm in width, which is the smallest line width replicated from nanostructured steel shims, is presented. Here we detail a micro-fabrication method where electron beam lithography, nano-imprint lithography and ion beam etching are combined to nanostructure the planar surface of a steel wafer. Injection molded plastic parts with enhanced surface properties, like anti-reflective, superhydrophobic and structural colors can be achieved by micro- and nanostructuring the surface of the steel molds. We investigate the minimum line width that can be realized by our fabrication method and the influence of etching angle on the structure profile during the ion beam etching process. Trenches down to 400 nm in width have been successfully fabricated into a 316 type electro-polished steel wafer. Afterward a plastic replica has been produced by injection molding with good structure transfer fidelity. Thus we have demonstrated that by utilizing well-established fabrication techniques, nanostructured steel shims that are used in injection molding, a technique that allows low cost mass fabrication of plastic items, are produced. (paper)

  19. Aging degradation of cast stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Chung, H.M.

    1985-10-01

    A program is being conducted to investigate the significance of in-service embrittlement of cast-duplex stainless steels under light-water reactor operating conditions. Data from room-temperature Charpy-impact tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450/sup 0/C are presented and compared with results from other studies. Microstructures of cast-duplex stainless steels subjected to long-term aging either in the laboratory or in reactor service have been characterized. The results indicate that at least two processes contribute to the low-temperature embrittleent of duplex stainless steels, viz., weakening of the ferrite/austenite phase boundary by carbide precipitation and embrittlement of ferrite matrix by the formation of additional phases such as G-phase, Type X, or the ..cap alpha..' phase. Carbide precipitation has a significant effect on the onset of embrittlement of CF-8 and -8M grades of stainless steels aged at 400 or 450/sup 0/C. The existing correlations do not accurately represent the embrittlement behavior over the temperature range 300 to 450/sup 0/C. 18 refs., 13 figs.

  20. Fabrication and ageing of cast austenitic steels

    International Nuclear Information System (INIS)

    An investigation has been undertaken to determine the magnitude of any reduction in properties which may occur in cast duplex stainless steels and weldments during long term exposure to reactor operating conditions. Test panels were fabricated in CF3 stainless steel by a manual metal arc (MMA) process using 19.9.L (Type 308L) consumables. The mechanical properties and intergranular corrosion resistance of parent material and weldments were measured following accelerated ageing at 3750 and 4000C for up to 10,000 hours. Both the impact energy and J/sub R/ fracture toughness properties of the cast austenitic/ferritic stainless steel were reduced following aging at 4000C for 10,000 hours, whereas austenitic stainless steel MMA weld metals exhibited a reduction in J/sub R/ fracture toughness but no change in impact energy. Even in the unaged state, MMA weld metals were shown to have a much lower resistance to stable crack growth than the parent cast steel, and, following aging, there is a further reduction in the ductile tearing resistance of such weld metals. Therefore, in any assessment of the structural integrity of the reactor coolant pump bowl for a pressurized water reactor (PWR), the weld metal fracture properties during service are likely to be of considerable importance

  1. Equilibrium Model of Precipitation in Microalloyed Steels

    Science.gov (United States)

    Xu, Kun; Thomas, Brian G.; O'Malley, Ron

    2011-02-01

    The formation of precipitates during thermal processing of microalloyed steels greatly influences their mechanical properties. Precipitation behavior varies with steel composition and temperature history and can lead to beneficial grain refinement or detrimental transverse surface cracks. This work presents an efficient computational model of equilibrium precipitation of oxides, sulfides, nitrides, and carbides in steels, based on satisfying solubility limits including Wagner interaction between elements, mutual solubility between precipitates, and mass conservation of alloying elements. The model predicts the compositions and amounts of stable precipitates for multicomponent microalloyed steels in liquid, ferrite, and austenite phases at any temperature. The model is first validated by comparing with analytical solutions of simple cases, predictions using the commercial package JMat-PRO, and previous experimental observations. Then it is applied to track the evolution of precipitate amounts during continuous casting of two commercial steels (1004 LCAK and 1006Nb HSLA) at two different casting speeds. This model is easy to modify to incorporate other precipitates, or new thermodynamic data, and is a useful tool for equilibrium precipitation analysis.

  2. Thermodynamic aspects of inclusion engineering in steels

    Institute of Scientific and Technical Information of China (English)

    A. Costa e Silva

    2006-01-01

    Tailoring non-metallic inclusions in accordance to the desired effect on steel properties has gained widespread acceptance in the last decades and has become known as "inclusion engineering". Effective inclusion engineering involves three steps: (a) a good knowledge of how inclusions influence properties, (b) understanding what is the effect of each type of inclusions on these properties and thus which is the most desirable inclusion in a given product and (c) adjusting the processing parameters to obtain these inclusions. A significant portion of the process adjustment is done during steel refining, where the steel can be tailored so that the desired chemical composition of the non-metallic inclusions that will precipitate can be altered. Understanding the relations between steel chemistry, processing variables and inclusion chemical composition requires significant understanding of the thermodynamics of the systems involved. These complex equilibrium calculations are best done using computational thermodynamics. In this work some of the basic techniques used to control inclusion composition are reviewed and the thermodynamic information required to perform this task is presented. Several examples of the application of computational thermodynamics to inclusion engineering of different steels grades are presented and compared with experimental results, whenever possible. The potential and limitations of the method are highlighted, in special those related to thermodynamic data and databases.

  3. Process development of thin strip steel casting

    Energy Technology Data Exchange (ETDEWEB)

    Sussman, R.C.; Williams, R.S.

    1990-12-01

    An important new frontier is being opened in steel processing with the emergence of thin strip casting. Casting steel directly to thin strip has enormous benefits in energy savings by potentially eliminating the need for hot reduction in a hot strip mill. This has been the driving force for numerous current research efforts into the direct strip casting of steel. The US Department of Energy initiated a program to evaluate the development of thin strip casting in the steel industry. In earlier phases of this program, planar flow casting on an experimental caster was studied by a team of engineers from Westinghouse Electric corporation and Armco Inc. A subsequent research program was designed as a fundamental and developmental study of both planar and melt overflow casting processes. This study was arranged as several separate and distinct tasks which were often completed by different teams of researchers. An early task was to design and build a water model to study fluid flow through different designs of planar flow casting nozzles. Another important task was mathematically modeling of melt overflow casting process. A mathematical solidification model for the formation of the strip in the melt overflow process was written. A study of the material and conditioning of casting substrates was made on the small wheel caster using the melt overflow casting process. This report discusses work on the development of thin steel casting.

  4. Aging degradation of cast stainless steel

    International Nuclear Information System (INIS)

    A program is being conducted to investigate the significance of in-service embrittlement of cast-duplex stainless steels under light-water reactor operating conditions. Data from room-temperature Charpy-impact tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 4500C are presented and compared with results from other studies. Microstructures of cast-duplex stainless steels subjected to long-term aging either in the laboratory or in reactor service have been characterized. The results indicate that at least two processes contribute to the low-temperature embrittleent of duplex stainless steels, viz., weakening of the ferrite/austenite phase boundary by carbide precipitation and embrittlement of ferrite matrix by the formation of additional phases such as G-phase, Type X, or the α' phase. Carbide precipitation has a significant effect on the onset of embrittlement of CF-8 and -8M grades of stainless steels aged at 400 or 4500C. The existing correlations do not accurately represent the embrittlement behavior over the temperature range 300 to 4500C. 18 refs., 13 figs

  5. Aging degradation of cast stainless steel

    International Nuclear Information System (INIS)

    A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water reactor operating conditions. Microstructures of cast materials subjected to long-term aging either in reactor service or in the laboratory have been characterized by TEM, SANS, and APFIM techniques. Two precipitate phases, i.e., the Cr-rich α' and Ni- and Si-rich G phase, have been identified in the ferrite matrix of the aged steels. The results indicate that the low-temperature embrittlement is primarily caused by α' precipitates which form by spinodal decomposition. The relative contribution of G phase to loss of toughness is now known. Microstructural data also indicate that weakening of ferrite/austenite phase boundary by carbide precipitates has a significant effect on the onset and extent of embrittlement of the high-carbon CF-8 and CF-8M grades of stainless steels, particularly after aging at 400 or 4500C. Data from Charpy-impact, tensile, and J-R curve tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 4500C are presented and correlated with the microstructural results. Thermal aging of the steels results in an increase in tensile strength and a decrease in impact energy, J/sub IC/, and tearing modulus. The fracture toughness results show good agreement with the Charpy-impact data. The effects of compositional and metallurgical variables on loss of toughness are discussed

  6. Symbiosis of Steel, Energy, and CO2 Evolution in Korea

    Science.gov (United States)

    Lee, Hyunjoung; Matsuura, Hiroyuki; Sohn, Il

    2016-05-01

    This study looks at the energy intensity of the steel industry and the greenhouse gas intensity involved with the production of steel. Using several sources of steel production data and the corresponding energy sources used provides a time-series analysis of the greenhouse gas (GHG) and energy intensity from 1990 to 2014. The impact of the steel economy with the gross domestic product (GDP) provides indirect importance of the general manufacturing sector within Korea and in particular the steel industry. Beyond 2008, the shift in excess materials production and significant increase in total imports have led to an imbalance in the Korean steel market and continue to inhibit the growth of the domestic steel market. The forecast of the GHG and energy intensity along with the steel production up to 2030 is provided using the auto regressive integrated moving average analysis.

  7. HTPro: Low-temperature Surface Hardening of Stainless Steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lundin; Somers, Marcel A. J.

    2013-01-01

    Low-temperature surface hardening of stainless steel provides the required performance properties without affecting corrosion resistance.......Low-temperature surface hardening of stainless steel provides the required performance properties without affecting corrosion resistance....

  8. Low temperature gaseous surface hardening of stainless steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2010-01-01

    The present contribution gives an overview of some of the technological aspects of low temperature thermochemical treatment of stainless steel. Examples of low temperature gaseous nitriding, carburising and nitrocarburising of stainless steel are presented and discussed. In particular, the...

  9. Low temperature gaseous surface hardening of stainless steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2011-01-01

    The present contribtion gives an overview of some of the technological aspects of low temperature thermochemical treatment of stainless steel. Examples of low temperature gaseous nitriding, carburising and nitrocarburising of stainless steel are presented and discussed. In particular, the...

  10. Symbiosis of Steel, Energy, and CO2 Evolution in Korea

    Science.gov (United States)

    Lee, Hyunjoung; Matsuura, Hiroyuki; Sohn, Il

    2016-09-01

    This study looks at the energy intensity of the steel industry and the greenhouse gas intensity involved with the production of steel. Using several sources of steel production data and the corresponding energy sources used provides a time-series analysis of the greenhouse gas (GHG) and energy intensity from 1990 to 2014. The impact of the steel economy with the gross domestic product (GDP) provides indirect importance of the general manufacturing sector within Korea and in particular the steel industry. Beyond 2008, the shift in excess materials production and significant increase in total imports have led to an imbalance in the Korean steel market and continue to inhibit the growth of the domestic steel market. The forecast of the GHG and energy intensity along with the steel production up to 2030 is provided using the auto regressive integrated moving average analysis.

  11. Nickel-free austenitic stainless steels for medical applications

    Directory of Open Access Journals (Sweden)

    Ke Yang and Yibin Ren

    2010-01-01

    Full Text Available The adverse effects of nickel ions being released into the human body have prompted the development of high-nitrogen nickel-free austenitic stainless steels for medical applications. Nitrogen not only replaces nickel for austenitic structure stability but also much improves steel properties. Here we review the harmful effects associated with nickel in medical stainless steels, the advantages of nitrogen in stainless steels, and emphatically, the development of high-nitrogen nickel-free stainless steels for medical applications. By combining the benefits of stable austenitic structure, high strength and good plasticity, better corrosion and wear resistances, and superior biocompatibility compared to the currently used 316L stainless steel, the newly developed high-nitrogen nickel-free stainless steel is a reliable substitute for the conventional medical stainless steels.

  12. Corrosion behaviour of galvanized steel and electroplating steel in aqueous solution: AC impedance study and XPS

    Energy Technology Data Exchange (ETDEWEB)

    Lebrini, M.; Fontaine, G. [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, LSPES UMR CNRS 8008, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Gengembre, L. [Unite de Catalyse et Chimie du solide UMR 8181 Bat C3, USTL, F-59655 Villeneuve d' Ascq Cedex (France); Traisnel, M. [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, LSPES UMR CNRS 8008, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France)], E-mail: Michel.Traisnel@ensc-lille.fr; Lerasle, O.; Genet, N. [TOTAL France, Centre de Recherche de Solaize, Chemin du canal, BP 22, F-69360 Solaize (France)

    2008-08-30

    The efficiency of a new triazole derivative, namely, 2-{l_brace}(2-hydroxyethyl)[(4-methyl-1H-1,2,3-benzotriazol-1-yl)methyl]amino{r_brace} ethanol (TTA) has been studied for corrosion inhibition of galvanized steel and electroplating steel in aqueous solution. Corrosion inhibition was studied using electrochemical impedance spectroscopy (EIS). These studies have shown that TTA was a very good inhibitor. Data obtained from EIS show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The corrosion behaviour of galvanized steel and electroplating steel in aqueous solution was also investigated in the presence of 4-methyl-1H-benzotriazole (TTA unsubstituted) by EIS. These studies have shown that the ability of the molecule to adsorb on the steel surface was dependent on the group in triazole ring substituent. X-ray photoelectron spectroscopy surface analysis with TTA shows that it chemisorbed on surface of galvanized steel and electroplating steel.

  13. Interaction model of steel ladle of continuous caster in steel works

    Directory of Open Access Journals (Sweden)

    Huang Bang Fu

    2016-01-01

    Full Text Available For further research on the precondition and interoperability model of interaction ladles among continuous caster, this article takes steel ladle of Y steel works as the object of research. On the basis of turnover number calculation model of single cast steel ladle, the relationship between cast number and the turnover number and turnover times and last turnover number are further analyzed. The simulation of steel ladle turnover rules was taken on the 2 continuous casters with Gantt chart. After that, the relationships between turnover number and last turnover number and non-turnover number are researched deeply. Combining with the Gantt chart, the expressions of start casting time and empty ladle ending time and heavy ladle starting time were put forward. The precondition of steel ladle interaction is obtained, which means the exchange ladle should not undertaking transport task in first stop continuous caster, and the empty ladle end time of exchange ladle of first stop continuous caster should early than the heavy ladle start time of last stop continuous caster. After applying the model to practice, 3 steel ladles of No.2 continuous caster can be reduced. This research results is supplying theoretical basis for steel ladle controlling and production organization optimization, and enriches the theory and method of metallurgical process integration.

  14. Rare Earth Additions in Continuously Cast Steel

    Science.gov (United States)

    Wilson, William G.; Heaslip, L. J.; Sommerville, I. D.

    1985-09-01

    Rare earth (lanthanide metals) addiiions to continuously cast steel are particularly advantageous because of their ability to refine as-cast structures, reduce segregation and increase hot ductility at temperatures just below that of solidification. The complete shape control of sulfides in steels containing Rare Earth Metals (REM), whether continuously cast or ingot cast, is primarily responsible for improvements in ductility related mechanical properties, weldability, fatigue resistance and resistance to hydrogen damage. Complete sulfide shape control can be obtained with REM additions at sulfur levels as high as.020%. The greatest improvements, however, are obtained with REM additions to low sulfur steels. However, to achieve full operational advantages afforded by REM, nozzle blockage problems must be circumvented. Water model studies indicate a possible solution.

  15. CO2 emissions in the steel industry

    Directory of Open Access Journals (Sweden)

    M. Kundak

    2009-07-01

    Full Text Available Global CO2 emissions caused by the burning of fossil fuels over the past century are presented. Taking into consideration the total world production of more than 1,3 billion tons of steel, the steel industry produces over two billion tons of CO2. Reductions in CO2 emissions as a result of technological improvements and structural changes in steel production in industrialized countries during the past 40 years are described. Substantial further reductions in those emissions will not be possible using conventional technologies. Instead, a radical cutback may be achieved if, instead of carbon, hydrogen is used for direct iron ore reduction. The cost and the ensuing CO2 generation in the production of hydrogen as a reducing agent from various sources are analysed.

  16. Activity of Reducing Steel Slag of EAF

    Institute of Scientific and Technical Information of China (English)

    GUO Chinhsiang; HWANG Chaolung; LIN Tingyi

    2011-01-01

    Reducing steel slag (RSS) was mainly acquired from five electric-arc furnace (EAF)steelmaking plants (among them, the products of two plants were carbon steel and those of other plants were stainless steel) for research tests. The chemical properties, compound compositions, activities and contents of main expansive compounds were tested. The results showed that the field sampled RSS had a very high crystallinity and hydraulicity with main chemical compositions close to those of Portland cement. It can be known from the study that in case of C/S ratio higher than 2.0, the main compound compositions are C2S, C3S, C2F and f-CaO. However, after the RSS was stored for six months, an obvious variation occurred with potential pre-hydration in RSS, where the SO3 content was slightly reduced and the compressive activity index was obviously higher than that at the 28th day.

  17. New ferritic steels for advanced steam plants

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, K.H; Koenig, H. [GEC ALSTHOM Energie GmbH, Nuremberg (Germany)

    1998-12-31

    During the last 15-20 years ferritic-martensitic 9-12 % chromium steels have been developed under international research programmes which permit inlet steam temperatures up to approx. 625 deg C and pressures up to about 300 bars, thus leading to improvements in thermal efficiency of around 8 % and a CO{sub 2} reduction of about 20 % versus conventional steam parameters. These new steels are already being applied in 13 European and 34 Japanese power stations with inlet steam temperature up to 610 deg C. This presentation will give an account of the content, scope and results of the research programmes and of the experience gained during the production of components which have been manufactured from the new steels. (orig.) 13 refs.

  18. Ultrasonic Spectroscopy of Stainless Steel Sandwich Panels

    Science.gov (United States)

    Cosgriff, Laura M.; Lerch, Bradley A.; Hebsur, Mohan G.; Baaklini, George Y.; Ghosn, Louis J.

    2003-01-01

    Enhanced, lightweight material systems, such as 17-4PH stainless steel sandwich panels are being developed for use as fan blades and fan containment material systems for next generation engines. In order to improve the production for these systems, nondestructive evaluation (NDE) techniques, such as ultrasonic spectroscopy, are being utilized to evaluate the brazing quality between the 17-4PH stainless steel face plates and the 17-4PH stainless steel foam core. Based on NDE data, shear tests are performed on sections representing various levels of brazing quality from an initial batch of these sandwich structures. Metallographic characterization of brazing is done to corroborate NDE findings and the observed shear failure mechanisms.

  19. Complex Protection of Vertical Stainless Steel Tanks

    Directory of Open Access Journals (Sweden)

    Fakhrislamov Radik Zakievich

    2014-03-01

    Full Text Available The authors consider the problem of fail-safe oil and oil products storage in stainless steel tanks and present the patented tank inner side protection technology. The latter provides process, ecological and fire safety and reducing soil evaporation of oil products, which is a specific problem. The above-mentioned technology includes corrosion protection and heat insulation protection providing increase of cover durability and RVS service life in general. The offered technological protection scheme is a collaboration of the author, Steel Paint GmbH firm and JSC “Koksokhimmontazhproyekt”. PU foam unicomponent materials of Steel Paint GmbH firm provide the protection of tank inner side and cover.

  20. Microstructure and cleavage in lath martensitic steels

    Directory of Open Access Journals (Sweden)

    John W Morris Jr, Chris Kinney, Ken Pytlewski and Y Adachi

    2013-01-01

    Full Text Available In this paper we discuss the microstructure of lath martensitic steels and the mechanisms by which it controls cleavage fracture. The specific experimental example is a 9Ni (9 wt% Ni steel annealed to have a large prior austenite grain size, then examined and tested in the as-quenched condition to produce a relatively coarse lath martensite. The microstructure is shown to approximate the recently identified 'classic' lath martensite structure: prior austenite grains are divided into packets, packets are subdivided into blocks, and blocks contain interleaved laths whose variants are the two Kurjumov–Sachs relations that share the same Bain axis of the transformation. When the steel is fractured in brittle cleavage, the laths in the block share {100} cleavage planes and cleave as a unit. However, cleavage cracks deflect or blunt at the boundaries between blocks with different Bain axes. It follows that, as predicted, the block size governs the effective grain size for cleavage.

  1. Low carbon manganese-nickel-niobium steel

    International Nuclear Information System (INIS)

    Experimental heats of a low carbon-manganese-0.5% nickel-0.15% niobium steel have been rolled to plates between 13.5 and 50 mm thickness and to a 16 mm hot strip. Various combinations of soaking temperatures form 11000C to 13000C and of finish rolling temperatures between 7100C and 9300C have been investigated. From mechanical properties obtained, one can conclude that the investigated steel composition provides very good properties e.g. for pipe steels X65 to X75. In particular, the toughness at low temperature is outstanding despite relaxed rolling conditions. Metalographic and special investigations such as electron microscopy, texture evaluation and chemical extraction, correlated with applied rolling schedules and the mechanical properties obtained resulted in a comprehensive understanding about the benefits of high niobium metallurgy combined with nickel addition. All practically applied welding processes generated mechanical properties, in particular toughness of the weldment, that meet arctic specifications.(Author)

  2. Phosphate coating on stainless steel 304 sensitized

    International Nuclear Information System (INIS)

    The stainless steel 304 can be sensitized when welding processes are applied, that causes the precipitation of chromium carbide in the grain limits, being promoted in this way the formation of galvanic cells and consequently the corrosion process. Using a phosphate coating is possible to retard the physiochemical damages that can to happen in the corrosion process. The stainless steel 304 substrate sensitized it is phosphate to base of Zn-Mn, in a immersion cell very hot. During the process was considered optimization values, for the characterization equipment of X-rays diffraction and scanning electron microscopy was used. The XRD technique confirmed the presence of the phases of manganese phosphate, zinc phosphate, as well as the phase of the stainless steel 304. When increasing the temperature from 60 to 90 C in the immersion process a homogeneous coating is obtained. (Author)

  3. Microstructure and cleavage in lath martensitic steels

    International Nuclear Information System (INIS)

    In this paper we discuss the microstructure of lath martensitic steels and the mechanisms by which it controls cleavage fracture. The specific experimental example is a 9Ni (9 wt% Ni) steel annealed to have a large prior austenite grain size, then examined and tested in the as-quenched condition to produce a relatively coarse lath martensite. The microstructure is shown to approximate the recently identified ‘classic’ lath martensite structure: prior austenite grains are divided into packets, packets are subdivided into blocks, and blocks contain interleaved laths whose variants are the two Kurjumov–Sachs relations that share the same Bain axis of the transformation. When the steel is fractured in brittle cleavage, the laths in the block share {100} cleavage planes and cleave as a unit. However, cleavage cracks deflect or blunt at the boundaries between blocks with different Bain axes. It follows that, as predicted, the block size governs the effective grain size for cleavage. (paper)

  4. Investigation of Fecraly Coating on Corrosion Behaviour of Mild Steel

    OpenAIRE

    Joseph B. AGBOOLA

    2009-01-01

    Steel has found wide application in hot rolling equipments in the steel industry and the oil rig structures in sea water. These equipments are frequently subjected to corrosive and temperature condition which causes severe damage to them, hence the need to develop steel suitable to withstand these conditions in terms of surface treatment. This research work investigates the effect of FeCrAlY coating on mild steel under high temperature and aggressive environment. Iron based coatings are used ...

  5. The Sino-Japan Steel Trade Negotiations Framework

    OpenAIRE

    Ian Dickson

    1996-01-01

    A factor influencing China's integration with world steel markets is steel's status as a canalised or "designated" commodity under Chinese trade laws. Canalisation limits the number of enterprises permitted to engage in import operations. Canalisation is particularly strict in the case of steel imports from Japan, the largest country supplier of ferrous metal products to China. Until mid-1995, steel supplies were organised under a system of bi-yearly contract negations between the Chinese sin...

  6. Contributions to steel semi-finished parts quality improvements

    International Nuclear Information System (INIS)

    The quality of finite steel products depends on steel content of hydrogen. On steel elaboration, in order to remove the dissolved hydrogen, at least one ladle secondary treatment is needed. The paper introduces the results obtained in the increase of hydrogen removal output, during steel secondary treatment inside the LF installation. Correlations were established between the hydrogen removal rate and the parameters of the secondary treatment (bubbling flow, bubbling time and bubbling pressures)

  7. Enhanced Inclusion Removal from Steel in the Tundish

    Energy Technology Data Exchange (ETDEWEB)

    R. C. Bradt; M.A.R. Sharif

    2009-09-25

    The objective of this project was to develop an effective chemical filtering system for significantly reducing the content of inclusion particles in the steel melts exiting the tundish for continuous casting. This project combined a multi-process approach that aimed to make significant progress towards an "inclusion free" steel by incorporating several interdependent concepts to reduce the content of inclusions in the molten steel exiting the tundish for the caster. The goal is to produce "cleaner" steel.

  8. Enhanced Incluison Removal from Steel in the Tundish

    Energy Technology Data Exchange (ETDEWEB)

    R.C. Bradt; M.A.R. Sharif

    2009-09-25

    The objective of this project was to develop an effective chemical filtering system for significantly reducing the content of inclusion particles in the steel melts exiting the tundish for continuous casting. This project combined a multi-process approach that aimed to make significant progress towards an "inclusion free" steel by incorporating several interdependent concepts to reduce the content of inclusions in the molten steel exiting the tundish for the caster. The goal is to produce "cleaner" steel.

  9. 46 CFR 154.172 - Contiguous steel hull structure.

    Science.gov (United States)

    2010-10-01

    ... construction of the contiguous steel hull structure must meet the thickness and steel grade in Table 1 for the... published in “Rules for Building and Classing Steel Vessels”, 1981 −10 °C (14 °F) T≤112.5 mm (1/2 in.) B 12... American Bureau of Shipping published in “Rules for Building and Classing Steel Vessels”, 1981....

  10. Mechanism of an acoustic wave impact on steel during solidification

    OpenAIRE

    K. Nowacki; P. Musiał; T. Lis

    2013-01-01

    Acoustic steel processing in an ingot mould may be the final stage in the process of quality improvement of a steel ingot. The impact of radiation and cavitation pressure as well as the phenomena related to the acoustic wave being emitted and delivered to liquid steel affect various aspects including the internal structure fragmentation, rigidity or density of steel. The article provides an analysis of the mechanism of impact of physical phenomena caused by an acoustic wave affecting the qual...

  11. Guidelines for the Protection of Steel Piles : Corrosive Marine Environment

    OpenAIRE

    Rhodes, Graham

    2011-01-01

    The corrosion of steel is a common phenomenon. In a marine environment, steel is corroded at an accelerated rate due to the atmospheric conditions. To combat this corrosion, steel piles are coated in order to protect them. As a major supplier of steel piles, Rautaruukki Oyj (Ruukki) commissioned this project in order to streamline their coating process. Currently Ruukki supplies a different coating system for almost every job; the aim of the project was to reduce the number of systems used to...

  12. Case Hardening of Hardox 450 Steel for Increased Ballistic Strength

    OpenAIRE

    Buberg, Tor Arne

    2011-01-01

    AbstractSteel alloys are the material that is most used in protective constructions today. The reason is the overall good properties of steels, with its high strength and hardness, high ductility, high formability and relatively low cost compared to other materials. Even though armour steels are affordable, work is done to limit expenses from production or come up with new and less expensive alloys.Case hardening is a technique for production of steel with a very hard and durable surface whil...

  13. Bending resistance of composite steel truss and concrete beam

    OpenAIRE

    Silva, Mickael; Piloto, P.A.G.; Roque, Sérgio; VILA REAL Paulo; Plizzari, Giovanni

    2013-01-01

    This study presents the numerical simulation of the bending resistance of CSTCB in stage 1 (element made only by the self-supported steel truss and base plate). Two different base plates were considered (Steel and Concrete) and two different types of steel trusses (Type I and II). The numerical results are also compared with analytical results, assuming the full interaction between steel truss and concrete, neglecting the tensile strength of concrete, considering the effective area of concret...

  14. Nickel-free austenitic stainless steels for medical applications

    OpenAIRE

    Ke Yang and Yibin Ren

    2010-01-01

    The adverse effects of nickel ions being released into the human body have prompted the development of high-nitrogen nickel-free austenitic stainless steels for medical applications. Nitrogen not only replaces nickel for austenitic structure stability but also much improves steel properties. Here we review the harmful effects associated with nickel in medical stainless steels, the advantages of nitrogen in stainless steels, and emphatically, the development of high-nitrogen nickel-free stainl...

  15. Initial oxidation of duplex stainless steel 2205

    Energy Technology Data Exchange (ETDEWEB)

    Donik, E.; Kocijan, A.; Jenko, M. [Institute of metals and technology, Ljubljana (Slovenia)

    2009-07-01

    Due to superior mechanical and corrosion properties of duplex stainless steels which result in weight reduction of the constructions, thus contributing to the decreases in total costs and also due to the large and versatile usage of the alloy, duplex stainless steel is gradually displacing stainless steels of the AISI 300 series. Pickling of duplex stainless steel has proven to be much more difficult than that of standard austenitic grade (AISI 300 series). There is no complete agreement in the literature on scale (high temperature oxidation) dissolution mechanism in neutral pickling solutions. During annealing, duplex stainless steel is heated in annealing furnace up to 1050 C and is kept at this temperature for some time to soften the metal in order to release the work hardening induced by hot and cold rolling. The elimination of surface defects by forming the oxide scale is required to improve the corrosion resistance. Three different techniques were used to produce thin oxide layers on polished and sputter cleaned duplex stainless steel samples. They were exposed to 10{sup -5} mb pure oxygen inside the vacuum chamber, exposed to ambient conditions for 24 hours and plasma oxidized. Oxide layers thus produced were analysed using XPS depth profiling for determination of the oxide layer's composition with depth. It was found that all techniques produce oxide layer with different traces of metallic components and with chromium oxide maximum concentration shifted towards the oxide layer - bulk metal interface. Depletion of Cr in bulk immediately below the interface was also observed. Simplified ARXPS procedure was used to corroborate thickness estimates for thinnest oxide layers. (authors)

  16. Electropolishing and chemical passivation of austenitic steel

    Directory of Open Access Journals (Sweden)

    A. Baron

    2008-12-01

    Full Text Available Purpose: The aim of the paper is investigations a dependence between the parameters of the electrochemical treatment of austenitic steel and their electrochemical behavior in Tyrod solution.Design/methodology/approach: Specimens (rode 30 mm × ø1 mm were to give in to the surface treatment – mechanically polishing, electrolytic polishing and passivation with various parameter. Electrochemical investigations concerning the corrosion resistance of austenitic steel samples were carried out by means of the potentiodynamic and electrochemical impedance spectroscopy method.Findings: The analysis of the obtained results leads to the conclusion that chemical passivation affects also the chemical composition of the passive layer of steel and changes its resistance to corrosion. Electrolytic polishing improves corrosion resistance, as can be proved by the shift of the value of the corrosion potential and break-down potential of the passive layer and the initiation of pittings.Research limitations/implications: The obtained results are the basis for the optimization of anodic passivation parameters of the austenitic steel as a metallic biomaterial. The future research should be focused on selected more suitable parameters of the electrochemical impedance spectroscopy test to better describe process on the solid/ liquid interface.Practical implications: In result of the presented investigations it has been found that the best corrosion resistance can be achieved thanks to the application of electrolytic polishing of the steel in a special bath and chemical passivation in nitric (V acid with an addition of chromic (VI acid temperature t = 60°C for one hour.Originality/value: The enormous demand for metal implants has given rise to a search for cheap materials with a good biotolerance and resistance to corrosion. Most commonly used are steel implants assigned to remain in the organism for some limited time only. It was compare two electrochemical methods

  17. Advanced cold rolled steels for automotive applications

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, H. [ThyssenKrupp Steel AG, Eberhardstrasse 12, 44145 Dortmund (Germany); Mattissen, D.; Schaumann, T.W. [ThyssenKrupp Steel AG, Duisburg (Germany)

    2006-09-15

    Advanced multiphase steels offer a great potential for bodies-in-white through their combination of formability and achievable component strength levels. They are first choice for strength and crash-relevant parts of challenging geometry. The intensive development of high-strength multiphase steels by ThyssenKrupp has led to hot dip galvanizing concepts with an outstanding forming potential. Hot rolled, hot dip galvanized complex phase steels are currently produced in addition to cold rolled DP and RA steels. New continuously annealed grades with tensile strength levels of up to 1000 MPa in combination with sufficient ductility for applications mainly in the field of structural automobile elements make use of the classic advantages of microalloying as well as the principles of DP and TRIP steels. Further improvement of properties will be reached by the new class of high manganese alloyed steels. (Abstract Copyright [2006], Wiley Periodicals, Inc.) [German] Fortschrittliche Multiphasen-Staehle eroeffnen wegen der inzwischen erreichbaren Kombination aus Umformbarkeit und Bauteilfestigkeit ein enormes Potenzial fuer Rohkarosserien. Sie stellen eine erste Wahl dar, wenn es um Festigkeit und um Crashsicherheit geht und besondere Anforderungen an die Bauteilgeometrien gestellt werden. Bei ThyssenKrupp hat die Entwicklung hochfester Multiphasen-Staehle in Verbindung mit dem Feuerverzinken zur Realisierung von Blechhalbzeugen gefuehrt, die hervorragend formbar sind. Es werden heute feuerverzinkte Komplexphasenstaehle neben den bewaehrten kaltgewalzten Dualphasen(DP) - und Retained Austenit(RA)-Staehlen produziert. Die neuen kontinuierlich gegluehten Stahlvarianten mit Festigkeiten bis zu 1000 MPa in Kombination mit der bei Strukturbauteilen im Automobilbau geforderten Duktilitaet nutzen sowohl die klassischen Vorteile des Mikrolegierens aus und dazu die Prinzipien, die man bei DP- und TRIP-Staehlen anwendet. Eine weitere Verbesserung des Eigenschaftsprofils wird mit dem

  18. Hydrogen degradation of high strength weldable steels

    Directory of Open Access Journals (Sweden)

    J. Ćwiek

    2007-01-01

    Full Text Available Purpose: Purpose of this paper is presentation of hydrogen degradation issue of high strength steels andespecially their welded joints. Establishing of applicable mechanisms of hydrogen-enhanced cracking was theaim of performed research.Design/methodology/approach: High strength quenched and tempered steels grade S690Q were used. Weldedjoints were prepared with typical technology used in shipyards. Susceptibility to hydrogen degradation in seawater under cathodic polarization was evaluated with the use of mechanical tests. Various kinds of loads wereapplied, i.e. monotonically increasing static, constant, and cyclic. Appropriate measures of hydrogen degradationwere chosen and analyzed. Mechanisms of hydrogen degradation were detected and established on the basis ofscanning electron microscopy (SEM observation of fracture samples surface.Findings: Tested high strength steels and their welded joints are susceptible to hydrogen embrittlement whenevaluated using a slow strain rate test (SSRT. On contrary, these steels and welded joints have high resistance tohydrogen delayed cracking under a constant load test. Significant reduction of a fatigue life time due to hydrogenabsorption has been observed during severe low-cycle fatigue tests.Research limitations/implications: There is no possibility to perform direct observation of exact hydrogenassistedcracking mechanisms in massive samples. Valid hydrogen-enhanced cracking model could be onlydeducted from degradation evidences like plasticity loss and fracture modes.Practical implications: Tested quenched and tempered S690Q steel grades could be safely utilized for marinewelded constructions under cathodic polarization. Hydrogen-assisted cracking should not occur unless a hugeoverprotection and plastic deformation take place.Originality/value: Hydrogen-enhanced localized plasticity (HELP model is the most applicable mechanism ofhydrogen degradation for weldable steels with yield strength up to 1000 MPa.

  19. Steel castings Ultrasonic examination, Part 2: Steel castings for highly stressed components

    CERN Document Server

    International Organization for Standardization. Geneva

    2004-01-01

    This European Standard specifies the requirements for the ultrasonic examination of steel castings (with ferritic structure) for highly stressed components and the methods for determining internal discontinuities by the pulse echo technique. This European Standard applies to the ultrasonic examination of steel castings which have usually received a grain refining heat treatment and which have wall thicknesses up to and including 600 mm. For greater wall thicknesses, special agreements apply with respect to test procedure and recording levels. This European Standard does not apply to austenitic steels and joint welds.

  20. Designing of the chemical composition of steels basing on the hardenability of constructional steels

    International Nuclear Information System (INIS)

    The paper presents the original method of modelling of the relationships between chemical composition of alloy constructional steel and its hardenability, employing neural networks. Basing on the experimental results of the hardenability investigations, which employed Jominy method, the model of the neural networks was developed and fully verified experimentally. The model makes it possible to obtain Jominy hardenability curves basing on the steel chemical composition. The model of neural networks, making it possible to design the steel chemical composition, basing on the known Jominy hardenability curve shape, was developed also and fully verified numerically. (author)