WorldWideScience

Sample records for treated steel pipe

  1. 49 CFR 192.55 - Steel pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for use...

  2. Defect rates in butt welded steel pipes

    International Nuclear Information System (INIS)

    Guille-Stevens, D.; Silcock, P.

    1980-01-01

    As the primary circuit of CANDU reactors consists largely of pipe, the reliability of pipe welds is of interest to reactor designers. A project involving 64 000 manual and semi-automatic pipe welds was inspected to the requirements of ANSI B31.3. Records of 6 000 carbon steel and 1 900 alloy steel butt welds ranging from 50 to 400 mm were inspected by radiography and ultrasonics, and analysed. No correlation between defects and number of weld passes was observed. However, small pipes exhibited a higher defect rate, per weld length and per weld volume, than did large pipes. Porosity was the major cause of defects (60 per cent) followed by root defects (27 per cent); only one crack was recorded. The results show that small (50 mm) pipe welds have the highest defect rate; however, the low overall rate shows that high standards can be maintained over many thousand welds [af

  3. Thermal aging of primary coolant pipe steel

    International Nuclear Information System (INIS)

    Miller, M.K.; Bentley, J.; Brenner, S.S.; Spitznagel, J.A.

    1985-01-01

    The long term mechanical integrity of the pipes used to carry the primary cooling water in a pressurized water nuclear reactor is of the utmost importance for safe operation. A combined atom probe field-ion microscopy (APFIM) and transmission electron microscopy (TEM) study was performed to characterize the microstructure of this cast stainless steel and to determine the changes that occur during long-term low-temperature thermal aging. The material used in this investigation was a commercial CF 8 type stainless. The steel was examined in the as-cast, unaged condition and also after aging for 7500 h at 673K. 3 refs., 4 figs., 2 tabs

  4. Morbidity profile of steel pipe production workers.

    Science.gov (United States)

    Pandit, Kirti; Tiwari, Rajnarayan R

    2008-08-01

    To study the different morbid conditions among steel pipe producing workers. The present cross-sectional study has been carried out among the workers of one of the steel pipes and tubes manufacturing factory of Gujarat. Hundred workers from the four major departments of the steel pipe production plant, namely welding, pressing machine, X-ray welding and loading/transportation department were covered. The information regarding demographic, occupational, clinical characteristics and diagnosis were recorded on a pre-designed proforma. Statistical analysis included calculation of percentages and proportions and was carried out using the statistical software Epi Info Version 3.3.2. The mean age of the study subjects was found to be 38.7+/-7.1 years. The mean duration of exposure was found to be 9.0+/-3.4 years. Forty-four percent of the subjects had an upper respiratory tract infection, as evidenced by symptoms like dry cough, cough with rhinitis and cough with fever. Symptoms suggestive of allergic bronchitis were observed in 12% of the subjects while symptoms suggestive of heat stress such as prickly heat, dehydration, perspiration and pyrexia were observed in 13% of the subjects.

  5. Modelling of the viscoelastic behaviour of steel reinforced thermoplastic pipes

    NARCIS (Netherlands)

    Kruijer, M.P.; Warnet, Laurent; Akkerman, Remko

    2006-01-01

    This paper describes the analysis of the time dependent behaviour of a steel reinforced thermoplastic pipe. This new class of composite pipes is constructed of a HDPE (high-density polyethylene) liner pipe, which is over wrapped with two layers of thermoplastic tape. The thermoplastic tapes are

  6. EFFORT OF STEEL PIPE JACKING IN TERMS OF IMPERFECTION PIPES AND HETEROGENEITY OF GROUND

    Directory of Open Access Journals (Sweden)

    K. Górski

    2016-06-01

    Full Text Available Purpose. The article presents problem of the influence of local inhomogeneities of ground on the internal forces in the steel pipe. Methodology. The authors presented the differences in the distributions of earth pressures for the pipes. One of the most common methods is the microtunneling technology. The examples of numerical analysis by finite element method (FEM have been calculated. Findings. The results of numerical analysis are presented for selected ground conditions and the distribution of internal forces in the flexible section of the steel pipe is also shown. Originality and Practical value. The obtained results clearly show the influence of flexural rigidity of the pipe on the internal forces, the influence of flexural rigidity and the soil stiffness on the size of the bending moments in the steel of pipe jacking. They depend on the interaction of soil – steel pipe.

  7. Crack stability analysis of low alloy steel primary coolant pipe

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T.; Kameyama, M. [Kansai Electric Power Company, Osaka (Japan); Urabe, Y. [Mitsubishi Heavy Industries, Ltd., Takasago (Japan)] [and others

    1997-04-01

    At present, cast duplex stainless steel has been used for the primary coolant piping of PWRs in Japan and joints of dissimilar material have been applied for welding to reactor vessels and steam generators. For the primary coolant piping of the next APWR plants, application of low alloy steel that results in designing main loops with the same material is being studied. It means that there is no need to weld low alloy steel with stainless steel and that makes it possible to reduce the welding length. Attenuation of Ultra Sonic Wave Intensity is lower for low alloy steel than for stainless steel and they have advantageous inspection characteristics. In addition to that, the thermal expansion rate is smaller for low alloy steel than for stainless steel. In consideration of the above features of low alloy steel, the overall reliability of primary coolant piping is expected to be improved. Therefore, for the evaluation of crack stability of low alloy steel piping to be applied for primary loops, elastic-plastic future mechanics analysis was performed by means of a three-dimensioned FEM. The evaluation results for the low alloy steel pipings show that cracks will not grow into unstable fractures under maximum design load conditions, even when such a circumferential crack is assumed to be 6 times the size of the wall thickness.

  8. Construction of Steel Pipe Sheet Piles with Newly Developed Joint ...

    African Journals Online (AJOL)

    H-joint in steel pipe sheet piles (SPSP) is introduced and developed, the joint is made by welding a cylindrical steel pile on either side of an H steel section, welding is continuous along their lengths therefore it is completely waterproof with high strength; the two connected piles are installed simultaneously hence short ...

  9. 49 CFR 192.105 - Design formula for steel pipe.

    Science.gov (United States)

    2010-10-01

    ... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following formula: P=(2 St/D)×F×E×T P=Design pressure in pounds per square inch (kPa) gauge. S=Yield strength in... external loads in accordance with § 192.103 may not be included in computing design pressure. F=Design...

  10. Quality control of stainless steel pipings for nuclear power generation

    International Nuclear Information System (INIS)

    Miki, Minoru; Kitamura, Ichiro; Ito, Hisao; Sasaki, Ryoichi

    1979-01-01

    The proportion of nuclear power in total power generation is increasing recently in order to avoid the concentrated dependence on petroleum resources, consequently the reliability of operation of nuclear power plants has become important. In order to improve the reliability of plants, the reliability of each machine or equipment must be improved, and for the purpose, the quality control at the time of manufacture is the important factor. The piping systems for BWRs are mostly made of carbon steel, and stainless steel pipings are used for the recirculation system cooling reactors and instrumentation system. Recently, grain boundary type stress corrosion cracking has occurred in the heat-affected zones of welded stainless steel pipings in some BWR plants. In this paper, the quality control of stainless steel pipings is described from the standpoint of preventing stress corrosion cracking in BWR plants. The pipings for nuclear power plants must have sufficient toughness so that the sudden rupture never occurs, and also sufficient corrosion resistance so that corrosion products do not raise the radioactivity level in reactors. The stress corrosion cracking occurred in SUS 304 pipings, the factors affecting the quality of stainless steel pipings, the working method which improves the corrosion resistance and welding control are explained. (Kako, I.)

  11. 76 FR 76437 - Certain Welded Stainless Steel Pipe From Korea and Taiwan

    Science.gov (United States)

    2011-12-07

    ... COMMISSION Certain Welded Stainless Steel Pipe From Korea and Taiwan Determination On the basis of the record... revocation of the antidumping duty orders on certain welded stainless steel pipe from Korea and Taiwan would... Publication 4280 (December 2011), entitled Certain Welded Stainless Steel Pipe from Korea and Taiwan...

  12. 75 FR 53714 - Stainless Steel Butt-Weld Pipe Fittings From Japan, Korea, and Taiwan

    Science.gov (United States)

    2010-09-01

    ... 564 (Third Review)] Stainless Steel Butt-Weld Pipe Fittings From Japan, Korea, and Taiwan AGENCY... antidumping duty orders on stainless steel butt-weld pipe fittings from Japan, Korea, and Taiwan. SUMMARY: The... stainless steel butt-weld pipe fittings from Japan, Korea, and Taiwan would be likely to lead to...

  13. 49 CFR 192.309 - Repair of steel pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Repair of steel pipe. 192.309 Section 192.309 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS...

  14. SCC-induced failure of a 304 stainless steel pipe

    International Nuclear Information System (INIS)

    Tapping, R.L.; Disney, D.J.; Szostak, F.J.

    1993-01-01

    On 1991 January 12, a 304 Stainless Steel (SS) suction line in the AECL-Research NRU reactor failed, shutting down the reactor for approximately 12 months. The pipe, a 32 mm schedule 40 304 stainless steel line exposed to D 2 O at temperatures ≤35 degrees C had been in service for approximately 20 years, although no manufacturing data or composition specifications were available. The failure and resultant leak resulted in a small loss of D 2 O moderator from the reactor vessel. The pipe cracked approximately 180 degrees C around the circumference of a weld. This failure was unexpected and hense a thorough metallographic examination was carried out on the failed section, on the rest of the line (Line 1212), and on representative samples from the rest of the reactor in order to assess the integrity of the remaining piping

  15. The method for measuring residual stress in stainless steel pipes

    International Nuclear Information System (INIS)

    Shimov, Georgy; Rozenbaum, Mikhail; Serebryakov, Alexandr; Serebryakov, Andrey

    2016-01-01

    The main reason of appearance and growth of corrosion damages of the nuclear steam generator heat exchanger tubes is the process of stress-corrosion cracking of metal under the influence of residual tensile stress. Methods used in the production for estimating residual stresses (such as a method of ring samples) allow measuring only the average tangential stress of the pipe wall. The method of ring samples does not allow to assess the level of residual stress in the surface layer of the pipe. This paper describes an experimental method for measuring the residual stresses on the pipe surface by etching a thin surface layer of the metal. The construction and working principle of a trial installation are described. The residual stresses in the wall of the tubes 16 × 1.5 mm (steel AISI 321) for nuclear steam generators is calculated. Keywords: heat exchange pipes, stress corrosion cracking, residual stresses, stress distribution, stress measurement.

  16. Moment resistance of steel pipes subjected to combined loads

    International Nuclear Information System (INIS)

    Ozkan, Istemi F.; Mohareb, Magdi

    2009-01-01

    The first part of this paper provides a review of recent investigations on steel pipes subjected to combined loads. Attention is given to studies involving both numerical and experimental components aimed at quantifying the modified moment resistance of pipes subjected to internal pressure and axial force. The comparison of experimental and finite element results indicate that the nonlinear shell finite element analysis is a reliable tool for predicting moment capacities of pipes. The second part of the paper reports two additional full-scale tests recently conducted at the University of Ottawa aimed at expanding the existing experimental database to pipes subjected to more complex load combinations involving twisting moment and shear (in addition to axial force, internal pressure, and bending). The finite element analysis for both tests is shown to provide excellent predictions of pipe moment capacity. The third part of the paper is a systematic parametric study based on the FEA model verified in previous and present investigations, aimed to assess the ability of pipe sections to attain their modified elastic and/or plastic moment resistance as predicted by analytically derived interaction equations. The parameters investigated are the applied torsion, internal pressure, axial force, and the diameter-to-thickness ratio of the pipe

  17. Steel Fibers Reinforced Concrete Pipes - Experimental Tests and Numerical Simulation

    Science.gov (United States)

    Doru, Zdrenghea

    2017-10-01

    The paper presents in the first part a state of the art review of reinforced concrete pipes used in micro tunnelling realised through pipes jacking method and design methods for steel fibres reinforced concrete. In part two experimental tests are presented on inner pipes with diameters of 1410mm and 2200mm, and specimens (100x100x500mm) of reinforced concrete with metal fibres (35 kg / m3). In part two experimental tests are presented on pipes with inner diameters of 1410mm and 2200mm, and specimens (100x100x500mm) of reinforced concrete with steel fibres (35 kg / m3). The results obtained are analysed and are calculated residual flexural tensile strengths which characterise the post-cracking behaviour of steel fibres reinforced concrete. In the third part are presented numerical simulations of the tests of pipes and specimens. The model adopted for the pipes test was a three-dimensional model and loads considered were those obtained in experimental tests at reaching breaking forces. Tensile stresses determined were compared with mean flexural tensile strength. To validate tensile parameters of steel fibres reinforced concrete, experimental tests of the specimens were modelled with MIDAS program to reproduce the flexural breaking behaviour. To simulate post - cracking behaviour was used the method σ — ε based on the relationship stress - strain, according to RILEM TC 162-TDF. For the specimens tested were plotted F — δ diagrams, which have been superimposed for comparison with the similar diagrams of experimental tests. The comparison of experimental results with those obtained from numerical simulation leads to the following conclusions: - the maximum forces obtained by numerical calculation have higher values than the experimental values for the same tensile stresses; - forces corresponding of residual strengths have very similar values between the experimental and numerical calculations; - generally the numerical model estimates a breaking force greater

  18. 75 FR 77838 - Circular Welded Non-Alloy Steel Pipe From the Republic of Korea: Preliminary Results of the...

    Science.gov (United States)

    2010-12-14

    ... related industries. Unfinished conduit pipe is also included in this review. All carbon-steel pipes and... used actual pipe size in millimeters instead of nominal pipe size, because SeAH works with actual...

  19. 76 FR 76369 - Circular Welded Non-Alloy Steel Pipe From the Republic of Korea: Preliminary Results of the...

    Science.gov (United States)

    2011-12-07

    ... related industries. Unfinished conduit pipe is also included in this review. All carbon-steel pipes and... used actual pipe size in millimeters instead of nominal pipe size because SeAH works with actual...

  20. Fracture properties evaluation of stainless steel piping for LBB applications

    International Nuclear Information System (INIS)

    Kim, Y.J.; Seok, C.S.; Chang, Y.S.

    1997-01-01

    The objective of this paper is to evaluate the material properties of SA312 TP316 and SA312 TP304 stainless steels and their associated welds manufactured for shutdown cooling line and safety injection line of nuclear generating stations. A total of 82 tensile tests and 58 fracture toughness tests on specimens taken from actual pipes were performed and the effect of various parameters such as the pipe size, the specimen orientation, the test temperature and the welding procedure on the material properties are discussed. Test results show that the effect of the test temperature on the fracture toughness was significant while the effects of the pipe size and the specimen orientation on the fracture toughness were negligible. The material properties of the GTAW weld metal was in general higher than those of the base metal

  1. Fatigue crack growth in austenitic stainless steel piping

    International Nuclear Information System (INIS)

    Bethmont, M.; Cheissoux, J.L.; Lebey, J.

    1981-04-01

    The study presented in this paper is being carried out with a view to substantiating the calculations of the fatigue crack growth in pipes made of 316 L stainless steel. The results obtained may be applied to P.W.R. primary piping. It is divided into two parts. First, fatigue tests (cyclic pressure) are carried out under hot and cold conditions with straight pipes machined with notches of various dimensions. The crack propagation and the fatigue crack growth rate are measured here. Second, calculations are made in order to interpret experimental results. From elastic calculations the stress intensity factor is assessed to predict the crack growth rate. The results obtained until now and presented in this paper relate to longitudinal notches

  2. Fracture properties evaluation of stainless steel piping for LBB applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y.J.; Seok, C.S.; Chang, Y.S. [Sung Kyun Kwan Univ., Suwon (Korea, Republic of)

    1997-04-01

    The objective of this paper is to evaluate the material properties of SA312 TP316 and SA312 TP304 stainless steels and their associated welds manufactured for shutdown cooling line and safety injection line of nuclear generating stations. A total of 82 tensile tests and 58 fracture toughness tests on specimens taken from actual pipes were performed and the effect of various parameters such as the pipe size, the specimen orientation, the test temperature and the welding procedure on the material properties are discussed. Test results show that the effect of the test temperature on the fracture toughness was significant while the effects of the pipe size and the specimen orientation on the fracture toughness were negligible. The material properties of the GTAW weld metal was in general higher than those of the base metal.

  3. Ferrittic steels sodium cooled fast reactor piping: an alternative to austenitic stainless steels

    International Nuclear Information System (INIS)

    Dubey, J.K.; Athmalingam, S.; Balasubramaniyan, V.; Srinivasan, G.

    2016-01-01

    Piping for Nuclear Steam Supply System (NSSS) in sodium cooled fast reactor constitutes a significant portion of the total plant cost. Optimal choice of piping material is therefore essential from the economy consideration. Material selection also plays an important role in reliable and safe operation of fast breeder reactor. The major factors considered in the selection of material include compatibility of material, operating conditions, availability of design data in nuclear codes, ease of fabrication, international experience, cost etc. Cost reduction is an important aspect for the future fast breeder reactor to be competitive. There are several components for which cheaper materials may satisfy the design requirements. Sodium piping in fast reactor is designed for low pressure and high temperature when compared to fossil power plant steam piping. Hence sodium piping is thin walled. Sodium piping has to be designed for normal, possible design basis events and transient load like seismic and sodium-water reaction pressure. This paper explores the various aspect of ferritic steel as alternative to austenitic stainless steel for piping of sodium cooled fast reactor

  4. Evaluation of stainless steel pipe cracking: causes and fixes

    International Nuclear Information System (INIS)

    Shack, W.J.; Kassner, T.F.; Maiya, P.S.; Nichols, F.A.; Park, J.Y.; Ruther, W.; Rybicki, E.F.

    1985-01-01

    This paper discusses (1) studies of impurity effects on susceptibility to intergranular stress corrosion cracking (IGSCC), (2) intergranular crack growth rate measurements, (3) finite-element studies of the residual stresses produced by induction heating stress improvement (IHSI) and the addition of weld overlays to flawed piping, (4) leak-before-break analyses of piping with 360 deg part-through cracks, and (5) parametric studies on the effect of through-wall residual stresses on intergranular crack growth behavior in large diameter piping weldments. The studies on the effect of impurities on IGSCC of Type 304 stainless steel show a strong synergistic interaction between dissolved oxygen and impurity concentration of the water. Low carbon stainless steels (Type 316NG) appear resistant to IGSCC even in impurity environments. However, they can become susceptible to transgranular SCC with low levels of sulfate or chloride present in the environment. The finite-element calculations show that IHSI and the weld overlay produce compressive residual stresses on the inner surface, and that the stresses at the crack tip remain compressive under design loads at least for shallow cracks. (author)

  5. 78 FR 45271 - Welded Stainless Steel Pressure Pipe From Malaysia, Thailand, and Vietnam

    Science.gov (United States)

    2013-07-26

    ... Stainless Steel Pressure Pipe From Malaysia, Thailand, and Vietnam Determination On the basis of the record... reason of imports from Malaysia, Thailand, and Vietnam of welded stainless steel pressure pipe, provided... appear as parties in Commission antidumping and countervailing duty investigations. The Secretary will...

  6. 75 FR 76025 - Stainless Steel Butt-Weld Pipe Fittings From Japan, Korea, and Taiwan

    Science.gov (United States)

    2010-12-07

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Stainless Steel Butt-Weld Pipe Fittings From Japan, Korea, and Taiwan AGENCY: United States... stainless steel butt-weld pipe fittings from Japan, Korea, and Taiwan would be likely to lead to...

  7. The behavior of welded joint in steel pipe members under monotonic and cyclic loading

    International Nuclear Information System (INIS)

    Chang, Kyong-Ho; Jang, Gab-Chul; Shin, Young-Eui; Han, Jung-Guen; Kim, Jong-Min

    2006-01-01

    Most steel pipe members are joined by welding. The residual stress and weld metal in a welded joint have the influence on the behavior of steel pipes. Therefore, to accurately predict the behavior of steel pipes with a welded joint, the influence of welding residual stress and weld metal on the behavior of steel pipe must be investigated. In this paper, the residual stress of steel pipes with a welded joint was investigated by using a three-dimensional non-steady heat conduction analysis and a three-dimensional thermal elastic-plastic analysis. Based on the results of monotonic and cyclic loading tests, a hysteresis model for weld metal was formulated. The hysteresis model was proposed by the authors and applied to a three-dimensional finite elements analysis. To investigate the influence of a welded joint in steel pipes under monotonic and cyclic loading, three-dimensional finite elements analysis considering the proposed model and residual stress was carried out. The influence of a welded joint on the behavior of steel pipe members was investigated by comparing the analytical result both steel pipe with a welded joint and that without a welded joint

  8. Use of Nitrocarburizing for Strengthening Threaded Joints of Drill Pipes from Medium-Carbon Alloy Steels

    Science.gov (United States)

    Priymak, E. Yu.; Stepanchukova, A. V.; Yakovleva, I. L.; Tereshchenko, N. A.

    2015-05-01

    Nitrocarburizing is tested at the Drill Equipment Plant for reinforcing threaded joints of drill pipes for units with retrievable core receiver (RCR). The effect of the nitrocarburizing on the mechanical properties of steels of different alloying systems is considered. Steels for the production of threaded joints of drill pipes are recommended.

  9. Research on Buckling State of Prestressed Fiber-Strengthened Steel Pipes

    Science.gov (United States)

    Wang, Ruheng; Lan, Kunchang

    2018-01-01

    The main restorative methods of damaged oil and gas pipelines include welding reinforcement, fixture reinforcement and fiber material reinforcement. Owing to the severe corrosion problems of pipes in practical use, the research on renovation and consolidation techniques of damaged pipes gains extensive attention by experts and scholars both at home and abroad. The analysis of mechanical behaviors of reinforced pressure pipelines and further studies focusing on “the critical buckling” and intensity of pressure pipeline failure are conducted in this paper, providing theoretical basis to restressed fiber-strengthened steel pipes. Deformation coordination equations and buckling control equations of steel pipes under the effect of prestress is deduced by using Rayleigh Ritz method, which is an approximation method based on potential energy stationary value theory and minimum potential energy principle. According to the deformation of prestressed steel pipes, the deflection differential equation of prestressed steel pipes is established, and the critical value of buckling under prestress is obtained.

  10. 77 FR 73674 - Circular Welded Carbon-Quality Steel Pipe From India, Oman, The United Arab Emirates, and Vietnam

    Science.gov (United States)

    2012-12-11

    ...-1191-1194 (Final)] Circular Welded Carbon-Quality Steel Pipe From India, Oman, The United Arab Emirates... of circular welded carbon-quality steel pipe from India, Oman, the United Arab Emirates, and Vietnam...- quality steel pipe from India, Oman, the United Arab Emirates, and Vietnam were subsidized and/or dumped...

  11. 76 FR 66893 - Certain Circular Welded Carbon Steel Pipes and Tubes From India, Thailand, and Turkey; Final...

    Science.gov (United States)

    2011-10-28

    ...] Certain Circular Welded Carbon Steel Pipes and Tubes From India, Thailand, and Turkey; Final Results of... circular welded carbon steel pipes and tubes from India, Thailand, and Turkey, pursuant to section 751(c..., Thailand, and Turkey. See Antidumping Duty Order; Certain Welded Carbon Steel Standard Pipes and Tubes from...

  12. 76 FR 78614 - Welded ASTM A-312 Stainless Steel Pipe From South Korea and Taiwan: Continuation of Antidumping...

    Science.gov (United States)

    2011-12-19

    ... International Trade Administration Welded ASTM A-312 Stainless Steel Pipe From South Korea and Taiwan... welded ASTM A-312 stainless steel pipe from South Korea (Korea) and Taiwan would likely lead to.... See Welded ASTM A-312 Stainless Steel Pipe From South Korea and Taiwan: Final Results of Expedited...

  13. Examination Of Mechanical Properties And Weld Zone Of X70 Pipe Steel After Welding

    OpenAIRE

    Zakir Tas

    2017-01-01

    The demand for large diameter pipes in terms of their strength and toughness properties is increasing day by day. The quality and mechanical strength values of the steels used in new gas pipeline projects are gradually increasing. Today high strength steels are used instead of the steels with low yield values. In this study the micro-structure mechanical properties of the high strength X70 steel used in the Trans Anatolian Gas Pipeline Project TANAP were investigated before and after the weld...

  14. Development of nuclear grade type 316 stainless steel for BWR pipings

    International Nuclear Information System (INIS)

    Kowaka, Masamichi; Nagano, Hiroo; Yoshikawa, Kunihiko; Miura, Minoru; Ota, Kunio.

    1981-01-01

    The countermeasures were established against the grain boundary stress corrosion cracking in the heat-affected zone of 304 stainless steel pipings used for recirculating system and others of BWRs. Sumitomo Metal Industries, Ltd. has engaged in the development of the stainless steel having excellent resistance to stress corrosion cracking, substituting for 304 stainless steel. In order to prevent stainless steel from becoming sensitive to the grain boundary stress corrosion cracking, the reduction of carbon content, or the addition of the elements stabilizing carbon in steel are conceivable. 316 L stainless steel was selected as the base for development, because it is a low carbon steel (C <= 0.03%) and contains Mo effective for improving the pitting corrosion resistance and restricting the steel to become sensitive. The requirements for the piping materials for BWRs are the resistance to stress corrosion cracking in high temperature, high pressure water, excellent strength and weldability, and the possibility of the commercial production of pipes. For the purpose of developing 316 stainless steel pipes, the effects of Mo and trace elements on the stress corrosion cracking resistance, the effects of C, N and grain size on the strength, and the effect of N on the weldability were examined, and the composition design of 316 stainless steel for atomic energy use was carried out. The result is given. (Kako, I.)

  15. 76 FR 67473 - Stainless Steel Butt-Weld Pipe Fittings from Italy, Malaysia, and The Philippines; Institution of...

    Science.gov (United States)

    2011-11-01

    ... Butt-Weld Pipe Fittings from Italy, Malaysia, and The Philippines; Institution of Five-Year Reviews Concerning the Antidumping Duty Orders on Stainless Steel Butt-Weld Pipe Fittings From Italy, Malaysia, and... antidumping duty orders on imports of stainless steel butt-weld pipe fittings from Italy, Malaysia, and the...

  16. 76 FR 66899 - Certain Circular Welded Non-Alloy Steel Pipe From Brazil, Mexico, the Republic of Korea, and...

    Science.gov (United States)

    2011-10-28

    ... construction, shipbuilding, trucking, farm equipment, and related industries. Unfinished conduit pipe is also..., shipbuilding, trucking, farm-equipment, and related industries. Unfinished conduit pipe is also included in the... Steel Tube Works Co., Ltd 11.63 Pusan Steel Pipe Co., Ltd 4.91 All Others 6.37 Taiwan: Kao Hsing Chang...

  17. 76 FR 21331 - Certain Carbon Steel Butt-Weld Pipe Fittings From Brazil, Japan, Taiwan, Thailand, and the People...

    Science.gov (United States)

    2011-04-15

    ...-807, A-570-814] Certain Carbon Steel Butt-Weld Pipe Fittings From Brazil, Japan, Taiwan, Thailand, and... butt-weld pipe fittings from Brazil, Japan, Taiwan, Thailand, and the People's Republic of China (PRC... duty orders on carbon steel butt-weld pipe fittings from Brazil, Japan, Taiwan, Thailand, and the PRC...

  18. 49 CFR 192.115 - Temperature derating factor (T) for steel pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Temperature derating factor (T) for steel pipe... § 192.115 Temperature derating factor (T) for steel pipe. The temperature derating factor to be used in... (Celsius) Temperature derating factor (T) 250 °F (121 °C) or less 1.000 300 °F (149 °C) 0.967 350 °F (177...

  19. 77 FR 39735 - Stainless Steel Butt-Weld Pipe Fittings From Italy, Malaysia, and the Philippines

    Science.gov (United States)

    2012-07-05

    ... revocation of the antidumping duty orders on stainless steel butt-weld pipe fittings From Italy, Malaysia... Butt-Weld Pipe Fittings From Italy, Malaysia, and the Philippines Determination On the basis of the..., Malaysia, and the Philippines: Inv. Nos. 731-TA-865-867 (Second Review). Issued: June 28, 2012. By order of...

  20. The effect of cyclic and dynamic loads on carbon steel pipe

    International Nuclear Information System (INIS)

    Rudland, D.L.; Scott, P.M.; Wilkowski, G.M.

    1996-02-01

    This report presents the results of four 152-mm (6-inch) diameter, unpressurized, circumferential through-wall-cracked, dynamic pipe experiments fabricated from STS410 carbon steel pipe manufactured in Japan. For three of these experiments, the through-wall crack was in the base metal. The displacement histories applied to these experiments were a quasi-static monotonic, dynamic monotonic, and dynamic, cyclic (R = -1) history. The through-wall crack for the third experiment was in a tungsten-inert-gas weld, fabricated in Japan, joining two lengths of STS410 pipe. The displacement history for this experiment was the same history applied to the dynamic, cyclic base metal experiment. The test temperature for each experiment was 300 C (572 F). The objective of these experiments was to compare a Japanese carbon steel pipe material with US pipe material, to ascertain whether this Japanese steel was as sensitive to dynamic and cyclic effects as US carbon steel pipe. In support of these pipe experiments, quasi-static and dynamic, tensile and fracture toughness tests were conducted. An analysis effort was performed that involved comparing experimental crack initiation and maximum moments with predictions based on available fracture prediction models, and calculating J-R curves for the pipe experiments using the η-factor method

  1. Development and characterization of high collapse boron alloys heat treated pipes for oil wells; Tubos de aco TiB para aplicacao em revestimento de pocos de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Fabio A.; Silva, Ronaldo; Chad, Luis [Tenaris Confab, Pindamonhangaba SP (Brazil); Fritz, Marcelo C. [Tenaris Confab, Pindamonhangaba SP (Brazil). Dept. de Engenharia do Produto

    2008-07-01

    The utilization of OCTG (Oil Country Tubular Goods) pipes will increase with the discovery of new oil wells in ultra deep waters. This study aims to evaluate the mechanical and microstructural performance of welded and heat treated pipes through quenching and tempering using a steel project based in titanium/boron for casing pipes. The objective of this development is to present a set of techniques used during the manufacturing of heated treated ERW pipes boron allowing, discussing mechanical and metallurgical aspects of the steel project, coil conformation, heat treatment and test procedures. The results are within the limits set by the API 5CT standard. It was found that the pipes obtained good geometry and uniformity of mechanical properties, showing that this product can be applied safely and reliability as wells' casing. (author)

  2. Boiling heat transfer during impingement of two or three pipe laminar jets onto moving steel sheet

    OpenAIRE

    Fujimoto, Hitoshi; Hayashi, Naoya; Nakahara, Junya; Morisawa, Kenta; Hama, Takayuki; Takuda, Hirohiko

    2016-01-01

    The impingement of pipe laminar jets is commonly used in run-out-table cooling in hot rolling mills. In this process, a moving hot steel sheet is cooled by pipe laminar array jets. When the spacing between two neighbor jets is small in the sheet width direction, flow interaction of cooling water on the sheet is inevitable, resulting in complex heat transfer phenomena. In the present study, the boiling heat transfer during the impingement of two or three pipe laminar jets onto a moving steel s...

  3. 77 FR 41967 - Certain Circular Welded Carbon Steel Pipes and Tubes From India, Thailand, and Turkey; Certain...

    Science.gov (United States)

    2012-07-17

    ... Determination of Sales at Less Than Fair Value: Certain Circular Welded Non-Alloy Steel Pipe From Korea, 57 FR... pipe tubing used for farming and support members for reconstruction or load bearing purposes in the...

  4. Global Fatigue Life Modelling of Steel Half-pipes Bolted Connections

    NARCIS (Netherlands)

    Jovašević, S.; Correia, J. A F O; Pavlovic, M.; Rebelo, C.; De Jesus, A. M P; Veljkovic, M.; Simoes da Silva, L

    2016-01-01

    A steel hybrid structural solution for onshore wind turbine towers was proposed in the European project SHOWTIME. This solution is used in the lattice structure for the lower portion of the tower. Recently, a procedure for fatigue life estimation of steel half-pipes bolted connections applied in

  5. 49 CFR 192.112 - Additional design requirements for steel pipe using alternative maximum allowable operating...

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE..., fully killed, continuously cast steel with calcium treatment. (2) The carbon equivalents of the steel... anomalies during construction, strength testing and anticipated operational stresses. (4) The pipe must be...

  6. Structural Repair of Steel Piping by In-Situ Sleeving of Nanostructured Materials

    Science.gov (United States)

    2009-06-03

    The focus of Task 1 is to demonstrate the repair of degraded pipeline steel using patches of high strength nanocrystalline metal. As mentioned in Bi-Monthly Research Progress Report #2, the cracking caused by corrosion damage in the steel pipe sectio...

  7. AWWA C303-17 concrete pressure pipe, bar-wrapped, steel-cylinder type

    CERN Document Server

    2017-01-01

    This standard describes the manufacture of concrete pressure pipe, reinforced with a steel cylinder that is helically wrapped with mild steel bar reinforcement, in sizes ranging from 10 in. through 72 in. (250 mm through 1,830 mm), inclusive, and for working pressures up to 400 psi (2,760 kPa).

  8. Residual Stress Distribution in Carbon Steel Pipe Welded Joint Measured by Neutron Diffraction

    OpenAIRE

    Makoto, HAYASHI; Masayuki, ISHIWATA; Yukio, MORII; Nobuaki, MINAKAWA; ROOT, John H.; Mechanical Engineering Research Laboratory, Hitachi, Ltd.,; Nuclear Engineering Division, Hitachi Ltd.,; Tokai Establishment, Japan Atomic Energy Research Institute; Tokai Establishment, Japan Atomic Energy Research Institute; National Research Council of Canada

    2000-01-01

    In order to estimate crack growth behavior of fatigue and stress corrosion cracking in pipes, the residual stress distribution near the pipe weld region has to be measured through the wall thickness.Since the penetration depth of neutron is deep enough to pass through the thick pipe wall, the neutron diffraction technique for the residual stress measurement is effective for this purpose.At the first step the residual stress distribution near the weld region in a butt-welded carbon steel pipe ...

  9. Examination of the X-ray piping diagnostic system using EGS4 (measuring the thickness of a steel pipe with rust)

    International Nuclear Information System (INIS)

    Kajiwara, G.

    2001-01-01

    In a series of papers entitled 'Examination of the X-ray piping diagnostic system using EGS4' presented the proceedings of the EGS4 users' meetings, I discussed the possibility of measuring the thickness of piping walls with rust. In the present paper, I describe, based on our earlier results, how the thickness of steel pipes with rust can be measured. I conducted EGS4 simulation to measure the thickness of a combination of steel and rust and made an energy absorption diagram for this combination. The equivalent thickness of steel was obtained through experiments and the system operation. The thickness of the steel determined by using the diagram agreed well with the actual steel thickness obtained by the experiments. In the future, we will focus on how to automate this measurement procedure and how to use the same procedure to measure the thickness of pipes filled with water. (author)

  10. An Investigation of Aging Behaviour in Microalloyed Steel (X70) UOE Pipe

    Science.gov (United States)

    Wiskel, J. B.; Ma, J.; Ivey, D. G.; Henein, H.

    Aging of microalloyed steel pipe can occur at relatively low temperatures associated with the pipe coating process and/or during long term storage or use. The aging phenomenon is primarily attributed to C diffusion to dislocations and subsequent pinning of these dislocations. Important factors in the aging process include time, temperature, chemical composition and plastic deformation (arising from the pipe forming process). The work presented in this paper uses a Box-Behnken experimental design to determine the effect of time, temperature, location in the UOE pipe (90° or 180° to the weld), position through the pipe wall thickness (ID, CL or OD) and the steel's C/Nb ratio (0.60, 1.25 and 1.80) on the change in yield strength of three (uncoated) X70 UOE pipes. Quantitative microstructure analysis is undertaken to determine the grain size and microconstituent fractions of the as-received pipe material. Quadratic equations and response surface(s) correlating the significant aging variables with changes in the longitudinal yield stress of the pipe are developed. Both through thickness position and the C/Nb ratio, followed by aging temperature, had the largest effect on the change in longitudinal yield strength.

  11. Finite element thermal analysis of the fusion welding of a P92 steel pipe

    Directory of Open Access Journals (Sweden)

    A. H. Yaghi

    2012-05-01

    Full Text Available Fusion welding is common in steel pipeline construction in fossil-fuel power generation plants. Steel pipes in service carry steam at high temperature and pressure, undergoing creep during years of service; their integrity is critical for the safe operation of a plant. The high-grade martensitic P92 steel is suitable for plant pipes for its enhanced creep strength. P92 steel pipes are usually joined together with a similar weld metal. Martensitic pipes are sometimes joined to austenitic steel pipes using nickel based weld consumables. Welding involves severe thermal cycles, inducing residual stresses in the welded structure, which, without post weld heat treatment (PWHT, can be detrimental to the integrity of the pipes. Welding residual stresses can be numerically simulated by applying the finite element (FE method in Abaqus. The simulation consists of a thermal analysis, determining the temperature history of the FE model, followed by a sequentially-coupled structural analysis, predicting residual stresses from the temperature history.

    In this paper, the FE thermal analysis of the arc welding of a typical P92 pipe is presented. The two parts of the P92 steel pipe are joined together using a dissimilar material, made of Inconel weld consumables, producing a multi-pass butt weld from 36 circumferential weld beads. Following the generation of the FE model, the FE mesh is controlled using Model Change in Abaqus to activate the weld elements for each bead at a time corresponding to weld deposition. The thermal analysis is simulated by applying a distributed heat flux to the model, the accuracy of which is judged by considering the fusion zones in both the parent pipe as well as the deposited weld metal. For realistic fusion zones, the heat flux must be prescribed in the deposited weld pass and also the adjacent pipe elements. The FE thermal results are validated by comparing experimental temperatures measured by five thermocouples on the

  12. Characterization of corrosion scale formed on stainless steel delivery pipe for reclaimed water treatment.

    Science.gov (United States)

    Cui, Yong; Liu, Shuming; Smith, Kate; Yu, Kanghua; Hu, Hongying; Jiang, Wei; Li, Yuhong

    2016-01-01

    To reveal corrosion behavior of stainless steel delivery pipe used in reclaimed water treatment, this research focused on the morphological, mineralogical and chemical characteristics of stainless steel corrosion scale and corroded passive film. Corrosion scale and coupon samples were taken from a type 304 pipe delivering reclaimed water to a clear well in service for more than 12 years. Stainless steel corrosion scales and four representative pipe coupons were investigated using mineralogy and material science research methods. The results showed corrosion scale was predominantly composed of goethite, lepidocrocite, hematite, magnetite, ferrous oxide, siderite, chrome green and chromite, the same as that of corroded pipe coupons. Hence, corrosion scale can be identified as podiform chromite deposit. The loss of chromium in passive film is a critical phenomenon when stainless steel passive film is damaged by localized corrosion. This may provide key insights toward improving a better comprehension of the formation of stainless steel corrosion scale and the process of localized corrosion. The localized corrosion behavior of stainless steel is directly connected with reclaimed water quality parameters such as residual chlorine, DO, Cl(-) and SO4(2-). In particular, when a certain amount of residual chlorine in reclaimed water is present as an oxidant, ferric iron is the main chemical state of iron minerals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. A simplified LBB evaluation procedure for austenitic and ferritic steel piping

    Energy Technology Data Exchange (ETDEWEB)

    Gamble, R.M.; Wichman, K.R.

    1997-04-01

    The NRC previously has approved application of LBB analysis as a means to demonstrate that the probability of pipe rupture was extremely low so that dynamic loads associated with postulated pipe break could be excluded from the design basis (1). The purpose of this work was to: (1) define simplified procedures that can be used by the NRC to compute allowable lengths for circumferential throughwall cracks and assess margin against pipe fracture, and (2) verify the accuracy of the simplified procedures by comparison with available experimental data for piping having circumferential throughwall flaws. The development of the procedures was performed using techniques similar to those employed to develop ASME Code flaw evaluation procedures. The procedures described in this report are applicable to pipe and pipe fittings with: (1) wrought austenitic steel (Ni-Cr-Fe alloy) having a specified minimum yield strength less than 45 ksi, and gas metal-arc, submerged arc and shielded metal-arc austentic welds, and (2) seamless or welded wrought carbon steel having a minimum yield strength not greater than 40 ksi, and associated weld materials. The procedures can be used for cast austenitic steel when adequate information is available to place the cast material toughness into one of the categories identified later in this report for austenitic wrought and weld materials.

  14. 76 FR 78313 - Circular Welded Carbon-Quality Steel Pipe From India, Oman, the United Arab Emirates, and Vietnam

    Science.gov (United States)

    2011-12-16

    ... COMMISSION Circular Welded Carbon-Quality Steel Pipe From India, Oman, the United Arab Emirates, and Vietnam... United Arab Emirates, and Vietnam of circular welded carbon- quality steel pipe, provided for in... of India, Oman, the United Arab Emirates, and Vietnam.\\2\\ \\1\\ The record is defined in sec. 207.2(f...

  15. 77 FR 37711 - Circular Welded Carbon-Quality Steel Pipe From India, Oman, the United Arab Emirates, and Vietnam...

    Science.gov (United States)

    2012-06-22

    ... COMMISSION Circular Welded Carbon-Quality Steel Pipe From India, Oman, the United Arab Emirates, and Vietnam...-fair-value imports from India, Oman, the United Arab Emirates, and Vietnam of circular welded carbon... respect to circular welded carbon-quality steel pipe from Oman and the United Arab Emirates being sold in...

  16. 75 FR 44763 - Certain Circular Welded Non-Alloy Steel Pipe From Mexico; Extension of Time Limit for Preliminary...

    Science.gov (United States)

    2010-07-29

    ... welded non- alloy steel pipe from Mexico. We also received review requests on November 30, 2009, from companies Tuberia Nacional, S.A. de C.V.'s (TUNA), Mueller Comercial de Mexico, S. de R.L. de C.V. (Mueller... International Trade Administration Certain Circular Welded Non-Alloy Steel Pipe From Mexico; Extension of Time...

  17. 76 FR 3083 - Certain Welded Carbon Steel Pipe and Tube From Turkey: Extension of Time Limit for Preliminary...

    Science.gov (United States)

    2011-01-19

    ... International Trade Administration Certain Welded Carbon Steel Pipe and Tube From Turkey: Extension of Time... administrative review of the antidumping duty order on certain welded carbon steel pipe and tube from Turkey... published in accordance with section 751(a)(3)(A) of the Act. Dated: January 12, 2011. Christian Marsh...

  18. 76 FR 71938 - Circular Welded Carbon Steel Pipes and Tubes From Thailand: Extension of Time Limit for...

    Science.gov (United States)

    2011-11-21

    ... International Trade Administration Circular Welded Carbon Steel Pipes and Tubes From Thailand: Extension of Time... the antidumping duty order on circular welded carbon steel pipes and tubes from Thailand for the...: November 15, 2011. Christian Marsh, Deputy Assistant Secretary for Antidumping and Countervailing Duty...

  19. 77 FR 2511 - Certain Welded Carbon Steel Pipe and Tube From Turkey: Extension of Time Limit for Preliminary...

    Science.gov (United States)

    2012-01-18

    ... International Trade Administration Certain Welded Carbon Steel Pipe and Tube From Turkey: Extension of Time... administrative review of the antidumping duty order on certain welded carbon steel pipe and tube from Turkey...)(A) and 777(i)(1) of the Act. Dated: January 11, 2012. Christian Marsh, Deputy Assistant Secretary...

  20. 76 FR 65179 - Certain Welded Carbon Steel Standard Pipe From Turkey: Extension of Time for Preliminary Results...

    Science.gov (United States)

    2011-10-20

    ... International Trade Administration Certain Welded Carbon Steel Standard Pipe From Turkey: Extension of Time for... countervailing duty order on certain welded carbon steel standard pipe from Turkey covering the period of review...: October 14, 2011. Christian Marsh, Deputy Assistant Secretary for Antidumping and Countervailing Duty...

  1. 76 FR 3612 - Circular Welded Carbon Steel Pipes and Tubes From Taiwan; Extension of Time Limit for Preliminary...

    Science.gov (United States)

    2011-01-20

    ... International Trade Administration Circular Welded Carbon Steel Pipes and Tubes From Taiwan; Extension of Time... rescinding the review with respect to Yieh Hsing. See Circular Welded Carbon Steel Pipes and Tubes From... accordance with sections 751(a)(3)(A) and 777(i) of the Act. Dated: January 13, 2011. Christian Marsh, Deputy...

  2. Investigations on the Suitability of Coated Steel Piping System for High Pressure Seawater Reverse Osmosis Application

    Science.gov (United States)

    Mobin, Mohammad

    2010-03-01

    This study deals with the investigations concerning with the suitability of coated steel piping system as an economically viable alternative to costly stainless steel piping for high pressure seawater reverse osmosis (SWRO) application. The piping system selected for investigation is a carbon steel piping coated internally and externally with thermoplastic coating (coating powder Plascoat PPA 571). The performance of thermoplastic coating was investigated by conducting SWRO pilot plant test, salt spray test, mechanical tests and testing of the coating under crevices (both in pilot plant and laboratory), and for leachable organics and inorganics (both in laboratory and pilot plant test). The testing of coating in the pilot plant resulted in the formation of some blisters on the internal surface of the pipes. The blisters were broken causing the corrosion of underneath steel. The coating showed a poor resistance to salt fog test. In general, the coating performed satisfactorily under the crevices but showed blistering on either side of the test panels. The adhesive strength of the coating was found to be poor; however, it showed good flexibility. The results of chemical analysis did not show the leaching of organic or inorganic pollutants from the coating.

  3. 77 FR 14002 - Stainless Steel Butt-Weld Pipe Fittings From Italy, Malaysia, and the Philippines: Final Results...

    Science.gov (United States)

    2012-03-08

    ... antidumping duty orders on butt-weld pipe fittings from Italy, Malaysia, or the Philippines. Additionally, we... revocation of the antidumping duty orders on butt-weld pipe fittings from Italy, Malaysia, and the... Duty Orders on Stainless Steel Butt-Weld Pipe Fittings from Italy, Malaysia, and the Philippines'' from...

  4. On the impact bending test technique for high-strength pipe steels

    Science.gov (United States)

    Arsenkin, A. M.; Odesskii, P. D.; Shabalov, I. P.; Likhachev, M. V.

    2015-10-01

    It is shown that the impact toughness (KCV-40 = 250 J/cm2) accepted for pipe steels of strength class K65 (σy ≥ 550 MPa) intended for large-diameter gas line pipes is ineffective to classify steels in fracture strength. The results obtained upon testing of specimens with a fatigue crack and additional sharp lateral grooves seem to be more effective. In energy consumption, a macrorelief with splits is found to be intermediate between ductile fracture and crystalline brittle fracture. A split formation mechanism is considered and a scheme is proposed for split formation.

  5. Evaluation of residual stress distribution in austenitic stainless steel pipe butt-welded joint

    International Nuclear Information System (INIS)

    Maekawa, Akira; Noda, Michiyasu; Takahashi, Shigeru; Oumaya, Toru; Serizawa, Hisashi; Murakawa, Hidekazu

    2009-01-01

    This paper reports measured and estimated results of residual stress distributions of butt-welded austenitic stainless steel pipe in order to improve estimation accuracy of welding residual stress. Neutron diffraction and strain gauge method were employed for the measurement of the welding residual stress and its detailed distributions on inner and outer surface of the pipe as well as the distributions within the pipe wall were obtained. Finite element method was employed for the estimation. Transient and residual stresses in 3D butt-welded joint model were computed by employing Iterative Substructure Method and also commercial FEM code ABAQUS for a reference. The measured and estimated distributions presented typical characteristic of straight butt-welded pipe which had decreasing trend along the axial direction and bending type distributions through wall of the pipe. Both results were compared and the accuracy of measurement and estimation was discussed. (author)

  6. Fatigue behaviour of 316 L stainless steel pipes containing flaws

    International Nuclear Information System (INIS)

    Bethmont, M.; Cheissoux, J.L.; Lebey, J.

    1981-01-01

    The main objective is to demonstrate that crack growth laws based on CT specimen testing are valid for piping products with realistic flaws under pressure and bending loads. The study is broken down into two phases: - crack growth experiments for various notch shapes in reduced scale piping (1/4) of reactor coolant piping at room temperature and at 285 0 C. - a numerical analysis to determine the K 1 stress intensity factor for tested notch shapes. Tests were carried out on piping with longitudinal and circumferential notches inside and outside. Fatigue crack growth rates are assessed through micrographic exams. The K 1 stress intensity factor was computed by finite element methods or the use of weight functions. (orig./GL)

  7. Estimates of margins in ASME Code strength values for stainless steel nuclear piping

    International Nuclear Information System (INIS)

    Ware, A.G.

    1995-01-01

    The margins in the ASME Code stainless steel allowable stress values that can be attributed to the variations in material strength are evaluated for nuclear piping steels. Best-fit curves were calculated for the material test data that were used to determine allowable stress values for stainless steels in the ASME Code, supplemented by more recent data, to estimate the mean stresses. The mean yield stresses from the test data are about 15 to 20% greater than the ASME Code yield stress values (the stainless steel S m values are based on the yield stress). The ASME Code yield stress values are estimated to approximately coincide with the 97% confidence limit from the test data. The mean and 97% confidence limit values can be used in probabilistic risk assessments of nuclear piping

  8. Characterization of a carbon fiber reinforced polymer repair system for structurally deficient steel piping

    Science.gov (United States)

    Wilson, Jeffrey M.

    This Dissertation investigates a carbon fiber reinforced polymer repair system for structurally deficient steel piping. Numerous techniques exist for the repair of high-pressure steel piping. One repair technology that is widely gaining acceptance is composite over-wraps. Thermal analytical evaluations of the epoxy matrix material produced glass transition temperature results, a cure kinetic model, and a workability chart. These results indicate a maximum glass transition temperature of 80°C (176°F) when cured in ambient conditions. Post-curing the epoxy, however, resulted in higher glass-transition temperatures. The accuracy of cure kinetic model presented is temperature dependent; its accuracy improves with increased cure temperatures. Cathodic disbondment evaluations of the composite over-wrap show the epoxy does not breakdown when subjected to a constant voltage of -1.5V and the epoxy does not allow corrosion to form under the wrap from permeation. Combustion analysis of the composite over-wrap system revealed the epoxy is flammable when in direct contact with fire. To prevent combustion, an intumescent coating was developed to be applied on the composite over-wrap. Results indicate that damaged pipes repaired with the carbon fiber composite over-wrap withstand substantially higher static pressures and exhibit better fatigue characteristics than pipes lacking repair. For loss up to 80 percent of the original pipe wall thickness, the composite over-wrap achieved failure pressures above the pipe's specified minimum yield stress during monotonic evaluations and reached the pipe's practical fatigue limit during cyclical pressure testing. Numerous repairs were made to circular, thru-wall defects and monotonic pressure tests revealed containment up to the pipe's specified minimum yield strength for small diameter defects. The energy release rate of the composite over-wrap/steel interface was obtained from these full-scale, leaking pipe evaluations and results

  9. In situ neutron diffraction measurement of residual stress relaxation in a welded steel pipe during heat treatment

    International Nuclear Information System (INIS)

    Chen, B.; Skouras, A.; Wang, Y.Q.; Kelleher, J.F.; Zhang, S.Y.; Smith, D.J.; Flewitt, P.E.J.; Pavier, M.J.

    2014-01-01

    Many previous studies have presented results on the relaxation of residual stress in a welded component as a result of postweld heat treatment. Techniques such as neutron diffraction and deep hole drilling have been used to measure the residual stress after the heat treatment and compare this with the residual stress for the component in the as-welded condition. The work described in this paper is novel: neutron diffraction is used to measure the relaxation of residual stress continuously as the heat treatment is being carried out. Residual stresses are measured in a butt-welded ferritic steel pipe as the pipe is heat treated to 650 °C and then cooled to room temperature. The results identify those parts of the heat treatment that lead to significant stress relaxation and the mechanisms responsible for this relaxation. The techniques developed during this work allow future heat treatments to be optimised to achieve the low levels of residual stress in welded components

  10. Viscoelastic behavior and durability of steel wire - reinforced polyethylene pipes under a high internal pressure

    NARCIS (Netherlands)

    Ivanov, S.; Anoshkin, A.N.; Zuyko, V.Yu

    2011-01-01

    The strength tests of steel-wire-reinforced polyethylene pipe specimens showed that, under a constant internal pressure exceeding 80% of their short-term ultimate pressure, the fracture of the specimens occurred in less than 24 hours. At pressures slightly lower than this level, some specimens did

  11. South African performance based standards (PBS) vehicle to transport steel pipes

    CSIR Research Space (South Africa)

    Dessein, T

    2010-03-01

    Full Text Available The preliminary design of a South African PBS vehicle to transport large-bore welded steel pipes is an important milestone in developing local expertise to analyse PBS designs. The design approach has drawn extensively from the PBS measures...

  12. 49 CFR 192.107 - Yield strength (S) for steel pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Yield strength (S) for steel pipe. 192.107 Section... specification or tensile properties are unknown, the yield strength to be used in the design formula in § 192... determined by the tensile tests. (ii) The lowest yield strength determined by the tensile tests. (2) If the...

  13. 75 FR 32911 - Preliminary Results of Antidumping Duty Administrative Review: Circular Welded Carbon Steel Pipes...

    Science.gov (United States)

    2010-06-10

    ... and tubes from Taiwan, which are defined as: Welded carbon steel pipes and tubes, of circular cross... and unaffiliated customers, net of all movement charges, direct selling expenses, and packing. Where... market prices, less any applicable movement charges, discounts, rebates, and direct and indirect selling...

  14. Effect of dynamic monotonic and cyclic loading on fracture behavior for Japanese carbon steel pipe STS410

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Kanji; Murayama, Kouichi; Ogata, Hiroyuki [and others

    1997-04-01

    The fracture behavior for Japanese carbon steel pipe STS410 was examined under dynamic monotonic and cyclic loading through a research program of International Piping Integrity Research Group (EPIRG-2), in order to evaluate the strength of pipe during the seismic event The tensile test and the fracture toughness test were conducted for base metal and TIG weld metal. Three base metal pipe specimens, 1,500mm in length and 6-inch diameter sch.120, were employed for a quasi-static monotonic, a dynamic monotonic and a dynamic cyclic loading pipe fracture tests. One weld joint pipe specimen was also employed for a dynamic cyclic loading test In the dynamic cyclic loading test, the displacement was controlled as applying the fully reversed load (R=-1). The pipe specimens with a circumferential through-wall crack were subjected four point bending load at 300C in air. Japanese STS410 carbon steel pipe material was found to have high toughness under dynamic loading condition through the CT fracture toughness test. As the results of pipe fracture tests, the maximum moment to pipe fracture under dynamic monotonic and cyclic loading condition, could be estimated by plastic collapse criterion and the effect of dynamic monotonic loading and cyclic loading was a little on the maximum moment to pipe fracture of the STS410 carbon steel pipe. The STS410 carbon steel pipe seemed to be less sensitive to dynamic and cyclic loading effects than the A106Gr.B carbon steel pipe evaluated in IPIRG-1 program.

  15. Fatigue crack growth studies on type 304LN stainless steel straight pipes

    International Nuclear Information System (INIS)

    Raghava, G.

    2016-01-01

    Fatigue crack initiation and growth rate studies in different exposure and loading conditions were carried out on 26 straight pipes made of Type 304LN stainless steel, which is a widely used steel in nuclear power plant piping components. The pipe dimensions were in two categories: 170 mm OD, 15 mm thickness and 324 mm OD, 28 mm thickness. The specimens contained pre-existing flaws in the form of part-through notch in one of the following locations: base metal, heat affected zone and weld metal. Notch length varied from 7.0 mm to 127.0 mm and notch depth varied from 3.0 mm to 10.9 mm. Twenty one specimens were tested under four point bending in air environment, three under four point bending in water environment; and two under combined torsion and bending in air environment. This paper presents details of the experimental investigations and the results of the studies. (author)

  16. Evaluation of residual stresses for the multipass welds of 316L stainless steel pipe

    International Nuclear Information System (INIS)

    Kim, S. H.; Joo, Y. S.; Lee, J. H.

    2003-01-01

    It is necessary to evaluate the influence of the residual stress and distortion in the design and fabrication of welded structure and the sound welded structure can be maintained by this consideration. Multipass welds of the 316L stainless steel have been widely employed in the pipes of Liquid Metal Reactor. In this study, the residual stresses in the 316L stainless steel pipe welds were calculated by the finite element method using ANSYS code. Also, the residual stresses both on the surface and in the interior of the thickness were measured by HRPD(High Resolution Powder Diffractometer) instrumented in HANARO Reactor. The residual stresses were measured for each 18 points in small(t/d=0.075) and large pipe specimens (t/d=0.034). The experimental and calculated results were compared and the characteristics of the distribution of the residual stress discussed

  17. Evaluation of weld defects in stainless steel 316L pipe using guided wave

    International Nuclear Information System (INIS)

    Lee, Joon Hyun; Lee, Jin Kyung

    2015-01-01

    Stainless steel is a popular structural materials for liquid-hydrogen storage containers and piping components for transporting high-temperature fluids because of its superior material properties such as high strength and high corrosion resistance at elevated temperatures. In general, tungsten inert gas (TIG) arc welding is used for bonding stainless steel. However, it is often reported that the thermal fatigue cracks or initial defects in stainless steel after welding decreases the reliability of the material. The objective of this paper is to clarify the characteristics of ultrasonic guided wave propagation in relation to a change in the initial crack length in the welding zone of stainless steel. For this purpose, three specimens with different artificial defects of 5 mm, 10 mm, and 20 mm in stainless steel welds were prepared. By considering the thickness of s stainless steel pipe, special attention was given to both the L(0,1) mode and L(0,2) mode in this study. It was clearly found that the L(0,2) mode was more sensitive to defects than the L(0,1) mode. Based on the results of the L(0,1) and L(0,2) mode analyses, the magnitude ratio of the two modes was more effective than studying each mode when evaluating defects near the welded zone of stainless steel because of its linear relationship with the length of the artificial defect.

  18. Modeling of residual stress mitigation in austenitic stainless steel pipe girth weldment

    International Nuclear Information System (INIS)

    Li, M.; Atteridge, D.G.; Anderson, W.E.; West, S.L.

    1994-01-01

    This study provides numerical procedures to model 40-cm-diameter, schedule 40, Type 304L stainless steel pipe girth welding and a newly proposed post-weld treatment. The treatment can be used to accomplish the goal of imparting compressive residual stresses at the inner surface of a pipe girth weldment to prevent/retard the intergranular stress corrosion cracking (IGSCC) of the piping system in nuclear reactors. This new post-weld treatment for mitigating residual stresses is cooling stress improvement (CSI). The concept of CSI is to establish and maintain a certain temperature gradient across the pipe wall thickness to change the final stress state. Thus, this process involves sub-zero low temperature cooling of the inner pipe surface of a completed girth weldment, while simultaneously keeping the outer pipe surface at a slightly elevated temperature with the help of a certain heating method. Analyses to obtain quantitative results on pipe girth welding and CSI by using a thermo-elastic-plastic finite element model are described in this paper. Results demonstrate the potential effectiveness of CSI for introducing compressive residual stresses to prevent/retard IGSCC. Because of the symmetric nature of CSI, it shows great potential for industrial application

  19. Experimentation and numerical simulation of steel fibre reinforced concrete pipes

    International Nuclear Information System (INIS)

    Fuente, A. de la; Domingues de Figueiredo, A.; Aguado, A.; Molins, C.; Chama Neto, P. J.

    2011-01-01

    The results concerning on an experimental and a numerical study related to SFRCP are presented. Eighteen pipes with an internal diameter of 600 mm and fibre dosages of 10, 20 and 40 kg/m3 were manufactured and tested. Some technological aspects were concluded. Likewise, a numerical parameterized model was implemented. With this model, the simulation of the resistant behaviour of SFRCP can be performed. In this sense, the results experimentally obtained were contrasted with those suggested by means MAP reaching very satisfactory correlations. Taking it into account, it could be said that the numerical model is a useful tool for the optimal design of the SFRCP fibre dosages, avoiding the need of the systematic employment of the test as an indirect design method. Consequently, the use of this model would reduce the overall cost of the pipes and would give fibres a boost as a solution for this structural typology. (Author) 27 refs.

  20. Failure probability estimate of type 304 stainless steel piping

    International Nuclear Information System (INIS)

    Daugherty, W.L.; Awadalla, N.G.; Sindelar, R.L.; Mehta, H.S.; Ranganath, S.

    1989-01-01

    The primary source of in-service degradation of the SRS production reactor process water piping is intergranular stress corrosion cracking (IGSCC). IGSCC has occurred in a limited number of weld heat affected zones, areas known to be susceptible to IGSCC. A model has been developed to combine crack growth rates, crack size distributions, in-service examination reliability estimates and other considerations to estimate the pipe large-break frequency. This frequency estimates the probability that an IGSCC crack will initiate, escape detection by ultrasonic (UT) examination, and grow to instability prior to extending through-wall and being detected by the sensitive leak detection system. These events are combined as the product of four factors: (1) the probability that a given weld heat affected zone contains IGSCC; (2) the conditional probability, given the presence of IGSCC, that the cracking will escape detection during UT examination; (3) the conditional probability, given a crack escapes detection by UT, that it will not grow through-wall and be detected by leakage; (4) the conditional probability, given a crack is not detected by leakage, that it grows to instability prior to the next UT exam. These four factors estimate the occurrence of several conditions that must coexist in order for a crack to lead to a large break of the process water piping. When evaluated for the SRS production reactors, they produce an extremely low break frequency. The objective of this paper is to present the assumptions, methodology, results and conclusions of a probabilistic evaluation for the direct failure of the primary coolant piping resulting from normal operation and seismic loads. This evaluation was performed to support the ongoing PRA effort and to complement deterministic analyses addressing the credibility of a double-ended guillotine break

  1. Transient Response to Rapid Cooling of a Stainless Steel Sodium Heat Pipe

    Science.gov (United States)

    Mireles, Omar R.; Houts, Michael G.

    2011-01-01

    Compact fission power systems are under consideration for use in long duration space exploration missions. Power demands on the order of 500 W, to 5 kW, will be required for up to 15 years of continuous service. One such small reactor design consists of a fast spectrum reactor cooled with an array of in-core alkali metal heat pipes coupled to thermoelectric or Stirling power conversion systems. Heat pipes advantageous attributes include a simplistic design, lack of moving parts, and well understood behavior. Concerns over reactor transients induced by heat pipe instability as a function of extreme thermal transients require experimental investigations. One particular concern is rapid cooling of the heat pipe condenser that would propagate to cool the evaporator. Rapid cooling of the reactor core beyond acceptable design limits could possibly induce unintended reactor control issues. This paper discusses a series of experimental demonstrations where a heat pipe operating at near prototypic conditions experienced rapid cooling of the condenser. The condenser section of a stainless steel sodium heat pipe was enclosed within a heat exchanger. The heat pipe - heat exchanger assembly was housed within a vacuum chamber held at a pressure of 50 Torr of helium. The heat pipe was brought to steady state operating conditions using graphite resistance heaters then cooled by a high flow of gaseous nitrogen through the heat exchanger. Subsequent thermal transient behavior was characterized by performing an energy balance using temperature, pressure and flow rate data obtained throughout the tests. Results indicate the degree of temperature change that results from a rapid cooling scenario will not significantly influence thermal stability of an operating heat pipe, even under extreme condenser cooling conditions.

  2. Hydrogen-related stress corrosion cracking in line pipe steel

    DEFF Research Database (Denmark)

    Nielsen, Lars Vendelbo

    1997-01-01

    A correlation between hydrogen concentration (C0) and the critical stress intensity factor for propagation of hydrogen-related cracks has been established by fracture mechanical testing of CT-specimens for the heat affected zone of an X-70 pipeline steel. This has been compared with field...

  3. Examination Of Mechanical Properties And Weld Zone Of X70 Pipe Steel After Welding

    Directory of Open Access Journals (Sweden)

    Zakir Tas

    2017-07-01

    Full Text Available The demand for large diameter pipes in terms of their strength and toughness properties is increasing day by day. The quality and mechanical strength values of the steels used in new gas pipeline projects are gradually increasing. Today high strength steels are used instead of the steels with low yield values. In this study the micro-structure mechanical properties of the high strength X70 steel used in the Trans Anatolian Gas Pipeline Project TANAP were investigated before and after the welding process and the weld zone was examined. The submerger arc welding process has been employed for the weld process. While the mechanical properties were determined by tensile notched bend impact bend and hardness measurements the microstructures were examined by using optical microscope and scanning electron microscope SEM. The radiographic and ultrasonic methods were employed in the non-destructive test of the weld zone.

  4. A pattern recognition reflector classification feasibility study in the ultrasonic inspection of stainless steel pipe welds

    International Nuclear Information System (INIS)

    Rose, J.L.; Singh, G.P.

    1979-01-01

    A feasibility study has been conducted in order to evaluate the potential of pattern recognition techniques for discriminating between geometrical and crack reflector signals obtained during ultrasonic inspection of the weld zone in 304 austenitic stainless-steel pipes. The analysis did not consider any arrival time or amplitude information, but was based on various Fourier transform features. A 100% reliability level was obtained for discriminating between a crack indication and a crown indication using automated pattern recognition algorithms. The success of the pattern recognition algorithm employed in this study demonstrates the applicability of this technique for solving such problems as discrimination between intergranular stress corrosion cracking and geometric reflectors in 304 stainless-steel pipe-welds. (author)

  5. Discrimination of ultrasonic indications from austenitic stainless-steel pipe welds

    International Nuclear Information System (INIS)

    Singh, G.P.; Manning, R.C.

    1983-01-01

    The inspection of butt-welded stainless-steel pipe joints in nuclear power plants is routinely performed using ultrasonic non-destructive evaluation methods. However, discrimination between crack and geometric/weld (malignant versus benign) indications is principally based on operator experience, variations in signal amplitude, and the location of the reflector. In response to the inspection problem, a pattern-recognition methodology has been developed to discriminate intergranular stress-corrosion cracking from geometric/weld reflectors in austenitic stainless-steel pipes. Results demonstrate that the algorithm can provide discrimination comparable to or better than those supplied by well trained operators. Preliminary results show that the pattern-recognition algorithm approach yields a better than 90% index of performance. (author)

  6. 77 FR 48965 - Certain Carbon Steel Butt-Weld Pipe Fittings From the People's Republic of China: Notice of Court...

    Science.gov (United States)

    2012-08-15

    ... that the scope language of the Order contains an end-use element that results in the exclusion of pipe... read the scope language at issue as not constituting an end-use restriction, such that King's imported... International Trade Administration Certain Carbon Steel Butt-Weld Pipe Fittings From the People's Republic of...

  7. 77 FR 42697 - Stainless Steel Butt-Weld Pipe Fittings From Italy, Malaysia, and the Philippines: Continuation...

    Science.gov (United States)

    2012-07-20

    ... from Italy, Malaysia, and the Philippines.\\2\\ \\1\\ See Antidumping Duty Orders: Stainless Steel Butt... revocation of the antidumping duty orders on butt-weld pipe fittings from Italy, Malaysia, and the... continuation of the antidumping duty orders on butt-weld pipe fittings from Italy, Malaysia, and the...

  8. 77 FR 10773 - Stainless Steel Butt-Weld Pipe Fittings From Italy, Malaysia, and the Philippines; Scheduling of...

    Science.gov (United States)

    2012-02-23

    ... Butt-Weld Pipe Fittings From Italy, Malaysia, and the Philippines; Scheduling of Expedited Five-Year... Act of 1930 (19 U.S.C. 1675(c)(3)) (the Act) to determine whether revocation of the antidumping duty orders on stainless steel butt-weld pipe fittings from Italy, Malaysia, and the Philippines would be...

  9. 76 FR 77770 - Certain Circular Welded Non-Alloy Steel Pipe From Mexico: Final Results of Antidumping Duty...

    Science.gov (United States)

    2011-12-14

    ... previous review or the original less-than-fair-value (LTFV) investigation, the cash deposit rate will... Determination of Sales at Less Than Fair Value: Circular Welded Non-Alloy Steel Pipe From Mexico, 57 FR 42953... structural pipe tubing used for framing and support members for reconstruction or load-bearing purposes in...

  10. 76 FR 49437 - Certain Circular Welded Non-Alloy Steel Pipe From Mexico: Preliminary Results of Antidumping Duty...

    Science.gov (United States)

    2011-08-10

    ... to Final Determination of Sales at Less Than Fair Value: Certain Welded Non-Alloy Steel Pipe from... established in the less-than-fair-value investigation (32.62 percent) if there is no rate for the intermediary... pipe tubing used for framing and support members for reconstruction or load-bearing purposes in the...

  11. 76 FR 19788 - Carbon Steel Butt-Weld Pipe Fittings From Brazil, China, Japan, Taiwan, and Thailand

    Science.gov (United States)

    2011-04-08

    ...)] Carbon Steel Butt-Weld Pipe Fittings From Brazil, China, Japan, Taiwan, and Thailand Determinations On... fittings from Brazil, China, Japan, Taiwan, and Thailand would be likely to lead to continuation or... Pipe Fittings from Brazil, China, Japan, Taiwan, and Thailand: Investigation Nos. 731-TA-308-310 and...

  12. Creep properties in similar weld joint of a thick-walled P92 steel pipe

    Czech Academy of Sciences Publication Activity Database

    Sklenička, Václav; Kuchařová, Květa; Svobodová, M.; Kvapilová, Marie; Král, Petr; Horváth, P.

    2016-01-01

    Roč. 119, č. 1 (2016), s. 1-12 ISSN 1044-5803 R&D Projects: GA ČR(CZ) GA16-09518S; GA MPO FR-TI4/406 Institutional support: RVO:68081723 Keywords : 9–12%Cr steels * Creep testing * High temperature creep * Thick-walled pipe * Welding Subject RIV: JG - Metallurgy Impact factor: 2.714, year: 2016

  13. Structural Health Monitoring of Steel Pipes under Different Boundary Conditions and Choice of Signal Processing Techniques

    Directory of Open Access Journals (Sweden)

    Rais Ahmad

    2012-01-01

    Full Text Available Guided wave technique is an efficient method for monitoring structural integrity by detecting and forecasting possible damages in distributed pipe networks. Efficient detection depends on appropriate selection of guided wave modes as well as signal processing techniques. Fourier analysis and wavelet analysis are two popular signal processing techniques that provide a flexible set of tools for solving various fundamental problems in science and engineering. In this paper, effective ways of using Fourier and Wavelet analyses on guided wave signals for detecting defects in steel pipes are discussed for different boundary conditions. This research investigates the effectiveness of Fourier transforms and Wavelet analysis in detecting defects in steel pipes. Cylindrical Guided waves are generated by piezo-electric transducers and propagated through the pipe wall boundaries in a pitch-catch system. Fourier transforms of received signals give information regarding the propagating guided wave modes which helps in detecting defects by selecting appropriate modes that are affected by the presence of defects. Continuous wavelet coefficients are found to be sensitive to defects. Several types of mother wavelet functions such as Daubechies, Symlet, and Meyer have been used for the continuous wavelet transform to investigate the most suitable wavelet function for defect detection. This research also investigates the effect of different boundary conditions on wavelet transforms for different mother wavelet functions.

  14. Microbiological corrosion of ASTM SA105 carbon steel pipe for industrial fire water usage

    Science.gov (United States)

    Chidambaram, S.; Ashok, K.; Karthik, V.; Venkatakrishnan, P. G.

    2018-02-01

    The large number of metallic systems developed for last few decades against both general uniform corrosion and localized corrosion. Among all microbiological induced corrosion (MIC) is attractive, multidisciplinary and complex in nature. Many chemical processing industries utilizes fresh water for fire service to nullify major/minor fire. One such fire water service line pipe attacked by micro-organisms leads to leakage which is industrially important from safety point of view. Also large numbers of leakage reported in similar fire water service of nearby food processing plant, paper & pulp plant, steel plant, electricity board etc…In present investigation one such industrial fire water service line failure analysis of carbon steel line pipe was analyzed to determine the cause of failure. The water sample subjected to various chemical and bacterial analyses. Turbidity, pH, calcium hardness, free chlorine, oxidation reduction potential, fungi, yeasts, sulphide reducing bacteria (SRB) and total bacteria (TB) were measured on water sample analysis. The corrosion rate was measured on steel samples and corrosion coupon measurements were installed in fire water for validating non flow assisted localized corrosion. The sulphide reducing bacteria (SRB) presents in fire water causes a localized micro biological corrosion attack of line pipe.

  15. Experimentation and numerical simulation of steel fibre reinforced concrete pipes

    Directory of Open Access Journals (Sweden)

    de la Fuente, Albert

    2011-06-01

    Full Text Available The results concerning on an experimental and a numerical study related to SFRCP are presented. Eighteen pipes with an internal diameter of 600 mm and fibre dosages of 10, 20 and 40 kg/m3 were manufactured and tested. Some technological aspects were concluded. Likewise, a numerical parameterized model was implemented. With this model, the simulation of the resistant behaviour of SFRCP can be performed. In this sense, the results experimentally obtained were contrasted with those suggested by means MAP reaching very satisfactory correlations. Taking it into account, it could be said that the numerical model is a useful tool for the optimal design of the SFRCP fibre dosages, avoiding the need of the systematic employment of the test as an indirect design method. Consequently, the use of this model would reduce the overall cost of the pipes and would give fibres a boost as a solution for this structural typology.

    En este artículo se presentan los resultados principales de un estudio experimental y numérico del comportamiento de tubos hormigón reforzado con fibras de acero (THFA. Se fabricaron y ensayaron 18 tubos de 600 mm de diámetro con cuantías de 10, 20 y 40 kg/m3 de fibras, concluyéndose varios aspectos tecnológicos relacionados con la fabricación y el ensayo así como del comportamiento resistente. Por otra parte, se ha desarrollado el modelo numérico MAP que permite la simulación del comportamiento resistente de THFA sometidos al ensayo de aplastamiento. Los resultados han sido satisfactorios para cualquier régimen de carga, permitiendo concluir que el modelo es una herramienta útil para el diseño óptimo de este tipo de tubos. Se concluye que el uso del modelo conduce a una reducción del coste del armado y da un impulso al uso de fibras como elemento de refuerzo en esta tipología estructural.

  16. Special Features of Structure Formation in Pipes from Medium-Carbon Low-Alloy Steel 32G2F Under Heat Treatment

    Science.gov (United States)

    Stepanov, A. I.; Belikov, S. V.; Musikhin, S. A.; Burmasov, S. P.; Popov, A. A.

    2017-03-01

    Special features of formation of structure and properties of seamless pipes from medium-carbon low-alloy steel for oil and gas applications are considered and associated with chemical inhomogeneity of the metal of the pipes.

  17. Heat Transfer Modeling of an Annular On-Line Spray Water Cooling Process for Electric-Resistance-Welded Steel Pipe.

    Science.gov (United States)

    Chen, Zejun; Han, Huiquan; Ren, Wei; Huang, Guangjie

    2015-01-01

    On-line spray water cooling (OSWC) of electric-resistance-welded (ERW) steel pipes can replace the conventional off-line heat treatment process and become an important and critical procedure. The OSWC process improves production efficiency, decreases costs, and enhances the mechanical properties of ERW steel pipe, especially the impact properties of the weld joint. In this paper, an annular OSWC process is investigated based on an experimental simulation platform that can obtain precise real-time measurements of the temperature of the pipe, the water pressure and flux, etc. The effects of the modes of annular spray water cooling and related cooling parameters on the mechanical properties of the pipe are investigated. The temperature evolutions of the inner and outer walls of the pipe are measured during the spray water cooling process, and the uniformity of mechanical properties along the circumferential and longitudinal directions is investigated. A heat transfer coefficient model of spray water cooling is developed based on measured temperature data in conjunction with simulation using the finite element method. Industrial tests prove the validity of the heat transfer model of a steel pipe undergoing spray water cooling. The research results can provide a basis for the industrial application of the OSWC process in the production of ERW steel pipes.

  18. Development of carbon steel with superior resistance to wall thinning and fracture for nuclear piping system

    International Nuclear Information System (INIS)

    Rhee, Chang Kyu; Lee, Min Ku; Park, Jin Ju

    2010-07-01

    Carbon steel is usually used for piping for secondary coolant system in nuclear power plant because of low cost and good machinability. However, it is generally reported that carbon steel was failed catastrophically because of its low resistance to wall thinning and fracture toughness. Especially, flow accelerated corrosion (FAC) is one of main problems of the wall thinning of piping in the nuclear power plant. Therefore, in this project, fabrication technology of new advanced carbon steel materials modified by dispersion of nano-carbide ceramics into the matrix is developed first in order to improve the resistance to wall thinning and fracture toughness drastically compared to the conventional one. In order to get highly wettable fine TiC ceramic particles into molten metal, the micro-sized TiC particles were first mechanically milled by Fe (MMed TiC/Fe) in a high energy ball mill machine in Ar gas atmosphere, and then mixed with surfactant metal elements (Sn, Cr, Ni) to obtain better wettability, as this lowered surface tension of the carbon steel melt. According to microscopic images revealed that an addition of MMed TiC/Fe-surfactant mixed powders favorably disperses the fine TiC particles in the carbon steel matrix. It was also found that the grain size refinement of the cast matrix is achieved remarkably when fine TiC particles were added due to the fact that they act as nucleation sites during the solidification process. As a results, a cast carbon steel dispersed with fine TiC particles shows improved mechanical properties such as hardness, tensile strength and cavitation resistance compared to that of without particles. However, the slight decrease of toughness was found

  19. Mechanical Properties of High-Nb X80 Steel Weld Pipes for the Second West-to-East Gas Transmission Pipeline Project

    Directory of Open Access Journals (Sweden)

    Gui-ying Qiao

    2017-01-01

    Full Text Available The mechanical properties of steel pipe have great effects on the integrality and operation safety of gas transmission pipeline. In order to reduce the cost of the steel pipe, the high-Nb X80 pipeline steels with the different alloying systems have been used in the Second West-to-East Gas Transmission Pipeline Project. Nevertheless, an investigation into the effects of chemical composition on the mechanical properties of steel pipes is lacking. In this work, the chemical composition and mechanical properties of high-Nb X80 grade steel pipes with a diameter of ϕ1,219 mm and a wall thickness of 22 mm, which are coiled by steels manufactured by three mills, have been analyzed. Furthermore, the effects of chemical composition of the steels on the mechanical properties of the pipe body and weld joint were discussed.

  20. The entire mean stress relaxation effects of 0Cr18Ni10Ti piping steel

    International Nuclear Information System (INIS)

    Yang Bing; Zhao Yongxiang

    2005-01-01

    Experimental study is performed on the mean stress relaxation effects of the Chinese new piping material, 0Cr18Ni10Ti steel. Six sets of specimens are respectively fatigued under a strain-controlled mode with the six straining ratios (R ε ) of -1, -0.52, -0.22, 0.029, 0.18, and 0.48 by an improved test method implied with an maximum likelihood statistical principle. The test results reveal that the material exhibits a Masing behaviour and, surprisingly, involves an entire mean stress relaxation. A challenge is then emerging to the traditional same treat of straining ratio and stressing ratio (R σ ) in fatigue analysis and assessment. There is still no effective method to describe this kind of relaxation. However the R ε effects can represent the relaxation effects appropriately by investigation on the material random cyclic stress-strain (σ-ε) relations and strain-life (ε-N) relations with different R ε . The intrinsic randomness of the responses is taken into account on a probabilistic sense. Significant differences are observed of the material cyclic responses under different R ε . For σ-ε relations, the R ε effects act as a decreasing trend to the stress amplitudes with the increasing survival probability and confidence. The strongest effect appears at R ε of 0.029, and a weaker one acts as R ε is far away from zero. For ε-N relations, R ε greater than zero exhibits a positive effect on the fatigue lives of about 1.3 to 1.6 times under a survival probability of 0.999 and a confidence of 95%, while a negative effect is exhibited in case of R ε less than zero. Present work indicates that systematic researches should be made to give a reasonable fatigue prediction in service on a basis of cyclic strain inspection of structures. (authors)

  1. An experimental analysis of temperature and stress fields in girth welded 304L stainless steel pipes

    International Nuclear Information System (INIS)

    Li, M.; Atteridge, D.G.; Anderson, W.E.; Hubbard, C.R.; Spooner, S.

    1996-01-01

    The thermal and deformation/strain histories were measured by a computer data acquisition system for three 406-mm-diameter, Type 304L stainless steel (SS), schedule 40 (12.7 mm thickness) pipe girth welds. Two welds were standard V groove preparations and completed in six and nine (discontinuous) passes with multiple start-stop positions, while the third one was a narrow groove configuration and finished with four continuous passes with one start-stop position. The thermomechanical history measurements were taken on the pipe inner surface, encompassing the weld centerline (WCL) and heat-affected zone; a total of 47 data acquisition instruments were used for each weld to monitor weld shrinkages, surface temperatures, surface strains, and radial deformations. The experimental data give the following general conclusions: (1) the temperature profiles in the two V groove weldments are, in general, axisymmetric, while the temperature profile in the narrow gap groove weldment is axisymmetric in locations far from WCL, but is not axisymmetric in locations near start-stop position; (2) the strain/deformation histories are controlled by the thermal histories with the final strain/deformation value largely determined by the last one or two passes of welding; (3) the strain/deformation profile in the weldment is not axisymmetric suggesting that the residual stress is not axisymmetrically distributed; (4) the four-pass narrow gap weldment experienced the fewest time and temperature cycles during welding, and has the lowest level of radial deformation among the three pipe weldments indicating that the narrow gap weldment would have the lowest overall residual stress level among the three pipe weldments. Residual stress measurements on the inner surface of four-pass pipe weldment were performed using the neutron diffraction (ND) technique. The ND results show that a tensile zone exists on the pipe inner surface and in the weld and its heat-affected zone (HAZ) area

  2. Thermomechanical history measurements on Type 304L stainless steel pipe girth welds

    International Nuclear Information System (INIS)

    Li, Ming; Atteridge, D.G.; Anderson, W.E.; Turpin, R.; West, S.L.

    1993-01-01

    Thermal and strain histories were recorded for three 40-cm-diameter (16 inch), Type 304L stainless steel (SS), schedule 40 (1.27 cm thickness) pipe girth welds. Two weld groove preparations were standard V grooves while the third was a narrow groove configuration. The welding parameters for the three pipe welds simulated expected field practice as closely as possible. The narrow gap weld was completed in four continuous passes while the other two welds required six and nine (discontinuous) passes, due to the use of different weld wire diameters. Thermomechanical history measurements were taken on the inner counterbore surface, encompassing the weld centerline and heat-affected zone (HAZ), as well as 10 cm of inner counterbore surface on either side of the weld centerline; a total of 47 data acquisition instruments were used for each weld. These instruments monitored: (1) weld shrinkages parallel to the pipe axis; (2) surface temperatures; (3) surface strains parallel to weld centerline; and (4) radial deformations. Results show that the weld and HAZ experienced cyclic deformation in the radial direction during welding, indicating that the final residual stress distribution in multi-pass pipe weldments is not axisymmetric. Measured radial and axial deformations were smaller for the narrow gap groove than for the standard V grooves, suggesting that the narrow gap groove weldment may have lower residual stress levels than the standard V groove weldments. This study provides the experimental database and a guideline for further computational modeling work

  3. Residual stress distribution in carbon steel pipe welded joint measured by neutron diffraction

    International Nuclear Information System (INIS)

    Hayashi, Makoto; Ishiwata, Masayuki; Morii, Yukio; Minakawa, Nobuaki

    2000-01-01

    In order to estimate crack growth behavior of fatigue and stress corrosion cracking in pipes, the residual stress distribution near the pipe weld region has to be measured through the wall thickness. Since the penetration depth of neutron is deep enough to pass through the thick pipe wall, the neutron diffraction technique for the residual stress measurement is effective for this purpose. At the first step the residual stress distribution near the weld region in a butt-welded carbon steel pipe was measured by the neutron diffraction. Significant stresses extended only to a distance of 30 mm from the center of the weld. The major tensile stresses occurred in the hoop direction in the fusion and heat affected zones of the weldment, and they attained a level greater than 200 MPa through the thickness. While the axial residual stress at the inside surface was 50 MPa, the stress at the outside surface was -100 MPa. The comparison of residual stress distributions measured by the neutron diffraction, the X-ray diffraction and the strain gauge method reveals that the neutron diffraction is the most effective for measuring the residual stress inside the structural components. (author)

  4. Mechanism of selective corrosion in electrical resistance seam welded carbon steel pipe

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Fajardo, Pedro; Godinez Salcedo, Jesus; Gonzalez Velasquez, Jorge L. [Instituto Politecnico Nacional, Mexico D.F., (Mexico). Escuela Superior de Ingenieria Quimica e Industrias Extractivas. Dept. de Ingenieria Metalurgica

    2009-07-01

    In this investigation the studies of the mechanism of selective corrosion in electrical resistance welded (ERW) carbon steel pipe was started. Metallographic characterizations and evaluations for inclusions were performed. The susceptibility of ERW pipe to selective corrosion in sea water (NACE 1D182, with O{sub 2} or CO{sub 2} + H{sub 2}S) was studied by the stepped potential Potentiostatic electrochemical test method in samples of 1 cm{sup 3} (ASTM G5) internal surface of the pipe (metal base-weld). The tests were looking for means for predicting the susceptibility of ERW pipe to selective corrosion, prior to placing the pipeline in service. Manganese sulfide inclusions are observed deformed by the welding process and they are close to the weld centerline. A slight decarburization at the weld line is observed, and a distinct out bent fiber pattern remains despite the post-weld seam annealing. The microstructure of the weld region consists of primarily polygonal ferrite grains mixed with small islands of pearlite. It is possible to observe the differences of sizes of grain of the present phases in the different zones. Finally, scanning electron microscopic observation revealed that the corrosion initiates with the dissolution of MnS inclusions and with small crack between the base metal and ZAC. (author)

  5. Ductile fracture behavior of 6-inch diameter type 304 stainless steel and STS 42 carbon steel piping containing a through-wall or part-through crack

    International Nuclear Information System (INIS)

    Shibata, Katsuyuki; Ohba, Toshihiro; Kawamura, Takaichi; Miyazono, Shohachiro; Kaneko, Tadashi; Yokoyama, Norio.

    1986-05-01

    The double ended guillotine break philosophy in the design base accident of the nuclear power plant is considered to be overly conservative from the view point of piping design. Through the past experiences and developments of the fabrication, inspection, and operation of nuclear power plants, it has been recognized that the Leak-Before-Break (LBB) concept can be justified in the LWR pressure boundary pipings. In order to verify the LBB concept, extensive experimental and theoretical works are being conducted in many countries. Furthermore, a revised piping design standard, in which LBB concept is introduced, is under preparation in Japan, U.S.A., and European countries. At JAERI, a research program to investigate the unstable ductile fracture behavior of LWR piping under bending load has been carried out as a part of the LBB verification researches since 1983. This report summarizes the result of the ductile fracture tests conducted at room temperature in 1983 and 84. The 6-inch diameter pipes of type 304 stainless steel and STS 42 carbon steel pipe with a through-wall or part-through crack were tested under bending load with low or high compliance condition at room temperature. Pipe fracture data were obtained from the test as regards to load- displacement curve, crack extension, net section stress, J-resistance curve, and so on. Besides, the influence of the compliance on the fracture behavior was examined. Discussions are performed on the ductile pipe fracture criterion, flaw evaluation criterion, and LBB evaluation method. (author)

  6. Loading rate effects on strength and fracture toughness of pipe steels used in Task 1 of the IPIRG program

    International Nuclear Information System (INIS)

    Marschall, C.W.; Landow, M.P.; Wilkowski, G.M.

    1993-10-01

    Material characterization tests were conducted on laboratory specimens machined from pipes to determine the effect of dynamic loading (i.e., rates comparable to those for high amplitude seismic events) on tensile properties and fracture resistance at 288 C (550 F). Specimens were fabricated from seven different pipes, including carbon steels and stainless steels (both base metal and weld metal), which were to be subjected to full-scale pipe tests in IPIRG Task 1.0. For the stainless steels tested at 288 C (550 F), tensile strength was unchanged, while yield strength and fracture resistance were increased. The increase in fracture resistance was modest for the wrought base metals and substantial for the weld metal and the cast base metal. The carbon steels tested were sensitive to dynamic strain aging, and hence the strength and toughness was affected by both temperature and strain rate effects. The carbon steel base metal and welds exhibited ultimate tensile strength values at 288 C (550 F) that were greater than at room temperature. Furthermore, the ultimate tensile strength at 288 C (550 F) was lowered significantly by increased strain rate and, in the carbon steel base metals, increased strain rate also lowered the fracture resistance, substantially in the base metal of one pipe. In comparing these results to the IPIRG pipe test results to date, it was found that the trends of these tests agree well with the Subtask 1.2 quasi-static and dynamic pipe fracture experiments. Loads measured in the Subtask 1.1 pipe experiments were, however, somewhat higher than would have been expected by the trends observed in the laboratory tests

  7. Loading rate effects on strength and fracture toughness of pipe steels used in Task 1 of the IPIRG program

    Energy Technology Data Exchange (ETDEWEB)

    Marschall, C.W.; Landow, M.P.; Wilkowski, G.M. [Battelle, Columbus, OH (United States)

    1993-10-01

    Material characterization tests were conducted on laboratory specimens machined from pipes to determine the effect of dynamic loading (i.e., rates comparable to those for high amplitude seismic events) on tensile properties and fracture resistance at 288 C (550 F). Specimens were fabricated from seven different pipes, including carbon steels and stainless steels (both base metal and weld metal), which were to be subjected to full-scale pipe tests in IPIRG Task 1.0. For the stainless steels tested at 288 C (550 F), tensile strength was unchanged, while yield strength and fracture resistance were increased. The increase in fracture resistance was modest for the wrought base metals and substantial for the weld metal and the cast base metal. The carbon steels tested were sensitive to dynamic strain aging, and hence the strength and toughness was affected by both temperature and strain rate effects. The carbon steel base metal and welds exhibited ultimate tensile strength values at 288 C (550 F) that were greater than at room temperature. Furthermore, the ultimate tensile strength at 288 C (550 F) was lowered significantly by increased strain rate and, in the carbon steel base metals, increased strain rate also lowered the fracture resistance, substantially in the base metal of one pipe. In comparing these results to the IPIRG pipe test results to date, it was found that the trends of these tests agree well with the Subtask 1.2 quasi-static and dynamic pipe fracture experiments. Loads measured in the Subtask 1.1 pipe experiments were, however, somewhat higher than would have been expected by the trends observed in the laboratory tests.

  8. Residual stress distribution in carbon steel pipe welded joints measured by neutron diffraction

    International Nuclear Information System (INIS)

    Hayashi, Makoto; Ishiwata, Masayuki; Morii, Yukio; Minakawa, Nobuaki.

    1996-01-01

    Three dimensional residual stress distributions in a 4 inch diameter carbon steel pipe welded joint were measured by neutron diffraction technique. The results showed that the residual stress distributed near the weld metal, namely within about 30mm. The major tensile stresses occurred in the hoop direction in the fusion and heat affected zones of the weldment, and they attained a level greater than 200 MPa throughout the pipe wall thickness. While the axial residual stress at the inside surface was 40 MPa, the stress at the outside surface was -100 MPa. These residual stress distributions were compared with those measured by the X-ray diffraction technique and strain gauge method, and they agreed with each other. (author)

  9. Plastic strain and residual stress distributions in an AISI 304 stainless steel BWR pipe weld

    Science.gov (United States)

    Saukkonen, Tapio; Aalto, Miikka; Virkkunen, Iikka; Ehrnstén, Ulla; Hänninen, Hannu

    In AISI 304 stainless steel pipe welds weld shrinkage causes large variations in residual plastic strain in different parts of the weld metal and heat-affected zone (HAZ). The amount of strain was analyzed by EBSD quantitatively by comparing the intra-grain misorientations to the calibration curve. Highest degrees of plastic strain (10...20%) were detected in the HAZ close to the root area of a prototypical BWR plant weld. Strain in the weld metal varies in the different directions of solidification, being high in the weld bead boundaries and near the fusion lines. Preliminary studies of the effects of mechanical and elastic anisotropy of the weld metal microstructure on the grain size level were performed by EBSD and nanoindentation. The residual stress distribution in the same weld cross-section was determined by a contour method. The residual strain and stress distributions are superimposed and EAC susceptibility of various areas of the pipe weld is evaluated and discussed.

  10. Ageing of the welds of pipes in austenitic stainless steels of the sodium fast reactors

    International Nuclear Information System (INIS)

    Dubuisson, Ph.; Monnet, I.; Bougault, A.

    2006-01-01

    Full text of publication follows: The austenitic stainless steels are largely employed for the industrial components which operate at temperatures ranging between 300 deg. C and 600 deg. C. In the Sodium Fast Reactors (SFR), these steels and in particular the steels stabilized with titanium are employed for pipes of the secondary circuit and the exchangers. The whole of these components, and more particularly those in Ti-stabilized steel (AISI 321), have been the subject of an attention supported for more than ten years. The non destructive examinations carried out on these pipes showed indications on the heat affected zones (HAZ) of some circular welds. The first metallographic expertises carried out on the welds confirm the presence of real defects, intergranular cracks which appear on the intern surface at the weld toes and parallel with the fusion line. These defects were attributed to the stress relief cracking. The expertises made it possible to highlight a certain number of significant parameters for this mechanism. Temperature. No case of cracking was observed on the circuits working at 350 deg. C, whereas some cases were revealed on the circuits at 475 deg. C, the percentage of affected welds increasing for the circuit at 550 deg. C. The presence of a defect at the weld root. Each cracked weld shows that intergranular crack was propagated from a shrinkage or a defect of rolling. Initial work hardening in weld root generally observed on the cracked welds. Local loadings, and in particular the residual stresses of welding. Geometrical discontinuities or difference in materials also constitute factors worsening with respect to the mechanism. Microstructural examinations carried out by transmission electron microscopy on different welds affected or not by the stress relief cracking mechanism made it possible to establish a grid of risk of appearance of this type of cracking based on four microstructural features: Dislocations density close to the interface

  11. Method of treating tool steel die materials

    International Nuclear Information System (INIS)

    Cook, C.S.; Damon, S.

    1981-01-01

    In a method of hardening pilger dies to provide a hard case containing residual compressive stresses and tough body, the tool steel die is heated to the austenitizing temperature range, followed by selectively removing heat from the die at a predetermined faster rate in the direction of the desired case than the rate of heat removal from the balance of the die, and thereafter tempering the die. The invention provides a fully hardened and tempered case on the working surface of the die and a tough body in the balance of the die, usually of lower hardness. (author)

  12. RESEARCH OF INFLUENCE OF THE HIGH-SPEED THERMAL PROCESSING REGIMES ON STRUCTURE AND MECHANICAL PROPERTIES OF PIPE STEEL 32G2

    Directory of Open Access Journals (Sweden)

    A. I. Gordienko

    2012-01-01

    Full Text Available Researches on influence of high-speed heating temperature, regimes of cooling and temperature of abatement on structure and mechanical properties of pipe steel 32G2 are carried out. Recommendations on the regimes of high-speed thermal processing of steel 32G2 which can be used at manufacturing of seamless pipes are given.

  13. Round Robin Analyses on Stress Intensity Factors of Inner Surface Cracks in Welded Stainless Steel Pipes

    Directory of Open Access Journals (Sweden)

    Chang-Gi Han

    2016-12-01

    Full Text Available Austenitic stainless steels (ASSs are widely used for nuclear pipes as they exhibit a good combination of mechanical properties and corrosion resistance. However, high tensile residual stresses may occur in ASS welds because postweld heat treatment is not generally conducted in order to avoid sensitization, which causes a stress corrosion crack. In this study, round robin analyses on stress intensity factors (SIFs were carried out to examine the appropriateness of structural integrity assessment methods for ASS pipe welds with two types of circumferential cracks. Typical stress profiles were generated from finite element analyses by considering residual stresses and normal operating conditions. Then, SIFs of cracked ASS pipes were determined by analytical equations represented in fitness-for-service assessment codes as well as reference finite element analyses. The discrepancies of estimated SIFs among round robin participants were confirmed due to different assessment procedures and relevant considerations, as well as the mistakes of participants. The effects of uncertainty factors on SIFs were deducted from sensitivity analyses and, based on the similarity and conservatism compared with detailed finite element analysis results, the R6 code, taking into account the applied internal pressure and combination of stress components, was recommended as the optimum procedure for SIF estimation.

  14. Variation behavior of residual stress distribution by manufacturing processes in welded pipes of austenitic stainless steel

    International Nuclear Information System (INIS)

    Ihara, Ryohei; Hashimoto, Tadafumi; Mochizuki, Masahito

    2012-01-01

    Stress corrosion cracking (SCC) has been observed near heat affected zone (HAZ) of primary loop recirculation pipes made of low-carbon austenitic stainless steel type 316L in the nuclear power plants. For the non-sensitization material, residual stress is the important factor of SCC, and it is generated by machining and welding. In the actual plants, welding is conducted after machining as manufacturing processes of welded pipes. It could be considered that residual stress generated by machining is varied by welding as a posterior process. This paper presents residual stress variation due to manufacturing processes of pipes using X-ray diffraction method. Residual stress distribution due to welding after machining had a local maximum stress in HAZ. Moreover, this value was higher than residual stress generated by welding or machining. Vickers hardness also had a local maximum hardness in HAZ. In order to clarify hardness variation, crystal orientation analysis with EBSD method was performed. Recovery and recrystallization were occurred by welding heat near the weld metal. These lead hardness decrease. The local maximum region showed no microstructure evolution. In this region, machined layer was remained. Therefore, the local maximum hardness was generated at machined layer. The local maximum stress was caused by the superposition effect of residual stress distributions due to machining and welding. Moreover, these local maximum residual stress and hardness are exceeded critical value of SCC initiation. In order to clarify the effect of residual stress on SCC initiation, evaluation including manufacturing processes is important. (author)

  15. Stress corrosion cracking of nuclear reactor pressure vessel and piping steels

    International Nuclear Information System (INIS)

    Speidel, M.O.; Magdowski, R.M.

    1988-01-01

    This paper presents an extensive investigation of stress corrosion cracking of nuclear reactor pressure vessel and piping steels exposed to hot water. Experimental fracture mechanics results are compared with data from the literature and other laboratories. Thus a comprehensive overview of the present knowledge concerning stress corrosion crack growth rates is provided. Several sets of data confirm that 'fast' stress corrosion cracks with growth rates between 10 -8 and 10 -7 m/s and threshold stress intensities around 20 MN m -3/2 can occur under certain conditions. However, it appears possible that specific environmental, mechanical and metallurgical conditions which may prevail in reactors can result in significantly lower stress corrosion crack growth rates. The presently known stress corrosion crack growth rate versus stress intensity curves are discussed with emphasis on their usefulness in establishing safety margins against stress corrosion cracking of components in service. Further substantial research efforts would be helpful to provide a data base which permits well founded predictions as to how stress corrosion cracking in pressure vessels and piping can be reliably excluded or tolerated. It is emphasized, however, that the nucleation of stress corrosion cracks (as opposed to their growth) is difficult and may contribute substantially to the stress corrosion free service behaviour of the overwhelming majority of pressure vessels and pipes. (author)

  16. Numerical simulation of micro-crack occurring in pipe made of stainless steel

    Directory of Open Access Journals (Sweden)

    Wotzka Daria

    2017-01-01

    Full Text Available Research works carried out regard to studies aiming at determination of the effect of cumulative duty operation on the development of micro-cracks in pipelines for transport of chemical substances. This paper presents results of computer simulations of a pipeline made of stainless steel. The model was investigated using the COMSOL Multiphysics environment. The object under study was divided into sub areas and then discretized according to the FEM method. The physico-chemical parameters of individual areas were defined based on measurement data. The main aim of research works was the modeling of acoustic emission wave, which is emitted in the vicinity of the tip of micro-crack as a result of its development. In order to solve the task, heterogeneity in the structure of the material, referred to damage/micro-crack, causing local stresses was assumed. The local stresses give rise to elastic waves, which propagate in the material in all directions. When the emission waves reach the boundaries of the pipe they are then transferred into acoustic waves and propagate in the surround air, until their natural attenuation. The numerical model takes into account the effect of high pressure (3.6 MPa and negative temperature (-100̊C of the gas, transported inside the pipe. The influence of changes of these values in the range of ± 20% on the obtained results was investigated. The main contribution of the works is the multiphysical simulation model of transportation pipe made of steel, coupling structural mechanics, thermal conductivity and acoustic waves.

  17. Neutron diffraction residual stress measurements on girth-welded 304 stainless steel pipes with weld metal deposited up to half and full pipe wall thickness

    International Nuclear Information System (INIS)

    Haigh, R.D.; Hutchings, M.T.; James, J.A.; Ganguly, S.; Mizuno, R.; Ogawa, K.; Okido, S.; Paradowska, A.M.; Fitzpatrick, M.E.

    2013-01-01

    The residual stress distribution has been measured in two girth-welded austenitic stainless steel pipe weldments using time-of-flight neutron diffraction. One had weld filler metal deposited up to half the pipe wall thickness, and one had weld metal deposited up to full pipe wall thickness. The aim of the work is to evaluate the evolution in residual stress profile on filling the weld, on which there is little experimental data, and where the selection of the correct hardening model used in finite element modelling can benefit greatly from an understanding of the intermediate residual stresses partway through the welding operation. The measured residual stresses are compared with those calculated by finite element modelling and measured using X-ray diffraction. The results show a change in the measured hoop stress at the weld toe from tension to compression between the half- and fully-filled weld. The finite element results show an overprediction of the residual stress, which may be a consequence of the simple isotropic hardening model applied. The results have implications for the likely occurrence of stress corrosion cracking in this important type of pipe-to-pipe weldment. Highlights: ► 304 steel girth welded with weld metal to half and full pipe wall thickness. ► Residual stresses measured by neutron and X-ray diffraction, and modelled by FE. ► Weld toe residual σ hoop changes from tensile to compressive from half to fully-filled. ► FE model for the fully-filled weld gives higher stress levels than those measured. ► Discrepancy is attributed to the isotropic hardening model used.

  18. Application of cyclic J-integral to low cycle fatigue crack growth of Japanese carbon steel pipe

    Energy Technology Data Exchange (ETDEWEB)

    Miura, N.; Fujioka, T.; Kashima, K. [and others

    1997-04-01

    Piping for LWR power plants is required to satisfy the LBB concept for postulated (not actual) defects. With this in mind, research has so far been conducted on the fatigue crack growth under cyclic loading, and on the ductile crack growth under excessive loading. It is important, however, for the evaluation of the piping structural integrity under seismic loading condition, to understand the fracture behavior under dynamic and cyclic loading conditions, that accompanies large-scale yielding. CRIEPI together with Hitachi have started a collaborative research program on dynamic and/or cyclic fracture of Japanese carbon steel (STS410) pipes in 1991. Fundamental tensile property tests were conducted to examine the effect of strain rate on tensile properties. Cracked pipe fracture tests under some loading conditions were also performed to investigate the effect of dynamic and/or cyclic loading on fracture behavior. Based on the analytical considerations for the above tests, the method to evaluate the failure life for a cracked pipe under cyclic loading was developed and verified. Cyclic J-integral was introduced to predict cyclic crack growth up to failure. This report presents the results of tensile property tests, cracked pipe fracture tests, and failure life analysis. The proposed method was applied to the cracked pipe fracture tests. The effect of dynamic and/or cyclic loading on pipe fracture was also investigated.

  19. Recent studies on the welding of austenitic stainless steel piping for BWR service

    International Nuclear Information System (INIS)

    Childs, W.J.

    1986-01-01

    The incidence of intergranular stress corrosion cracking (IGSCC) in stainless steel piping in BWR power plants has led to the development of various countermeasures. Replacement of the susceptible Type 304 stainless steel with Type 316 nuclear grade stainless steel has been done by a number of plants. In order to minimize radiation exposure to welding personnel, automatic GTA welding has been used wherever possible when we make the field welds. Studies have shown that the residual stresses in the welded butt joints are affected by the welding process, weld joint design and welding procedures. A new weld joint design has been developed which minimizes the volume of deposited metal while providing adequate access for welding. It also minimizes axial and radial shrinkage and the resulting residual stresses. Other countermeasures, which have been used, include stress modifications such as induction heating stress improvement (IHSI) and last pass heat sink welding (LPHSW). It has been shown that these remedies must be process adjusted to account for the welding process employed. In some cases where UT cracking indication have been detected or where through wall cracking has occurred, weld surfacing has been used to extend life. A further approach to preventing IGSCC in the weld HAZ has been through improvement of the water chemistry by injecting hydrogen to reduce the oxygen level and by keeping the impurity level low

  20. Study of pitting corrosion in line-pipe steel under the influence of remanent magnetization

    Energy Technology Data Exchange (ETDEWEB)

    Espina-Hernandez, J.H.; Caleyo, F.; Hallen, J.M. [Instituto Politecnico Nacional (IPN), Zacatenco (Mexico)

    2009-07-01

    The influence of remanent magnetization on pitting corrosion in line-pipe steels is studied. Pitting corrosion experiments have been carried out on samples of an API 5L grade 52 steel under a magnetization level of the same order of magnitude of the remanent magnetization in the pipeline wall after in-line inspection based on magnetic flux leakage. The samples were magnetized using rings of the same grade as the investigated steel. Immediately after magnetization, the investigated samples were subjected to pitting by immersing them in a solution containing dissolved Cl{sup -} and SO{sup 2-}{sub 4} and ions. The pitting experiments were conducted during a seven days period. The pit depth distribution and the maximum pit depth in each sample were recorded and used to conduct extreme value analyses of the pitting process in magnetized and non-magnetized control samples. The statistical assessment of the pitting corrosion data collected during this study shows that the magnetic field reduces the average depth of the pit population and also the extreme pit depth values that can be predicted from the maximum values observed in the magnetized samples in comparison with to the non-magnetized control samples. Scanning electron microscopy observations show that the magnetic field alters the pit morphology by increasing the pit mouth opening. (author)

  1. 78 FR 5170 - Circular Welded Carbon Quality Steel Pipe From the People's Republic of China: Rescission of...

    Science.gov (United States)

    2013-01-24

    ... International Trade Co., Ltd., Weifang East Steel Pipe Co., Ltd., WISCO & CRM Wuhan Material & Trade., Wuxi... relevant entries during this review period. Failure to comply with this requirement could result in the.... Failure to comply with the regulations and terms of an APO is a violation which is subject to sanction...

  2. 77 FR 18266 - Stainless Steel Butt-Weld Pipe Fittings From Italy, Malaysia, and the Philippines; Revised...

    Science.gov (United States)

    2012-03-27

    ... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 731-TA-865-867 (Second Review)] Stainless Steel Butt-Weld Pipe Fittings From Italy, Malaysia, and the Philippines; Revised Schedule for the Subject Reviews AGENCY: United States International Trade Commission. ACTION: Notice. DATES: Effective Date: March...

  3. 75 FR 20342 - Certain Circular Welded Non-Alloy Steel Pipe From Mexico: Final Results of Antidumping Duty...

    Science.gov (United States)

    2010-04-19

    ... covered in this review, but was covered in a previous review or the original less-than-fair-value (LTFV... investigation. See Final Determination of Sales at Less Than Fair Value: Circular Welded Non- Alloy Steel Pipe... for framing and support members for reconstruction or load-bearing purposes in the construction...

  4. 76 FR 36089 - Circular Welded Non-Alloy Steel Pipe From the Republic of Korea: Final Results of the Antidumping...

    Science.gov (United States)

    2011-06-21

    ..., or the original less-than-fair-value (``LTFV'') investigation, but the manufacturer is, the cash... Determination of Sales at Less Than Fair Value: Certain Circular Welded Non-Alloy Steel Pipe from Korea, 57 FR... for reconstruction or load- bearing purposes in the construction, shipbuilding, trucking, farm...

  5. 77 FR 32562 - Circular Welded Carbon-Quality Steel Pipe From India: Preliminary Determination of Sales at Less...

    Science.gov (United States)

    2012-06-01

    ...-Quality Steel Pipe From India: Preliminary Determination of Sales at Less Than Fair Value AGENCY: Import... India is being, or is likely to be, sold in the United States at less than fair value (LTFV) as provided... merchandise. See Notice of Final Determination of Sales at Less Than Fair Value and Affirmative Final...

  6. 77 FR 32531 - Circular Welded Carbon-Quality Steel Pipe From the Sultanate of Oman: Preliminary Determination...

    Science.gov (United States)

    2012-06-01

    ...-Quality Steel Pipe From the Sultanate of Oman: Preliminary Determination of Sales at Less Than Fair Value... than fair value, as provided in section 733(b) of the Tariff Act of 1930, as amended (the Act). The... characteristics of the merchandise. See Notice of Final Determination of Sales at Less Than Fair Value and...

  7. 76 FR 78887 - Circular Welded Carbon Quality Steel Pipe From the People's Republic of China: Rescission of...

    Science.gov (United States)

    2011-12-20

    ... International Trade Administration Circular Welded Carbon Quality Steel Pipe From the People's Republic of China... opportunity to request an administrative review of the countervailing duty order on circular welded carbon.... Christian Marsh, Deputy Assistant Secretary for Antidumping and Countervailing Duty Operations. BILLING CODE...

  8. 77 FR 32508 - Circular Welded Carbon Steel Pipes and Tubes From Turkey: Notice of Preliminary Results of...

    Science.gov (United States)

    2012-06-01

    ... welded non- alloy steel pipes and tubes, of circular cross-section, not more than 406.4 millimeters (16... prices of sales to affiliated and unaffiliated customers net of all movement charges, direct selling... in the marketing process and selling functions along the chain of distribution between the producer...

  9. 76 FR 33204 - Certain Welded Carbon Steel Pipe and Tube From Turkey; Notice of Preliminary Results of...

    Science.gov (United States)

    2011-06-08

    ... covered by this order include circular welded non- alloy steel pipes and tubes, of circular cross-section... movement charges, direct selling expenses, discounts, and packing. Where the prices to that affiliated..., we examine stages in the marketing process and selling functions along the chain of distribution...

  10. 76 FR 5205 - Carbon Steel Butt-Weld Pipe Fittings from Brazil, China, Japan, Taiwan, and Thailand

    Science.gov (United States)

    2011-01-28

    ...)] Carbon Steel Butt-Weld Pipe Fittings from Brazil, China, Japan, Taiwan, and Thailand AGENCY: United... Thailand. SUMMARY: The Commission hereby gives notice of the scheduling of expedited reviews pursuant to..., Taiwan, and Thailand would be likely to lead to continuation or recurrence of material injury within a...

  11. 75 FR 60814 - Carbon Steel Butt-Weld Pipe Fittings From Brazil, China, Japan, Taiwan, and Thailand

    Science.gov (United States)

    2010-10-01

    ...)] Carbon Steel Butt-Weld Pipe Fittings From Brazil, China, Japan, Taiwan, and Thailand AGENCY: United... Thailand. SUMMARY: The Commission hereby gives notice that it has instituted reviews pursuant to section... Thailand would be likely to lead to continuation or recurrence of material injury. Pursuant to section 751...

  12. An assessment of composite repair system in offshore platform for corroded circumferential welds in super duplex steel pipe

    Directory of Open Access Journals (Sweden)

    Silvio de Barros

    2018-04-01

    Full Text Available The main aim of this study is to assess the effectiveness of a composite repair system in severely corroded circumferential welds in super duplex stainless steel pipes as a preventive measure against the premature corrosion damage at the welds. Artificial defects were fabricated on the super duplex steel tube in order to reproduce the localized corrosion damage defects found in real welded joints. Three kinds of through thickness defects were considered: 25%, 50% and 96% of the perimeter of the pipe. The performance of the repaired pipe was assessed by hydrostatic tests as per ISO 24817 standard. The results showed that the composite repair system can sustain the designed failure pressure even for the pipe damaged with through-wall defect up to 96% of the perimeter of the pipe. Hence, the composite repair system can be used as a preliminary tool to protect the unexpected or premature failure at the welds and maintain an adequate level of mechanical strength for a given operating pressure. This composite repair system can assure that the pipe will not leak until a planned maintenance of the line. Nevertheless, further work is still desirable to improve the confidence in the long-term performance of bonded composite

  13. Electron Cloud in Steel Beam Pipe vs Titanium Nitride Coated and Amorphous Carbon Coated Beam Pipes in Fermilab's Main Injector

    Energy Technology Data Exchange (ETDEWEB)

    Backfish, Michael

    2013-04-01

    This paper documents the use of four retarding field analyzers (RFAs) to measure electron cloud signals created in Fermilab’s Main Injector during 120 GeV operations. The first data set was taken from September 11, 2009 to July 4, 2010. This data set is used to compare two different types of beam pipe that were installed in the accelerator. Two RFAs were installed in a normal steel beam pipe like the rest of the Main Injector while another two were installed in a one meter section of beam pipe that was coated on the inside with titanium nitride (TiN). A second data run started on August 23, 2010 and ended on January 10, 2011 when Main Injector beam intensities were reduced thus eliminating the electron cloud. This second run uses the same RFA setup but the TiN coated beam pipe was replaced by a one meter section coated with amorphous carbon (aC). This section of beam pipe was provided by CERN in an effort to better understand how an aC coating will perform over time in an accelerator. The research consists of three basic parts: (a) continuously monitoring the conditioning of the three different types of beam pipe over both time and absorbed electrons (b) measurement of the characteristics of the surrounding magnetic fields in the Main Injector in order to better relate actual data observed in the Main Injector with that of simulations (c) measurement of the energy spectrum of the electron cloud signals using retarding field analyzers in all three types of beam pipe.

  14. Guided Wave Sensing In a Carbon Steel Pipe Using a Laser Vibrometer System

    Science.gov (United States)

    Ruíz Toledo, Abelardo; Salazar Soler, Jordi; Chávez Domínguez, Juan Antonio; García Hernández, Miguel Jesús; Turó Peroy, Antoni

    2010-05-01

    Non-Destructive Evaluation (NDE) techniques have achieved a great development during the last decades as a valuable tool for material characterization, manufacturing control and structural integrity tests. Among these tools, the guided wave technology has been rapidly extended because it reduces inspection time and costs compared to the ordinary point by point testing in large structures, as well as because of the possibility of inspecting under insulation and coating conditions. This fast development has motivated the creation of several inspection and material characterization systems including different technologies which can be combined with this technique. Different measurements systems based on laser techniques have been presented in order to inspect pipes, plates and diverse structures. Many of them are experimental systems of high cost and complexity which combine the employment of a laser for generation of waves in the structure and an interferometer for detection. Some of them employ air-coupled ultrasound generation transducers, with high losses in air and which demand high energy for exciting waves in materials of high stiffness. The combined employment of a commercial vibrometer system for Lamb wave sensing in plates has been successfully shown in the literature. In this paper we present a measurement system based on the combined employment of a piezoelectric wedge transducer and a laser vibrometer to sense guided acoustic waves in carbon steel pipes. The measurement system here presented is mainly compounded of an angular wedge transducer, employed to generate the guided wave and a commercial laser vibrometer used in the detection process. The wedge transducer is excited by means of a signal function generator whose output signal has been amplified with a power signal amplifier. A high precision positioning system is employed to place the laser beam at different points through the pipe surface. The signal detected by the laser vibrometer system is

  15. Application of Leak Before Break concept in 316LN austenitic steel pipes welded using 316L

    International Nuclear Information System (INIS)

    Cunto, Gabriel Giannini de

    2017-01-01

    This work presents a study of application of the Leak Before Break (LBB) concept, usually applied in nuclear power plants, in a pipe made from steel AISI type 316LN welded a coated electrode AISI type 316L. LBB concept is a criterion based on fracture mechanics analysis to show that a crack leak, present in a pipe, can be detected by leak detection systems, before this crack reaches a critical size that results in pipe fail. In the studied pipe, tensile tests and Ramberg-Osgood analyses were performed, as well as fracture toughness tests for obtaining the material resistance curve J-R. The tests were performed considering the base metal, weld and heat affected zone (HAZ), at the same operating temperatures of a nuclear power plant. For the mechanical properties found in these tests, load limit analyses were performed in order to determine the size of a crack which could cause a detectable leakage and the critical crack size, considering failure by plastic collapse. For the critical crack size found in the weld, which is the region that presented the lowest toughness, Integral J and tearing modulus T analyses were performed, considering failure by tearing instability. Results show a well-defined behavior between the base metal, HAZ and weld zones, where the base metal has a high toughness behavior, the weld has a low toughness behavior and the HAZ showed intermediate mechanical properties between the base metal and the weld. Using the PICEP software, the leak rate curves versus crack size and also the critical crack size were determined by considering load limit analysis. It was observed that after a certain crack size, the leak rate in base metal is much higher than for the HAZ and the weld, considering the same crack length. This occurs because in the base metal crack, it is expected that the crack grows in a more rounded form due to its higher toughness. The lowest critical crack size was found for the base metal presenting circumferential cracks. For the

  16. Stress corrosion evaluation on stainless steel 304 pipes in Laguna Verde Nuclear Power Plant

    International Nuclear Information System (INIS)

    Arganis J, C.R.

    1996-01-01

    Inside the frame of the project IAEA/MEX-41044 'Stress corrosion as a starting event of accidents in nuclear plants', and of the institutional project IA-252 under the same name, it was required from the Laguna Verde Nuclear Plant, material equivalent to the one employed in the piping of the primary recycling system. Laguna Verde Nuclear Plant granted two tracks of tubes, that could be used to substitute the ones that are in operation, as is the tube SA-358TP304 CL-QC with transversal welding, designated as ER-316-LQA. According to the report entitles 'Revision of the operational experience related to corrosion in the nuclear plants' it was found that the stress corrosion is the principal mechanism of corrosion present in the nuclear plants. Previous records indicate that sensitized stainless steels are resistant to stress corrosion in testings of constant loading in sea water (3.5% of chlorides approximately) to 80 Centigrade and to 80% of the limit of conveyance and that a solution of 22% of NaCl to 90 Centigrade, produces cracking due to stress corrosion in highly sensitized steels, in tests of speed of slow extension (SSRT), to a speed of 1x10 -6 s -1 . Daniels reports that there is a direct relation between the speed limit of detection of the SSRT test and the concentration of chlorides, for stainless steels tested to 100 Centigrade. The minimum detection speed of susceptibility to stress corrosion for solution to 20% of NaCl, is of 1x10 -7 s -1 . Taking into account these considerations, the employment of a solution with 22% of NaCl to 90 Centigrade to a speed of 1x10 -6 s -1 seems a good choice for the evaluation of stainless steel. (Author)

  17. Stuck pipe risk reducing due drilling fluid treating

    Directory of Open Access Journals (Sweden)

    POPOV Anatoly Nikolaevich

    2017-03-01

    Full Text Available Drilling fluids for deep and extended reach wells are complex multicomponent systems that contain dissolved salts, polymers, surfactants and coarse solids. Complexity of drilling mud is caused by wide range of functions: creating pressure on the formation, retention of cuttings particles in suspension, bottomhole cleaning and transportation of sludge on the surface, preservation of reservoir properties of the target formation and other. Tribological properties are one of the most important properties of the drilling fluids. It is possible to control properties through introduction of lubricant additives. Their components are characterized by high, sometimes unique, surface activity, they create superplastic nanofilms on the surface of the protective pipe, contribute to chemical modification of the surface layers of metal. The choice of such components is complicated, first of all, by price (to construct wells one needs large volumes of mud, and secondly by strict environmental requirements. Therefore, when lubricant additive is developed, it is necessary to ground the choice of rational content for each of its components. This necessitates the use of mathematical modeling methods, i.e. construction of regression equations according to several experiments of the planned experiment. The paper presents a possible way to use the two-step method of choosing the rational ratio of the components in the lubricant additive. As a rule tribological properties of drilling fluids are considered from three different points of view or different positions – friction pairs: «metal – rock», «metal – metal» and «metal – filter cake». This article is devoted to the study of drilling fluids in relation to a pair of «metal – filter cake».

  18. Study on the residual stress relaxation in girth-welded steel pipes under bending load using diffraction methods

    International Nuclear Information System (INIS)

    Hempel, Nico; Nitschke-Pagel, Thomas; Dilger, Klaus

    2017-01-01

    This research is dedicated to the experimental investigation of the residual stress relaxation in girth-welded pipes due to quasi-static bending loads. Ferritic-pearlitic steel pipes are welded with two passes, resulting in a characteristic residual stress state with high tensile residual stresses at the weld root. Also, four-point bending is applied to generate axial load stress causing changes in the residual stress state. These are determined both on the outer and inner surfaces of the pipes, as well as in the pipe wall, using X-ray and neutron diffraction. Focusing on the effect of tensile load stress, it is revealed that not only the tensile residual stresses are reduced due to exceeding the yield stress, but also the compressive residual stresses for equilibrium reasons. Furthermore, residual stress relaxation occurs both parallel and perpendicular to the applied load stress.

  19. Effect of Pipe Body Alloy on Weldability of X80 Steel

    Science.gov (United States)

    Kong, Xianglei; Huang, Guojian; Fu, Kuijun; Liu, Fangfang; Huang, Minghao; Zhang, Yinghui

    Effect of Mo, Ni, and Cr on impact property of pipe seam and heat-affected zone (HAZ) of X80 steel was investigated by thermal simulation test and butt welding test. The results showed that, there was an obvious relationship between strip's composition and the toughness of weld and HAZ, the more content of Mo, Ni and less of Cr in the strip matrix, the better of impact toughness of weld and HAZ. Metallographic microscope was used to compare microstructures of welding specimens, every welded seam microstructure was mainly acicular ferrite (AF) and a little volume of proeutectoid ferrite (PF), and with some granular precipitations on original austenite grain boundary, the difference was that there were more PF and less precipitations of the specimen with more content of Mo, Ni and less of Cr in the strip matrix. Because of the high price of Mo and Ni, alloy design must be considered comprehensively with the cost and property requirements in the production.

  20. An Online MFL Sensing Method for Steel Pipe Based on the Magnetic Guiding Effect.

    Science.gov (United States)

    Wu, Jianbo; Fang, Hui; Huang, Xiaoming; Xia, Hui; Kang, Yihua; Tang, Chaoqing

    2017-12-15

    In order to improve the sensitivity of online magnetic flux leakage (MFL) testing for steel pipe, a sensing method based on the magnetic guiding effect is proposed and investigated in this paper. Compared to the conventional contact sensing method using a non-ferromagnetic support, the proposed method creatively utilizes a ferromagnetic one to guide more magnetic flux to leak out. Based on Hopkinson's law, the principle of the magnetic guiding effect of the ferromagnetic support is theoretically illustrated. Then, numerical simulations are conducted to investigate the MFL changes influenced by the ferromagnetic support. Finally, the probe based on the proposed method is designed and developed, and online MFL experiments are performed to validate the feasibility of the proposed method. Online tests show that the proposed sensing method can greatly improve the MFL sensitivity.

  1. Applications of the essay at slow deformation velocity in pipes of stainless steel AISI-304

    International Nuclear Information System (INIS)

    Zamora R, L.; Mora R, T. De la

    2004-01-01

    Nowadays is carried out research related with the degradation mechanisms of structures, systems and/or components in the nuclear power plants, since many of the involved processes are those responsible for the dependability of these, of the integrity of the components and of the aspects of safety. The purpose of this work, was to determine the grade of susceptibility to the corrosion of a pipe of Austenitic stainless steel AISI 304, in a solution of Na CI (3.5%) to the temperatures of 60 and 90 C, in two different thermal treatments - 1. - Sensitive 650 C by 4 hours and cooled in water. 2. Solubilized to 1050 C by 1 hour and cooled in water

  2. Experimental and numerical analysis on aluminum/steel pipe using magnetic pulse welding

    Science.gov (United States)

    Shim, J. Y.; Kim, I. S.; Lee, K. J.; Kang, B. Y.

    2011-12-01

    Recently, there has been a trend in the automotive industry to focus on the improvement of lightweight materials, such as aluminum and magnesium because the welding of dissimilar metals causes many welding defects. Magnetic pulse welding (MPW), one of the solid state welding technologies, uses electromagnetic force from current discharged through a working coil which develops a repulsive force between the induced currents flowing parallel and in the opposite direction in the tube to be welded. The objective of this paper is to develop a numerical model for analysis of the interaction between the outer pipe and the working coil using a finite element method (FEM) in the MPW process. Four Maxwell equations are solved using a general electromagnetic mechanics computer program, ANSYS/EMAG code. Experiments were also carried out with a W-MPW60 machine manufactured by WELMATE CO., LTD. with the Al1070 and SM45C for Al pipe and steel bar respectively. The calculated and measured results were compared to verify the proposed model.

  3. Analysis of noncoplanar pressurized laminations in X2 steel pipes by non-linear finite element

    Energy Technology Data Exchange (ETDEWEB)

    Morales, Alfredo [Instituto Tecnologico de Puebla (Mexico). Dept. de Posgrado; Gonzalez, Jorge L.; Hallen, Jose M. [Instituto Politecnico Nacional (Mexico). Escuela Superior de Ingenieria Quimica e Industrias Extractivas (ESIQIE). Dept. de Ingenieria Metalurgica

    2005-07-01

    Hydrogen induced cracking is of great interest in the mechanical integrity assessment of sour gas pipelines. Multiple stepwise cracks with internal pressure called laminations are often observed in pipelines and their interaction and coalescence may significantly affect the residual strength of the pipes. In this work, the interacting fields of non coplanar pressurized laminations in the wall of a pipe under pressure are analyzed by non-lineal finite element, considering an isotropic hardening law and the real tensile properties of the X52 steel. The results are presented as the evolution of the stress fields in the interlaminar region as a function of the pressure inside the laminations. It is found that for two approaching stepwise laminations the critical pressure follows a hyperbolic type law, thus the effect of the lamination length is principal for greater lengths and for shorter lengths the effect is minimum. The critical pressure is defined as pressure inside the lamination that causes plastification of the interlaminar region. (author)

  4. Assessment of Crack Detection in Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-Frequency Ultrasonic Methods

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Michael T.; Crawford, Susan L.; Cumblidge, Stephen E.; Denslow, Kayte M.; Diaz, Aaron A.; Doctor, Steven R.

    2007-03-01

    Studies conducted at the Pacific Northwest National Laboratory in Richland, Washington, have focused on assessing the effectiveness and reliability of novel approaches to nondestructive examination (NDE) for inspecting coarse-grained, cast stainless steel reactor components. The primary objective of this work is to provide information to the U.S. Nuclear Regulatory Commission on the effectiveness and reliability of advanced NDE methods as related to the inservice inspection of safety-related components in pressurized water reactors (PWRs). This report provides progress, recent developments, and results from an assessment of low frequency ultrasonic testing (UT) for detection of inside surface-breaking cracks in cast stainless steel reactor piping weldments as applied from the outside surface of the components. Vintage centrifugally cast stainless steel piping segments were examined to assess the capability of low-frequency UT to adequately penetrate challenging microstructures and determine acoustic propagation limitations or conditions that may interfere with reliable flaw detection. In addition, welded specimens containing mechanical and thermal fatigue cracks were examined. The specimens were fabricated using vintage centrifugally cast and statically cast stainless steel materials, which are typical of configurations installed in PWR primary coolant circuits. Ultrasonic studies on the vintage centrifugally cast stainless steel piping segments were conducted with a 400-kHz synthetic aperture focusing technique and phased array technology applied at 500 kHz, 750 kHz, and 1.0 MHz. Flaw detection and characterization on the welded specimens was performed with the phased array method operating at the frequencies stated above. This report documents the methodologies used and provides results from laboratory studies to assess baseline material noise, crack detection, and length-sizing capability for low-frequency UT in cast stainless steel piping.

  5. Corrosion resistance of ERW (Electric Resistance Welded) seam welds as compared to metal base in API 5L steel pipes

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Velasquez, Jorge L.; Godinez Salcedo, Jesus G.; Lopez Fajardo, Pedro [Instituto Politecnico Nacional (IPN), Mexico D.F. (Mexico). Escuela Superior de Ingenieria Quimica e Industrias Extractivas (ESIQIE). Dept. de Ingenieria Metalurgica

    2009-07-01

    The corrosion resistance of ERW seam welds and the base metal in API 5L X70 steel pipes was evaluated by Tafel tests. The procedure was according to ASTM G3 standard. The study was completed with metallographic and chemical characterization of the tested zones, that is, the welded zone and the base metal away of the weld. All tests were made on the internal surface of the pipe in order to assess the internal corrosion of an in-service pipeline made of the API 5L X70 steel. The test solution was acid brine prepared according to NACE Publications 1D182 and 1D196. The results showed that the ERW seam weld corrodes as much as three times faster than the base material. This behavior is attributed to a more heterogeneous microstructure with higher internal energy in the ERW seam weld zone, as compared to the base metal, which is basically a ferrite pearlite microstructure in a normalized condition. This result also indicates that pipeline segments made of ERW steel pipe where the seam weld is located near or at the bottom of the pipe are prone to a highly localized attack that may form channels of metal loss if there is water accumulation at the bottom of the pipeline. (author)

  6. Seismic fragility analysis of buried steel piping at P, L, and K reactors

    International Nuclear Information System (INIS)

    Wingo, H.E.

    1989-10-01

    Analysis of seismic strength of buried cooling water piping in reactor areas is necessary to evaluate the risk of reactor operation because seismic events could damage these buried pipes and cause loss of coolant accidents. This report documents analysis of the ability of this piping to withstand the combined effects of the propagation of seismic waves, the possibility that the piping may not behave in a completely ductile fashion, and the distortions caused by relative displacements of structures connected to the piping

  7. Local microstructures, Hardness and mechanical properties of a stainless steel pipe-welded joint

    International Nuclear Information System (INIS)

    Zhao Yongxiang; Gao Qing; Cai Lixun

    2000-01-01

    An experimental investigation is carefully performed into the local microstructures, hardness values and monotonic mechanical properties of the three zones (the base metal, heat affecting zone and weld metal) of 1Cr18Ni9Ti stainless steel pipe-welded joint. The local microstructures are observed by a metallurgical test and a surface replica technology, the local hardness values are measures by a random Vickers hardness test, and the local mechanical properties are characterized by the Ramberg-Osgood and modified Ramberg-Osgood stress-stain relations. The investigation reveals that there are significant differences of the three zones in the local microstructures, hardness values and monotonic mechanical properties, especially of the three zones in the local microstructure, hardness values and monotonic mechanical properties, especially of the weld metal. The weld metal exhibits the largest heterogeneity of local microstructures and monotonic mechanical properties, and the largest scatter of local hardness values. It is necessary to consider these difference and introduce the reliability method to model the scatter in the pipe analysis. In addition, it is verified that a columnar grain structure, which is made up of matrix-rich δ ferrite bands, can characterize the weld metal and the distance between the neighboring rich δ ferrite bands is an appropriate measurement of the columnar grain structure. This measurement is in accordance with the transition point between the microstructural short crack and physical small crack stages, which are generally used for characterizing the short fatigue crack behavior of materials. This indicates that the microstructure controls the fatigue damage character of the present material

  8. Improving pitting corrosion resistance of type 304 austenitic stainless steel pipe weldments using purging gases with low amounts of oxygen

    International Nuclear Information System (INIS)

    Huang, W.; Paciej, R.; Link, L.; Mckeown, M.

    1993-01-01

    Pitting corrosion on the welded joints of water pipe lines may cause the shut down of nuclear power plants. The susceptibility to pitting corrosion is usually increased by high temperature oxidation during welding. In this study, an attempt was made to improve the pitting corrosion resistance of type 304 austenitic stainless steel pipe weldments by reducing the oxygen level in the purging gases. The pitting corrosion resistance of the as-received weldments was determined using stepwise cyclic polarization in aqueous solution containing chloride ions. It was found that relatively high oxygen levels (1-2%) in the purging gases caused severe high temperature oxidation, resulting in a non-uniform, porous, cracked, and thick surface oxide layer on the fusion and heat affected zones on the root pass of the pipe weldments. This high temperature oxidation also created a non-uniform distribution of chromium in the surface oxide layer, which, in turn, caused preferential pitting in the chromium depleted areas

  9. The influence of repeated loading on work of the steel fiber concrete drainage trays and pipes on the roads

    Directory of Open Access Journals (Sweden)

    Andriichuk Oleksandr

    2017-01-01

    Full Text Available The drainage system is one of the components of the road design. The condition of the subgrade and pavement depends on its effectiveness. The main structural elements of the drainage system on the roads are gutters and pipes. They are made of concrete or reinforced concrete. Under the influence of climatic factors and fluctuations of the vibration caused by the vehicles movement on the surface, it occurs destruction: formation of cracks, potholes, husking of concrete, destruction of protective layer of concrete, etc. It should be noted that these structures perceive the dynamic and thermal effects. The low fracture materials toughness poses the issue of searching ways of its increase. One solution of this problem is the use of dispersion-reinforced concrete gutters and pipes. The article presents the results of research strength, crack resistance and deformability of gutters and pipes using steel fiber reinforced concrete under the action of repeated loads

  10. CREEP LIFE ASSESSMENT OF 2.25Cr-1Mo PIPING STEEL AND OF ITS SIMULATED HAZ MATERIAL

    OpenAIRE

    Kazunari, FUJIYAMA; Takashi, ISEKI; Atsushi, KOMATSU; Nagatoshi, OKABE; Heavy Apparatus Engineering Laboratory, Toshiba Corporation; Keihin Product Operations, Toshiba Corporation; Keihin Product Operations, Toshiba Corporation; Department of Mechanical Engineering, Ehime University

    1997-01-01

    A creep life assessment method was proposed for base metal and HAZ of 2.25Cr-1Mo steel STPA24 used in high temperature steam piping of fossil power plants. Microstructuiral observations and hardness measurements were carried out for base metal and simulated HAZ after thermal aging and creep testing. Simulated HAZ material showed significant softening during thermal and creep exposure, but base metal showed less softening. Hardness equation was established based on the kinetics of carbide coar...

  11. 77 FR 64478 - Circular Welded Carbon-Quality Steel Pipe From India: Final Determination of Sales at Less Than...

    Science.gov (United States)

    2012-10-22

    ....D. and 0.165 inch wall thickness (gage 8) 4.000 inch O.D. and 0.148 inch wall thickness (gage 9) 4.000 inch O.D. and 0.165 inch wall thickness (gage 8) 4.500 inch O.D. and 0.203 inch wall thickness... investigation is Zenith Birla (India) Limited (previously known as Zenith Steel Pipes and Industries Ltd...

  12. The influence of heat treatment on strain aging phenomena of the low alloyed carbon steel piping

    International Nuclear Information System (INIS)

    Lee, J. S.; Kim, I. S.; Kim, J. W.

    2001-01-01

    Strain aging characteristics were studied on the low alloyed carbon steel. Intercritical annealing in two phase region was performed to the SA106 Gr.C steel to reduce the detrimental strain aging effects. Tensile tests were carried out at various temperatures before and after treatment. Yield point return technique was used to measure the relative interstitial solute content. Tensile test results of heat treated specimen showed that the extent of ductility loss due to dynamic strain aging was reduced and that the temperature regions of the minimum ductility were shifted to higher temperature compared to the as received. The heat treatment seemed to reduce interstitial solute content in the ferrite matrix, which exhibited the decreased aging index as well as increased source hardening and yield point elongation. Activation energies of interstitial solute bulk diffusion determined by yield point return technique were 113.9 and 122.8 kJ/mol before and after heat treatment, respectively

  13. Weldability of Thermomechanically Treated Steels Having a High Yield Point

    Directory of Open Access Journals (Sweden)

    Górka J.

    2015-04-01

    Full Text Available The article concerns the issue of weldability of S700MC steel, treated thermo-mechanically, with high yield point. The weakest area of welded joints of this steel is a high - temperature coarse heat affected zone (HAZ in which due to the nucleation effect of the dissolved phases, strengthening the matrix and their subsequent uncontrolled separation precipitation in the form of finely disperse and rapid decrease impact strength is observed. Performed arc welding tests here have shown that in order to ensure high quality of welded joints, it is necessary to limit the welding linear heat input. During the welding process of S700MC steel, it is not recommended to use pre heating before the welding process and heat treatment after welding, and the number of repairs should be kept to a minimum, because it leads to a reduction of strength and plastic properties in the HAZ area, as a result of aging processes, dissolution of strengthening phases in the matrix and their subsequent uncontrolled precipitation during cooling.

  14. Dynamic Recrystallization Behavior of Vanadium Microalloyed Cryogenic Fine Grain Structural Steel Pipe at High Strain Rate

    Science.gov (United States)

    Zhou, S. S.; Liu, X. Q.; Liu, Z. L.; Hou, Z. G.; Tian, Q. C.

    2017-10-01

    Dynamic recrystallization (DRX) behavior of a vanadium microalloyed steel pipe was systematically investigated at temperatures range of 850-1,200 °C and a strain rate of 5 s-1 on a Gleeble-3800 thermo-simulation machine. Constitutive equation was obtained by characteristic points of DRX which derived from the strain hardening rate and stress curves. DRX kinetics model was established for determining the recrystallization volume fraction (X). Effect of dynamic precipitation of V(C, N) imposed on DRX at temperatures from 850-1,000 °C was analyzed. Results show that true stress-strain curves exhibited no clearly defined stress peaks with typical dynamic recovery behavior. X increased from 43.9 % to 100 % with increasing deformation temperature, which was in reasonable agreement with the observation of microstructure. Moreover, the calculation pinning force of V(C, N) precipitates was weaker than the recrystallization driving force, revealing that V(C, N) precipitates could effectively retard rather than prevent the progress of DRX.

  15. In-plane and out-of-plane bending tests on carbon steel pipe bends

    International Nuclear Information System (INIS)

    Brouard, D.; Tremblais, A.; Vrillon, B.

    1979-01-01

    The objectives of these tests were to obtain experimental results on bends behaviour in elastic and plastic regime by in plane and out of plane bending. Results were used to improve the computer model, for large distorsion of bends, to be used in a simplified beam type computer code for piping calculations. Tests were made on type ANSI B 169 DN 5 bends in ASTM A 106 Grade B carbon steel. These tests made it possible to measure, for identical bends, in elastic regime, the flexibility factors and, in plastic regime, the total evolution in opening, in closing and out of plane. Flexibility factors of 180 0 bend without flanges are approximately the same in opening and in closing. The end effect due to flanges is not very significant, but it is important for 90 0 bends. In plastic regime, collapse loads or collapse moments of bends depends also of both the end effects and the angle bend. The end effects and the angle bend are more sensitive in opening than in closing. The interest of these tests is to procure some precise evolution curves of identical bends well characterized in geometry and metal strength, deflected in large distorsions. (orig./HP)

  16. Residual Stresses Due to Circumferential Girth Welding of Austenitic Stainless Steel Pipes

    Science.gov (United States)

    Tarak, Farzan

    Welding, as a joining method in fabrication of engineering products and structural elements, has a direct influence on thermo-mechanical behavior of components in numerous structural applications. Since these thermo-mechanical behaviors have a major role in the life of welding components, predicting thermo-mechanical effects of welding is a major factor in designing of welding components. One of the major of these effects is generation of residual stresses due to welding. These residual stresses are not the causes of failure in the components solely, but they will add to external loads and stresses in operating time. Since, experimental methods are time consuming and expensive, computational simulation of welding process is an effective method to calculate these residual stresses. This investigation focuses on the evaluation of residual stresses and distortions due to circumferential girth welding of austenitic stainless steel pipes using the commercial finite element software ESI Visual-Environment and SYSWELDRTM to simulate welding process. Of particular importance is the comparison of results from three different types of mechanics models: 1) Axisymmetric, 2) Shell, and 3) Full 3-D.

  17. Effect of length of thinning area on the failure behavior of carbon steel pipe containing a defect of wall thinning

    International Nuclear Information System (INIS)

    Kim, Jin Weon; Park, Chi Yong

    2003-01-01

    The present study performed pipe failure tests using 102 mm-Sch. 80 carbon steel pipe with various simulated wall thinning defects, to investigate the effect of axial length of wall thinning and internal pressure on the failure behavior of pipe thinned by flow accelerated corrosion (FAC). The tests were conducted under loading conditions of four-point bending with and without internal pressure. The results showed that a failure mode of pipe with a defect depended on the magnitude of internal pressure and axial thinning length as well as stress type and thinning depth and circumferential angle. Both load carrying capability (LCC) and deformation capability (DC) were depended on stress type in the thinning area and dimensions of thinning defect. For applying tensile stress to the thinned area, the dependence of LCC on the axial length of wall thinning was determined by circumferential thinning angle, and the DC was proportionally increased with increase in axial length of wall thinning regardless of the circumferential angle. For applying compressive stress to thinned area, however, the LCC was decreased with increase in axial length of the thinned area. Also, the effect of internal pressure on failure behavior was characterized by failure mode of thinned pipe, and it promoted crack occurrence and mitigated a local buckling of the thinned area

  18. Non-linear finite element-based material constitutive law for zero slump steel fiber reinforced concrete pipe structures

    Science.gov (United States)

    Mikhaylova, Alena

    This study presents a comprehensive investigation of performance and behavior of steel-fiber reinforced concrete pipes (SFRCP). The main goal of this study is to develop the material constitutive model for steel fiber reinforced concrete used in dry-cast application. To accomplish this goal a range of pipe sizes varying from 15 in. (400 mm) to 48 in. (1200 mm) in diameter and fiber content of 0.17%, 0.25%, 0.33%, 0.5%, 0.67% and 83% by volume were produced. The pipes were tested in three-edge bearing condition to obtain the load-deformation response and overall performance of the pipe. The pipes were also subjected to hydrostatic joint and joint shear tests to evaluate the performance of the fiber-pipe joints for water tightness and under differential displacements, respectively. In addition, testing on hardened concrete was performed to obtain the basic mechanical material properties. High variation in the test results for material testing was identified as a part of experimental investigation. A three-dimensional non-linear finite element model of the pipe under the three edge bearing condition was developed to identify the constitutive material relations of fiber-concrete composite. A constitutive model of concrete implementing the concrete plasticity and continuum fracture mechanics was considered for defining the complex non-linear behavior of fiber-concrete. Three main concrete damage algorithms were examined: concrete brittle cracking, concrete damaged plasticity with adaptive meshing technique and concrete damaged plasticity with visco-plastic regularization. The latter was identified as the most robust and efficient to model the post-cracking behavior of fiber reinforced concrete and was used in the subsequent studies. The tension stiffening material constitutive law for composite concrete was determined by converging the FEM solution of load-deformation response with the results of experimental testing. This was achieved by iteratively modifying the non

  19. Hydrogen embrittlement of thermomechanically treated 18Ni Maraging steel

    International Nuclear Information System (INIS)

    Munford, J.W.; Rack, H.J.; Kass, W.J.

    1977-01-01

    The influence of thermomechanical treatments on susceptibility to cracking in 100 percent relative humidity air and low pressure (93.3 KPa) gaseous hydrogen has been investigated for 18Ni (350 ksi) Maraging steel. Two thermomechanical treatments were studied, ausforming and marforming and compared with the standard solution treated and aged material. Although little difference exists for the strength and toughness values between these treatments, a two to five-fold increase in the stress intensity threshold for cracking was found for both the ausformed and marformed material. A dramatic difference in cracking kinetics was also apparent as shown by the failure times at comparable stress intensities. Fractographic analysis showed that the primary fracture mode was 100 percent intergranular for the solution treated and aged samples while the ausform and marform failures were predominately quasi-cleavage or intergranular depending on orientation. Finally, permeation and diffusion measurements were conducted on the above materials and these results are correlated with the environmental cracking behavior

  20. A simple computational method for predicting magnetic field in the vicinity of a three-phase underground cable with a fluid-filled steel-pipe enclosure

    International Nuclear Information System (INIS)

    Xu, X.B.; Yang, X.M.

    1994-01-01

    This paper presents a simple computational method for predicting the magnetic field above ground, generated by an underground three-phase pipe-type cable. In the computation, an approximation is made to simplify the problem a Fourier series technique and an iterative procedure are employed to handle the nonlinear B-H characteristic of the steel pipe. To validate the computational method, measurements were made and the numerical results are compared with the measurement data. Also, data of magnetic fields generated by the pipe type cable are compared with those due to the cable in absence of the pipe. The advantages and disadvantages of this simple method are discussed

  1. 49 CFR 192.113 - Longitudinal joint factor (E) for steel pipe.

    Science.gov (United States)

    2010-10-01

    ... SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Pipe Design... design formula in § 192.105 is determined in accordance with the following table: Specification Pipe... Electric-fusion-welded 1.00 ASTM A 691 Electric-fusion-welded 1.00 API 5 L Seamless 1.00 Electric...

  2. Burst pressure of super duplex stainless steel pipes subject to combined axial tension, internal pressure and elevated temperature

    International Nuclear Information System (INIS)

    Lasebikan, B.A.; Akisanya, A.R.

    2014-01-01

    The burst pressure of super duplex stainless steel pipe is measured under combined internal pressure, external axial tension and elevated temperature up to 160 °C. The experimental results are compared with existing burst pressure prediction models. Existing models are found to provide reasonable estimate of the burst pressure at room temperature but significantly over estimate the burst pressure at elevated temperature. Increasing externally applied axial stress and elevated temperature reduces the pressure capacity. - Highlights: • The burst pressure of super duplex steel is measured under combined loading. • Effect of elevated temperature on burst pressure is determined. • Burst pressure decreases with increasing temperature. • Existing models are reliable at room temperature. • Burst strength at elevated temperature is lower than predictions

  3. Influence of stress concentrator shape and testing temperature on impact bending fracture of 17Mn1Si pipe steel

    Science.gov (United States)

    Panin, S. V.; Vlasov, I. V.; Maruschak, P. O.; Moiseenko, D. D.; Berto, F.; Vinogradov, A.

    2017-12-01

    The influence of the notch shape on the impact fracture of 17Mn1Si steel is investigated at different temperatures, with the focus placed on the low temperature behavior. An approach towards fracture characterization has been suggested based on the description of elastic-plastic deformation of impact loaded specimens on the stage of crack initiation and growth at ambient and lower temperatures. The analysis of the impact loading diagrams and fracture energy values for the 17Mn1Si pipe steel reveals the fracture mechanisms depending on the notch shape. It has been found that the testing temperature reduction plays a decisive role in plastic strain localization followed by dynamic fracture of the specimens with differently shaped notches.

  4. 75 FR 973 - Certain Welded Stainless Steel Pipes From the Republic of Korea: Preliminary Results of...

    Science.gov (United States)

    2010-01-07

    ... and transport lines, general food processing lines, automotive paint lines, and paper process machines... purchased hot-rolled stainless steel coil from a Korean affiliate, Pohang Iron and Steel Company (POSCO...

  5. Feasibility of new ladle-treated Hadfield steel for mining purposes

    Science.gov (United States)

    El Fawkhry, M. K.

    2018-03-01

    A debate has arisen over the possibility of using a new ladle-treated Hadfield steel instead of conventional heat-treated Hadfield steel in mining applications. This debate might be solved by identifying the differences between the mechanical properties and strain-hardening properties of conventional heat-treated Hadfield steel and its counterpart ladle-treated Hadfield steel. Tensile and compression tests demonstrated that the ductility of ladle-treated Hadfield steel is similar to that of conventional heat-treated steel. However, the strain-hardening property of the ladle-treated Hadfield steel is almost two times higher than that of the heat-treated Hadfield steel. The results of this study demonstrate that the improvement of the strain-hardening behavior is attributable to the low stacking-fault energy of the main austenite matrix, which results from the high segregation coefficient of carbon and manganese solutes of the main austenite matrix into the new eutectic phase. Superior wear abrasion resistance is a potential consequence of different strain-hardening properties under low and high loads.

  6. Explosive cutting of thick-walled steel pipes in the reactor HDR

    International Nuclear Information System (INIS)

    Wegener, H.; Freund, H.U.

    1990-01-01

    Cutting of a real pipe system by explosive technique has been tested and proven feasible inside the HDR reactor containment. Circumferential cuts were performed on a pipe loop with 400 mm diameter, 20 mm wall thickness. The cutting tool consists of an array of modular explosive charges which are wrapped around the pipe in a collar like mode. Mounting of the charge array is performed manually in a quick and easy way. In order to retain the fragments originating from the charge a fragment retaining structure was used in the experiments. This ring shape structure (fragment catcher) also substantially reduces the explosive blast load on the immediate vicinity. However, handling a fragment catcher of 700 kg weight requires a pulley or crane and, consequently, rather restricts the application of this technique. In addition to the control of the fragments and the blast wave in the area of cutting operation the transient load on the pipe system and on the reactor containment structure has to be kept below critical values. In principle, the load produced in pipe cutting by explosive methods must be subdivided into the local and the global loads acting on the HDR. The various contributions of the dynamic loading have been measured and analyzed carefully. Fourier analyses conducted on the basis of displacement measurements indicate the frequencies. The ground mode, of the long pipe branch are between 2.5 Hz and 3.5 Hz, and for the second ground mode, between 7.5 Hz and 8.5 Hz. Predictions of the axial momentum on the basis of short pipe segment cutting are a factor of 3 too high in the calculated deflection of the separated pipe ends, while the calculated pipe excitation frequencies (2.5 to 10 Hz) are in rather good agreement with the measurement. (orig./GL)

  7. Ultrasound propagation in steel piping at electric power plant using clamp-on ultrasonic pulse doppler velocity-profile flowmeter

    International Nuclear Information System (INIS)

    Tezuka, Kenichi; Mori, Michitsugu; Wada, Sanehiro; Aritomi, Masanori; Kikura, Hiroshige

    2008-01-01

    Venturi nozzles are widely used to measure the flow rates of reactor feedwater. This flow rate of nuclear reactor feedwater is an important factor in the operation of nuclear power reactors. Some other types of flowmeters have been proposed to improve measurement accuracy. The ultrasonic pulse Doppler velocity-profile flowmeter is expected to be a candidate method because it can measure the flow profiles across the pipe cross sections. For the accurate estimation of the flow velocity, the incidence angle of ultrasonic entering the fluid should be carefully estimated by the theoretical approach. However, the evaluation of the ultrasound propagation is not straightforward for the several reasons such as temperature gradient in the wedge or mode conversion at the interface between the wedge and pipe. In recent years, the simulation code for ultrasound propagation has come into use in the nuclear field for nondestructive testing. This article analyzes and discusses ultrasound propagation in steel piping and water, using the 3D-FEM simulation code and the Kirchhoff method, as it relates to the flow profile measurements in power plants with the ultrasonic pulse Doppler velocity-profile flowmeter. (author)

  8. Polyoxometalate and Zirconium-Phosphate Conversion Coating for Steel Piping, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — In Sub-topic O3.04, NASA has identified a need for control of material degradation to extend the life and reduce the life-cycle costs of piping systems subject to...

  9. Polyoxometalate and Zirconium-Phosphate Conversion Coating for Steel Piping, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In Sub-topic O3-04, NASA has identified a need for control of material degradation to extend the life and reduce the life-cycle costs of piping systems subject to...

  10. Transverse and z-Direction CVN Impact Tests of X65 Line Pipe Steels of Two Centerline Segregation Ratings

    Science.gov (United States)

    Su, Lihong; Li, Huijun; Lu, Cheng; Li, Jintao; Fletcher, Leigh; Simpson, Ian; Barbaro, Frank; Zheng, Lei; Bai, Mingzhuo; Shen, Jianlan; Qu, Xianyong

    2016-08-01

    Centerline segregation occurs as a positive concentration of alloying elements in the mid-thickness region of continuously cast slab. Depending upon its severity, it may affect mechanical properties and potentially downstream processing such as weldability, particularly for high-strength line pipe. The segregation fraction in continuously cast slabs and corresponding hot-rolled strips was assessed on API 5L grade X65 line pipe steels with different levels of segregation, rated as Mannesmann 2.0 and 1.4. The results showed that the segregation fraction in hot-rolled strip samples was in accordance with that assessed in the cast slabs, and the segregated regions in hot-rolled strip samples were found to be discontinuous. Transverse and z-direction CVN impact tests were conducted on the two strips and the results showed that centerline segregation does have an influence on the Charpy impact properties of line pipe steel. Specimens located at segregated regions exhibited lower Charpy impact toughness and strips rolled from slabs with higher segregation levels are more likely to exhibit greater variability in Charpy impact toughness. The influence of centerline segregation on z-direction Charpy impact toughness is more severe than on transverse Charpy impact toughness. Lower Charpy impact toughness and brittle fracture surface with cleavage facets along with rod-shaped MnS inclusions were observed for the strip rolled from slab with 2.0 segregation rating if the Charpy specimens were located at segregated regions. The influence on Charpy impact toughness can be associated with the pearlite structure at the centerline and level of MnS inclusions.

  11. corrosion of a carbon steel covered by treated bentonites in ...

    African Journals Online (AJOL)

    F. Arbaoui

    2017-09-01

    Sep 1, 2017 ... Keywords: Corrosion inhibitor, Carbon steel, Electrochemical Impedances Spectroscopy;. Algerian bentonites; Tungstate. ... layer of corrosion products formed on the steel surface remains thinner than in aqueous solutions [11]. ..... chloride-induced crevice corrosion of Alloy 22. Corrosion Science, 2013, 68, ...

  12. A Failure Estimation Method of Steel Pipe Elbows under In-plane Cyclic Loading

    Directory of Open Access Journals (Sweden)

    Bub-Gyu Jeon

    2017-02-01

    Full Text Available The relative displacement of a piping system installed between isolated and nonisolated structures in a severe earthquake might be larger when without a seismic isolation system. As a result of the relative displacement, the seismic risks of some components in the building could increase. The possibility of an increase in seismic risks is especially high in the crossover piping system in the buildings. Previous studies found that an elbow which could be ruptured by low-cycle ratcheting fatigue is one of the weakest elements. Fatigue curves for elbows were suggested based on component tests. However, it is hard to find a quantitative evaluation of the ultimate state of piping elbows. Generally, the energy dissipation of a solid structure can be calculated from the relation between displacement and force. Therefore, in this study, the ultimate state of the pipe elbow, normally considered as failure of the pipe elbow, is defined as leakage under in-plane cyclic loading tests, and a failure estimation method is proposed using a damage index based on energy dissipation.

  13. A failure estimation method of steel pipe elbows under in-plane cyclic loading

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Bub Gyu; Kim, Sung Wan; Choi, Hyoung Suk; Park, Dong Uk [Seismic Simulation Tester Center, Pusan National University, Yangsan (Korea, Republic of); Kim, Nam Sik [Dept. of Civil and Environmental Engineering, Pusan National University, Busan (Korea, Republic of)

    2017-02-15

    The relative displacement of a piping system installed between isolated and nonisolated structures in a severe earthquake might be larger when without a seismic isolation system. As a result of the relative displacement, the seismic risks of some components in the building could increase. The possibility of an increase in seismic risks is especially high in the crossover piping system in the buildings. Previous studies found that an elbow which could be ruptured by low-cycle ratcheting fatigue is one of the weakest elements. Fatigue curves for elbows were suggested based on component tests. However, it is hard to find a quantitative evaluation of the ultimate state of piping elbows. Generally, the energy dissipation of a solid structure can be calculated from the relation between displacement and force. Therefore, in this study, the ultimate state of the pipe elbow, normally considered as failure of the pipe elbow, is defined as leakage under in-plane cyclic loading tests, and a failure estimation method is proposed using a damage index based on energy dissipation.

  14. Corrosion of pipe steel in CO2 containing impurities and possible solutions

    NARCIS (Netherlands)

    Zhang, X.; Zevenbergen, J.F.; Spruijt, M.P.N.; Borys, M.

    2013-01-01

    CO2 flue gases acquired from different sources contain a significant amount of impurities and water, which are corrosive to the pipeline steel. To design the pipelines for large scale of CO2 flue gas transport, the corrosion of pipeline steels has to be investigated in the realistic conditions. In

  15. Studying the effect of elastic-plastic strain and hydrogen sulphide on the magnetic behaviour of pipe steels as applied to their testing

    Directory of Open Access Journals (Sweden)

    Povolotskaya Anna

    2018-01-01

    Full Text Available The paper reports results of magnetic measurements made on samples of the 12GB pipe steel (strength group X42SS designed for producing pipes to be used in media with high hydrogen sulphide content, both in the initial state and after exposure to hydrogen sulphide, for 96, 192 and 384 hours under uniaxial elastic-plastic tension. At the stage of elastic deformation there is a unique correlation between the coercive force measured on a minor hysteresis loop in weak fields and tensile stress, which enables this parameter to be used for the evaluation of elastic stresses in pipes made of the 12 GB pipe steel under different conditions, including a hydrogen sulphide containing medium. The effect of the value of preliminary plastic strain, viewed as the initial stress-strain state, on the magnetic behaviour of X70 pipe steels under elastic tension and compression is studied. Plastic strain history affects the magnetic behaviour of the material during subsequent elastic deformation since plastic strain induces various residual stresses, and this necessitates taking into account the initial stress-strain state of products when developing magnetic techniques for the determination of their stress-strain parameters during operation.

  16. EFFECT OF Na₂B₄O₇ ADDITION ON THE STRUCTURE AND PROPERTIES OF Al₂O₃ CERAMIC-LINED STEEL PIPE PREPARED BY THE GS-SHS METHOD

    Directory of Open Access Journals (Sweden)

    Xinghui Hou

    2017-12-01

    Full Text Available By adding Na₂B₄O₇ into the Al-Fe₂O₃-Cr₂O₃ reaction system, the Al₂O₃ ceramic-lined steel pipe was prepared with the gravitational separation SHS method, and the influence of the Na₂B₄O₇ addition on the structure and properties of the produced composite steel pipe was investigated. The obtained results showed that the phase composition of the ceramic coating was Al₂O₃-FeCr Alloy-(Al0.9Cr0.1₂O₃ composite, and with the increase of the amount of Na₂B₄O₇ addition, the Fe-Cr alloy particles left in the ceramic coating increased and distributed uniformly, and the denser ceramic coating was obtained. However, when the amount of Na₂B₄O₇ addition increased further to over 4%, the ceramic coating became fractures, the hardness of ceramic coating decreased. The transition structure of steel pipe-transition layer-ceramic coating was formed, the thickness of the transition layer decreased with the addition of Na₂B₄O₇, and the boundaries between the transition layer and the ceramic layer were less obvious, which would have a significant effect on the improvement of the bonding quality of the composite steel pipe.

  17. Experimental use of Line-X coated steel pipe piles, Clay Hill Bridge (#2157) replacement project over the Mousam River, Route 9/Western Avenue, Kennebunk, Maine.

    Science.gov (United States)

    2013-02-01

    Steel pipe piles used by MaineDOT for bridge construction are typically coated with a fusion-bonded epoxy (FBE). FBE is a powder-based coating with properties similar to traditional : epoxies. Its name is derived from the process by which it adheres ...

  18. Corrosion of a carbon steel covered by treated bentonites in ...

    African Journals Online (AJOL)

    Electrochemical impedance spectroscopy results prove that tungstate reduces iron and chlorides ions transport through the clay. This deduction is supported also by microscopic observations. Keywords: Corrosion inhibitor, Carbon steel, Electrochemical Impedances Spectroscopy; Algerian bentonites; Tungstate ...

  19. Magnetoelastic acoustic emission in heat treated structural steels

    International Nuclear Information System (INIS)

    Gorkunov, Eh.S.; Khamitov, V.A.; Bartenev, O.A.; Somova, V.M.; Volkov, V.A.

    1987-01-01

    Effect of thermal treatment on magnetoelastic acoustic emission (MAE) in medium alloy and high-carbon low-alloy structural steels has been investigated to use the possible MAE method for controlling their structural state and strength characteristics. The MAE signal are shown to depend on the value of internal stresses as well as structural changes and phase transformations occurring in steels during heat treatment

  20. 78 FR 21107 - Circular Welded Carbon Steel Pipes and Tubes from Turkey: Preliminary Results of Countervailing...

    Science.gov (United States)

    2013-04-09

    ... Duties and Value-Added Tax (VAT) Exemptions under the Free Zones Law IV. Programs Preliminarily Determined to Not Be Used A. Stamp Duties and Fees Exemptions under the Free Zones Law B. Other Programs Not... Pipes and Tubes from Turkey: Preliminary Results of Countervailing Duty Administrative Review; Calendar...

  1. 77 FR 20782 - Circular Welded Carbon Steel Pipes and Tubes From Thailand: Preliminary Results of Antidumping...

    Science.gov (United States)

    2012-04-06

    ... Memorandum. We revised Pacific Pipe's financial expense ratio calculation to be based on its consolidated financial statements rather than its unconsolidated financial statements as reported. We increased Pacific... Saha Thai's financial expense ratio to zero. For more information on the changes to Saha Thai's COP...

  2. Measurement of the residual stresses in a stainless steel pipe girth weld containing long and short repairs

    International Nuclear Information System (INIS)

    Bouchard, P.J.; George, D.; Santisteban, J.R.; Bruno, G.; Dutta, M.; Edwards, L.; Kingston, E.; Smith, D.J.

    2005-01-01

    A series of residual measurements were made to obtain the through-thickness residual stress profiles in an as-welded and repair welded stainless steel pipe. Long and short length repairs were manufactured after initial measurements in the original girth weld. Measurements were made using neutron diffraction, deep hole and surface hole techniques. The various measurement methods were found to complement each other well. All the measurements revealed a characteristic profile for the through-thickness distribution of the residual stresses in the heat-affected zone. The residual stresses at mid-length of the heat affected zone of the short repair were found to be higher than in the long repair

  3. Finite element analysis of the collapse and post-collapse behavior of steel pipes applications to the oil industry

    CERN Document Server

    Dvorkin, Eduardo N

    2013-01-01

    This book presents a detailed discussion of the models that were developed to simulate the collapse and post-collapse behavior of steel pipes. The finite element method offers to engineers the possibility of developing models to simulate the collapse behavior of casings inside oil wells and the collapse behavior of deepwater pipelines. However, if technological decisions are going to be reached from these model results, with implications for the economic success of industrial operations, for the occupational safety and health and for the environment, the engineering models need to be highly reliable. Using these models engineers can quantify the effect of manufacturing tolerances, wear, corrosion, etc. This book describes in great details the experimental programs that are developed to validate the numerical results.

  4. Ultrasonic phased array sound field mapping through large-bore coarse grained cast austenitic stainless steel (CASS) piping materials

    Science.gov (United States)

    Cinson, A. D.; Crawford, S. L.; Prowant, M. S.; Diaz, A. A.; Hathaway, J. E.; Anderson, M. T.

    2012-04-01

    A sound field beam mapping exercise was conducted to further understand the effects of coarse-grained microstructures found in cast austenitic stainless steel (CASS) materials on phased array ultrasonic wave propagation. Laboratory measurements were made on three CASS specimens with different microstructures; the specimens were polished and etched to reveal measurable grain sizes, shapes, and orientations. Three longitudinal, phased array probes were fixed on a specimen's outside diameter with the sound field directed toward one end (face) of the pipe segment over a fixed range of angles. A point receiver was raster scanned over the surface of the specimen face generating a sound field image. A slice of CASS material was then removed from the specimen end and the beam mapping exercise repeated. The sound fields acquired were analyzed for spot size, coherency, and beam redirection. Qualitative analyses were conducted between the resulting sound fields and the microstructural characteristics of each specimen.

  5. 49 CFR 192.328 - Additional construction requirements for steel pipe using alternative maximum allowable operating...

    Science.gov (United States)

    2010-10-01

    ... experienced failures indicative of systemic material defects during strength testing, including initial... 49 Transportation 3 2010-10-01 2010-10-01 false Additional construction requirements for steel... Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY...

  6. Surveillance of evolution of defects in stainless steel piping subject to fatigue cycles in temperature

    International Nuclear Information System (INIS)

    Marini, J.

    1976-01-01

    The surveillance of internal crack growth in austenitic ICL 167 CN steel is possible by using ultrasonic techniques. The fracture mechanics allows to predict the evolution of these cracks under fatigue loading [fr

  7. Dependency of single-phase FAC of carbon and low-alloy steels for NPP system piping on pH, orifice distance and material

    International Nuclear Information System (INIS)

    Moon, Jeong Ho; Chung, Hung Ho; Sung, Ki Woung; Kim, Uh Chul; Rho, Jae Seong

    2005-01-01

    To investigate the Flow-Accelerated Corrosion (FAC) dependency of carbon steel (A106 Gr. B) and low-alloy steels (1Cr-1/2Mo, 2 1/4Cr-1Mo) on pH, orifice distance, and material, experiments were carried out. These experiments were performed using a flow velocity of 4 m/sec (partly 9 m/sec) at pH 8.0∼10.0 in an oxygen-free aqueous solution re-circulated in an Erosion-Corrosion Test Loop at 130 .deg. ... for 500 hours. The weight loss of the carbon steel specimens appeared to be positively dependent on the flow velocity. That of the carbon and low-alloy steel specimens also showed to be distinguishably dependent on the pH. At pH levels of 8.0∼9.5 it decreased, but increased from 9.5 to 10.0. Utility water chemistry personnel should carefully consider this kind of pH dependency to control the water system pH to mitigate FAC of the piping system material. The weight loss of the specimens located further from the orifice in the distance range of 6.8∼27.2 mm was shown to be greater, except for 2 1/4Cr-1Mo, which showed no orifice distance dependency. Low alloy steel specimens exhibited a factor of two times better resistance to FAC than that of the carbon steel. Based on this kind of FAC dependency of the carbon and low-alloy steels on the orifice distance and material, we conclude that it is necessary to alternate the composition of the secondary piping system material of NPPs, using low-alloy steels, such as 2 1/4Cr-1Mo, particularly when the system piping has to be replaced

  8. Properties and Microstructure of Laser Welded VM12-SHC Steel Pipes Joints

    OpenAIRE

    Skrzypczyk A.; Danielewski H.

    2016-01-01

    Paper presents results of microstructure and tests of welded joints of new generation VM12-SHC martensitic steel using high power CO2 laser (LBW method) with bifocal welding head. VM12-SHC is dedicated to energetic installation material, designed to replace currently used. High content of chromium and others alloying elements improve its resistance and strength characteristic. Use of VM12-SHC steel for production of the superheaters, heating chambers and walls in steam boilers resulted in var...

  9. Residual stress distribution in austenitic stainless steel pipe butt-welded joint measured by neutron diffraction technique

    International Nuclear Information System (INIS)

    Maekawa, Akira; Noda, Michiyasu; Oumaya, Toru; Takahashi, Shigeru

    2009-01-01

    Residual stress is inevitable consequence of welding or manufacturing process, which might greatly affect propagation of high-cycle fatigue or SCC crack. In order to evaluate damages due to the crack, it is required to estimate residual stress and to reflect them to the evaluation process as well. The magnitude and distribution of residual stress greatly depend on the individual process of welding or manufacturing, while the accuracy of prediction or measurement is still insufficient. This paper reports the result of residual stress measurement of butt-welded pipe made of austenitic stainless steel. It also intended to improve prediction and measurement techniques concerning to residual stress. The measurement was conducted by neutron diffraction technique employing the diffractometer for residual stress analysis developed by Japan Atomic Energy Agency. The measured results showed typical characteristics of butt-welded pipe both in decline of stress along axial direction and in radial distribution of bending due to axial stress. The measured result agreed qualitatively with the result predicted by the finite element analysis. A quantitative comparison between measured result and analysis showed a shift of the measured stress toward higher tensile. The measured result was also compared with the results by X-ray diffraction and strain-gauge methods to grasp the distinctive results of the methods. (author)

  10. Evaluation of fatigue properties of EN31 steel heat treated using biodegradable gingili oil

    Science.gov (United States)

    Harichandra, B. P.; Prashanth, Mrudula; Prakash, S. V.

    2016-09-01

    Rotating bending fatigue is the most commonly encountered loading in most machines and machine tools. At the same time, modern literature in this area is very little. EN31 steel is a steel which is commonly used in load bearing applications which encounters fatigue loading. Further, studies on heat treated EN31 steel to improve fatigue strength is hardly reported. This paper takes this rare issue further ahead by using bio-degradable gingili oil to heat treat EN31 steel for fatigue applications. This paper reports the results of rotating bending fatigue study of EN31 steel. Fatigue tests were conducted for three conditions a) Untreated, b) Heat treated with water, and c) Heat treated with gingili oil, with cantilever loads ranging from 30% to 90% using double sided rotating bending fatigue testing machine. It is seen that EN31 steel heat treated using gingili oil has far superior fatigue properties than water treated and untreated ones, with gingili oil quenched specimen have ∼10 times more fatigue life than water quenched specimen and ∼100 times more than unquenched specimens when lower bending stresses are involved.

  11. Establishing a design procedure for buried steel-reinforced high-density polyethylene pipes : a field study, [technical summary].

    Science.gov (United States)

    2015-11-01

    Several national standards and specification have been developed for design, installation, : and materials for precast concrete pipe, corrugated metal pipe, and HDPE pipes. However, : no national accepted installation standard or design method is ava...

  12. Characterization of the corroded surface morphology of a carbon steel piping elbow affected by flow-accelerated corrosion

    International Nuclear Information System (INIS)

    Abe, Hiroshi; Watanabe, Yutaka; Nakashima, Makoto; Tatsuki, Tadashi

    2017-01-01

    It has been widely recognized that the inner surface of carbon steel piping affected by relatively severe flow-accelerated corrosion (FAC) shows typical morphology in terms of roughness in many cases. Although hydrodynamic parameters would determine the characteristics of the rough surface developed in such cases, the detailed mechanism of the roughness formation is not fully known. In this study, the local FAC rate profile and morphology in terms of surface roughness for an entire 90-degree carbon steel piping elbow used in a fossil power plant have been investigated under two-phase flow in order to discuss the relationships between the FAC rate and characteristics of the inner surface morphology. For the axial direction, the FAC rate gradually increased with distance from the inlet, and it reaches the peak value in the downstream side, beyond which, the value kept decreasing slightly. Distributed horse-shoe pits and scalloped patterns were observed on the extrados side. The finding suggests that the extrados side of the pipe wall was covered with a continuous liquid film (single-phase). The result shows the possibility of the occurrence of FAC by a single-phase flow in the area where there is a sudden change in flow regime, even when the nominal phase state of the fluid is a two-phase flow regime. Both the local FAC rate and scallop coverage increase steeply near the middle parts of the elbow. There was a good correlation between the two, but it was not a one-to-one relationship because a significant decrease in FAC rate was observed in the downstream side; in contrast, the entire surface was covered with a fine scalloped pattern. The change in the morphology in terms of surface roughness clearly indicated that the overlapping of horse-shoe shaped pits gave a scalloped appearance. The results revealed that the inner surface shape affected by FAC is considered to essentially depend on the number density of nucleation sites for pit formation. (author)

  13. Structural and mechanical degradation of 09Mn2Si pipe steel after long-term operation

    Science.gov (United States)

    Panin, S. V.; Marushchak, P. O.; Vlasov, I. V.; Eremin, A. V.; Byakov, A. V.; Syromyatnikova, A. S.; Stankevich, R.

    2017-12-01

    A comprehensive study of the structure and impact toughness of 09Mn2Si steel used in the construction of the main gas pipeline "Mastakh-Berge-Yakutsk" (taken from the linear part with the outer diameter of 530 mm and the wall thickness of 7 mm) after 37 years of operation was carried out. A comparative analysis of results obtained for the emergency stock steel was conducted. It was shown that long-term operation does not give rise to a substantial redistribution of cementite. Deformation aging is slightly expressed and is manifested through precipitation of finely dispersed carbides in the grain bulk. The revealed structure degradation almost does not make sense under hardness measurement. The most pronounced manifestation of structure changes is related to decreasing impact toughness of 09Mn2Si steel which reaches ˜2 times under negative temperatures.

  14. Effects of phosphate addition on biofilm bacterial communities and water quality in annular reactors equipped with stainless steel and ductile cast iron pipes.

    Science.gov (United States)

    Jang, Hyun-Jung; Choi, Young-June; Ro, Hee-Myong; Ka, Jong-Ok

    2012-02-01

    The impact of orthophosphate addition on biofilm formation and water quality was studied in corrosion-resistant stainless steel (STS) pipe and corrosion-susceptible ductile cast iron (DCI) pipe using cultivation and culture-independent approaches. Sample coupons of DCI pipe and STS pipe were installed in annular reactors, which were operated for 9 months under hydraulic conditions similar to a domestic plumbing system. Addition of 5 mg/L of phosphate to the plumbing systems, under low residual chlorine conditions, promoted a more significant growth of biofilm and led to a greater rate reduction of disinfection by-products in DCI pipe than in STS pipe. While the level of THMs (trihalomethanes) increased under conditions of low biofilm concentration, the levels of HAAs (halo acetic acids) and CH (chloral hydrate) decreased in all cases in proportion to the amount of biofilm. It was also observed that chloroform, the main species of THM, was not readily decomposed biologically and decomposition was not proportional to the biofilm concentration; however, it was easily biodegraded after the addition of phosphate. Analysis of the 16S rDNA sequences of 102 biofilm isolates revealed that Proteobacteria (50%) was the most frequently detected phylum, followed by Firmicutes (10%) and Actinobacteria (2%), with 37% of the bacteria unclassified. Bradyrhizobium was the dominant genus on corroded DCI pipe, while Sphingomonas was predominant on non-corroded STS pipe. Methylobacterium and Afipia were detected only in the reactor without added phosphate. PCR-DGGE analysis showed that the diversity of species in biofilm tended to increase when phosphate was added regardless of the pipe material, indicating that phosphate addition upset the biological stability in the plumbing systems.

  15. Ultrasonic inspection of liquid-metal-filled austenitic stainless steel piping welds

    International Nuclear Information System (INIS)

    Mech, S.J.; Martin, J.D.

    1982-01-01

    The goal of this effort is to reliably detect a crack extending 25 to 50% through the wall of Schedule 40 sodium filled pipe at refueling temperatures (204 0 C [400 0 F]) using remote examination techniques. The task of demonstrating a prototype ultrasonic ISI system under simulated refueling conditions was laid out in two phases. The first phase was initiation of long-lead efforts which were key elements of a practical prototype system, including ultrasonic signal analysis efforts and laboratory prototype support systems. The second phase, dependent on successful completion of the first, consisted of development and demonstration of a prototype system in a simulated ISI environment

  16. Drying Effects on Corrosion Properties of Cr(VI) and Cr(III) Treated Electrogalvanized Steel

    NARCIS (Netherlands)

    Zhang, X.; Van den Bos, C.; Sloof, W.G.; Hovestad, A.; Terryn, H.; De Wit, J.H.W.

    2006-01-01

    Drying effects on corrosion performance of Cr(VI)- and Cr(III)-treated electro-galvanized steel have been studied in NaCl solution using potentiodynamic measurements and electrochemical impedance spectroscopy (EIS). The Cr(VI) and the Cr(III) treated specimens were dried at three different

  17. Stress Corrosion Cracking Behavior of Hardening-Treated 13Cr Stainless Steel

    Science.gov (United States)

    Niu, Li-Bin; Ishitake, Hisamitsu; Izumi, Sakae; Shiokawa, Kunio; Yamashita, Mitsuo; Sakai, Yoshihiro

    2018-03-01

    Stress corrosion cracking (SCC) behavior of the hardening-treated materials of 13Cr stainless steel was examined with SSRT tests and constant load tests. In the simulated geothermal water and even in the test water without addition of impurities, the hardening-treated materials showed a brittle intergranular fracture due to the sensitization, which was caused by the present hardening-treatments.

  18. Flow accelerated corrosion of carbon steel feeder pipes from Indian reactors

    International Nuclear Information System (INIS)

    Singh, J.L.; Kumar, Umesh; Kumawat, N.; Kumar, Sunil; Anantharaman, S.; Kain, Vivekanand

    2011-01-01

    En-masse feeder replacement was done at RAPS-2 after occurrence of a pinhole leak in B12 (S) outlet feeder elbow. Some of the feeders, removed after a service of 15.67 EFPY were received for detailed investigation. Ultrasonic thickness measurement of the feeders was carried out to ascertain the loss in wall thickness due to Flow Accelerated Corrosion (FAC) and marking the region of interest from outside. Surface morphology of inner surface of a number of feeder samples were carried out by SEM near the HAZ and adjoining area. Maximum FAC had occurred in the heat-affected zone of the weld in 32 NB elbows. Weld was affected to a lower extent than the parent metal due to higher chromium content. IGSCC cracks were also observed in parent metal portion of the middle elbow in 32 NB outlet feeder pipe due to bending residual stresses. There are two life limiting reasons to curtail the useful life in the reactors namely FAC and IGSCC. The problem of FAC can be reduced by increasing chromium content and reducing the flow velocity by opting for higher diameter feeder pipes. The welding defects and residual stresses in HAZ and surrounding areas are detrimental for FAC and IGSCC in the elbow region. This paper presents some of the microstructural observations and findings on FAC to explain the mechanism of degradation of feeders. (author)

  19. Heat treated 9 Cr-1 Mo steel material for high temperature application

    Science.gov (United States)

    Jablonski, Paul D.; Alman, David; Dogan, Omer; Holcomb, Gordon; Cowen, Christopher

    2012-08-21

    The invention relates to a composition and heat treatment for a high-temperature, titanium alloyed, 9 Cr-1 Mo steel exhibiting improved creep strength and oxidation resistance at service temperatures up to 650.degree. C. The novel combination of composition and heat treatment produces a heat treated material containing both large primary titanium carbides and small secondary titanium carbides. The primary titanium carbides contribute to creep strength while the secondary titanium carbides act to maintain a higher level of chromium in the finished steel for increased oxidation resistance, and strengthen the steel by impeding the movement of dislocations through the crystal structure. The heat treated material provides improved performance at comparable cost to commonly used high-temperature steels such as ASTM P91 and ASTM P92, and requires heat treatment consisting solely of austenization, rapid cooling, tempering, and final cooling, avoiding the need for any hot-working in the austenite temperature range.

  20. Properties and Microstructure of Laser Welded VM12-SHC Steel Pipes Joints

    Directory of Open Access Journals (Sweden)

    Skrzypczyk A.

    2016-06-01

    Full Text Available Paper presents results of microstructure and tests of welded joints of new generation VM12-SHC martensitic steel using high power CO2 laser (LBW method with bifocal welding head. VM12-SHC is dedicated to energetic installation material, designed to replace currently used. High content of chromium and others alloying elements improve its resistance and strength characteristic. Use of VM12-SHC steel for production of the superheaters, heating chambers and walls in steam boilers resulted in various weldability researches. In article are presented results of destructive and non-destructive tests. For destructive: static bending and Vickers hardness tests, and for non-destructive: VT, RT, UT, micro and macroscopic tests were performed.

  1. Ratchetting behavior of primary heat transport (PHT) piping material SA-333 carbon steel subjected to cyclic loads at room temperature

    International Nuclear Information System (INIS)

    Kulkarni, S.; Desai, Y.M.; Kant, T.; Reddy, G.R.; Gupta, C.; Chakravarthy, J.K.

    2004-01-01

    Ratchetting behavior of SA-333 Gr. 6 carbon steel used as primary heat transport (PHT) piping material has been investigated with three constitutive models proposed by Armstrong-Frederick, Chaboche and Ohno-Wang involving different hardening rules. Performance of the above mentioned models have been evaluated for a broad set of uniaxial and biaxial loading histories. The uniaxial ratchetting simulations have been performed for a range of stress ratios (R) by imposing different stress amplitudes and mean stress conditions. Numerical simulations indicated significant ratchetting and opening of hysteresis loop for negative stress ratio with constant mean stress. Application of cyclic stress without mean stress (R = -1.0) has been observed to produce negligible ratchet-strain accumulation in the material. Simulation under the biaxial stress condition was based on modeling of an internally pressurized thin walled pipe subjected to cyclic bending load. Numerical results have been validated with the experiments as per simulation conditions. All three models have been found to predict the observed accumulation of circumferential strain with increasing number of cycles. However, the Armstrong Frederick (A-F) model was found to be inadequate in simulating the ratchetting response for both uniaxial as well as biaxial loading cases. The A-F model actually over-predicted the ratchetting strain in comparison with the experimental strain values. On the other hand, results obtained with the Chaboche and the Ohno-Wang models for both the uniaxial as well as biaxial loading histories have been observed to closely simulate the experimental results. The Ohno-Wang model resulted in better simulation for the presents sets of experimental results in comparison with the Chaboche model. It can be concluded that the Ohno-Wang model suited well compared to the Chaboche model for above sets of uniaxial and biaxial loading histories. (authors)

  2. Application of heat treated low-carbon electrical steels in small motors

    Energy Technology Data Exchange (ETDEWEB)

    Agueero, A.C.; Moyano, H.R. [CEMCOR-CIMM, Cordoba (Argentina). Inst. Nacional de Tecnologia Industrial; Actis, F.A. [SIDERAR S.A.I.C., Centro Siderurgico Gral. Savio, San Nicolas (Argentina); Casais, O. [Tamyr S.A., Benavidez, Buenos Aires (Argentina)

    1999-08-01

    In this work the influence of the magnetic properties of steels, at different processing conditions, on the performance of a synchronous permanent magnet motor (SPMM) with 2.7 watt power is studied. A commercial low-carbon steel was subjected to 2 different thermal treatments and characterized for microstructure, carbon content and magnetic properties. A computer model using finite element method was developed to calculate the influence of the heat treatment properties on the ampere-turns reduction. Several motor prototypes were constructed using steels in the as-received and heat-treated conditions. Torque measurements were used as indication of the motors performance. (orig.) 4 refs.

  3. Steel heat treating: mathematical modelling and numerical simulation of a problem arising in the automotive industry

    Directory of Open Access Journals (Sweden)

    Jose Manuel Diaz Moreno

    2017-12-01

    Full Text Available We describe a mathematical model for the industrial heating and cooling processes of a steel workpiece representing the steering rack of an automobile. The goal of steel heat treating is to provide a hardened surface on critical parts of the workpiece while keeping the rest soft and ductile in order to reduce fatigue. The high hardness is due to the phase transformation of steel accompanying the rapid cooling. This work takes into account both heating-cooling stage and viscoplastic model. Once the general mathematical formulation is derived, we can perform some numerical simulations.

  4. Inspection according to the RSE-M code for the nondestructive testing processes example of fatigue defects detection in austenitic steel pipes

    International Nuclear Information System (INIS)

    Rotter, B.; Birac, C.; Benoist, Ph.; Mahaut, S.

    2001-01-01

    The RSE-M code provides rules and requirement concerning the inspection of PWR type nuclear power plants. By the presentation of fatigue crack detection examples, this paper wants to show the importance of physical phenomena simulation. It allows to perfect tests without multiplying the number of models or physical experiments. The modelling contribution is discussed and illustrated with many examples concerning the ultrasonic detection of fatigue defects in stainless steel pipes. (A.L.B.)

  5. Tribological Response of Heat Treated AISI 52100 Steels Against Steel and Ceramic Counterparts

    Directory of Open Access Journals (Sweden)

    Türedi E.

    2017-09-01

    Full Text Available AISI 52100 bearing steels are commonly used in applications requiring high hardness and abrasion resistance. The bearing steels are working under dynamic loads in service conditions and their toughness properties become important. In order to provide the desired mechanical properties, various heat treatments (austenizing, quenching and tempering are usually applied. In this study, AISI 52100 bearing steel samples were austenized at 900°C for ½ h and water quenched to room temperature. Then tempering was carried out at 795°C, 400°C and 200°C for ½ h. In order to investigate the effect of heat treatment conditions on wear behavior, dry friction tests were performed according to ASTM G99-05 Standard with a ‘ball-on-disk’ type tribometer. The samples were tested against steel and ceramic counterparts using the parameters of 100 m distance and 30 N load and 0.063 m/s rotational speed. After wear test, the surface characterization was carried out using microscopy. Wear loss values were calculated using a novel optical method on both flat and counterpart specimens.

  6. Investigation of the development and optimisation of cutting loads for the cutting of steel pipes with typical properties and material properties for nuclear power stations

    International Nuclear Information System (INIS)

    Schumann, S.; Freund, H.U.; Hollenberg, K.; Horning, W.; Esser, H.J.

    1987-04-01

    The aim of the project was to develop a type of cutter loading for the cutting of thickwalled steel pipes by explosive technique which, due to its construction and cutting performance, is suitable for use when dismantling pipelines in shutdown nuclear power stations. The loading sleeve is built up of individual linear elements and can be placed as a polygon (e.g. octagon) around pipes of different diameters. A steel pipe with dimensions 610 mm diameter x 36 mm wall thickness (live steam pipe of a German BWR of a new type) was completely and accurately cut using a cutting load sleeve with 1.84 kg of explosive. The great tamping of the cutting loader type developed, minimises the quantity of explosive required and reduces the air shock or blast wave peak pressure to about 30% compared to a charge without tamping. The distance at which the value of peak pressure of the blast wave of 1 bar (which could cause damage) is exceeded, is reduced to 3.0 metres compared to 5.3 metres for an untamped charge of the same cutting power. (orig./HP) [de

  7. X-ray diffraction study of microstructural changes during fatigue damage initiation in pipe steels: Role of the initial dislocation structure

    International Nuclear Information System (INIS)

    Pinheiro, B.; Lesage, J.; Pasqualino, I.; Bemporad, E.; Benseddiq, N.

    2013-01-01

    The present work is the second part of an ongoing study of microstructural changes during fatigue damage initiation in pipe steels [B. Pinheiro et al., Mat. Sci. Eng., A 532 (2012) 158–166]. Microdeformations and residual stresses (macrostresses) are evaluated by X-ray diffraction during alternating bending fatigue tests on samples taken from an API 5L X60 grade steel pipe. Microdeformations are evaluated from the full width at half maximum (FWHM) of the diffraction peak and residual stresses are estimated from the peak shift. Here, to understand the role of the initial dislocation structure, annealed samples are considered. As previously found for as-machined samples, the evolution of microdeformations shows three regular successive stages, but now with an increase during the first stage. The amplitude of each stage is accentuated with increasing stress amplitude, while its duration is reduced. Residual stresses show a similar trend, with stages of the same durations than those observed for FWHM, respectively. Additionally, changes in density and distribution of dislocations are observed by transmission electron microscopy combined with the technique of focused ion beam. The results are very encouraging for the development of a future indicator of fatigue damage initiation for pipe steels based on microstructural changes measured by X-ray diffraction

  8. X-ray diffraction study of microstructural changes during fatigue damage initiation in pipe steels: Role of the initial dislocation structure

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, B., E-mail: bianca@lts.coppe.ufrj.br [Laboratory of Mechanics of Lille (LML), UMR CNRS 8107, University Lille 1, Boulevard Paul Langevin, Cité Scientifique, 59655 Villeneuve d' Ascq (France); Lesage, J. [Laboratory of Mechanics of Lille (LML), UMR CNRS 8107, University Lille 1, Boulevard Paul Langevin, Cité Scientifique, 59655 Villeneuve d' Ascq (France); Pasqualino, I. [Subsea Technology Laboratory (LTS), Ocean Engineering Department, COPPE/Federal University of Rio de Janeiro, PO Box 68508, Cidade Universitária, CEP 21945-970, Rio de Janeiro/RJ (Brazil); Bemporad, E. [University of Rome “ROMA TRE”, Mechanical and Industrial Eng. Dept., Via Vasca Navale 79, 00146 Rome (Italy); Benseddiq, N. [Laboratory of Mechanics of Lille (LML), UMR CNRS 8107, University Lille 1, Boulevard Paul Langevin, Cité Scientifique, 59655 Villeneuve d' Ascq (France)

    2013-09-15

    The present work is the second part of an ongoing study of microstructural changes during fatigue damage initiation in pipe steels [B. Pinheiro et al., Mat. Sci. Eng., A 532 (2012) 158–166]. Microdeformations and residual stresses (macrostresses) are evaluated by X-ray diffraction during alternating bending fatigue tests on samples taken from an API 5L X60 grade steel pipe. Microdeformations are evaluated from the full width at half maximum (FWHM) of the diffraction peak and residual stresses are estimated from the peak shift. Here, to understand the role of the initial dislocation structure, annealed samples are considered. As previously found for as-machined samples, the evolution of microdeformations shows three regular successive stages, but now with an increase during the first stage. The amplitude of each stage is accentuated with increasing stress amplitude, while its duration is reduced. Residual stresses show a similar trend, with stages of the same durations than those observed for FWHM, respectively. Additionally, changes in density and distribution of dislocations are observed by transmission electron microscopy combined with the technique of focused ion beam. The results are very encouraging for the development of a future indicator of fatigue damage initiation for pipe steels based on microstructural changes measured by X-ray diffraction.

  9. Development of super duplex stainless steel for water-supply pipe and valve in nuclear plants

    International Nuclear Information System (INIS)

    Park, Chan Jin; Kim, Jun Sick; Kwon, Hyuk Sang; Park, Young Hwan; Lee, Zin Hyung

    2000-01-01

    Austenitic-ferritic duplex stainless steels are very attractive as material for water-supply facilities in atomic power plants where both high mechanical strength and excellent resistance to localized and stress corrosion are required. However, these alloys have a problem to get sensitive to embrittlement when exposed to temperatures of 250 ∼ 1050 deg C. So far, there have been large efforts to improve this alloy. In this paper, a new developed alloy designed to improve not resistance to the embrittlement but also mechanical and corrosion properties compared with existing commercial alloys were introduced with some experimental results. (author)

  10. Finite-element analysis of flawed and unflawed pipe tests

    International Nuclear Information System (INIS)

    James, R.J.; Nickell, R.E.; Sullaway, M.F.

    1989-12-01

    Contemporary versions of the general purpose, nonlinear finite element program ABAQUS have been used in structural response verification exercises on flawed and unflawed austenitic stainless steel and ferritic steel piping. Among the topics examined, through comparison between ABAQUS calculations and test results, were: (1) the effect of using variations in the stress-strain relationship from the test article material on the calculated response; (2) the convergence properties of various finite element representations of the pipe geometry, using shell, beam and continuum models; (3) the effect of test system compliance; and (4) the validity of ABAQUS J-integral routines for flawed pipe evaluations. The study was culminated by the development and demonstration of a ''macroelement'' representation for the flawed pipe section. The macroelement can be inserted into an existing piping system model, in order to accurately treat the crack-opening and crack-closing static and dynamic response. 11 refs., 20 figs., 1 tab

  11. Characteristics of thermochemical treated EN10090 X50 steel

    International Nuclear Information System (INIS)

    Schmitz, S.; Graf, K.; Scheid, A.; Moreno, A.

    2014-01-01

    EN10090 X50 steel is commonly used for engine valves to withstand severe operation conditions involving high temperature and corrosion from fuel and combustion gas. Usually, to enhance wear performance, valves undergo nitriding thermochemical treatment by salt baths. The aim of this work is to produce diffusion layers at least 20μm thick with hardness higher than 700HV by plasma surface treatment with no continuous compounds layer using nitrogen and methane based atmospheres. Samples were characterized by laser Confocal and scanning electron microscopy, X-ray diffraction and Vickers hardness. Salt bath treatment induced formation of undesirable compounds layer at the surface and a diffusion layer thicker than 40μm, with hardness arising 1280HV 0,010 . Plasma surface treatment produced diffusion layer thicker than 40μm with no continuous compounds layer and mean hardness varying from 750 to 960HV 0,010 . (author)

  12. Modification of the Stress-Strain Curve for High-Strength Line Pipe Steel

    Science.gov (United States)

    Jonsson, Katherine

    2013-01-01

    This thesis presents work performed to improve the work hardening behaviour of an X80 microalloyed steel through various Interrupted Thermal Treatments (ITT). The aim of this work was to determine the relationships between thermal history, microstructure and mechanical properties through both qualitative and quantitative measures. Prior to the ITT experiments, a continuous cooling transformation (CCT) diagram was constructed under no-strain conditions to identify the transformation temperatures and products that are achievable in X80 steel. The thermal treatments were applied using a Gleeble thermal-mechanical simulator to generate a variety of microstructures in various fractions and morphologies. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to investigate and quantify the microstructures in terms of phase fraction and grain size. The ITT experiments successfully generated microstructures comprised of ferrite, bainitic ferrite, martensite and martensite-austenite (M-A) without the addition of strain. The effect of cooling rates, interrupt temperature, re-heat temperature and hold times were investigated and the mechanical performance was correlated with the quantified microstructures. Although the ITT experiments did not improve the strength relative to a continuously cooled sample, the work hardening coefficient was increased as a result of the interrupted thermal treatments.

  13. Effect of artificial aging on the microstructure of weldment on API 5L X-52 steel pipe

    International Nuclear Information System (INIS)

    Vargas-Arista, B.; Hallen, J.M.; Albiter, A.

    2007-01-01

    The effects of artificial aging on the microstructure in the weldment of an API 5L X-52 steel pipe were studied. Aging was performed at 250 deg. C over a period of 1000 h and values were recorded at every 100 h intervals. Transmission electron microscopy observations showed precipitation strengthening from nearly circular Nb-C containing nanoparticles for the base metal and heat affected zone, and cementite for the weld metal. The largest amount of precipitation in the weldment zone was obtained at 500 h, due to peak-aging, which showed the highest particle density. The weld metal was more susceptible to aging, exhibiting the highest increase in precipitation at 500 h, followed by the heat affected zone. After 500 h, the deterioration in the microstructure was caused by the coarsening of particles due to over-aging. The base metal showed the larger increment in particle size after 900 h of aging accompanied by a bigger decrease in fine particles than in the weld metal

  14. Atomic force microscopy of surface topography of nitrogen plasma treated steel

    CERN Document Server

    Mahboubi, F

    2002-01-01

    Nitriding of steels, using plasma environments has been practiced for many years. A lot of efforts have been put on developing new methods, such as plasma immersion ion implantation (Pl sup 3) and radio frequency (RF) plasma nitriding, for mass transfer of nitrogen into the surface of the work piece. This article presents the results obtained from an in depth investigation of the surface morphology of the treated samples, carried out using an atomic force microscope. Samples from a microalloyed steel, were treated by both methods for 5 hours at different temperatures ranging from 350 to 550 sup d eg sup C in 75% N sub 2 -25% H sub 2 atmosphere. It has been found that the surface of the samples treated by PI sup 3 technique, although having more favorable properties, were rougher than the surfaces treated by RF plasma nitriding.

  15. Enhanced carbide precipitation during tempering of sub-zero Celsius treated AISI 52100 bearing steel

    DEFF Research Database (Denmark)

    Villa, Matteo; Pantleon, Karen; Somers, Marcel A. J.

    A 1.5%Cr, 1%C bearing steel was sub-zero Celsius treated after quenching.Transmission and reflection (synchrotron) X-Ray Diffraction were applied ex-situ at the HZBBESSY II synchrotron facility to quantify the phase fractions of martensite and austenite and determine the stress state in austenite...

  16. Corrosion of welded steel piping in domestic hot water: A case history. Corrosion de una instalacion de tubos soldados de acero galvanizado para agua caliente

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, E.J.; Soria, L.; Gallardo, J.M.

    1993-01-01

    Many leaks had occurred after seven years of service in the hot sanitary water system of building. The results of the failure analysis have led to the conclusion that the reduced life of the piping system was primarily promoted by the use of a dissimilar metal (galvanized steel-copper) installation and by an excessive service temperature. Through precuations were taking to electrically insulate both types of tubing by employing dielectric fittings and water flow followed the ''rule of flow'' (zinc[yields] copper), an indirect galvanic attach on galvanized steel took place. Localized corrosion was originated by microcells formed by plating out of soluble copper. Corrosive attack was most severe at weld seams. The microstructure of the weld zone was very different from that of the surrounding pipe. In addition, some pipes presented signs of incomplete fusion (welding without filling metal) and others had protruding weld seams which produced crevice attack and erosion-corrosion, respectively. Author (10 refs.)

  17. Mean strain effects on the random cyclic strain-life relations of 0Cr18Ni10Ti pipe steel

    International Nuclear Information System (INIS)

    Zhao Yongxiang; Yang Bing

    2005-01-01

    Experimental study is performed on the mean strain effects on the random cyclic strain-life relations of the new nuclear material, 0Cr18Ni10Ti pipe steel. In order to save costs of specimens and tests, an improved maximum likelihood fatigue test method is applied to manage the present strain-controlled fatigue tests. Six straining ratios, respectively, -1, -0.52, 0.22, 0.029, 0.18, and 0.48, are applied to study the effects. Total 104 specimens are fatigued. Since the material exhibits an entirely relaxation effect of mean stress under the six ratios and, in addition, there is no effectively method for the description of the mean straining effects under this case, previous Zhao's random strain-life relations are therefore applied for effective characterization of the scattering test data under the six ratios on a basis of Coffin-Manson equation.Then the effects of the ratios are analyzed respectively on the average fatigue lives, the standard deviations of the logarithms of fatigue lives, and the fatigue lives under different survival probabilities and confidences. The results reveal that the ratios greater than zero exhibit a positive effect of about 1.3 to 1.6 times under the survival probability of 0.999 and the confidence of 95%. A negative effect is exhibited for the case of the ratios less than zero. In addition, the assessment of the effects from the sense of average fatigue lives might result in a wrong conclusion for the practice of higher reliabilities. The effects can be appropriately assessed from a probabilistic sense to take into account the average lives, the scattering regularity of test data, and the size of sampling. (author)

  18. Modification of the Steel Surface Treated by a Volume Discharge Plasma in Nitrogen at Atmospheric Pressure

    Science.gov (United States)

    Erofeev, M. V.; Shulepov, M. A.; Ivanov, Yu. F.; Oskomov, K. V.; Tarasenko, V. F.

    2016-03-01

    Effect of volume discharge plasma initiated by an avalanche electron beam on the composition, structure, and properties of the surface steel layer is investigated. Voltage pulses with incident wave amplitude up to 30 kV, full width at half maximum of about 4 ns, and wave front of about 2.5 ns were applied to the gap with an inhomogeneous electric field. Changes indicating the hardening effect of the volume discharge initiated by an avalanche electron beam are revealed in St3-grade steel specimens treated by the discharge of this type.

  19. Hydrogen assisted cracking and CO2 corrosion behaviors of low-alloy steel with high strength used for armor layer of flexible pipe

    Science.gov (United States)

    Liu, Zhenguang; Gao, Xiuhua; Du, Linxiu; Li, Jianping; Zhou, Xiaowei; Wang, Xiaonan; Wang, Yuxin; Liu, Chuan; Xu, Guoxiang; Misra, R. D. K.

    2018-05-01

    In this study, hydrogen induced cracking (HIC), sulfide stress corrosion cracking (SSCC) and hydrogen embrittlement (HE) were carried out to study hydrogen assisted cracking behavior (HIC, SSCC and HE) of high strength pipeline steel used for armor layer of flexible pipe in ocean. The CO2 corrosion behavior of designed steel with high strength was studied by using immersion experiment. The experimental results demonstrate that the corrosion resistance of designed steel with tempered martensite to HIC, SSCC and HE is excellent according to specific standards, which contributes to the low concentration of dislocation and vacancies previously formed in cold rolling process. The corrosion mechanism of hydrogen induced cracking of designed steel, which involves in producing process, microstructure and cracking behavior, is proposed. The designed steel with tempered martensite shows excellent corrosion resistance to CO2 corrosion. Cr-rich compound was first formed on the coupon surface exposed to CO2-saturated brine condition and chlorine, one of the corrosion ions in solution, was rich in the inner layer of corrosion products.

  20. Flexible ocean upwelling pipe

    Science.gov (United States)

    Person, Abraham

    1980-01-01

    In an ocean thermal energy conversion facility, a cold water riser pipe is releasably supported at its upper end by the hull of the floating facility. The pipe is substantially vertical and has its lower end far below the hull above the ocean floor. The pipe is defined essentially entirely of a material which has a modulus of elasticity substantially less than that of steel, e.g., high density polyethylene, so that the pipe is flexible and compliant to rather than resistant to applied bending moments. The position of the lower end of the pipe relative to the hull is stabilized by a weight suspended below the lower end of the pipe on a flexible line. The pipe, apart from the weight, is positively buoyant. If support of the upper end of the pipe is released, the pipe sinks to the ocean floor, but is not damaged as the length of the line between the pipe and the weight is sufficient to allow the buoyant pipe to come to a stop within the line length after the weight contacts the ocean floor, and thereafter to float submerged above the ocean floor while moored to the ocean floor by the weight. The upper end of the pipe, while supported by the hull, communicates to a sump in the hull in which the water level is maintained below the ambient water level. The sump volume is sufficient to keep the pipe full during heaving of the hull, thereby preventing collapse of the pipe.

  1. CREEP PROPERTIES EVALUATION AT 600°C OF MARAGING 300 STEEL SOLUTION TREATED

    Directory of Open Access Journals (Sweden)

    Adriano Gonçalves dos Reis

    2014-03-01

    Full Text Available Maraging steels are alloys with Ni-Co-Mo-Ti with ultra-high resistance and broad application, with fundamental interest in the aerospace sector due to high mechanical resistance combined with a good fracture toughness. This steel has been proposed to replace the steels 300M and 4340 in the Brazilian rocket engine case for Satellite Launcher Vehicles. Maraging steels have a metastable martensitic structure that can revert to austenite when heated in temperatures close to the aging temperature, and this effect can be enhanced with the temperature increasing and time of treatment. Therefore, the study of creep behavior in elevated temperatures has technological importance to the development of this material. In this work the creep behavior of a 300 grade commercial maraging steel solution treated is evaluated by carrying out creep tests at 600ºC and in a stress range of 200MPa to 500 MPa. Creep parameters, such as steady state creep rate (ε·s, final creep time (tf, and stress exponent from secondary creep (n are determined, considering that they are important to evaluate the creep resistance of the material.

  2. Electrochemical corrosion response of a low carbon heat treated steel in a NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Osorio, W.R.; Peixoto, L.C.; Garcia, L.R.; Garcia, A. [Department of Materials Engineering, State University of Campinas, SP (Brazil)

    2009-10-15

    Dual-phase (DP) steels are produced from a specific heat treatment procedure and have recently emerged as a potential class of engineering materials for a number of structural and automobile applications. Such steels have high strength-to-weight ratio and reasonable formability. The present study aims to investigate the effects of four different and conventional heat treatments (i.e., hot rolling, normalizing, annealing, and intercritical annealing) on the resulting microstructural patterns and on the electrochemical corrosion behavior. Electrochemical impedance spectroscopy (EIS) and Tafel plots were carried out on heat treated steel samples in a 0.5 M NaCl solution at 25 C with neutral pH. An equivalent circuit analysis was also used to provide quantitative support for the discussions. The normalizing and the annealing heat treatments have provided the highest and the lowest corrosion resistances, respectively. The intercritical annealing and as-received (hot rolled) low carbon steel samples have shown similar corrosion behavior. Although a deleterious effect on the corrosion resistance has been verified for DP steel due to the residual stress from the martensite formation, it combines good mechanical properties with intermediate electrochemical corrosion resistance. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  3. Effect of Microstructure on the Wear Behavior of Heat Treated SS-304 Stainless Steel

    Directory of Open Access Journals (Sweden)

    S. Kumar

    2016-12-01

    Full Text Available Sliding wear characteristics of some heat treated SS-304 stainless steel against EN-8 steel in dry condition have been studied in the present experimental work. Samples of SS-304 stainless steel have been heated in a muffle furnace in desired temperature and allowed to dwell for two hours. The heated specimen are then cooled in different media namely inside the furnace, open air, cutting grade oil (grade 44 and water at room temperature to obtain different grades of heat treatment. Microstructures and corresponding micro hardness of the samples have been measured along with Feritscopic studies. Wear characteristics have been studied in a multi tribo-tester (Ducom in dry sliding condition against EN-8 steel roller. Speed, load on job and duration of test run have been considered as the experimental parameters. The wear of the samples have been obtained directly from ‘Winducom 2006’ software. Mass loss of the samples before and after operation has also been considered as the measure of wear in the present study. All the samples have been slid against EN-8 steel roller with fixed experimental parameters. The data have been plotted, compared and analyzed. Effect of microstructures as well as micro hardness on the wear behavior has been studied and concluded accordingly.

  4. 77 FR 19211 - Circular Welded Carbon-Quality Steel Pipe From the Socialist Republic of Vietnam: Preliminary...

    Science.gov (United States)

    2012-03-30

    ... the Brazilian, Korean, and Mexican orders on these products exclude ``Standard pipe that is dual or triple certified/stenciled that enters the U.S. as line pipe of a kind used for oil and gas pipelines... classifications while more recent proceedings on the product would not. Compare Countervailing Duty Order: Oil...

  5. Effect of austenitizing temperature on microstructure in 16Mn steel treated by cerium

    Science.gov (United States)

    Wen, Bin; Song, Bo; Pan, Ning; Hu, Qing-Yun; Mao, Jing-Hong

    2011-12-01

    The change of inclusions and microstructure of 16Mn steel treated by Ce were observed, and the effect of austenitizing temperature on the microstructure was also examined. The results show that the inclusions are transformed from Si-Mn-Al composite oxide and MnS into AlCeO3, Ce2O2S, and MnS composite inclusions after being treated by Ce. Plenty of intragranular ferrites are formed in 16Mn steel containing ˜0.017wt% Ce. A large amount of intragranular acicular ferrites are formed after being austenitized for 20 min at 1473 K. The prior austenite grain size fit for the formation of intragranular acicular ferrites is about 120 μm.

  6. Problems in repair-welding of duplex-treated tool steels

    Directory of Open Access Journals (Sweden)

    T. Muhič

    2009-01-01

    Full Text Available The present paper addresses problems in laser welding of die-cast tools used for aluminum pressure die-castings and plastic moulds. To extend life cycle of tools various surface improvements are used. These surface improvements significantly reduce weldability of the material. This paper presents development of defects in repair welding of duplex-treated tool steel. The procedure is aimed at reduction of defects by the newly developed repair laser welding techniques. Effects of different repair welding process parameters and techniques are considered. A microstructural analysis is conducted to detect defect formation and reveal the best laser welding method for duplex-treated tools.

  7. Assessment of the sulfide corrosion fatigue strength for a multi-pass welded A106 Gr B steel pipe below the low SSCC limit

    International Nuclear Information System (INIS)

    Lee, Gyu Young; Bae, Dong Ho

    2009-01-01

    In the area of heavy construction, welding processes are vital in the production and maintenance of pipelines and power plants. Welding processes happen to produce residual stresses and change the metal structure as a result of the large nonlinear thermal loading that is created by a moving heat source. The fusion welding process generates formidable welding residual stresses and metallurgical change, which increase the crack driving force and reduce the resistance to the brittle fracture as well as the environmental fracture. This is a serious problem with many alloys as well as the A106 Gr B steel pipe. This pipe that is used in petrochemical and heavy chemical plants either degrades due to corrosive environments, e.g., chlorides and sulfides, and/or become damaged during service due to the various corrosion damage mechanisms. Thus, in this study, after numerically and experimentally analyzing the welding residual stress of a multi-pass welded A106 Gr B steel pipe, the sulfide stress corrosion cracking (SSCC) characteristics were assessed in a 3.5 wt.% NaCl solution that was saturated with H 2 S gas at room temperature on the basis of NACE TM 0177-90. The specimens used are of two kinds: un-notched and notched. Then, the sulfide corrosion fatigue (SCF) strength for the un-notched specimen was assessed below the low SSCC limit that was previously obtained from the SSCC tests for the notched specimen. From the results, in terms of the SSCC and SCF, all the specimens failed at the heat-affected zone, where a high welding residual stress is distributed. It was found that the low SSCC limit of un-notched specimens (σSSCCun-notched) was 46% (230 MPa) of the ultimate tensile strength (σU=502 MPa) of a multi-pass welded A106 Gr B steel pipe, and the notched specimens (σSSCCnotched) had 40% (200 MPa) of the ultimate tensile strength. Thus, it was determined that σSSCCun-notched was 13% lower than σSSCCnotched. Further, the sulfide corrosion fatigue limit (

  8. Displaced avulsion fractures of the posterior cruciate ligament: Treated by stellate steel plate fixation.

    Science.gov (United States)

    Li, Lijun; Tian, Wei

    2015-01-01

    The open reduction with internal fixation is an effective approach for treatment of avulsion fracture of posterior cruciate ligament. The previously used internal fixation materials including hollow screws, absorbable screw, tension bands and sutures have great defects such as insufficient fixation strength, susceptibility to re-fracture, etc. Stellate steel plate is novel material for internal fixation which has unique gear-like structure design. We used stellate steel plate for treatment of displaced avulsion fractures of posterior cruciate ligament in this study. 14 patients (9 men, 5 women; aged, 19-35 years; mean age, 28 years) with displaced avulsion fractures of the tibial insertion of the posterior cruciate ligament were retrospectively analyzed between June 2009 and June 2011. The mean duration from injury to the operation was 8.3 days (range 6-15 days). All the patients were treated with open reduction and internal fixation of a stellate steel plate (DePuy, Raynham, MA 02767, USA). The Lysholm-Tegner knee function score criteria were used to analyze results. The mean followup was 24.6 months (range 18-32 months). After 6 months, all the fractures healed and knee joint activity was normal, with no knee stiffness or instability. The Lysholm-Tegner scores were 97.1 ± 1.7 points at the final followup. Owing to its unique gear structure, the stellate steel plate design can effectively fix an avulsion fracture block and it is a simple operation with short postoperative rehabilitation time and firm fixation.

  9. Surface analysis of 316 stainless steel treated with cold atmospheric plasma

    Science.gov (United States)

    Williams, David F.; Kellar, Ewen J. C.; Jesson, David A.; Watts, John F.

    2017-05-01

    The surface of 316 stainless steel has been modified using cold atmospheric plasma (CAP) to increase the surface free energy (by cleaning the and chemically activating the surface)IN preparation for subsequent processes such as painting, coating or adhesive bonding. The analyses carried out, on CAP treated 316 stainless steel surfaces, includes X-ray photoelectron spectroscopy (XPS), imaging XPS (iXPS), and surface free energy (SFE) analysis using contact angle measurements. The CAP treatment is shown to increase the SFE of as-received 316 stainless steel from ∼39 mJ m-1 to >72 mJ m-1 after a short exposure to the plasma torch. This was found to correlate to a reduction in adventitious carbon, as determined by XPS analysis of the surface. The reduction from ∼90 at% to ∼30% and ∼39 at%, after being plasma treated for 5 min and 15 s respectively, shows that the process is relatively quick at changing the surface. It is suggested that the mechanism that causes the increase in surface free energy is chain scission of the hydrocarbon contamination triggered by free electrons in the plasma plume followed by chemical functionalisation of the metal oxide surface and some of the remaining carbon contamination layer.

  10. Impact test on a pipe

    International Nuclear Information System (INIS)

    Noronha, R.F.; Shimura, S.H.

    1995-01-01

    A carbon steel pipe was submitted to a series of progressive impact loadings on a drop table. Strain and acceleration were measured in relevant places of the pipe and recorded in time and frequency domain. The pipe withstood impact loads up to 560 G without any visual deformation being noticed. Strains 50% over the yield point strain were measured. A high level of damping coming from the supports may have attenuated the response of the pipe. (author). 4 refs., 1 fig., 1 tab

  11. Laser gas assisted treatment of steel 309: Corrosion and scratch resistance of treated surface

    Science.gov (United States)

    Toor, Ihsan-ul-Haq; Yilbas, B. S.; Ahmed, Junaid; Karatas, C.

    2017-10-01

    Laser gas assisted surface treatment of steel 309 is carried out and the characteristics of the resulting surface are analyzed using the analytical tools. Scanning electron and 3-D optical microscopes are used to assess the morphological and metallurgical changes in the laser treated layer. Energy spectroscopy and X-ray diffraction are carried out to determine the elemental composition and compounds formed on the laser treated surface. The friction coefficient of the laser treated surface is measured using the micro-tribometer and compared to that of the as received surface. The corrosion resistance of the laser treated and as received surfaces is measured incorporating the electrochemical tests. It is found that laser treatment results in a dense layer and formation of nitride compounds at the surface. This enhances the microhardness at the laser treated surface. The friction coefficient attains lower values at the laser treated surface than that corresponding to the as received surface. The corrosion rate of the surface reduces significantly after the laser treatment process, which can be attributed to the passive layer at the surface via formation of a dense layer and nitride compounds in the surface vicinity. In addition, the number of pit sites decreased for the laser treated surface than that of as received surface.

  12. Surface analysis of 316 stainless steel treated with cold atmospheric plasma

    Energy Technology Data Exchange (ETDEWEB)

    Williams, David F., E-mail: david.williams@surrey.ac.uk [Department of Mechanical Engineering Sciences, University Of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); TWI Ltd Granta Park Great Abington, Cambridge CB21 6AL (United Kingdom); Kellar, Ewen J.C. [TWI Ltd Granta Park Great Abington, Cambridge CB21 6AL (United Kingdom); Jesson, David A.; Watts, John F. [Department of Mechanical Engineering Sciences, University Of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2017-05-01

    Highlights: • Reduction in carbon contamination from ∼80 at.% to 40 at.% after 15 s treatment. • Associated carbon thickness reduction from 4.5 nm to 0.5 nm. • Area treated by torch has a diameter of 11 mm measured using imaging XPS. - Abstract: The surface of 316 stainless steel has been modified using cold atmospheric plasma (CAP) to increase the surface free energy (by cleaning the and chemically activating the surface)IN preparation for subsequent processes such as painting, coating or adhesive bonding. The analyses carried out, on CAP treated 316 stainless steel surfaces, includes X-ray photoelectron spectroscopy (XPS), imaging XPS (iXPS), and surface free energy (SFE) analysis using contact angle measurements. The CAP treatment is shown to increase the SFE of as-received 316 stainless steel from ∼39 mJ m{sup −1} to >72 mJ m{sup −1} after a short exposure to the plasma torch. This was found to correlate to a reduction in adventitious carbon, as determined by XPS analysis of the surface. The reduction from ∼90 at% to ∼30% and ∼39 at%, after being plasma treated for 5 min and 15 s respectively, shows that the process is relatively quick at changing the surface. It is suggested that the mechanism that causes the increase in surface free energy is chain scission of the hydrocarbon contamination triggered by free electrons in the plasma plume followed by chemical functionalisation of the metal oxide surface and some of the remaining carbon contamination layer.

  13. Corrosion of Spiral Rib Aluminized Pipe

    Science.gov (United States)

    2012-08-01

    Large diameter, corrugated steel pipes are a common sight in the culverts that run alongside many Florida roads. Spiral-ribbed aluminized pipe (SRAP) has been widely specified by the Florida Department of Transportation (FDOT) for runoff drainage. Th...

  14. Corrosion of Spiral Rib Aluminized Pipe : [Summary

    Science.gov (United States)

    2012-01-01

    Large diameter, corrugated steel pipes are a common sight in the culverts that run alongside many Florida roads. Spiral-ribbed aluminized pipe (SRAP) has been widely specified by the Florida Department of Transportation (FDOT) for runoff drainage. Th...

  15. Displaced avulsion fractures of the posterior cruciate ligament: Treated by stellate steel plate fixation

    Directory of Open Access Journals (Sweden)

    Lijun Li

    2015-01-01

    Full Text Available Background: The open reduction with internal fixation is an effective approach for treatment of avulsion fracture of posterior cruciate ligament. The previously used internal fixation materials including hollow screws, absorbable screw, tension bands and sutures have great defects such as insufficient fixation strength, susceptibility to re-fracture, etc. Stellate steel plate is novel material for internal fixation which has unique gear-like structure design. We used stellate steel plate for treatment of displaced avulsion fractures of posterior cruciate ligament in this study. Materials and Methods: 14 patients (9 men, 5 women; aged, 19-35 years; mean age, 28 years with displaced avulsion fractures of the tibial insertion of the posterior cruciate ligament were retrospectively analyzed between June 2009 and June 2011. The mean duration from injury to the operation was 8.3 days (range 6-15 days. All the patients were treated with open reduction and internal fixation of a stellate steel plate (DePuy, Raynham, MA 02767, USA. The Lysholm-Tegner knee function score criteria were used to analyze results. Results: The mean followup was 24.6 months (range 18-32 months. After 6 months, all the fractures healed and knee joint activity was normal, with no knee stiffness or instability. The Lysholm-Tegner scores were 97.1 ± 1.7 points at the final followup. Conclusion: Owing to its unique gear structure, the stellate steel plate design can effectively fix an avulsion fracture block and it is a simple operation with short postoperative rehabilitation time and firm fixation.

  16. 77 FR 64465 - Circular Welded Carbon-Quality Steel Pipe From the United Arab Emirates: Final Affirmative...

    Science.gov (United States)

    2012-10-22

    ... of the Government of the UAE's (``GUAE''), Universal Tube and Plastic Industries, Ltd., KHK... Universal Tube and Plastic Industries, Ltd.; KHK 2.06 Scaffolding and Formwork LLC; Universal Tube and Pipe... Industry Usage Data Comment 4 Countervailability of Alita's Tariff Exemptions B. Subsidies Within the Jebel...

  17. 76 FR 4633 - Carbon Steel Butt-Weld Pipe Fittings From the People's Republic of China: Notice of Court...

    Science.gov (United States)

    2011-01-26

    ... pipe fittings from the People's Republic of China (``PRC'') used in structural applications, pursuant... Timken Co. v. United States, 893 F.2d 337 (Fed. Cir. 1990) (``Timken''), as clarified by Diamond Sawblades Mfrs. Coalition v. United States, 626 F.3d 1374 (Fed. Cir. 2010) (``Diamond Sawblades''), the...

  18. Detection of Internal Metal Loss in Steel Pipes and Storage Tanks via Magnetic-Based Fiber Optic Sensor.

    Science.gov (United States)

    Almahmoud, Safieh; Shiryayev, Oleg; Vahdati, Nader; Rostron, Paul

    2018-03-08

    A monitoring solution was developed for detection of material loss in metals such as carbon steel using the force generated by permanent magnets in addition to the optical strain sensing technology. The working principle of the sensing system is related to the change in thickness of a steel plate, which typically occurs due to corrosion. As thickness decreases, the magnetostatic force between the magnet and the steel structure also decreases. This, in turn, affects the strain measured using the optical fiber. The sensor prototype was designed and built after verifying its sensitivity using a numerical model. The prototype was tested on steel plates of different thicknesses to establish the relationship between the metal thickness and measured strain. The results of experiments and numerical models demonstrate a strong relationship between the metal thickness and the measured strain values.

  19. Microstructure and Microsegregation of an Inconel 625 Weld Overlay Produced on Steel Pipes by the Cold Metal Transfer Technique

    Directory of Open Access Journals (Sweden)

    Rozmus-Górnikowska M.

    2014-10-01

    Full Text Available The aim of this work was to investigate the development of microstructure and variations in chemical composition in commercial Inconel 625 coatings on a ferritic-pearlitic steel overlaid by the CMT method.

  20. Inhibition effect of phosphorus-based chemicals on corrosion of carbon steel in secondary-treated municipal wastewater.

    Science.gov (United States)

    Shen, Zhanhui; Ren, Hongqiang; Xu, Ke; Geng, Jinju; Ding, Lili

    2013-01-01

    Secondary-treated municipal wastewater (MWW) could supply a viable alternative water resource for cooling water systems. Inorganic salts in the concentrated cooling water pose a great challenge to corrosion control chemicals. In this study, the inhibition effect of 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP), trimethylene phosphonic acid (ATMP) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) on corrosion of carbon steel in secondary-treated MWW was investigated by the means of potentiodynamic polarization and electrochemical impedance spectroscopy. The inhibition effect increased with increasing concentration of inhibitors. The corrosion rates of carbon steel were 1.5, 0.8, 0.2 and 0.5 mm a(-1) for blank, HEDP, ATMP and PBTCA samples at 50 mg L(-1), respectively. The phosphorus-based chemicals could adsorb onto the surface of the carbon steel electrode, form a coat of protective film and then protect the carbon steel from corrosion in the test solution.

  1. Volatile organic compounds in natural biofilm in polyethylene pipes supplied with lake water and treated water from the distribution network.

    Science.gov (United States)

    Skjevrak, Ingun; Lund, Vidar; Ormerod, Kari; Herikstad, Hallgeir

    2005-10-01

    The objective of this work was investigation of volatile organic compounds (VOC) in natural biofilm inside polyethylene (HDPE) pipelines at continuously flowing water. VOC in biofilm may contribute to off-flavour episodes in drinking water. The pipelines were supplied with raw lake water and treated water from the distribution network. Biofilm was established at test sites located at two different drinking water distribution networks and their raw water sources. A whole range of volatile compounds were identified in the biofilm, including compounds frequently associated with cyanobacteria and algae, such as ectocarpene, dictyopterene A and C', geosmin, beta-ionone and 6-methyl-5-hepten-2-one. In addition, volatile amines, dimethyldisulphide and 2-nonanone, presumably originating from microorganisms growing in the biofilm, were identified. C8-compounds such as 1-octen-3-one and 3-octanone were believed to be products from microfungi in the biofilm. Degradation products from antioxidants such as Irgafos 168, Irganox 1010 and Irganox 1076 used in HDPE pipes, corresponding to 2,4-di-tert-butylphenol and 2,6-di-tert-butylbenzoquinone, were present in the biofilm.

  2. Using X-Ray portable fluorescence for alloy contents measurement of steel pipe and optimization of Flow Accelerated Corrosion kinetic calculation with BRT-CICEROTM

    International Nuclear Information System (INIS)

    Trevin, Stephane; Moutrille, Marie-Pierre; Qiu, Gonghao; Miller, Cecile; Mellin, Nicolas

    2012-09-01

    EDF has developed during these 15 last years a software called BRT-CICERO TM for the surveillance of the secondary piping system of its Pressurized Water Reactors (PWRs). This software enables the operator to calculate the FAC wear rates taking into account all the influencing parameters such as: pipe isometrics, chromium content of the steel, chemical conditioning and operating parameters of the secondary circuit (temperature, pressure, etc.). This is a major tool for the operators to organize the maintenance and to plan the inspections. In the framework of the French pressure vessel law issued on March 15, 2000, the software BRT-CICERO TM has been recognized by the French authority for the FAC surveillance on the secondary pressure piping lines of the EDF 58 NPPs. It takes advantage of the experience feedback of EDF's fleet, of the R and D improvements (especially from the laboratory tests conducted on EDF's CIROCO loop) and is frequently updated. Kinetics calculations made with BRT-CICERO TM are highly dependent of chromium, copper and molybdenum contents of steel. These values are measured on site by X-ray portable fluorescence. EDF elaborated a measurement procedure with a validation process and verification of the measurement devices using certified blocks standard. This procedure enables EDF and service provider companies to measure more than 6 thousand components per year. These values are input in BRT-CICERO TM and the flow accelerated corrosion kinetic is calculated with a higher accuracy than before alloy contents measurement. The next version of BRT-CICERO will take into account chromium, copper and molybdenum contents. The actual version is using only chromium contents. This paper describes the X-Ray fluorescence and the procedure used at EDF. The advantage and drawbacks of this technique are discussed. According to research and development studies, the future algorithm for FAC calculation with these 3 alloys contents is described. Because of

  3. Experimentation and numerical simulation of steel fibre reinforced concrete pipes; Experimentacion y simulacion numerica de tubos de hormigon con fibras

    Energy Technology Data Exchange (ETDEWEB)

    Fuente, A. de la; Domingues de Figueiredo, A.; Aguado, A.; Molins, C.; Chama Neto, P. J.

    2011-07-01

    The results concerning on an experimental and a numerical study related to SFRCP are presented. Eighteen pipes with an internal diameter of 600 mm and fibre dosages of 10, 20 and 40 kg/m3 were manufactured and tested. Some technological aspects were concluded. Likewise, a numerical parameterized model was implemented. With this model, the simulation of the resistant behaviour of SFRCP can be performed. In this sense, the results experimentally obtained were contrasted with those suggested by means MAP reaching very satisfactory correlations. Taking it into account, it could be said that the numerical model is a useful tool for the optimal design of the SFRCP fibre dosages, avoiding the need of the systematic employment of the test as an indirect design method. Consequently, the use of this model would reduce the overall cost of the pipes and would give fibres a boost as a solution for this structural typology. (Author) 27 refs.

  4. Residual stress evaluation by X-Ray diffraction and hole-drilling in an API 5L X70 steel pipe bent by hot induction

    Energy Technology Data Exchange (ETDEWEB)

    Ceglias, Rodrigo Braga; Alves, Juciane Maria; Botelho, Ramon Alves; Baeta Junior, Eustaquio de Souza; Santos, Igor Cuzzuol dos; Moraes, Nicki Robbers Darciano Cajueiro de; Oliveira, Rebeca Vieira de; Diniz, Saulo Brinco; Brandao, Luiz Paulo, E-mail: brandao@ime.eb.br [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Mecanica e de Materiais

    2016-09-15

    The API 5L X70 steel is used in high-pressure gas transmission pipelines. Because of this, knowledge of presence of residual stress and their magnitude is important to assess the material integrity in service. For the pipeline manufacturing, tubes need to be curved which is often made using the hot induction bending process. This process can introduce different residual stress depending of tube position. For this research, in order to evaluate the residual stress, was used an API 5L X70 tube that was previously curved by hot induction process. Samples were taken from the extrados, intrados, neutral line and straight section of the curved tube. Residual stresses were studied by two conventional methods: X-Ray Diffraction (XRD) and Hole-Drilling, which are destructive and non-destructive methods, respectively, in order to assess their qualitative responses. Each of these methods presents particular methodologies in sample preparation and material analysis, but also they differ in factors such time consumption and cost of the analysis. The qualitative responses obtained by the two different methods were comparable and satisfactory and pointed out the existence of a compressive residual stress state in steel pipe. (author)

  5. High-temperature creep rupture of low alloy ferritic steel butt-welded pipes subjected to combined internal pressure and end loadings.

    Science.gov (United States)

    Vakili-Tahami, F; Hayhurst, D R; Wong, M T

    2005-11-15

    Constitutive equations are reviewed and presented for low alloy ferritic steels which undergo creep deformation and damage at high temperatures; and, a thermodynamic framework is provided for the deformation rate potentials used in the equations. Finite element continuum damage mechanics studies have been carried out using these constitutive equations on butt-welded low alloy ferritic steel pipes subjected to combined internal pressure and axial loads at 590 and 620 degrees C. Two dominant modes of failure have been identified: firstly, fusion boundary failure at high stresses; and, secondly, Type IV failure at low stresses. The stress level at which the switch in failure mechanism takes place has been found to be associated with the relative creep resistance and lifetimes, over a wide range of uniaxial stresses, for parent, heat affected zone, Type IV and weld materials. The equi-biaxial stress loading condition (mean diameter stress equal to the axial stress) has been confirmed to be the worst loading condition. For this condition, simple design formulae are proposed for both 590 and 620 degrees C.

  6. Multiple regression analysis of Jominy hardenability data for boron treated steels

    International Nuclear Information System (INIS)

    Komenda, J.; Sandstroem, R.; Tukiainen, M.

    1997-01-01

    The relations between chemical composition and their hardenability of boron treated steels have been investigated using a multiple regression analysis method. A linear model of regression was chosen. The free boron content that is effective for the hardenability was calculated using a model proposed by Jansson. The regression analysis for 1261 steel heats provided equations that were statistically significant at the 95% level. All heats met the specification according to the nordic countries producers classification. The variation in chemical composition explained typically 80 to 90% of the variation in the hardenability. In the regression analysis elements which did not significantly contribute to the calculated hardness according to the F test were eliminated. Carbon, silicon, manganese, phosphorus and chromium were of importance at all Jominy distances, nickel, vanadium, boron and nitrogen at distances above 6 mm. After the regression analysis it was demonstrated that very few outliers were present in the data set, i.e. data points outside four times the standard deviation. The model has successfully been used in industrial practice replacing some of the necessary Jominy tests. (orig.)

  7. Reduced myofibroblast differentiation on femtosecond laser treated 316LS stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Oberringer, Martin [Department of Trauma, Hand and Reconstructive Surgery, Saarland University, Homburg (Germany); Akman, Erhan [Laser Technologies Research and Application Center (LATARUM), Kocaeli University, Yenikoey/Kocaeli (Turkey); Lee, Juseok [CVD/Biosurfaces Division, INM - Leibniz Institute for New Materials, Saarbruecken (Germany); Metzger, Wolfgang [Department of Trauma, Hand and Reconstructive Surgery, Saarland University, Homburg (Germany); Akkan, Cagri Kaan [CVD/Biosurfaces Division, INM - Leibniz Institute for New Materials, Saarbruecken (Germany); Kacar, Elif [Laser Technologies Research and Application Center (LATARUM), Kocaeli University, Yenikoey/Kocaeli (Turkey); Demir, Arif [Laser Technologies Research and Application Center (LATARUM), Kocaeli University, Yenikoey/Kocaeli (Turkey); BEAM Ar-Ge Optic, Laser and Spectroscopy, KOU Technopark, Kocaeli, 41275 (Turkey); Abdul-Khaliq, Hashim [Clinic for Pediatric Cardiology, Saarland University Hospital, Homburg (Germany); Puetz, Norbert; Wennemuth, Gunther [Department of Anatomy and Cell Biology, Saarland University, Homburg (Germany); Pohlemann, Tim [Department of Trauma, Hand and Reconstructive Surgery, Saarland University, Homburg (Germany); Veith, Michael [CVD/Biosurfaces Division, INM - Leibniz Institute for New Materials, Saarbruecken (Germany); Aktas, Cenk, E-mail: cenk.aktas@inm-gmbh.de [CVD/Biosurfaces Division, INM - Leibniz Institute for New Materials, Saarbruecken (Germany)

    2013-03-01

    In-stent restenosis is a common complication after stent surgery which leads to a dangerous wall narrowing of a blood vessel. Laser assisted patterning is one of the effective methods to modify the stent surface to control cell-surface interactions which play a major role in the restenosis. In this current study, 316LS stainless steel substrates are structured by focusing a femtosecond laser beam down to a spot size of 50 {mu}m. By altering the laser induced spot density three distinct surfaces (low density (LD), medium density (MD) and high density (HD)) were prepared. While such surfaces are composed of primary microstructures, due to fast melting and re-solidification by ultra-short laser pulses, nanofeatures are also observed as secondary structures. Following a detailed surface characterization (chemical and physical properties of the surface), we used a well-established co-culture assay of human microvascular endothelial cells and human fibroblasts to check the cell compatibility of the prepared surfaces. The surfaces were analyzed in terms of cell adherence, proliferation, cell morphology and the differentiation of the fibroblast into the myofibroblast, which is a process indicating a general fibrotic shift within a certain tissue. It is observed that myofibroblast proliferation decreases significantly on laser treated samples in comparison to non-treated ones. On the other hand endothelial cell proliferation is not affected by the surface topography which is composed of micro- and nanostructures. Such surfaces may be used to modify stent surfaces for prevention or at least reduction of restenosis. - Highlights: Black-Right-Pointing-Pointer Reduced myofibroblast proliferation by micro- and nanotopography Black-Right-Pointing-Pointer Ultra-hydrophobic surfaces by femtosecond laser structuring Black-Right-Pointing-Pointer Micro- and nanostructuring of stainless steel surfaces by a femtosecond laser.

  8. PTA-1 computer program for treating pressure transients in hydraulic networks including the effect of pipe plasticity

    International Nuclear Information System (INIS)

    Youngdahl, C.K.; Kot, C.A.

    1977-01-01

    Pressure pulses in the intermediate sodium system of a liquid-metal-cooled fast breeder reactor, such as may originate from a sodium/water reaction in a steam generator, are propagated through the complex sodium piping network to system components such as the pump and intermediate heat exchanger. To assess the effects of such pulses on continued reliable operation of these components and to contribute to system designs which result in the mitigation of these effects, Pressure Transient Analysis (PTA) computer codes are being developed for accurately computing the transmission of pressure pulses through a complicated fluid transport system, consisting of piping, fittings and junctions, and components. PTA-1 provides an extension of the well-accepted and verified fluid hammer formulation for computing hydraulic transients in elastic or rigid piping systems to include plastic deformation effects. The accuracy of the modeling of pipe plasticity effects on transient propagation has been validated using results from two sets of Stanford Research Institute experiments. Validation of PTA-1 using the latter set of experiments is described briefly. The comparisons of PTA-1 computations with experiments show that (1) elastic-plastic deformation of LMFBR-type piping can have a significant qualitative and quantitative effect on pressure pulse propagation, even in simple systems; (2) classical fluid-hammer theory gives erroneous results when applied to situations where piping deforms plastically; and (3) the computational model incorporated in PTA-1 for predicting plastic deformation and its effect on transient propagation is accurate

  9. Numerical investigation on residual stress distribution and evolution during multipass narrow gap welding of thick-walled stainless steel pipes

    International Nuclear Information System (INIS)

    Liu, C.; Zhang, J.X.; Xue, C.B.

    2011-01-01

    Research highlights: → We performed pass-by-pass simulation of stresses for welding of thick-walled pipes. → The distributions and evolution of the residual stresses are demonstrated. → After the groove is filled to a height, the through-wall stress is almost unchanged. - Abstracts: The detailed pass-by-pass finite element (FE) simulation is presented to investigate the residual stresses in narrow gap multipass welding of pipes with a wall thickness of 70 mm and 73 weld passes. The simulated residual stress on the outer surface is validated with the experimental one. The distribution and evolution of the through-wall residual stresses are demonstrated. The investigated results show that the residual stresses on the outer and inner surfaces are tensile in the weld zone and its vicinity. The through-wall axial residual stresses at the weld center line and the HAZ line demonstrate a distribution of bending type. The through-wall hoop residual stress within the weld is mostly tensile. After the groove is filled to a certain height, the peak tensile stresses and the stress distribution patterns for both axial and hoop stresses remain almost unchanged.

  10. Austenite Grain Growth Kinetics in API X65 and X70 Line-Pipe Steels during Isothermal Heating

    Directory of Open Access Journals (Sweden)

    Asiful Hossain Seikh

    2014-01-01

    Full Text Available The aim of the present work is to investigate the microstructural behavior of austenite grain size (AGS during the reheating process of two different API steel grades (X65 and X70. The steel samples were austenitized at 1150°C, 1200°C, and 1250°C for various holding times from 10 to 60 minutes and quenched in ice water. The samples were then annealed at 500°C for 24 hours to reveal the prior AGS using optical microscopy. It was noticed that the AGS in X65 grade is coarser than that of X70 grade. Additionally, the grain size increases with increasing the reheating temperature and time for both steels. The kinetics of grain growth was studied using the equation dn-d0n=Atexp-Q/RT , where d is the measured grain size, do is the initial grain size, n is the grain size exponent, t is the heating time, T is the heating temperature, Q is the activation energy, R is the gas constant, and A is a constant. To characterize the grain growth process the values of n, Q, and A were determined. Good agreement is obtained between the prediction of the model and the experimental grain size values.

  11. Entry and diffusion of electrolytic hydrogen in some surface treated steels

    International Nuclear Information System (INIS)

    Waheed, A.F.M.

    1986-01-01

    Hydrogen diffusion and permeation through metals specially ferrous material is a subject that has a large volume of researches. the most important reason is the technological importance associated with the degradation of ferrous materials resulting from hydrogen absorption. The embrittling effect of hydrogen in steels and the catastrophic nature of failures caused by hydrogen embrittlement has led also to the importance of understanding hydrogen entry and surface processes. the effect of surface treatment of some types of steels on hydrogen entry and diffusion at room temperature (25 degree C) was studied. the two types of steels used in this study are plain carbon steel and low alloy steel

  12. Synthesis and application of hybrid polymer composites based on silver nanoparticles as corrosion protection for line pipe steel.

    Science.gov (United States)

    Atta, Ayman M; El-Mahdy, Gamal A; Al-Lohedan, Hamad A; Ezzat, Abdurrahman O

    2014-05-16

    A facile method was developed to synthesize in high yield dispersed silver nanoparticles (AgNPs) with small particle sizes of less than 10 nm. Silver nitrate was reduced to silver nanoparticles by p-chloroaniline in the presence of polyoxyethylene maleate 4-nonyl-2-propylene-phenol (NMA) as a stabilizer. The produced AgNPs were used to prepare hybrid polymer based on N-isopropylacrylamide (NIPAm), 2-acrylamido-2-methylpropane sulfonic acid (AMPS), N,N-methylenebisacrylamide (MBA) and potassium persulfate (KPS) using a semi-batch solution polymerization method. The prepared AgNPs and hybrid polymer were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM). The corrosion inhibition activity of the AgNPs and hybrid polymer towards steel corrosion in the presence of hydrochloric acid has been investigated by polarization and electrochemical impedance spectroscopy (EIS) methods. Polarization measurements indicate that the AgNPs and hybrid polymer acts as a mixed type-inhibitor and the inhibition efficiency increases with inhibitor concentration. The results of potentiodynamic polarization and EIS measurements clearly showed that the inhibition mechanism involves blocking of the steel surface by inhibitor molecules via adsorption.

  13. Review of the models and mechanisms for environmentally-assisted crack growth of pressure vessel and piping steels in PWR environments

    International Nuclear Information System (INIS)

    Cullen, W.; Gabetta, G.; Hanninen, H.

    1985-12-01

    The crack-tip micromechanisms and the computational models for environmentally-assisted cracking in pressure vessel and piping steels in high-temperature, low-oxygen (PWR), reactor-grade water are described and evaluated in this report. The report begins with a brief description of the critical variables which are known to affect environmentally-assisted subcritical cracking in these metal/environment systems. The micromechanistic models are discussed in some detail, with anodic dissolution and hydrogen assistance being the prime candidates for the successful explanation of the observed phenomena. The anodic dissolution model offers far better quantification of the environmentally-assisted crack growth rates, but tends to overpredict the rates for a large number of conditions. The hydrogen assistance models qualitatively could account for a wider range of effects, but quantification of the model is virtually nonexistent. A variety of calculational models are in various stages of development; all of them are far from use as a predictive tool. Crack-tip strain rate models have received the most attention, and the approach to their use has been to partition the environmentally-assisted growth rates into a mechanically-driven component, with the environmental enhancement superposed. The environment component is then correlated with a calculated crack-tip strain rate. 141 refs., 59 figs

  14. Effect of ferrite on the precipitation of σ phase in cast austenitic stainless steel used for primary coolant pipes of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yongqiang; Li, Na, E-mail: wangyongqiang1124@163.com [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology, Beijing (China)

    2017-11-15

    The effect of ferrite phase on the precipitation of σ phase in a Z3CN20.09M cast austenitic stainless steel (CASS) used for primary coolant pipes of pressurized water reactor (PWR) nuclear power plants was investigated by using isothermal heat-treatment, optical microscopy (OM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA) techniques. The influence of different morphologies and volume fractions of ferrite in the σ phase formation mechanism was discussed. The amount of σ phase precipitated in all specimens with different microstructures increased with increasing of aging time, however, the precipitation rate is significant different. The formation of σ phase in specimens with the coarsest ferrite and the dispersively smallest ferrite is slowest. The lowest level Cr content in ferrite and fewest α/γ interfaces in specimen are the main reasons for the slowest σ precipitation due to they are unfavorable for the kinetics and thermodynamics of phase transformation respectively. By contraries, the fastest formation of σ phase takes place in specimens with narrow and long ferrite due to the most α/γ interfaces and higher Cr content in ferrite which are beneficial for preferential nucleation and formation thermodynamics of σ phase. (author)

  15. Flexible Heat Pipe

    Science.gov (United States)

    Bienert, W. B.; Wolf, D. A.

    1985-01-01

    Narrow Tube carries 10 watts or more to moving parts. Heat pipe 12 inches long and diameter of 0.312 inch (7.92mm). Bent to minimum radius of 2.5 blocks. Flexible section made of 321 stainless steel tubing (Cajon Flexible Tubing or equivalent). Evaporator and condenser made of oxygen free copper. Working fluid methanol.

  16. Ice plugging of pipes using liquid nitrogen

    International Nuclear Information System (INIS)

    Twigg, R.J.

    1987-03-01

    This report presents a study on the ice plugging of pipe using liquid nitrogen, and is based on a literature review and on discussions with individuals who use the technique. Emphasis is placed on ferritic alloys, primarily carbon steels, in pipe sized up to 60 cm in diameter and on austenitic stainless steels in pipe sizes up to 30 cm in diameter. This technique is frequently used for leak testing in nuclear facilities

  17. 78 FR 34342 - Certain Circular Welded Non-Alloy Steel Pipe From Mexico: Final Results and Partial Rescission of...

    Science.gov (United States)

    2013-06-07

    ... Preliminary Results. In response to the Department's invitation to comment on the Preliminary Results... Decision Memorandum Issue 1: Whether PYTCO Had Reviewable Sales Issue 2: Treating PYTCO and Conduit as a...

  18. 75 FR 57449 - Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe from the People's...

    Science.gov (United States)

    2010-09-21

    ... invitation to comment on the Preliminary Determination and Amended Preliminary Determination, on July 14...: Treating Certain Ancillary Materials as Inputs Comment 39: Application of Certain Adjustment to the Factors...

  19. Review of nuclear piping seismic design requirements

    International Nuclear Information System (INIS)

    Slagis, G.C.; Moore, S.E.

    1994-01-01

    Modern-day nuclear plant piping systems are designed with a large number of seismic supports and snubbers that may be detrimental to plant reliability. Experimental tests have demonstrated the inherent ruggedness of ductile steel piping for seismic loading. Present methods to predict seismic loads on piping are based on linear-elastic analysis methods with low damping. These methods overpredict the seismic response of ductile steel pipe. Section III of the ASME Boiler and Pressure Vessel Code stresses limits for piping systems that are based on considerations of static loads and hence are overly conservative. Appropriate stress limits for seismic loads on piping should be incorporated into the code to allow more flexible piping designs. The existing requirements and methods for seismic design of piping systems, including inherent conservations, are explained to provide a technical foundation for modifications to those requirements. 30 refs., 5 figs., 3 tabs

  20. 76 FR 11758 - Drill Pipe From the People's Republic of China: Countervailing Duty Order

    Science.gov (United States)

    2011-03-03

    ... collars without regard to the specific chemistry of the steel (i.e., carbon, stainless steel, or other... (including all drill collar green tubes) and unfinished drill pipe (including drill pipe green tubes, which...

  1. Effect of surface etching on the oxidation behavior of plasma chromizing-treated AISI440B stainless steel

    Science.gov (United States)

    Meng, T. X.; Guo, Q.; Xi, W.; Ding, W. Q.; Liu, X. Z.; Lin, N. M.; Yu, S. W.; Liu, X. P.

    2018-03-01

    Double glow plasma surface alloying was applied to prepare chromizing layer in the surface of AISI440B stainless steel. Prior to chromizing, the stainless steel was etched by microwave plasma chemical vapor deposition to change the surface morphology and composition, and then heated for chromizing at 950 °C for 3 h. The cyclical oxidation of steel after chromizing was carried out at 900 °C for 100 h. Scanning electron microscopy, glow discharge optical emission spectrometer and X-ray diffractometer were used to characterize microstructure, composition and phase structure of alloyed and oxidized samples. The results show that the surface was composed of the Cr-rich top layer and Cr23C6, Cr7C3 and {Cr,Fe}7C3 below layer after chromizing. The bonding between the chromizing layer and the substrate after etching treatment was obviously strengthened. AISI440B steel shows a poor oxidation resistance and the weight gain oxidized for 100 h was up to 31.1 mg/cm2. Weight gains for chromizing and etching + chromizing treated samples were 0.67 mg/cm2 and 8 mg/cm2, respectively. Both oxidized surfaces of chromizing and etching + chromizing were composed of Cr2O3, but the oxide scale of etching + chromizing treated samples was more compact than that of samples without etching.

  2. 49 CFR Appendix B to Part 192 - Qualification of Pipe

    Science.gov (United States)

    2010-10-01

    ... impair the strength or tightness of the pipe. D. Tensile Properties. If the tensile properties of the... yield and tensile strength, elongation, and yield to tensile ratio, and testing requirements to verify... Pipe I. Listed Pipe Specifications API 5L—Steel pipe, “API Specification for Line Pipe” (incorporated...

  3. A Computational approach in optimizing process parameters of GTAW for SA 106 Grade B steel pipes using Response surface methodology

    Science.gov (United States)

    Sumesh, A.; Sai Ramnadh, L. V.; Manish, P.; Harnath, V.; Lakshman, V.

    2016-09-01

    Welding is one of the most common metal joining techniques used in industry for decades. As in the global manufacturing scenario the products should be more cost effective. Therefore the selection of right process with optimal parameters will help the industry in minimizing their cost of production. SA 106 Grade B steel has a wide application in Automobile chassis structure, Boiler tubes and pressure vessels industries. Employing central composite design the process parameters for Gas Tungsten Arc Welding was optimized. The input parameters chosen were weld current, peak current and frequency. The joint tensile strength was the response considered in this study. Analysis of variance was performed to determine the statistical significance of the parameters and a Regression analysis was performed to determine the effect of input parameters over the response. From the experiment the maximum tensile strength obtained was 95 KN reported for a weld current of 95 Amp, frequency of 50 Hz and peak current of 100 Amp. With an aim of maximizing the joint strength using Response optimizer a target value of 100 KN is selected and regression models were optimized. The output results are achievable with a Weld current of 62.6148 Amp, Frequency of 23.1821 Hz, and Peak current of 65.9104 Amp. Using Die penetration test the weld joints were also classified in to 2 categories as good weld and weld with defect. This will also help in getting a defect free joint when welding is performed using GTAW process.

  4. Predicting Charpy Impact Energy for Heat-Treated Steel using a Quantum-Membership-Function-based Fuzzy Model

    OpenAIRE

    Muscat, R.; Mahfouf, M.

    2016-01-01

    This study employs quantum membership functions in a neuro-fuzzy modelling structure to model a complex data set derived from the Charpy impact test of heat treated steel for predicting Charpy energy. This is a challenging modelling problem because although the test is governed by a specific standard, several sources of disturbance give rise to uncertainty in the data. The data are also multidimensional, sparsely distributed and the relation between the variables and the output is highly nonl...

  5. Surface Plastic Deformation and Nanocrystallization Mechanism of Welded Joint of 16MnR Steel Treated by Ultrasonic Impact

    Directory of Open Access Journals (Sweden)

    Yingxia YU

    2015-11-01

    Full Text Available The welded joint surfaces of 16MnR steel were treated using an ultrasonic impact machine. The effects of ultrasonic impact treating (UIT on the plastic deformation and nanocrystallization mechanism of the welded joints of 16MnR steel were studied. The micro-structural features of the surface layer produced by UIT were observed by scanning electron microscopy (SEM and high resolution transmission electron microscopy (HRTEM, and micro-hardness measurements were performed. Experimental results showed that the thickness of the plastic deformation layer was approximately 80 μm. It was found that grains in the surfaces of the welded joints of 16MnR were greatly refined by UIT. Obvious grain refinement was observed, with resultant gain sizes less than 100nm. The micro-hardness of the treated surface layer of the welded joint was enhanced significantly compared to that of the un-treated sample. The micro-hardness on the treated surface of the welded joint was 62.3% higher than that of the un-treated surface.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9563

  6. 46 CFR 34.25-15 - Piping-T/ALL.

    Science.gov (United States)

    2010-10-01

    ... requirements of subchapter F (Marine Engineering) of this chapter. (b) Distribution piping shall be of materials resistant to corrosion, except that steel or iron pipe may be used if inside corrosion resistant...

  7. Effects of mean strain on the random cyclic stress-strain relations of 0Cr18Ni10Ti pipe steel

    International Nuclear Information System (INIS)

    Zhao Yongxiang; Yang Bing

    2005-01-01

    Experimental study is performed for the effects of the mean strain on the random cyclic stress-strain relations of the new nuclear material, 0Cr18Ni10Ti pipe steel. From saving the size of specimens, an improved maximum likelihood fatigue test method is proposed to operate the present strain-controlled fatigue tests. Six straining ratios, -1, -0.52, -0.22, 0.029, 0.18, and 0.48, respectively, are applied to study the effects. Fatigue test has been carried out on totally 104 specimens. The test results reveal that the material exhibits a Masing behaviour and the saturation hysteresis loops under the six ratios hold an entirely relaxation effect of mean stress. There is no effectively method for the description of the mean straining effects under this case. Previous Zhao's random stress-strain relations are therefore applied to characterizing effectively the scattering test data under the six ratios on a basis of Ramberg-Osgood equation. Then the effects of the ratios are analyzed respectively on the average stress amplitudes, the standard deviations of the stress amplitudes, and the stress amplitudes under different survival probabilities and confidences. The results reveal that the ratios act a relatively decreasing effect to the stress amplitudes under higher survival probabilities and confidences. The strongest effect appears at the ratio of 0.029, and a weaker effect acts as the distance increase of the ratio from the zero. In addition, it is indicated that the effects from the sense of average fatigue lives might result in a wrong conclusion. The effects can be appropriately assessed from a probabilistic sense to take into account the scattering regularity of test data and the size of sampling. (author)

  8. PPOOLEX experiments with two parallel blowdown pipes

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Puustinen, M.; Raesaenen, A. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2011-01-15

    This report summarizes the results of the experiments with two transparent blowdown pipes carried out with the scaled down PPOOLEX test facility designed and constructed at Lappeenranta University of Technology. Steam was blown into the dry well compartment and from there through either one or two vertical transparent blowdown pipes to the condensation pool. Five experiments with one pipe and six with two parallel pipes were carried out. The main purpose of the experiments was to study loads caused by chugging (rapid condensation) while steam is discharged into the condensation pool filled with sub-cooled water. The PPOOLEX test facility is a closed stainless steel vessel divided into two compartments, dry well and wet well. In the experiments the initial temperature of the condensation pool water varied from 12 deg. C to 55 deg. C, the steam flow rate from 40 g/s to 1 300 g/s and the temperature of incoming steam from 120 deg. C to 185 deg. C. In the experiments with only one transparent blowdown pipe chugging phenomenon didn't occur as intensified as in the preceding experiments carried out with a DN200 stainless steel pipe. With the steel blowdown pipe even 10 times higher pressure pulses were registered inside the pipe. Meanwhile, loads registered in the pool didn't indicate significant differences between the steel and polycarbonate pipe experiments. In the experiments with two transparent blowdown pipes, the steamwater interface moved almost synchronously up and down inside both pipes. Chugging was stronger than in the one pipe experiments and even two times higher loads were measured inside the pipes. The loads at the blowdown pipe outlet were approximately the same as in the one pipe cases. Other registered loads around the pool were about 50-100 % higher than with one pipe. The experiments with two parallel blowdown pipes gave contradictory results compared to the earlier studies dealing with chugging loads in case of multiple pipes. Contributing

  9. Behaviour of steel pipe exposed to fouling by heavy oil during core-annular flow; Comportamento de tubo de aco exposto a sujeira de oleo pesado durante escoamento nucleo-anular

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Adriana; Bannwart, Antonio C. [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Engenharia de Petroleo

    2004-07-01

    The use of water-assisted technologies such as core-annular flow to the pipelines of viscous oils has been proposed as an attractive alternative for production and transportation of heavy crudes in both onshore and offshore scenarios. Usually, core-annular flow can be created by injecting a relatively small water flow rate laterally in the pipe, so as to form a thin water annulus surrounding the viscous oil, which is pumped through the center. The reduction in friction losses obtained thanks to lubrication by water is significant, since the pressure drop in a steady state core flow becomes comparable to water flow only. For a complete assessment of core flow technology, however, unwanted effects associated with possible oil adhesion onto the pipe wall should be investigated, since these may cause severe fouling of the wall and pressure drop increase. It has been observed that oil adhesion on metallic surfaces may occur for certain types of crude and oilphilic pipe materials. In this work we present results of pressure drop monitoring during 35 hour-operation of a heavy oil-water core annular flow in a 26.08 mm. i.d. horizontal steel pipe. The oil used is described in terms of its main components and the results of static wet ability tests are also presented for comparison (author)

  10. Properties and service performance : Application of FeE460, a comparative investigation towards normalized, quenched and tempered, and thermomechanically treated steel types

    NARCIS (Netherlands)

    Vuik, J.; Wortel, J. van

    1996-01-01

    In this summary, the items that have been investigated and the main results of the research contract 7210/KA/607-F1.3/88, 'Application of FeE460, a comparative investigation towards normalized, quenched and tempered, and thermomechanically treated steel types' are described. The steels mentioned

  11. NEP heat pipe radiators. [Nuclear Electric Propulsion

    Science.gov (United States)

    Ernst, D. M.

    1979-01-01

    This paper covers improvements of heat pipe radiators for the thermionic NEP design. Liquid metal heat pipes are suitable as spacecraft radiator elements because of high thermal conductance, low mass and reliability, but the NEP thermionic system design was too large and difficult to fabricate. The current integral collector-radiator design consisting of several layers of thermionic converters, the annular-tangential collector heat pipe, the radiator heat pipe, and the transition zone designed to minimize the temperature difference between the collector heat pipe and radiator heat pipe are described. Finally, the design of micrometeoroid armor protection and the fabrication of the stainless steel annular heat pipe with a tangential arm are discussed, and it is concluded that the heat rejection system for the thermionic NEP system is well advanced, but the collector-radiator heat pipe transition and the 8 to 10 m radiator heat pipe with two bends require evaluation.

  12. Characterizing AISI 1045 steel surface duplex-treated by alternating current field enhanced pack aluminizing and nitriding

    Science.gov (United States)

    Xie, Fei; Zhang, Ge; Pan, Jianwei

    2018-02-01

    Thin cases and long treating time are shortcomings of conventional duplex treatment of aluminizing followed by nitriding (DTAN). Alternating current field (ACF) enhanced DTAN was carried out on AISI 1045 steel by applying an ACF to treated samples and treating agents with a pair of electrodes for overcoming those shortcomings. By investigating cases' structures, phases, composition and hardness distributions of differently treated samples, preliminary studies were made on characterizations of the ACF enhanced duplex treatment to AISI 1045 steel. The results show that, with the help of the ACF, the surface Al-rich phase Al5Fe2 formed in conventional pack aluminizing can be easily avoided and the aluminizing process is dramatically promoted. The aluminizing case can be nitrided either with conventional pack nitriding or ACF enhanced pack nitriding. By applying ACF to pack nitriding, the diffusion of nitrogen into the aluminizing case is promoted. AlN, Fe2∼3N and solid solution of N in iron are efficiently formed as a result of reactions of N with the aluminizing case. A duplex treated case with an effective thickness of more than 170 μm can be obtained by the alternating current field enhanced 4 h pack aluminizing plus 4 h pack nitriding.

  13. Atomic force microscopy applied to the quantification of nano-precipitates in thermo-mechanically treated microalloyed steels

    Energy Technology Data Exchange (ETDEWEB)

    Renteria-Borja, Luciano [Instituto Tecnologico de Morelia, Av. Tecnologico No. 1500, Lomas de Santiaguito, 58120 Morelia (Mexico); Hurtado-Delgado, Eduardo, E-mail: hurtado@itmorelia.edu.mx [Instituto Tecnologico de Morelia, Av. Tecnologico No. 1500, Lomas de Santiaguito, 58120 Morelia (Mexico); Garnica-Gonzalez, Pedro [Instituto Tecnologico de Morelia, Av. Tecnologico No. 1500, Lomas de Santiaguito, 58120 Morelia (Mexico); Dominguez-Lopez, Ivan; Garcia-Garcia, Adrian Luis [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-IPN Unidad Queretaro, Cerro Blanco No. 141, Colinas del Cimatario, 76090 Queretaro (Mexico)

    2012-07-15

    Quantification of nanometer-size precipitates in microalloyed steels has been traditionally performed using transmission electron microscopy (TEM), in spite of its complicated sample preparation procedures, prone to preparation errors and sample perturbation. In contrast to TEM procedures, atomic force microscopy (AFM) is performed on the as-prepared specimen, with sample preparation requirements similar to those for optical microscopy (OM), rendering three-dimensional representations of the sample surface with vertical resolution of a fraction of a nanometer. In AFM, contrast mechanisms are directly related to surface properties such as topography, adhesion, and stiffness, among others. Chemical etching was performed using 0.5% nital, at time intervals between 4 and 20 s, in 4 s steps, until reaching the desired surface finish. For the present application, an average surface-roughness peak-height below 200 nm was sought. Quantification results of nanometric precipitates were obtained from the statistical analysis of AFM images of the microstructure developed by microalloyed Nb and V-Mo steels. Topography and phase contrast AFM images were used for quantification. The results obtained using AFM are consistent with similar TEM reports. - Highlights: Black-Right-Pointing-Pointer We quantified nanometric precipitates in Nb and V-Mo microalloyed steels using AFM. Black-Right-Pointing-Pointer Microstructures of the thermo-mechanically treated microalloyed steels were used. Black-Right-Pointing-Pointer Topography and phase contrast AFM images were used for quantification. Black-Right-Pointing-Pointer AFM results are comparable with traditionally obtained TEM measurements.

  14. Effects of Mn and Al on the Intragranular Acicular Ferrite Formation in Rare Earth Treated C-Mn Steel

    Science.gov (United States)

    Song, Mingming; Song, Bo; Yang, Zhanbing; Zhang, Shenghua; Hu, Chunlin

    2017-07-01

    The influence of Al, Mn and rare earth (RE) on microstructure of C-Mn steel was investigated. The capacities of different RE inclusions to induce intragranular acicular ferrite (AF) formation were compared. Result shows that RE treatment could make C-Mn steel from large amounts of intragranular AF. Al killed is detrimental to the formation of intragranular AF in RE-treated C-Mn steel. An upper bainite structure would replace the AF when Al content increased to 0.027 mass %. The optimal Mn content to form AF is about 0.75-1.31 mass %. The effective RE inclusion which could induce AF nucleation is La2O2S. When patches of MnS are attached on the surface of La2O2S inclusion, AF nucleation capacity of RE-containing inclusion could enlarge obviously. The existence of manganese-depleted zone and low lattice misfit would be the main reason of La-containing inclusion inducing AF nucleation in C-Mn steel.

  15. Investigation of Steel Surfaces Treated by a Hybrid Ion Implantation Technique

    International Nuclear Information System (INIS)

    Reuther, H.; Richter, E.; Prokert, F.; Ueda, M.; Beloto, A. F.; Gomes, G. F.

    2004-01-01

    Implantation of nitrogen ions into stainless steel in combination with oxidation often results in a decrease or even complete removal of the chromium in the nitrogen containing outermost surface layer. While iron nitrides can be formed easily by this method, due to the absence of chromium, the formation of chromium nitrides is impossible and the beneficial influence of chromium in the steel for corrosion resistance cannot be used. To overcome this problem we use the following hybrid technique. A thin chromium layer is deposited on steel and subsequently implanted with nitrogen ions. Chromium can be implanted by recoil into the steel surface and thus the formation of iron/chromium nitrides should be possible. Both beam line ion implantation and plasma immersion ion implantation are used. Due to the variation of the process parameters, different implantation profiles and different compounds are produced. The produced layers are characterized by Auger electron spectroscopy, conversion electron Moessbauer spectroscopy and X-ray diffraction. The obtained results show that due to the variation of the implantation parameters, the formation of iron/chromium nitrides can be achieved and that plasma immersion ion implantation is the most suitable technique for the enrichment of chromium in the outermost surface layer of the steel when compared to the beam line implantation.

  16. Hardness survey of cold-worked and heat-treated JBK-75 stainless steel alloy

    International Nuclear Information System (INIS)

    Jackson, R.J.; Lucas, R.L.

    1977-01-01

    The alloy JBK-75, an age-hardenable austenitic stainless steel, is similar to commercial A-286, but has certain chemistry modifications to improve weldability and hydrogen compatibility. The principal changes are an increase in nickel and a decrease in manganese with lower limits on carbon, phosphorus, sulfur, silicon, and boron. In this study, the effects of solutionizing time and temperature, quench rate, cold working, and the effects of cold working on precipitation kinetics were examined. Findings show that the solutionizing temperature has a moderate effect on the as-quenched hardness, while times greater than that required for solutionizing do not significantly affect hardness. Quench rate was found to have a small effect on as-quenched hardness, however, hardness gradients did not develop in small bars. It was found that JBK-75 can be significantly strengthened by cold working. Cold working alone produced hardness increases from Rockwell-A 49 to R/sub A/ 68. A recovery-related hardness change was noted on heat treating at 300 and 400 0 C for both as-quenched and as-worked JBK-75. Significant age-hardening was observed at temperatures as low as 500 0 C for as-worked metal. Aging at 600 0 C resulted in maximum hardness in the 75 percent worked sample at about 6 hours (R/sub A/ 73.5) while the 50 percent worked sample was near maximum hardness (R/sub A 72.5) after seven days. THE 25 and 0 percent worked samples were considerably underaged after seven days. Similar type kinetic data were obtained for worked and nonworked metal at 650, 700, 800, 850, 900, 1000, and 1100 0 C for times from 10 minutes to 10,000 minutes (6.7 days). The overall purpose of the hardness survey was to better define the effects of cold work on the stress-relieving range, coherent precipitation range, incoherent precipitation range, recrystallization range, solutionizing range, and grain-growth range

  17. An Experimental Investigation on Hardness and Microstructure of Heat Treated EN 9 Steel

    Science.gov (United States)

    Biswas, Palash; Kundu, Arnab; Mondal, Dhiraj

    2017-08-01

    In the modern engineering world, extensive research has led to the development of some special grades of steel, often suited for enhanced functions. EN 9 steel is one such grade, having major applications in power plants, automobile and aerospace industry. Different heat treatment processes are employed to achieve high hardness and high wear resistance, but machinability subsequently decreases. Existing literature is not sufficient to achieve a balance between hardness and machinability. The aim of this experimental work is to determine the hardness values and observe microstructural changes in EN9 steel, when it is subjected to annealing, normalizing and quenching. Finally, the effects of tempering after each of these heat treatments on hardness and microstructure have also been shown. It is seen that the tempering after normalizing the specimen achieved satisfactory results. The microstructure was also observed to be consisting of fine grains.

  18. The optimization of the removal process of nitrogen content from steels treated in vacuum facilities

    Science.gov (United States)

    Magaon, Miruna; Vǎtǎşescu, Mihail; HepuÅ£, Teodor; Crişan, Eugen

    2017-07-01

    Purity in gases has a considerable influence on the quality of steel, more precisely nitrogen and hydrogen. In this paper are presented the results of researches conducted at an electrical steelwork, in order to establish correlations between a series of vacuuming parameters, which influence the amount of nitrogen removed from the liquid steel. The steelwork is equipped with CAE (Electric Arc Furnace) type EBT (Eccentric Bottom Tapping), LF (Ladle-Furnace) and VD (Vacuum-Degassing) facilities and a 5 wires MTC (Continuous Casting Machine). All the data obtained during the research was processed in the MATLAB calculation program, the results being presented both in analytical and graphical form. The technological analyze of the correlation equations and the graphical representations allowed to establish the variation limits of the independent parameters, in order to advancely reduce the steel hydrogen content.

  19. Numerical model to predict microstructure of the heat treated of steel elements

    Directory of Open Access Journals (Sweden)

    T. Domański

    2011-04-01

    Full Text Available In work the presented numerical models of tool steel hardening processes take into account thermal phenomena and phase transformations. Numerical algorithm of thermal phenomena was based on the Finite Elements Methods of the heat transfer equations. In the model of phase transformations, in simulations heating process continuous heating (CHT was applied, whereas in cooling process continuous cooling (CCT of the steel at issue. The phase fraction transformed (austenite during heating and fractions during cooling of ferrite, pearlite or bainite are determined by Johnson-Mehl-Avrami formulas. The nescent fraction of martensite is determined by Koistinen and Marburger formula or modified Koistinen and Marburger formula. In the simulations of hardening was subject the fang lathe of cone (axisymmetrical object made of tool steel.

  20. UOE Pipe Manufacturing Process Simulation: Equipment Designing and Construction

    Science.gov (United States)

    Delistoian, Dmitri; Chirchor, Mihael

    2017-12-01

    UOE pipe manufacturing process influence directly on pipeline resilience and operation capacity. At present most spreaded pipe manufacturing method is UOE. This method is based on cold forming. After each technological step appears a certain stress and strain level. For pipe stress strain study is designed and constructed special equipment that simulate entire technological process.UOE pipe equipment is dedicated for manufacturing of longitudinally submerged arc welded DN 400 (16 inch) steel pipe.

  1. Nanoscale evaluation of laser-based surface treated 12Ni maraging steel

    Science.gov (United States)

    Grum, J.; Slabe, J. M.

    2005-07-01

    Maraging steels are used in several high-tech areas. Among them are highly thermo-mechanically loaded vital parts of die casting dies for pressure die casting of aluminium and magnesium alloys. From the economic point of view, the operation life of dies is extremely important to the price of the castings. Operational life can be successfully extended by a regular maintenance of die parts. Laser surfacing is a very promising process for rebuilding of worn out surfaces of vital die parts. In this research, the state in the maraging steel 1.2799 (DIN) after the application of laser surfacing process has been analysed using scanning electron microscope. The analysis revealed diverse microstructure through-depth of the laser-surfaced specimens. On the basis of the estimated size and volume fraction of the nano-precipitates in the individual microstructure zones located through-depth of the heat-affected zone, a through-depth variation of microhardness was predicted. The results are supported by Vickers microhardness tests. It was confirmed that the mechanical properties of the 1.2799 maraging steel strongly depend on the characteristic at the nano or micro level. Some of the results obtained can be also applied to laser surface heat treatment of maraging steels.

  2. Phase transformations and mechanical properties in heat treated superaustenitic stainless steels

    International Nuclear Information System (INIS)

    Koutsoukis, T.; Redjaïmia, A.; Fourlaris, G.

    2013-01-01

    A microstructure–properties relationship study in two superaustenitic stainless steels (S31254 and S32654) was carried out, following exposure at elevated temperatures for various ageing times. Due to high temperature ageing, most stainless steel grades suffer the formation of various precipitates, directly affecting their properties. The full characterization of those precipitates and the correlation with the mechanical behavior of the steels is the primary aim of this study. Samples of the steel grades studied, were exposed to isothermal heat treatments within the temperature range of 650–950 °C, for ageing times varying between 0.5 h and 3000 h, followed by water quenching at room temperature. Microstructural examination indicated the formation of four different secondary phases, sigma phase (σ), chi phase (χ), Laves phase and β-Cr 2 N nitride, which were characterized by transmission electron microscopy (TEM) and electron diffraction. The results obtained permitted the construction of the time–temperature–precipitation (TTP) plots. In addition, tensile and Vickers hardness testing were utilized and the modulus of toughness was calculated. The kinetics of the formation of various precipitates with increasing temperature and aging duration was also observed. It was found that various precipitates had a significant effect on all mechanical properties studied.

  3. Dry Sliding Wear Behavior of EN25 Steel Treated by Different Quenching Media

    Directory of Open Access Journals (Sweden)

    Bassam Ali Ahmed

    2010-10-01

    Full Text Available The present investigation aims to study the effect of heat treatment by quenching in different quenching media (salt water, water and oil following by tempering on wear resistance of EN25 steel. EN25 steel is an alloy of medium carbon low alloy steel which is used for many applications requiring high tensile strength and wear resistance such as connecting rods, adapters and in power sectors extensively. The specimens are machined to 20 mm in length and 10 mm in diameter. This study is done by two stages: The first stage is done by austenitizing EN25 steel to 850 for 1 hr by quenching the specimens in three different quenching media and then tempered at 300 in air. While the second stage is performed by wear test. Dry sliding wear test is done by using pin –on-disc technique by varying the loads as 5, 10, 15, 20 and 25 N, also varying the time as 5, 10, 15, 20, 25 and 30 min respectively. The microstructure examination, hardness and followed roughness tests are also done for the specimens before and after wear test. The results of this work showed that an improving in wear resistance and hardness for the specimen quenched by salt water more than for water and oil. At the same time the roughness decreasing for the specimen quenched by salt water more than for water and oil.

  4. 76 FR 74831 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water

    Science.gov (United States)

    2011-12-01

    ... inhibitor in place of other aging management activities. As a result, aging effects such as loss of material... of the Water Chemistry Program to manage loss of material and cracking of stainless steel structures... this extension will allow stakeholders a chance to better prepare their responses to LR-ISG-2011-01...

  5. Failure Analysis Of Industrial Boiler Pipe

    International Nuclear Information System (INIS)

    Natsir, Muhammad; Soedardjo, B.; Arhatari, Dewi; Andryansyah; Haryanto, Mudi; Triyadi, Ari

    2000-01-01

    Failure analysis of industrial boiler pipe has been done. The tested pipe material is carbon steel SA 178 Grade A refer to specification data which taken from Fertilizer Company. Steps in analysis were ; collection of background operation and material specification, visual inspection, dye penetrant test, radiography test, chemical composition test, hardness test, metallography test. From the test and analysis result, it is shown that the pipe failure caused by erosion and welding was shown porosity and incomplete penetration. The main cause of failure pipe is erosion due to cavitation, which decreases the pipe thickness. Break in pipe thickness can be done due to decreasing in pipe thickness. To anticipate this problem, the ppe will be replaced with new pipe

  6. Hardness and microstructural characterization of API 5L X70 steel pipes welded by HF/ERW process; Caracterizacao microestrutural e de dureza em tubos de aco API 5L X70 soldados pelo processo HF/ERW

    Energy Technology Data Exchange (ETDEWEB)

    Calcada, Mauricio Vieira; Voorwald, Herman Jacobus Cornelis; Nascimento, Marcelino Pereira do [UNESP, Guaratingueta, SP (Brazil). Faculdade de Engenharia

    2010-07-01

    The materials that stand in the manufacture of steel pipes are called API, that should have, high mechanical resistance, high corrosion resistance, high fatigue resistance, good weldability, and other properties. Thus, the purpose of this project was to evaluate the microstructure and hardness of welded joints by the HF/ERW process of API 5L X70 steel pipes. The microstructural analysis was performed using a surface finish with grit sizes from 220 to 25 {mu}m e polishing with diamond paste from 9 {mu}m to 0.05 {mu}m; the revelation was made with 3% Nital attack. The Vickers hardness was performed across the welded joint by 33 points to indentation. The results were: 80.5 {+-} 3.4% of ferrite and 19.5 {+-} 3.4% of perlite for microanalysis. As for hardness, the values were: 215.69 HV10 for weld line, 218.65 HV10 for ZTA and 218.95 HV10 for base metal. (author)

  7. Characterization and corrosion behavior of F6NM stainless steel treated in high temperature water

    Science.gov (United States)

    Li, Zheng-yang; Cai, Zhen-bing; Yang, Wen-jin; Shen, Xiao-yao; Xue, Guo-hong; Zhu, Min-hao

    2018-03-01

    F6NM martensitic stainless steel was exposed to 350 °C water condition for 500, 1500, and 2500 h to simulate pressurized water reactor (PWR) condition. The characterization and corrosion behavior of the oxide film were investigated. Results indicate that the exposed steel surface formed a double-layer oxide film. The outer oxide film is Fe-rich and contains two type oxide particles. However, the inner oxide film is Cr-rich, and two oxide films, whose thicknesses increase with increasing exposure time. The oxide film reduces the corrosion behavior because the outer oxide film has many crack and pores. Finally, the mechanism and factors affecting the formation of the oxide film were investigated.

  8. TEM characterization on new 9% Cr advanced steels thermomechanical treated after tempering

    Science.gov (United States)

    Fernández, P.; Hoffmann, J.; Rieth, M.; Roldán, M.; Gómez-Herrero, A.

    2018-03-01

    Phase transformation on new six reduced activation ferritic/martensitic steels (RAFMs) was investigated to provide the basis for the design and development of advanced steels to maintain adequate strength and creep resistance above 500 °C. The new alloys are designed to increase the amount of fine MX precipitates and reduce coarse M23C6 carbides through alloy composition refinement and the application of thermomechanical treatments. The microstructural investigations by TEM have shown M23C6, M2X, and MX precipitation after tempering at 700 °C/2h with low dislocation recovery, while at 825 °C/2h the martensite developed to subgrain formation and growth. At this stage, only M23C6 and MX were detected. Preliminary results demonstrate that it is feasible to produce fine MX strengthened particles dispersed in the matrix with further optimization of tempering treatments.

  9. Partial-Isothermally-Treated Low Alloy Ultrahigh Strength Steel with Martensitic/Bainitic Microstructure

    Science.gov (United States)

    Luo, Quanshun; Kitchen, Matthew; Patel, Vinay; Filleul, Martin; Owens, Dave

    We introduce a new strengthening heat treatment of a Ni-Cr-Mo-V alloyed spring steel by partial isothermal salt-bath and subsequent air-cooling and tempering. Detailed isothermal treatments were made at temperatures below or above the Ms point (230°C). The salt bath time was controlled between 10 and 80 minutes. Through the new treatment, the candidate steel developed ultrahigh tensile strength 2,100 MPa, yield strength 1,800 MPa, elongation 8-10 %, hardness 580-710 HV, and V-notch Charpy toughness 10-12 J. Optical and electron microscopic observations and X-ray diffraction revealed multi-phase microstructures of bainitic/martensitic ferrites, fine carbide precipitates and retained austenite. Carbon partitioning during the bainitic/martensitic transformation was investigated for its remarkable influence on the strengthening mechanism.

  10. Austenite stability in reversion-treated structures of a 301LN steel under tensile loading

    Czech Academy of Sciences Publication Activity Database

    Järvenpää, A.; Jaskari, M.; Man, Jiří; Karjalainen, L. P.

    2017-01-01

    Roč. 127, MAY (2017), s. 12-26 ISSN 1044-5803 R&D Projects: GA ČR GA13-32665S Institutional support: RVO:68081723 Keywords : austenitic stainless steel * austenite stability * grain size * reversion annealing * tensile straining * deformation induced martensite Subject RIV: JL - Materials Fatigue, Friction Mechanics OBOR OECD: Audio engineering, reliability analysis Impact factor: 2.714, year: 2016

  11. Texture evolution in Fe-3% Si steel treated under unconventional annealing conditions

    Czech Academy of Sciences Publication Activity Database

    Stoyka, V.; Kováč, F.; Stupakov, Oleksandr; Petryshynets, I.

    2010-01-01

    Roč. 61, č. 11 (2010), 1066-1073 ISSN 1044-5803 R&D Projects: GA ČR GP102/09/P108 Institutional research plan: CEZ:AV0Z10100520 Keywords : grain oriented steels * annealing * abnormal grain growth * crystallographic texture * hysteresis losses * electron backscattering Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.496, year: 2010

  12. 46 CFR 154.660 - Pipe welding.

    Science.gov (United States)

    2010-10-01

    ... butt welds must meet the following: (1) Butt welds of pipes made from carbon, carbon manganese, or low alloy steels must meet § 56.50-105 of this chapter, including the requirements for post-weld heat treatment. (2) Except for piping inside an independent cargo tank type A, B, or C, butt welds must be 100...

  13. Ambient temperature contamination of process piping and the effects of pretreatment

    International Nuclear Information System (INIS)

    Adeleye, S.A.; White, D.A.; Taylor, J.B.

    1996-01-01

    The results are presented of a study of pretreatment methods as possible controls on the buildup (plateout) of cobalt and cesium activity on the inside surfaces of mild and stainless steel piping used to carry radioactive liquors. Coupon specimens of mild steel and Type 304L and 18/13/1 stainless steel piping are treated by contacting with acid and electroetching. Also, the effect on plateout of saturating steel coupons with inactive cobalt is investigated. In addition, the transient effects of pH, concentration changes, and liquid turbulence on untreated surface buildup are presented. Surface treatment is shown to delay activity buildup in certain instances bu does not affect the magnitude of overall surface activity. For untreated and treated surfaces, plateout is dependent on solution pH and isotope concentration. The higher the pH and the higher the concentration, the greater the deposition will be. The effects of turbulence cause only a marginal decrease in plateout at each pH level and concentration studied. The steel type has a major effect on the activity picked up. The mild steel specimen shows the greatest activity buildup

  14. Intergranular stress corrosion cracking of type 304 stainless steels treated with inhibitive chemicals in high temperature pure water

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, T.K. [Nuclear Science and Technology Development Center, National Tsing-Hua Univ. Taiwan (China); Lee, M.Y.; Tsai, C.H. [Department of Engineering and System Science, National Tsing-Hua Univ. Taiwan (China)

    2002-07-01

    Electrochemical potentiodynamic polarizations, electrochemical corrosion potential (ECP) measurements and slow strain rate tensile (SSRT) tests were conducted to investigate the intergranular stress corrosion cracking (IGSCC) characteristics of Type 304 stainless steels treated with inhibitive chemicals in simulated boiling water reactor (BWR) environments. A number of thermally sensitized specimens were prepared and were pre-oxidized in a 288 C environment with the presence of 300 ppb dissolved oxygen for 360 hours. Most of the specimens were then treated with various chemicals including powdered zirconium oxide (ZrO{sub 2}), powdered titanium oxide (TiO{sub 2}), and zirconyl nitrate [ZrO(NO{sub 3}){sub 2}] via static immersion at 90 C, 150 C, and 200 C. Test environments were specifically designed in a circulation loop to create a dissolved oxygen concentration of 300 ppb. Test results showed that the corrosion current densities of all treated specimens were lower than that of the untreated, pre-oxidized specimen at ambient temperature in a solution mixed with 1 mM K{sub 3}Fe(CN){sub 6} and 1 mM K{sub 4}Fe(CN){sub 6}. The ECPs of the treated specimens could be lower or higher than that of the pre-oxidized one at 288 C, depending upon the type of treating chemical and the treating temperature. In addition, IGSCC was observed on all specimens (treated or untreated) in the same environment. However, the untreated specimen exhibited lower elongation, shorter failure time, and more secondary cracks on the side surfaces. It was therefore suggested that inhibitive chemicals such as ZrO{sub 2}, TiO{sub 2}, and ZrO(NO{sub 3}){sub 2} did provide a certain degree of enhancement in improving the mechanical behavior of the treated specimens and in prolonging the IGSCC initiation time. (authors)

  15. Pit formation on stainless steel surfaces pre-treated with biosurfactants produced by Pseudomonas fluorescens

    International Nuclear Information System (INIS)

    Dagbert, Catherine; Meylheuc, Thierry; Bellon-Fontaine, Marie-Noelle

    2008-01-01

    Today, it is widely established that the surface tension of water can be reduced by some microorganisms capable of synthesizing surface-active compounds called biosurfactants (BS). BS characteristics depend on the microorganism that produces them and therefore, on the microorganism culture conditions. Some studies on chemical surfactants have shown that the adsorption of surface-active compounds plays a major role in corrosion; indeed they are used as a good corrosion inhibition tool. The purpose of this study was first, to estimate the importance and behavior of the stainless steels passive film on the adsorption of BS, produced by the Gram negative bacteria Pseudomonas fluorescens, and secondly, to study the impact of these treatments on the pitting corrosion. In this paper, the galvanostatic polarization technique, used as accelerated method for determining the characteristic pit potentials on stainless steels, is examined. Pit growth, shape and cover formation were also observed. The surface topography of the corroded specimens was investigated using field emission scanning electron microscopy (FESEM)

  16. Pit formation on stainless steel surfaces pre-treated with biosurfactants produced by Pseudomonas fluorescens

    Energy Technology Data Exchange (ETDEWEB)

    Dagbert, Catherine [ECP-LGPM, Grande Voie des Vignes, 92295 Chatenay-Malabry (France)], E-mail: catherine.dagbert@ecp.fr; Meylheuc, Thierry; Bellon-Fontaine, Marie-Noelle [INRA, UMR 763 Bioadhesion et Hygiene des Materiaux, F-91300 Massy (France); AGROPARISTECH, UMR 763 Bioadhesion et Hygiene des Materiaux, F-91300 Massy (France)

    2008-12-01

    Today, it is widely established that the surface tension of water can be reduced by some microorganisms capable of synthesizing surface-active compounds called biosurfactants (BS). BS characteristics depend on the microorganism that produces them and therefore, on the microorganism culture conditions. Some studies on chemical surfactants have shown that the adsorption of surface-active compounds plays a major role in corrosion; indeed they are used as a good corrosion inhibition tool. The purpose of this study was first, to estimate the importance and behavior of the stainless steels passive film on the adsorption of BS, produced by the Gram negative bacteria Pseudomonas fluorescens, and secondly, to study the impact of these treatments on the pitting corrosion. In this paper, the galvanostatic polarization technique, used as accelerated method for determining the characteristic pit potentials on stainless steels, is examined. Pit growth, shape and cover formation were also observed. The surface topography of the corroded specimens was investigated using field emission scanning electron microscopy (FESEM)

  17. The influence of low oxygen and contaminated sodium environments on the fatigue behavior of solution treated AISI 316 stainless steel

    International Nuclear Information System (INIS)

    Marshall, P.

    1977-01-01

    The influence of air and sodium environments on the fatigue properties of solution treated AISI 316 steel was studied by predictive methods and by conducting tests in air, in high temperature sodium, or following pre-exposure to sodium. The sodium environments studied included contaminated sodium or the products of sodium/water flames possibly typical of fast reactor fault conditions, and low oxygen sodium more appropriate to normal plant operation. Generally, fatigue properties were reduced by contaminated sodium or the products of sodium/water flames and improved by low oxygen sodium when compared with similar tests conducted in air. However, complex effects were observed with respect to crack initiation. The experimental results are discussed and generally follow trends predicted by physically based fatigue models. (author)

  18. Microstructures and phase formations in the surface layer of an AISI D2 steel treated with pulsed electron beam

    International Nuclear Information System (INIS)

    Zou, J.X.; Grosdidier, T.; Zhang, K.M.; Gao, B.; Hao, S.Z.; Dong, C.

    2007-01-01

    The nanostructures and metastable phase transformations in the surface layer of an AISI D2 steel treated with high current pulsed electron beam (HCPEB) were investigated. The surface structure is marked by two distinct features, i.e. the formation of sub-micrometer fine austenite γ grains (50-150 nm), and the disappearance of carbides via dissolution and crater eruption. The γ phase directly grows from the melt and is retained down to room temperature. Although the cooling rate is as high as 10 7 K/s in our case, the martensitic transformation could completely be suppressed. Such an effect is due to the increased stability of the austenite phase through grain refinement and chemistry modification

  19. Applications of the essay at slow deformation velocity in pipes of stainless steel AISI-304; Aplicaciones del ensayo a velocidad de deformacion lenta en tuberias de acero inoxidable AISI-304

    Energy Technology Data Exchange (ETDEWEB)

    Zamora R, L.; Mora R, T. De la [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2004-07-01

    Nowadays is carried out research related with the degradation mechanisms of structures, systems and/or components in the nuclear power plants, since many of the involved processes are those responsible for the dependability of these, of the integrity of the components and of the aspects of safety. The purpose of this work, was to determine the grade of susceptibility to the corrosion of a pipe of Austenitic stainless steel AISI 304, in a solution of Na CI (3.5%) to the temperatures of 60 and 90 C, in two different thermal treatments - 1. - Sensitive 650 C by 4 hours and cooled in water. 2. Solubilized to 1050 C by 1 hour and cooled in water.

  20. The choice of the optimal technology for processing pipe steels by analyzing the stages of the fracture process in impact tests

    Science.gov (United States)

    Derevyagina, Lyudmila S.; Gordienko, Antonina I.; Vlasov, Ilya V.

    2017-12-01

    The fracture toughness and cold resistance of low-carbon steels 10Mn2VNbAl and 12GBA subjected to different thermomechanical processing have been studied. It is shown that the helical rolling of 10Mn2VNbAl steel significantly improves its low-temperature fracture characteristics and reduces the ductile-brittle transition temperature from -32°C for the initial state to the temperature range below -55°C. As a result of warm rolling, the impact toughness KCV of 12GBA steel at room temperature increased 2.8 times. The test temperature reduction leads to a sharp decrease in the KCV values, with the ductile-brittle transition temperature maintained at the level of the initial state of the steel.

  1. Thermographic Assessment of the HAZ Properties and Structure of Thermomechanically Treated Steel

    Science.gov (United States)

    Górka, Jacek; Janicki, Damian; Fidali, Marek; Jamrozik, Wojciech

    2017-12-01

    Thermomechanically processed steels are materials of great mechanical properties connected with more than good weldability. This mixture makes them interesting for different types of industrial applications. When creating welded joints, a specified amount of heat is introduced into the welding area and a so called heat-affected zone (HAZ) is formed. The key issue is to reduce the width of the HAZ, because properties of the material in the HAZ are worse than in the base material. In the paper, thermographic measurements of HAZ temperatures were presented as a potential tool for quality assuring the welding process in terms of monitoring and control. The main issue solved was the precise temperature measurement in terms of varying emissivity during a welding thermal cycle. A model of emissivity changes was elaborated and successfully applied. Additionally, material in the HAZ was tested to reveal its properties and connect changes of those properties with heating parameters. The obtained results prove that correctly modeled emissivity allows measurement of temperature, which is a valuable tool for welding process monitoring.

  2. Agglomeration Behavior of Non-Metallic Particles on the Surface of Ca-Treated High-Carbon Liquid Steel: An In Situ Investigation

    Directory of Open Access Journals (Sweden)

    Yasuhiro Tanaka

    2018-03-01

    Full Text Available The agglomeration behavior of non-metallic inclusion is a critical phenomenon that needs to be controlled as it has a direct relationship with the performance of produced steel. Although the agglomerates can be potential points for serious defects in every grade of steel, they are likely to be more serious in high-carbon steel due to the low ductility of these grades of steels as well as their usage in severe conditions. Confocal scanning laser microscopes (CSLM have been used by different researchers to investigate the agglomeration behavior of non-metallic particles at the interface of liquid steel and Ar gas, in situ. In recent decades, the agglomeration of Al2O3 particle in and on the surface of low-carbon steel has been widely investigated. However, there are very few studies focussing on non-Al2O3 inclusions which are included in a Ca-treated high-carbon steel. In this study, the agglomeration behaviors of sulfide/sulfide and sulfide/oxide particles on the surface of liquid high-carbon steel have been investigated in detail using CSLM. Agglomerations on the liquid surface are governed by capillary forces similar to the Al2O3 particle but this study demonstrates that agglomeration forces among non-Al2O3 particles on the surface of re-melted high-carbon samples are lower than pure-Al2O3 on the surface of low-carbon steel. Despite this, they show similar or longer acting lengths than pure-Al2O3.

  3. Survival of indicator organisms, e.g. E. coli in drinking water pipes

    DEFF Research Database (Denmark)

    Albrechtsen, Hans-Jørgen; Silhan, J.; Corfitzen, Charlotte B.

    2006-01-01

    The survival of E. coli was investigated in used drinking water pipes from households. The investigation showed that E. coli survived longer in plastic pipes than in cupper pipes and galvanized steel pipes. The investigation also showed longer survival at cold water temperatures (15?C) than at hot...

  4. Heat pipes

    CERN Document Server

    Dunn, Peter D

    1994-01-01

    It is approximately 10 years since the Third Edition of Heat Pipes was published and the text is now established as the standard work on the subject. This new edition has been extensively updated, with revisions to most chapters. The introduction of new working fluids and extended life test data have been taken into account in chapter 3. A number of new types of heat pipes have become popular, and others have proved less effective. This is reflected in the contents of chapter 5. Heat pipes are employed in a wide range of applications, including electronics cooling, diecasting and injection mo

  5. Carneiro hidráulico com tubulação de alimentação em aço galvanizado e em PVC Hydraulic ram pump perfomance with PVC and steel pipes

    Directory of Open Access Journals (Sweden)

    Caroline Abate

    2002-03-01

    Full Text Available A recente crise da energia convencional tem ocasionado a exploração de fontes alternativas de energia. O bombeamento de água utilizando carneiro hidráulico é amplamente empregado em propriedades onde a energia elétrica é escassa ou inexistente. Procurando dar subsídios técnicos para a utilização do PVC nos sistemas de alimentação de um carneiro hidráulico, foi desenvolvido um experimento com objetivo de avaliar o desempenho de um carneiro hidráulico quando alimentado por uma tubulação de PVC e outra de aço galvanizado, sob três alturas de queda (2,1, 3,8 e 4,7 m. Foi utilizada a equação de D'Aubussion's para a avaliação do rendimento, calculado a partir de leituras de altura de recalque, vazão de escape, vazão de recalque e altura de alimentação. Pode-se conseguir o máximo rendimento com o carneiro hidráulico utilizando-se de tubulação de PVC com até 4,2 m de desnível; além desse valor a tubulação de aço galvanizado é mais eficiente.The recent conventional energy crisis is leading to the exploration of alternative energy sources. The pumping of water using ram pumps is widely used in farms where electric energy is scarce or inexistent. This experiment was carried out to evaluate the performance of an hydraulic ram pump utilizing two kinds of supply pipes (PVC and steel using three different supply heads (2.1, 3.8 and 4.7. Delivery head, delivery discharge, waste discharge and supply head were utilized to calculate the yield of the hydraulic ram by the equation of D'Aubussion. The maximum yield of the hydraulic ram was obtained for the PVC pipe for the 4.2 m head; for heads higher than 4.2 m the steel pipe was more efficient.

  6. Strain limits for concrete filled steel tubes in AASHTO seismic provisions.

    Science.gov (United States)

    2013-08-01

    Reinforced concrete filled steel tubes (RCFSTs) are commonly used as bridge pipe piles in high seismic regions. The pipe piles in high : seismic regions. The pipe-piles consist of reinforced concrete encased in a steel tube. The steel tube is used as...

  7. Pipe grabber

    Energy Technology Data Exchange (ETDEWEB)

    Sharafutdinov, I.G.; Mubashirov, S.G.; Prokopov, O.I.

    1981-05-15

    A pipe grabber is suggested which contains a housing, clamping elements and centering mechanism with drive installed on the lower end of the housing. In order to improve the reliable operation of the pipe grabber, the centering mechanism is made in the form of a reinforced ringed flexible shaft, while the drive is made in the form of elastic rotating discs. In this case the direction of rotation of the discs and the flexible shaft is the opposite.

  8. Manufacture of mold of polymeric composite water pipe reinforced charcoal

    Science.gov (United States)

    Zulfikar; Misdawati; Idris, M.; Nasution, F. K.; Harahap, U. N.; Simanjuntak, R. K.; Jufrizal; Pranoto, S.

    2018-03-01

    In general, household wastewater pipelines currently use thermoplastic pipes of Polyvinyl Chloride (PVC). This material is known to be not high heat resistant, contains hazardous chemicals (toxins), relatively inhospitable, and relatively more expensive. Therefore, researchers make innovations utilizing natural materials in the form of wood charcoal as the basic material of making the water pipe. Making this pipe requires a simple mold design that can be worked in the scale of household and intermediate industries. This research aims to produce water pipe mold with simple design, easy to do, and making time relatively short. Some considerations for molding materials are weight of mold, ease of raw material, strong, sturdy, and able to cast. Pipe molds are grouped into 4 (four) main parts, including: outer diameter pipe molding, pipe inside diameter, pipe holder, and pipe alignment control. Some materials have been tested as raw materials for outer diameter of pipes, such as wood, iron / steel, cement, and thermoset. The best results are obtained on thermoset material, where the process of disassembling is easier and the resulting mold weight is relatively lighter. For the inside diameter of the pipe is used stainless steel, because in addition to be resistant to chemical processes that occur, in this part of the mold must hold the press load due to shrinkage of raw materials of the pipe during the process of hardening (polymerization). Therefore, it needs high pressure resistant material and does not blend with the raw material of the pipe. The base of the mold is made of stainless steel material because it must be resistant to corrosion due to chemical processes. As for the adjustment of the pipe is made of ST 37 carbon steel, because its function is only as a regulator of the alignment of the pipe structure.

  9. The effect of hot bending and thermal ageing on creep and microstructure evolution in thick-walled P92 steel pipe

    Czech Academy of Sciences Publication Activity Database

    Sklenička, Václav; Kuchařová, Květa; Král, Petr; Kvapilová, Marie; Svobodová, M.; Čmakal, J.

    2015-01-01

    Roč. 644, SEP (2015), s. 297-309 ISSN 0921-5093 R&D Projects: GA TA ČR TA02010260; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : Steel * Thermomechanical processing * Mechanical characterization * Electron microscopy * Ageing Subject RIV: JG - Metallurgy Impact factor: 2.647, year: 2015

  10. Piping inspection round robin

    International Nuclear Information System (INIS)

    Heasler, P.G.; Doctor, S.R.

    1996-04-01

    The piping inspection round robin was conducted in 1981 at the Pacific Northwest National Laboratory (PNNL) to quantify the capability of ultrasonics for inservice inspection and to address some aspects of reliability for this type of nondestructive evaluation (NDE). The round robin measured the crack detection capabilities of seven field inspection teams who employed procedures that met or exceeded the 1977 edition through the 1978 addenda of the American Society of Mechanical Engineers (ASME) Section 11 Code requirements. Three different types of materials were employed in the study (cast stainless steel, clad ferritic, and wrought stainless steel), and two different types of flaws were implanted into the specimens (intergranular stress corrosion cracks (IGSCCs) and thermal fatigue cracks (TFCs)). When considering near-side inspection, far-side inspection, and false call rate, the overall performance was found to be best in clad ferritic, less effective in wrought stainless steel and the worst in cast stainless steel. Depth sizing performance showed little correlation with the true crack depths

  11. Investigation of the Microstructural Changes and Hardness Variations of Sub-Zero Treated Cr-V Ledeburitic Tool Steel Due to the Tempering Treatment

    Science.gov (United States)

    Jurči, Peter; Dománková, Mária; Ptačinová, Jana; Pašák, Matej; Kusý, Martin; Priknerová, Petra

    2018-03-01

    The microstructure and tempering response of Cr-V ledeburitic steel Vanadis 6 subjected to sub-zero treatment at - 196 °C for 4 h have been examined with reference to the same steel after conventional heat treatment. The obtained experimental results infer that sub-zero treatment significantly reduces the retained austenite amount, makes an overall refinement of microstructure, and induces a significant increase in the number and population density of small globular carbides with a size 100-500 nm. At low tempering temperatures, the transient M3C-carbides precipitated, whereas their number was enhanced by sub-zero treatment. The presence of chromium-based M7C3 precipitates was evidenced after tempering at the temperature of normal secondary hardening; this phase was detected along with the M3C. Tempering above 470 °C converts almost all the retained austenite in conventionally quenched specimens while the transformation of retained austenite is rather accelerated in sub-zero treated material. As a result of tempering, a decrease in the population density of small globular carbides was recorded; however, the number of these particles retained much higher in sub-zero treated steel. Elevated hardness of sub-zero treated steel can be referred to more completed martensitic transformation and enhanced number of small globular carbides; this state is retained up to a tempering temperature of around 500 °C in certain extent. Correspondingly, lower as-tempered hardness of sub-zero treated steel tempered above 500 °C is referred to much lower contribution of the transformation of retained austenite, and to an expectedly lower amount of precipitated alloy carbides.

  12. Comparison of ICEPEL predictions with single elbow flexible piping system experiment

    International Nuclear Information System (INIS)

    A-Moneim, M.T.; Chang, Y.W.

    1978-01-01

    The ICEPEL Code for coupled hydrodynamic-structural response analysis of piping systems is used to analyze an experiment on the response of flexible piping systems to internal pressure pulses. The piping system consisted of two flexible Nickel-200 pipes connected in series through a 90 0 thick-walled stainless steel elbow. A tailored pressure pulse generated by a calibrated pulse gun is stabilized in a long thick-walled stainless steel pipe leading to the flexible piping system which ended with a heavy blind flange. The analytical results of pressure and circumferential strain histories are discussed and compared against the experimental data obtained by Stanford Research Institute

  13. EXPERIMENTAL AND NUMERICAL INVESTIGATION OF FLEXIBLE BURIED PIPE DEFORMATION BEHAVIOR UNDER VARIOUS BACKFILL CONDITIONS

    OpenAIRE

    Niyazi Uğur TERZİ; Sönmez YILDIRIM

    2009-01-01

    Deformation characteristics of polyethylene based flexible pipes are different than rigid pipes such as concrete and iron pipes. Deflection patterns and stress-strain behaviors of flexible pipes have strict relation between the engineering properties of backfill and its settlement method. In this study, deformation behavior of a 100 mm HDPE flexible pipe under vertical loads is investigated in laboratory conditions. Steel test box, pressurized membrane, raining system, linear position transdu...

  14. Vacuum pipe for e+e- interactions

    International Nuclear Information System (INIS)

    Hoard, C.T.

    1982-10-01

    The design, fabrication and testing of the beryllium vacuum chamber within the Mark II detector at SLAC is described. The Be chamber encloses one interaction point of the PEP circulating ring and is a part of its beam pipe. The Be chamber is captured within the Secondary Vertex Detector (SVD), a drift chamber, which is in turn centered in the Mark II drift chamber. Both ends of the beryllium pipe are brazed to aluminum/stainless transitions for connection to stainless steel bellows. A concentric radiation-screen liner of titanium foil runs the full length of the beryllium pipe

  15. Pipe crawlers: Versatile adaptations for real applications

    Energy Technology Data Exchange (ETDEWEB)

    Hapstack, M.; Talarek, T.R.

    1990-01-01

    A problem at the Savannah River Site requires the unique application of a pipe crawler. A number of stainless steel pipes buried in concrete require ultrasonic inspection of the heat affected zones of the welds for detection of flaws or cracks. The paper describes the utilization of an inch-worm motion pipe crawler which negotiates a 90 degree reducing elbow with significant changes in diameter and vertical sections before entering the area of concern. After a discussion of general considerations and problem description, special requirements to meet the objectives and the design approach regarding the tractor, control system, instrument carriage, and radiation protection are discussed. 2 refs., 11 figs. (MB)

  16. Analysis and Optimisation of Carcass Production for Flexible Pipes

    DEFF Research Database (Denmark)

    Nielsen, Peter Søe

    Un-bonded flexible pipes are used in the offshore oil and gas industry worldwide transporting hydrocarbons from seafloor to floating production vessels topside. Flexible pipes are advantageous over rigid pipelines in dynamic applications and during installation as they are delivered in full length...... on reels. Flexible pipes are constructed in a layer structure in which each layer adds specific properties to the pipe such as; collapse strength, fluid integrity, bursting strength, tensile strength etc. The inner-most layer of a flexible pipe is the carcass; a flexible interlocking stainless steel...... structure that provides mechanical and collapse strength for the flexible pipe. The manufacturing process of carcass is a combination of roll forming stainless steel strips and helical winding the profiles around a mandrel interlocking the profiles with themselves. The focus of the present project...

  17. Effect of retained austenite stability and morphology on the hydrogen embrittlement susceptibility in quenching and partitioning treated steels

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xu [State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhang, Ke [School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China); Li, Wei, E-mail: weilee@sjtu.edu.cn [State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Jin, Xuejun, E-mail: jin@sjtu.edu.cn [Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2016-03-21

    The effect of retained austenite (RA) stability and morphology on the hydrogen embrittlement (HE) susceptibility were investigated in a high strength steel subjected to three different heat treatments, i.e., the intercritical annealing quenching and partitioning (IAQP), quenching and partitioning (QP) and quenching and tempering (QT). IAQP treatment results in the coexistence of blocky and filmy morphologies and both QP and QT treatments lead to only filmy RA. No martensitic transformation occurs in QT steel during deformation, while the QP and IAQP undergo the transformation with the same extent. It is shown that the HE susceptibility increases in the following order: QT, QP and IAQP. Despite of the highest strength level and the highest hydrogen diffusion rate, the QT steel is relative immune to HE, suggesting that the metastable RA which transforms to martensite during deformation is detrimental to the HE resistance. The improved resistance to HE by QP treatment compared with IAQP steel is mainly attributed to the morphology effect of RA. Massive hydrogen-induced cracking (HIC) cracks are found to initiate in the blocky RA of IAQP steel, while only isolate voids are observed in QP steel. It is thus deduced that filmy RA is less susceptible to HE than the blocky RA.

  18. Some elevated temperature tensile and strain-controlled fatigue properties for a 9%Cr1Mo steel heat treated to simulate thick section material

    International Nuclear Information System (INIS)

    Sanderson, S.J.; Jacques, S.

    Current interest has been expressed in the usage of thick section 9%Cr1%Mo steel, particularly for UK Commercial Demonstration Fast Reactor (CDFR) steam generator tubeplates. This paper presents the results of some preliminary mechanical property test work on a single cast of the steel, heat treated to simulate heavy ruling sections encompassing thicknesses likely to be met in the CDFR context. The microstructures of the simulated thick section material were found to remain predominantly as tempered martensite even at the slowest transformation cooling rates used (50 deg. C/h). The effect of microstructure is reflected in the elevated temperature proof stress, tensile strength and strain-controlled fatigue endurance which were found to be comparable with the properties established for thin section normalised and tempered 9%Cr1%Mo steel. These results are extremely encouraging and, taken in conjunction with the results from other simulation work on this material, further demonstrate the potential of thick section 9%Cr1%Mo steel. (author)

  19. Welding simulation of large-diameter thick-walled stainless steel pipe joints. Fast computation of residual stress and influence of heat source model

    International Nuclear Information System (INIS)

    Maekawa, Akira; Serizawa, Hisashi; Nakacho, Keiji; Murakawa, Hidekazu

    2011-01-01

    There are many weld zones in the apparatus and piping installed in nuclear power plants and residual stress generated in the zone by weld process is the most important influence factor for maintaining structural integrity. Though the weld residual stress is frequently evaluated using numerical simulation, fast simulation techniques have been demanded because of the enormous calculation times used. Recently, the fast weld residual stress evaluation based on three-dimensional accurate analysis became available through development of the Iterative Substructure Method (ISM). In this study, the computational performance of the welding simulation code using the ISM was improved to get faster computations and more accurate welding simulation. By adding functions such as parallel processing, the computation speed was much faster than that of the conventional finite element method code. Furthermore, the accuracy of the improved code was validated by measurements. The influence of two different weld heat source models on the simulation results was also investigated and it was found that the moving heat source was effective to achieve accurate weld simulation for multi-pass welds. (author)

  20. Storage analysis of steel pipes used in pipelines; Analise do sistema de estocagem de tubos de aco para dutos de transporte

    Energy Technology Data Exchange (ETDEWEB)

    Provenzano, Carlos E.C.; Silva, Breno S.; Fernandes, Lincoln F.; Santos Junior, Sergio J.F. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Louzada, Carlos H.C.M.

    2005-07-01

    New pipelines, request the use of great amount of tubes stored during its construction. Therefore, the cost generated by the storage areas motivates the reconsideration of the stockpiling system. Large areas demand high costs related to its acquisition or rent. The use of small areas can reduce the immediate cost with rent, but also can increase the total cost due to damage of the tubes or increase the risk at the storage conditions. The same considerations could be made for inadequate use of support materials on the stockpiling piles, regarding the quality or amount used. This work presents the modelling of the pyramidal stockpiling system of steel tubes and evaluations to a better configuration. (author)

  1. Intergranular corrosion in unserviced austenitic stainless steel pipes made of alloy 904L; Kornzerfall in nicht betriebsbeanspruchten rostfreien austenitischen Rohren aus Alloy 904L

    Energy Technology Data Exchange (ETDEWEB)

    Neidel, Andreas; Cagliyan, Erhan; Fischer, Boromir; Giller, Madeleine; Riesenbeck, Susanne [Siemens AG, Energy Sector, Berlin (Germany). Gasturbinenwerk Berlin

    2017-09-01

    Seamless tubes of the highly corrosion resistant austenitic steel 1.4539, X1NiCrMoCu25-20-5 (Alloy 904L) were observed to exhibit signs of inter-crystalline damage to a depth of several layers of grains and in particular on their internal surface. The material had been stored and had not been put into service. A number of hypotheses had been discussed to explain the predominant cause of the damage. Using optical light and scanning electron microscopy investigation techniques, clear evidence was obtained indicating it to be inter-crystalline corrosion due to the sensitisation of the grain boundaries. The most probable cause of this was determined to be the presence of residual deposits from the rolling process, which due to poor cleaning, had not been completely removed prior to the final solution annealing treatment. This explaining why predominantly the internal surface of the tubes was affected.

  2. Test of Seal System for Flexible Pipe End Fitting

    DEFF Research Database (Denmark)

    Banke, Lars; Jensen, Thomas Gregers

    1999-01-01

    The purpose of the end fitting seal system is to ensure leak proof termination of flexible pipes. The seal system of an NKT end fitting normally consists of a number of ring joint gaskets mounted in a steel sleeve on the outside of the polymeric inner liner of the pipe. The seal system is activated...

  3. Automatic guided wave communication system using steel pipes as communication channel for flood detection in steel offshoreoilrigs; Sistema automatico de comunicacion de ondas guiadas para la deteccion de tubos de refuerzo inundados en plataformas petroleras costa fuera

    Energy Technology Data Exchange (ETDEWEB)

    Mijarez Cstro, Rito; Martinez Ramirez, Fernando [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2010-10-09

    An automatic guided wave Pulse Position Modulation (PPM) system, using steel tubes as communication channel, for detecting flooding in the hollow sub-sea structures of offshore oilrigs is presented. The system employs two smart piezoelectric based sensors and modulators and a demodulator based on a piezoelectric transducer, a Digital Signal Processor (DSP) and a microcontroller. Experiments performed in the laboratory, in a tubular steel heliport structure and the base of a deck of an oilrig under construction, have successfully distinguished automatically guided wave encoded information. [Spanish] Este articulo presenta un trabajo de investigacion en el cual se desarrolla un sistema automatico de comunicacion de ondas guiadas por modulacion por posicion de pulsos (PPM), orientado a la deteccion de miembros inundados en los tubos de refuerzo de las plataformas petroleras costa fuera. El sistema utiliza de manera novedosa tubos de acero como medio de comunicacion y emplea dos sensores/moduladores inteligentes compuestos de cristales piezoelectricos, electronica basada en un microcontrolador y baterias. La instrumentacion del demodulador consta de un transductor piezoelectrico de ultrasonido, un procesador digital de senales (DSP) y un microcontrolador, el cual lleva a cabo de manera automatica la deteccion de ondas guiadas. Los experimentos se realizaron en aire, en laboratorio, en una estructura tubular de acero del helipuerto y en la base de una plataforma bajo construccion.

  4. 76 FR 11757 - Drill Pipe From the People's Republic of China: Antidumping Duty Order

    Science.gov (United States)

    2011-03-03

    ... are finished drill pipe and drill collars without regard to the specific chemistry of the steel (i.e... included are unfinished drill collars (including all drill collar green tubes) and unfinished drill pipe (including drill pipe green tubes, which are tubes meeting the following description: seamless tubes with an...

  5. 46 CFR 56.50-103 - Fixed oxygen-acetylene distribution piping.

    Science.gov (United States)

    2010-10-01

    ... distribution of oxygen and acetylene carried in cylinders as vessels stores. (b) The distribution piping shall... outlet stations. (c) Acetylene distribution piping and pipe fittings must be seamless steel. Copper... openings to spaces or tanks. (j) Outlet stations are to be provided with suitable protective devices which...

  6. Determination of cryogenic fracture characteristics of austenitic stainless steel JN1 welded joint and heat-treated materials by means of small punch testing method

    International Nuclear Information System (INIS)

    Kwon, Il-Hyun; Hashida, Toshiyuki; Takahashi, Hideaki; Liu, Shi-Cheng; Saucedo, M.L.

    1997-01-01

    Fracture characteristics of a TIG welded joint and heat-treated materials of JN1, which is an austenitic stainless steel recently developed for use as a cryogenic structural material, were evaluated by the small punch (SP) testing method using miniaturized specimens at 77 K and 4 K. The area under the load-displacement curve up to the maximum load was defined as the SP energy to evaluate the fracture characteristics of the materials in SP tests. Fracture surfaces were also observed using a scanning electron microscope. Solution-treated JN1 steel showed ductile fracture behavior with a high SP energy value even at 4 K, and serrations were observed in the load-displacement curve at 4 K. In the weld metal and fusion line specimens of the TIG welded joint, serrations also occurred at 4 K, but the fusion line specimens showed lower SP energy values than weld metal and solution-treated JN1 steel at 77 K and 4 K. In addition, the fusion line specimens showed pop-in behavior at 4 K, that is, cracks approximately 0.1-1mm long were induced by pop-in in the vicinity of the fusion line at the early stage of loading. JN1 materials heat-treated under the conditions of 650degC-5h and 700degC-1h showed similar fracture characteristics to those of the fusion line specimens at 77 K and 4 K except for the cracks induced by pop-in. With increasing temperature and time of heat treatment, SP energy decreased significantly, and the fracture surface showed a transition from ductile dimple to brittle intergranular cracking. It is shown that the SP testing method is useful for evaluating the fracture behaviors of microscopic regions such as the fusion lines of welds at cryogenic temperatures. (author)

  7. Changes in mechanical properties and structure of electrolytic plasma treated X 12 CrNi 18 10 Ti stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Kurbanbekov, Sherzod; Baklanov, Viktor; Karakozov, Batyrzhan [Republican State Enterprise National Nuclear Center of Kazakhstan, Kurchatov (Kazakhstan). Inst. of Atomic Energy Branch; Skakov, Mazhyn [Republican State Enterprise National Nuclear Center of Kazakhstan, Kurchatov (Kazakhstan)

    2017-05-01

    The paper addresses findings regarding the influence of electrolytic plasma treatment on the mechanical properties as well as structural and phase states of X 12 CrNi 18 10 Ti steel. Electrolytic plasma treatment is based on carburizing of stainless steel heated in electrolytes. Treatment of steel samples has been performed as follows: the samples were heated up to a temperature between 850 and 950 C and then they were cured for 7 minutes in an electrolyte of an aqueous solution containing 10 % glycerol (C{sub 3}H{sub 8}O{sub 3}) and 15 % sodium carbonate (Na{sub 2}CO{sub 3}). It is found that, after plasma electrolytic treatment, the surface of X 12 CrNi 18 10 Ti steel had a modified structure and high hardness. Increasing wear resistance of X 12 CrNi 18 10 Ti steel has been observed after carburizing and the coefficient of friction has been reduced. X-ray analysis showed that retained austenite γ-Fe is a main phase, and there are some diffraction lines of orthorhombic Fe{sub 3}C phase as well as Fe{sub 3}O{sub 4} cubic phase. It has been determined, that, after plasma electrolytic treatment, a carbide phase in the modified surface layer, irrespective of the location in the steel structure has the chemical composition Fe{sub 3}C. High concentration of carbon atoms in a solid solution based on γ- and α-iron, a large dislocation density, presence of particles of carbide phase and retained austenite layers have been found.

  8. Heat pipes

    CERN Document Server

    Dunn, Peter D

    1982-01-01

    A comprehensive, up-to-date coverage of the theory, design and manufacture of heat pipes and their applications. This latest edition has been thoroughly revised, up-dated and expanded to give an in-depth coverage of the new developments in the field. Significant new material has been added to all the chapters and the applications section has been totally rewritten to ensure that topical and important applications are appropriately emphasised. The bibliography has been considerably enlarged to incorporate much valuable new information. Thus readers of the previous edition, which has established

  9. 1998 Annual Study Report. Standardization of methods for evaluating characteristics of high-strength, large-diameter steel pipes for superhigh-pressure natural gas pipelines; 1998 nendo seika hokokusho. Chokoatsu tennen gas pipeline yo kokyodo daikei kokan no tokusei hoho no hyojunka

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The pipelines for safely transmitting superhigh-pressure natural gas should have excellent characteristics. The steel pipe is required to have a sufficient toughness, more concretely Charpy impact-absorbing energy, to prevent propagating shear fracture characteristic of natural gas pipelines. Recently, the natural gas pipeline is increasingly required to have higher design pressures (15 Mpa or higher) and grade (X80 or higher). In order to develop the techniques for simulating crack propagation in the propagating shear fracture of natural gas pipe lines as part of the programs to cope with these trends, the 1998 efforts were directed to reviewing the research results obtained so far and analysis of the problems to be solved and tasks to be taken, based on which the analytical procedure for gas releasing phenomena during the fracture process was basically developed, the material characteristic data were collected by the laboratory scale toughness tests, and the preliminary tests with rupture disks were conducted to verify the above analytical procedure. These efforts have established the bases for evaluating the characteristics of high-strength, large-diameter steel pipes in the light of safety against fracture, and greatly advanced the program towards the final target of developing the international specification drafts for toughness. (NEDO)

  10. Microstructural characterization of pipe bomb fragments

    International Nuclear Information System (INIS)

    Gregory, Otto; Oxley, Jimmie; Smith, James; Platek, Michael; Ghonem, Hamouda; Bernier, Evan; Downey, Markus; Cumminskey, Christopher

    2010-01-01

    Recovered pipe bomb fragments, exploded under controlled conditions, have been characterized using scanning electron microscopy, optical microscopy and microhardness. Specifically, this paper examines the microstructural changes in plain carbon-steel fragments collected after the controlled explosion of galvanized, schedule 40, continuously welded, steel pipes filled with various smokeless powders. A number of microstructural changes were observed in the recovered pipe fragments: deformation of the soft alpha-ferrite grains, deformation of pearlite colonies, twin formation, bands of distorted pearlite colonies, slip bands, and cross-slip bands. These microstructural changes were correlated with the relative energy of the smokeless powder fillers. The energy of the smokeless powder was reflected in a reduction in thickness of the pipe fragments (due to plastic strain prior to fracture) and an increase in microhardness. Moreover, within fragments from a single pipe, there was a radial variation in microhardness, with the microhardness at the outer wall being greater than that at the inner wall. These findings were consistent with the premise that, with the high energy fillers, extensive plastic deformation and wall thinning occurred prior to pipe fracture. Ultimately, the information collected from this investigation will be used to develop a database, where the fragment microstructure and microhardness will be correlated with type of explosive filler and bomb design. Some analyses, specifically wall thinning and microhardness, may aid in field characterization of explosive devices.

  11. The nature of the surface film on steel treated with cerium and lanthanum cinnamate based corrosion inhibitors

    International Nuclear Information System (INIS)

    Blin, Frederic; Leary, Stuart G.; Deacon, Glen B.; Junk, Peter C.; Forsyth, Maria

    2006-01-01

    The corrosion inhibition mechanisms of new cerium and lanthanum cinnamate based compounds have been investigated through the surface characterisation of the steel exposed to NaCl solution of neutral pH. Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy was used to identify the nature of the deposits on the metal surface and demonstrated that after accelerated tests the corrosion product commonly observed on steel (i.e. lepidocrocite, γ-FeOOH) is absent. The cinnamate species were clearly present on the steel surface upon exposure to NaCl solution for short periods and appeared to coordinate through the iron. At longer times the Rare Earth Metal (REM) oxyhydroxide species are proposed to form as identified through the bands in the 1400-1500 cm -1 region. These latter bands have been previously assigned to carbonate species adsorbed onto REM oxyhydroxide surfaces. The protection mechanism appears to involve the adsorption of the REM-cinnamate complex followed by the hydrolysis of the REM to form a barrier oxide on the steel surface

  12. Corrosion and Fatigue Behavior of High-Strength Steel Treated with a Zn-Alloy Thermo-diffusion Coating

    Science.gov (United States)

    Mulligan, C. P.; Vigilante, G. N.; Cannon, J. J.

    2017-11-01

    High and low cycle fatigue tests were conducted on high-strength steel using four-point bending. The materials tested were ASTM A723 steel in the as-machined condition, grit-blasted condition, MIL-DTL-16232 heavy manganese phosphate-coated condition, and ASTM A1059 Zn-alloy thermo-diffusion coated (Zn-TDC). The ASTM A723 steel base material exhibits a yield strength of 1000 MPa. The effects of the surface treatments versus uncoated steel were examined. The fatigue life of the Zn-TDC specimens was generally reduced on as-coated specimens versus uncoated or phosphate-coated specimens. Several mechanisms are examined including the role of compressive residual stress relief with the Zn-TDC process as well as fatigue crack initiation from the hardened Zn-Fe alloy surface layer produced in the gas-metal reaction. Additionally, the effects of corrosion pitting on the fatigue life of coated specimens are explored as the Zn-TDC specimens exhibit significantly improved corrosion resistance over phosphate-coated and oiled specimens.

  13. Effect of heat treatment on the grooving corrosion resistance of ERW pipes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Kwon; Lee, Jae Young; Lim, Soo Hyun; Park, Ji Hwan; Seo, Bo Min; Kim, Seon Hwa [Soonchunhyang University, Asan (Korea, Republic of)

    2002-06-15

    The v-sharp grooving corrosion of ERW(electrical resistance welding) steel pipes limited their wide application in the industry in spite of their high productivity and efficiency. The grooving corrosion is caused mainly by the different microstructures between the matrix and weld that is formed during the rapid heating and cooling cycle in welding. By this localized corrosion reaction of pipes, it evolves economic problems such as the early damage of industrial facilities and pipe lines of apartment, and water pollution. Even though the diminishing of sulfur content is most effective to decrease the susceptibility of grooving corrosion, it requires costly process. In this study, improvement of grooving corrosion resistance was pursuited by post weld heat treatment in the temperature range between 650 .deg. C and 950 .deg. C. Also, the effect of heat input in the welding was investigated. By employing chromnoamperometry and potentiodynamic experiment, the corrosion rate and grooving corrosion index({alpha}) were obtained. It was found that heat treatment could improve the grooving corrosion resistance. Among them, the heat treated at 900 .deg. C and 950 .deg. C had excellent grooving corrosion resistance. The index of heat treated specimen at 900 .deg. C and 950 .deg. C were 1.0, 1.2, respectively, which are almost immune to the grooving corrosion. Potential difference after the heat treatment, between base and weld metal was decreased considerably. While the as-received one measured 61{approx}71 mV, that of the 900 .deg. C heat treated steel pipe measured only 10mV. The results were explained and discussed

  14. Automatic welding machine for piping

    International Nuclear Information System (INIS)

    Yoshida, Kazuhiro; Koyama, Takaichi; Iizuka, Tomio; Ito, Yoshitoshi; Takami, Katsumi.

    1978-01-01

    A remotely controlled automatic special welding machine for piping was developed. This machine is utilized for long distance pipe lines, chemical plants, thermal power generating plants and nuclear power plants effectively from the viewpoint of good quality control, reduction of labor and good controllability. The function of this welding machine is to inspect the shape and dimensions of edge preparation before welding work by the sense of touch, to detect the temperature of melt pool, inspect the bead form by the sense of touch, and check the welding state by ITV during welding work, and to grind the bead surface and inspect the weld metal by ultrasonic test automatically after welding work. The construction of this welding system, the main specification of the apparatus, the welding procedure in detail, the electrical source of this welding machine, the cooling system, the structure and handling of guide ring, the central control system and the operating characteristics are explained. The working procedure and the effect by using this welding machine, and the application to nuclear power plants and the other industrial field are outlined. The HIDIC 08 is used as the controlling computer. This welding machine is useful for welding SUS piping as well as carbon steel piping. (Nakai, Y.)

  15. Interpretation of pipe networks by magnetic sensing

    International Nuclear Information System (INIS)

    Whittaker, W.L.; Motazed, B.

    1986-01-01

    The imaging and sizing of buried pipes in soil or steel rods in concrete has wide utility. The accurate detection of embedded reinforcement is useful to enforce the correct placement of steel in new concrete, and is even more important in assessing as-built structures. Rebar mapping is essential in post-construction operations such as coring and anchor emplacement in nuclear power plants. Pipe mapping is invaluable to the excavation and repair of utility distribution systems. This paper identifies some limitations of conventional manual methods of detecting and sizing buried ferrous cylinders. The body of the paper presents an alternate, automated methodology that rationalizes and enhances the mapping process. The methodology integrates automated scanning, image processing and image understanding techniques to characterize buried steel from sensor data

  16. 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

  17. Automated Steel Cleanliness Analysis Tool (ASCAT)

    International Nuclear Information System (INIS)

    Gary Casuccio; Michael Potter; Fred Schwerer; Richard J. Fruehan; Dr. Scott Story

    2005-01-01

    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

  18. Evaluation of Corrosion Behavior of Galvanized Steel Treated with Conventional Conversion Coatings and a Chromate-Free Organic Inhibitor

    Directory of Open Access Journals (Sweden)

    Laura A. Hernandez-Alvarado

    2012-01-01

    Full Text Available Conventional weight loss tests and both DC and AC electrochemical techniques were used to study if an organic inhibitor containing an alkanolamine salt of a polycarboxylic acid can substitute toxic coatings as chromating and certain phosphating procedures in the protection of galvanized steel. The electrolyte used was a 0.5 M aerated NaCl solution. All tests gave concordant results, indicating that the chromate-free organic inhibitor does protect galvanized steel in this environment, even though the provided protection was less than that of the chromate conversion coating. It was observed that, after a moderate initial attack, the corrosion rate diminishes due to the appearance and growth of passivating corrosion products layers, mainly constituted by zinc hydroxychloride (Zn5(OH8CI2⋅H2O and two varieties of zinc hydroxide, among other crystalline compounds.

  19. Microstructure – Toughness relationships in sub-zero treated and tempered Vanadis 6 steel compared to conventional treatment

    Czech Academy of Sciences Publication Activity Database

    Ptačinová, J.; Sedlická, V.; Hudáková, M.; Dlouhý, Ivo; Jurči, P.

    2017-01-01

    Roč. 702, AUG (2017), s. 241-258 ISSN 0921-5093 R&D Projects: GA MŠk LM2015069 Institutional support: RVO:68081723 Keywords : Ledeburitic steel * Sub-zero treatment * Microstructure * Carbide particles effect * Fracture toughness * Fracture surface roughness Subject RIV: JG - Metallurgy OBOR OECD: Material s engineering Impact factor: 3.094, year: 2016 https://www. science direct.com/ science /article/pii/S0921509317308936

  20. Modelling of fiberglass pipe destruction process

    Directory of Open Access Journals (Sweden)

    А. К. Николаев

    2017-03-01

    Full Text Available The article deals with important current issue of oil and gas industry of using tubes made of high-strength composite corrosion resistant materials. In order to improve operational safety of industrial pipes it is feasible to use composite fiberglass tubes. More than half of the accidents at oil and gas sites happen at oil gathering systems due to high corrosiveness of pumped fluid. To reduce number of accidents and improve environmental protection we need to solve the issue of industrial pipes durability. This problem could be solved by using composite materials from fiberglass, which have required physical and mechanical properties for oil pipes. The durability and strength can be monitored by a fiberglass winding method, number of layers in composite material and high corrosion-resistance properties of fiberglass. Usage of high-strength composite materials in oil production is economically feasible; fiberglass pipes production is cheaper than steel pipes. Fiberglass has small volume weight, which simplifies pipe transportation and installation. In order to identify the efficiency of using high-strength composite materials at oil production sites we conducted a research of their physical-mechanical properties and modelled fiber pipe destruction process.

  1. Contribution to the study of heat pipes

    International Nuclear Information System (INIS)

    Schmidt, Eberhard

    1968-01-01

    This research thesis reports the study of heat pipes. A heat pipe is a vacuum tube closed at its both ends and containing few grams of a liquid. The evaporation of the liquid at one end and its condensation at the other end perform the heat transfer without significant drop of temperature. In this research, the author studied the thermal-hydrodynamic behaviour of heat pipes built in stainless steel and containing highly pure sodium as heat transfer metal. He more particularly studied the operation of heat pipes, including their start up, and the influence of the geometry of the capillary network on the thermal power limiting the heat pipe operation. He first proposes an analytical model to compute the threshold heat power with respect to physical properties of the heat transfer metal and to the heat pipe and capillary network geometries. He also presents an experimental device, reports experimental results and their interpretation. Analytical and experimental results are then compared, and some noticed divergences are discussed. Remaining problems for a better understanding of heat pipe operation are finally indicated [fr

  2. Shield For Flexible Pipe

    Science.gov (United States)

    Ponton, Michael K.; Williford, Clifford B.; Lagen, Nicholas T.

    1995-01-01

    Cylindrical shield designed to fit around flexible pipe to protect nearby workers from injury and equipment from damage if pipe ruptures. Designed as pressure-relief device. Absorbs impact of debris ejected radially from broken flexible pipe. Also redirects flow of pressurized fluid escaping from broken pipe onto flow path allowing for relief of pressure while minimizing potential for harm.

  3. A RSM-based predictive model to characterize heat treating parameters of D2 steel using combined Barkhausen noise and hysteresis loop methods

    Science.gov (United States)

    Kahrobaee, Saeed; Hejazi, Taha-Hossein

    2017-07-01

    Austenitizing and tempering temperatures are the effective characteristics in heat treating process of AISI D2 tool steel. Therefore, controlling them enables the heat treatment process to be designed more accurately which results in more balanced mechanical properties. The aim of this work is to develop a multiresponse predictive model that enables finding these characteristics based on nondestructive tests by a set of parameters of the magnetic Barkhausen noise technique and hysteresis loop method. To produce various microstructural changes, identical specimens from the AISI D2 steel sheet were austenitized in the range 1025-1130 °C, for 30 min, oil-quenched and finally tempered at various temperatures between 200 °C and 650 °C. A set of nondestructive data have been gathered based on general factorial design of experiments and used for training and testing the multiple response surface model. Finally, an optimization model has been proposed to achieve minimal error prediction. Results revealed that applying Barkhausen and hysteresis loop methods, simultaneously, coupling to the multiresponse model, has a potential to be used as a reliable and accurate nondestructive tool for predicting austenitizing and tempering temperatures (which, in turn, led to characterizing the microstructural changes) of the parts with unknown heat treating conditions.

  4. The preparation of polytrifluorochloroethylene (PCTFE) micro-particles and application on treating bearing steel surfaces to improve the lubrication effect for copper-graphite (Cu/C)

    Science.gov (United States)

    Lu, Hailin; Zhang, Pengpeng; Ren, Shanshan; Guo, Junde; Li, Xing; Dong, Guangneng

    2018-01-01

    Contact mechanical seal is a normal technology applied on middle axis of liquid rocket turbo pump, and the kinetic and static seal rings contact low temperature rocket propellant. Copper-graphite (Cu/C) composite as an excellent self-lubrication material was widely used in aerospace industry, this study took Cu/C as ball and bearing steel as disk to investigate the tribology properties, and distilled water were used to simulate the lox tribology performances. This study prepared polytrifluorochloroethylene (PCTFE) micro-particles which were coated on the oxide surfaces of bearing steel disk at temperature of 150 °C. The tribology results showed that the oxide surfaces treated with micro PCTFE particles have lower fiction coefficient and lower wear rate than original disk in water, and the wear morphology revealed that the treated surfaces obviously had less Cu/C composite transfer film than original disk. Meanwhile SEM, EDS, XRD, XPS and light microscope etc revealed that PCTFE micro-particles could associate with the oxide surfaces and caused higher water contact angle, due to the properties of the fluorine-containing composite may cause the good lubrication effect in water. Thus this technology shows great potential to enhance tribological performances for aerospace industry on a large scale.

  5. Fundamentals of piping design

    CERN Document Server

    Smith, Peter

    2013-01-01

    Written for the piping engineer and designer in the field, this two-part series helps to fill a void in piping literature,since the Rip Weaver books of the '90s were taken out of print at the advent of the Computer Aid Design(CAD) era. Technology may have changed, however the fundamentals of piping rules still apply in the digitalrepresentation of process piping systems. The Fundamentals of Piping Design is an introduction to the designof piping systems, various processes and the layout of pipe work connecting the major items of equipment forthe new hire, the engineering student and the vetera

  6. A RSM-based predictive model to characterize heat treating parameters of D2 steel using combined Barkhausen noise and hysteresis loop methods

    Energy Technology Data Exchange (ETDEWEB)

    Kahrobaee, Saeed, E-mail: kahrobaee@sadjad.ac.ir [Department of Mechanical and Materials Engineering, Sadjad University of Technology, P.O. Box 91881-48848, Mashhad (Iran, Islamic Republic of); Hejazi, Taha-Hossein [Department of Industrial Engineering and Management, Sadjad University of Technology, P.O. Box 91881-48848, Mashhad (Iran, Islamic Republic of)

    2017-07-01

    Highlights: • A statistical relationship between NDE inputs and heat treating outputs was provided. • Predicting austenitizing/tempering temperatures at unknown heat treating conditions. • An optimization model that achieves minimum error in prediction was developed. • Applying two simultaneous magnetic NDE methods led to better measuring reliability. - Abstract: Austenitizing and tempering temperatures are the effective characteristics in heat treating process of AISI D2 tool steel. Therefore, controlling them enables the heat treatment process to be designed more accurately which results in more balanced mechanical properties. The aim of this work is to develop a multiresponse predictive model that enables finding these characteristics based on nondestructive tests by a set of parameters of the magnetic Barkhausen noise technique and hysteresis loop method. To produce various microstructural changes, identical specimens from the AISI D2 steel sheet were austenitized in the range 1025–1130 °C, for 30 min, oil-quenched and finally tempered at various temperatures between 200 °C and 650 °C. A set of nondestructive data have been gathered based on general factorial design of experiments and used for training and testing the multiple response surface model. Finally, an optimization model has been proposed to achieve minimal error prediction. Results revealed that applying Barkhausen and hysteresis loop methods, simultaneously, coupling to the multiresponse model, has a potential to be used as a reliable and accurate nondestructive tool for predicting austenitizing and tempering temperatures (which, in turn, led to characterizing the microstructural changes) of the parts with unknown heat treating conditions.

  7. Insulated pipe clamp design

    International Nuclear Information System (INIS)

    Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

    1980-01-01

    Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. 5 refs

  8. Effect of temperature and pipe material on biofilm formation and survival of Escherichia coli in used drinking water pipes

    DEFF Research Database (Denmark)

    Silhan, J.; Corfitzen, Charlotte B.; Albrechtsen, Hans-Jørgen

    2006-01-01

    Segments of used drinking water pipes of galvanised steel (GS), cross-linked polyethylene (PEX), copper pipes (Cu) or new medium-density polyethylene (PE) were investigated for the formation of biofilm and survival of E coli in biofilm and in the water phase. Pipes were filled with water and incu......Segments of used drinking water pipes of galvanised steel (GS), cross-linked polyethylene (PEX), copper pipes (Cu) or new medium-density polyethylene (PE) were investigated for the formation of biofilm and survival of E coli in biofilm and in the water phase. Pipes were filled with water...... and incubated at 15 degrees C or 35 degrees C under static conditions. Biofilm formation was followed during 32, 40 and 56 (58) d. The most dense biofilm was formed on GS, reaching approximately 4.7 x 10(5) CFU/cm(2) measured as heterotrophic plate count (HPC), and at the other materials the density reached 3 x...... confirmed the general trends observed by HPC. Higher temperature was seen to be an important factor reducing E coli survival in the water phase in drinking water pipes. At 1 VC E coli survived more than 4 d in GS and Cu pipes and 8 d in PE-pipes, but was not detected after 48 h at 35 degrees C. The E coli...

  9. Characterizing the Performance of Pipe Bombs.

    Science.gov (United States)

    Oxley, Jimmie C; Smith, James L; Bernier, Evan T; Sandstrom, Fredrick; Weiss, Gregory G; Recht, Gunther W; Schatzer, David

    2018-01-01

    Pipe bombs of steel or PVC fragment in reproducible patterns when similarly configured. The power of the explosion correlates with number, mass, and size of the fragments recovered, where a large number of small, low-mass fragments indicate a high-power event and vice versa. In discussing performance, describing pipe fragmentation pattern by fragment weight distribution mapping (FWDM) or fragment surface area distribution mapping (FSADM) was useful. When fillers detonated, detonation velocities of ~4.4 mm/μs were measured. In such cases, side walls of the pipe were thrown first; the average fragment velocity was ~1000 km/s. In deflagrations, the end cap was first thrown; fragment velocities were only ~240 km/s. Blast overpressures varied; at 10 feet, 2 × 12 inch steel pipes containing ~550 g of detonable mixture produced overpressures of 5-6 psi; similar nondetonating pipes produced less than 2 psi. Maximum fragment throw distances were 250-300 m, with an average of ~100 m. © 2017 American Academy of Forensic Sciences.

  10. Electrical design of a 110-ft long muon pipe with automatic degaussing

    International Nuclear Information System (INIS)

    Visser, A.T.

    1985-11-01

    This memo describes a magnetized cylindrical pipe made from tape wound grain oriented low carbon steel rolls. Grain oriented steel yields much higher magnetic fields at low ampereturns than cast iron or other steel pipes. This is especially important when only a few windings are allowed in the inner bore. The power supply and operating cost are also much lower. The pipe has a high (approx.9 kG) remnant field, but is automatically degaussed upon shutdown of the DC excitation power supply. A remnant field detector senses whether degaussing was successful. The pipe is used in the muon beam line. Its magnetic field deflects unwanted halo muons. Tests need to be conducted with and without pipe field. It is therefore desirable that the pipe field automatically returns to zero when the DC excitation is shut off. This can be rather easily accomplished

  11. Casing free district heating pipes; Mantelfria fjaerrvaermeroer

    Energy Technology Data Exchange (ETDEWEB)

    Saellberg, Sven-Erik; Nilsson, Stefan [Swedish National Testing and Research Inst., Goeteborg (Sweden)

    2005-07-01

    Previous studies have shown that polyurethane insulation (PUR foam) on district heating pipes acts as protection against water if it is of good quality, i.e. free from cracks, cavities and other defects. On the other hand water vapour easily diffuses through PUR foam. However this is not a problem as long as the steel pipe is warmer than the surface layer, since the high temperature will prevent the vapour from condensating. What will happen with the insulation of a casing free district heating pipe where the ground water level occasionally reaches above the pipe has not been studied in detail. The current project has studied to what extent moisture enters the PUR foam insulation of two approximately one meter long district heating pipes without casing which have been in the ground for four years. Occasionally, the ground-water has entirely covered the pipes. In addition, the foam has been studied with respect to damage from the surrounding backfill material. Test specimens were taken out of the casing free pipes and were analysed with respect to moisture content. Additional measurements were done with a moisture indicator, and the electric resistance between the steel pipes and the four surveillance wires in each pipe was measured. The results from the various measurement techniques were the compared. The results show that the PUR foam remains dry as long as the service pipe is hot if no defects, such as crack and cavities, are present. Close to the service pipe, the foam actually dries out over time. The moisture content of the middle layer remains more or less constant. Only the colder parts on the outside exhibit an increase in moisture content. It was also seen that defects may lead to water ingress with subsequent humidification of the foam. However, the damaged foam area is limited. This is not the case for a regular pipe with a vapour tight casing, where experience show that moisture tend to spread along the pipe. The pipes were buried in sand and no

  12. Rupture hardware minimization in pressurized water reactor piping

    International Nuclear Information System (INIS)

    Mukherjee, S.K.; Ski, J.J.; Chexal, V.; Norris, D.M.; Goldstein, N.A.; Beaudoin, B.F.; Quinones, D.F.; Server, W.L.

    1989-01-01

    For much of the high-energy piping in light reactor systems, fracture mechanics calculations can be used to assure pipe failure resistance, thus allowing the elimination of excessive rupture restraint hardware both inside and outside containment. These calculations use the concept of leak-before-break (LBB) and include part-through-wall flaw fatigue crack propagation, through-wall flaw detectable leakage, and through-wall flaw stability analyses. Performing these analyses not only reduces initial construction, future maintenance, and radiation exposure costs, but also improves the overall safety and integrity of the plant since much more is known about the piping and its capabilities than would be the case had the analyses not been performed. This paper presents the LBB methodology applied a Beaver Valley Power Station- Unit 2 (BVPS-2); the application for two specific lines, one inside containment (stainless steel) and the other outside containment (ferrutic steel), is shown in a generic sense using a simple parametric matrix. The overall results for BVPS-2 indicate that pipe rupture hardware is not necessary for stainless steel lines inside containment greater than or equal to 6-in. (152-mm) nominal pipe size that have passed a screening criteria designed to eliminate potential problem systems (such as the feedwater system). Similarly, some ferritic steel line as small as 3-in. (76-mm) diameter (outside containment) can qualify for pipe rupture hardware elemination

  13. Pipe rupture hardware minimization in pressurized water reactor system

    International Nuclear Information System (INIS)

    Mukherjee, S.K.; Szyslowski, J.J.; Chexal, V.; Norris, D.M.; Goldstein, N.A.; Beaudoin, B.; Quinones, D.; Server, W.

    1987-01-01

    For much of the high energy piping in light water reactor systems, fracture mechanics calculations can be used to assure pipe failure resistance, thus allowing the elimination of excessive rupture restraint hardware both inside and outside containment. These calculations use the concept of leak-before-break (LBB) and include part-through-wall flaw fatigue crack propagation, through-wall flaw detectable leakage, and through-wall flaw stability analyses. Performing these analyses not only reduces initial construction, future maintenance, and radiation exposure costs, but the overall safety and integrity of the plant are improved since much more is known about the piping and its capabilities than would be the case had the analyses not been performed. This paper presents the LBB methodology applied at Beaver Valley Power Station - Unit 2 (BVPS-2); the application for two specific lines, one inside containment (stainless steel) and the other outside containment (ferritic steel), is shown in a generic sense using a simple parametric matrix. The overall results for BVPS-2 indicate that pipe rupture hardware is not necessary for stainless steel lines inside containment greater than or equal to 6-in (152 mm) nominal pipe size that have passed a screening criteria designed to eliminate potential problem systems (such as the feedwater system). Similarly, some ferritic steel lines as small as 3-in (76 mm) diameter (outside containment) can qualify for pipe rupture hardware elimination

  14. Flow behaviour and local concentration of coarse particles-water mixture in inclined pipes

    Directory of Open Access Journals (Sweden)

    Vlasak Pavel

    2017-06-01

    Full Text Available Narrow particle size distribution basalt pebbles of mean particle size 11.5 mm conveyed by water in the pipe sections of different inclination were investigated on an experimental pipe loop, consisting of smooth stainless steel pipes of inner diameter D = 100 mm. Mixture flow-behaviour and particles motion along the pipe invert were studied in a pipe viewing section, the concentration distribution in pipe cross-section was studied with the application of a gamma-ray densitometer. The study refers to the effect of mixture velocity, overall concentration, and angle of pipe inclination on chord-averaged concentration profiles and local concentration maps, and flow behaviour of the coarse particle-water mixtures. The study revealed that the coarse particle-water mixtures in the inclined pipe sections were significantly stratified, the solid particles moved principally close to the pipe invert, and for higher and moderate flow velocities particle saltation becomes the dominant mode of particle conveying.

  15. Field investigation on structural performance of the buried UPVC pipes with and without geogrid reinforcement

    Science.gov (United States)

    Teja, Akkineni Surya; Rajkumar, R.; Gokula Krishnan, B.; Aravindh, R.

    2018-02-01

    Buried pipes are used mainly for water supply and drainage besides many other applications such as oil, liquefied natural gas, coal slurries and mine tailings. The pipes used may be rigid (reinforced concrete, vitrified clay and ductile iron) or flexible (Steel, UPVC, aluminium, Fiber glass and High-density polyethylene) although the distinction between them is blurring. Flexible pipe design is governed by deflection or buckling. UPVC pipes are preferred due to light weight, long term chemical stability and cost efficiency. This project aims to study the load deformation behaviour of the buried pipe and stress variation across the cross section of the pipe under static loading along with the influence of depth of embedment, density of backfill on the deformation and stresses in pipe and the deformation behaviour of buried pipe when soil is reinforced with geogrid reinforcement and evaluate the structural performance of the pipe.

  16. [Study on pipe material's influence on chlorine dioxide drinking water disinfection].

    Science.gov (United States)

    He, Tao; Yue, Yinling; Ling, Bo; Zhang, Lan

    2010-09-01

    To study the pipe material's influence on chlorine dioxide drinking water disinfection. 0.8 mg/L chlorine dioxide solution was injected into 5 kinds of pipes respectively, PPR, PVC-U, Steel with Zinc coating, copper and PE pipes. Dipped free from light for 48 hours and the concentrations of chlorine dioxide, chlorite and chlorate were tested from samples taken from each kind of pipe at 1, 2, 3, 4, 5, 6, 12, 24 and 48 hours respectively. Chlorine dioxides decay rates in the water dipping the pipes increase as the dipping time increases and the decay of chlorine dioxide mainly occurs within 6 hours after the dipping. But for different pipe, the influence of decay differs. The consumption of chlorine dioxide of the metal pipes is more than that of the plastic pipes. And with 2 hours after the dipping experiment begins, the concentrations of the chlorite of the copper pipe and of the steel with zinc coating pipe increase quickly and reach the maximum concentration. But then the chlorite concentration decreases greatly. After dipped 24 hours, the chlorite in the water in the pipe can not be detected. For other plastic piples, all the chlorite concentrations in the dipping water increase as the dipping time increase. Compared with the start of the dipping experiment, the chlorate concentration in the dipping water of each pipe has no obvious change. The material of the water transportation pipe does have influence on chlorine dioxide drinking water disinfection.

  17. Insulated pipe clamp design

    International Nuclear Information System (INIS)

    Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

    1980-01-01

    Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. The design considerations and methods along with the development tests are presented. Special considerations to guard against adverse cracking of the insulation material, to maintain the clamp-pipe stiffness desired during a seismic event, to minimize clamp restraint on the pipe during normal pipe heatup, and to resist clamp rotation or spinning on the pipe are emphasized

  18. Piping Stress Analysis

    International Nuclear Information System (INIS)

    Setjo, Renaningsih

    2000-01-01

    Piping stress analysis on Primary Sampling System, Reactor Cooling System, and Feedwater System for AP600 have been performed. Piping stress analysis is one of the requirements in the design of piping system. Piping stress is occurred due to static and dynamic loads during service. Analysis was carried out. Using PS+CAEPIPE software based on the individual and combination loads with assumption that failure could be happened during normal, upset, emergency and faulted condition as describe in ASME III/ANSI B31.1. With performing the piping stress analysis, the layout (proper pipe routing) of the piping system can be design with the requirements of piping stress and pipe supports in mind I.e sufficient flexibility for thermal expansion, etc to commensurate with the i tended service such as temperatures, pressure, seismic and anticipated loading

  19. Pipe drafting and design

    CERN Document Server

    Parisher, Roy A; Parisher

    2000-01-01

    Pipe designers and drafters provide thousands of piping drawings used in the layout of industrial and other facilities. The layouts must comply with safety codes, government standards, client specifications, budget, and start-up date. Pipe Drafting and Design, Second Edition provides step-by-step instructions to walk pipe designers and drafters and students in Engineering Design Graphics and Engineering Technology through the creation of piping arrangement and isometric drawings using symbols for fittings, flanges, valves, and mechanical equipment. The book is appropriate primarily for pipe

  20. Coarse particles-water mixtures flow in pipes

    Directory of Open Access Journals (Sweden)

    П. Власак

    2017-06-01

    Full Text Available The present paper is focused on evaluation of the effect of average mixture velocity and overall concentration on the pressure drop versus the slurry average velocity relationship, on slurry flow behaviour and local concentration distribution. The experimental investigation was carried out on the pipe loop of inner diameter D =100 mm, which consists of smooth stainless steel pipes and horizontal, inclinable and vertical pipe sections. The frictional pressure drop in the horizontal pipe section were significantly higher than that in the vertical pipe due to the fact, that for stratified flow the contact load produced significant energy losses. The frictional pressure drop of coarse particles mixtures in vertical pipe increased with the increasing mixture concentration and velocity, what confirmed effect of inner friction, inter-particles collision, and the drag due to particle-liquid slip. It was found that for stratified coarse particles-water mixture the frictional pressure drop was not significantly influenced by the pipe inclination, especially for low concentration values. The effect of pipe inclination decreased with increasing mixture velocity in ascending pipe section; the maximum value was reached for inclination between 20 and 40 degrees. Inclination of pressure drop maximum increased with decreasing mixture velocity. In descending pipe section the frictional pressure drop gradually decreased with increasing pipe inclination. The effect of inclination on frictional pressure drops could be practically neglected, especially for low mixture concentration and higher flow velocities. The study revealed that the coarse particle-water mixtures in the horizontal and inclined pipe sections were significantly stratified. The particles moved principally in a layer close to the pipe invert. However, for higher and moderate flow velocities the particles moved also in the central part of the pipe cross-section, and particle saltation [1] was found to

  1. Residual stress improvement for pipe weld by means of induction heating pre-flawed pipe

    International Nuclear Information System (INIS)

    Umemoto, T.; Yoshida, K.; Okamoto, A.

    1980-01-01

    The intergranular stress corrosion cracking (IGSCC) has been found in type 304 stainless steel piping of several BWR plants. It is already well known that IGSCC is most likely to occur when three essential factors, material sensitization, high tensile stress and corrosive environment, are present. If the welding residual stress is sufficiently high (200 to approximately 400 MPa) in the inside piping surface near the welded joint, then it may be one of the biggest contributors to IGSCC. If the residual stress is reduced or reversed by some way, the IGSCC will be effectively mitigated. In this paper a method to improve the residual stress named IHSI (Induction Heating Stress Improvement) is explained. IHSI aims to improve the condition of residual stress in the inside pipe surface using the thermal stress induced by the temperature difference in pipe wall, that is produced when the pipe is heated from the outside surface by an induction heating coil and cooled on the inside surface by water simultaneously. This method becomes more attractive when it can be successfully applied to in-service piping which might have some pre-flaw. In order to verify the validity of IHSI for such piping, some experiments and calculations using finite element method were conducted. These results are mainly discussed in this paper from the view-points of residual stress, flaw behaviour during IHSI and material deterioration. (author)

  2. Fracture mechanics evaluation for at typical PWR primary coolant pipe

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T. [Kansai Electric Power Company, Osaka (Japan); Shimizu, S.; Ogata, Y. [Mitsubishi Heavy Industries, Ltd., Kobe (Japan)

    1997-04-01

    For the primary coolant piping of PWRs in Japan, cast duplex stainless steel which is excellent in terms of strength, corrosion resistance, and weldability has conventionally been used. The cast duplex stainless steel contains the ferrite phase in the austenite matrix and thermal aging after long term service is known to change its material characteristics. It is considered appropriate to apply the methodology of elastic plastic fracture mechanics for an evaluation of the integrity of the primary coolant piping after thermal aging. Therefore we evaluated the integrity of the primary coolant piping for an initial PWR plant in Japan by means of elastic plastic fracture mechanics. The evaluation results show that the crack will not grow into an unstable fracture and the integrity of the piping will be secured, even when such through wall crack length is assumed to equal the fatigue crack growth length for a service period of up to 60 years.

  3. A numerical study on the conjugate natural convection in a circular pipe containing water

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Myoung-Young; Choi, Hyoung-Gwon [Seoul National University of Science & Technology, Seoul (Korea, Republic of)

    2017-07-15

    In this paper, the effect of material property of pipe on the conjugate natural convection in a circular pipe containing water was investigated by solving the unsteady incompressible Navier-Stokes equations coupled with energy equations of the water and pipe. Natural convection and conduction of water inside the pipe was coupled with the conduction of the pipe whose bottom was subject to uniform heat source. From the present grid resolution and time-step independent solutions, it has been confirmed that the water temperature inside a PVC pipe was higher than that inside a steel pipe due to the smaller heat capacity of PVC and that the streamline patterns of the two cases were found to be opposite because the thermal diffusivity of steel (PVC) is larger (smaller) than that of water such that steel (PVC) pipe is heated faster (slower) than water. Furthermore, a quantitative comparison of heat flux to water was performed by examining the distributions of the heat flux along the inside walls of steel/PVC. The average temperature of water inside steel was found to be higher than that inside PVC at the initial stage of heating. On the other hand, PVC provided a larger heat flux to water when it reached a steady value.

  4. Nonlinear piping damping and response predictions

    International Nuclear Information System (INIS)

    Severud, L.K.; Weiner, E.O.; Lindquist, M.R.; Anderson, M.J.; Wagner, S.E.

    1986-10-01

    The high level dynamic testing of four prototypic piping systems, used to provide benchmarks for analytical prediction comparisons, is overviewed. The size of pipe tested ranged from one-inch to six-inches in diameter and consisted of carbon steel or stainless steel material. Failure of the tested systems included progressive gross deformation or some combination of ratchetting-fatigue. Pretest failure predictions and post test comparisons using simplified elastic and elasto-plastic methods are presented. Detailed non-linear inelastic analyses are also shown, along with a typical ratchet-fatigue failure calculation. A simplified method for calculating modal equivalent viscous damping for snubbers and plastic hinges is also described. Conclusions are made regarding the applicability of the various analytical failure predictive methods and recommendations are made for future analytic and test efforts

  5. Pipe-to-pipe impact program

    International Nuclear Information System (INIS)

    Alzheimer, J.M.; Bampton, M.C.C.; Friley, J.R.; Simonen, F.A.

    1984-06-01

    This report documents the tests and analyses performed as part of the Pipe-to-Pipe Impact (PTPI) Program at the Pacific Northwest Laboratory. This work was performed to assist the NRC in making licensing decisions regarding pipe-to-pipe impact events following postulated breaks in high energy fluid system piping. The report scope encompasses work conducted from the program's start through the completion of the initial hot oil tests. The test equipment, procedures, and results are described, as are analytic studies of failure potential and data correlation. Because the PTPI Program is only partially completed, the total significance of the current test results cannot yet be accurately assessed. Therefore, although trends in the data are discussed, final conclusions and recommendations will be possible only after the completion of the program, which is scheduled to end in FY 1984

  6. Design and fabrication of polymer-concrete-lined pipe for testing in geothermal-energy processes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kaeding, A.O.

    1981-12-01

    A specific polymer-concrete formulation was applied as a steel pipe liner in response to a need for durable, economical materials for use in contact with high temperature geothermal brine. Processes are described for centrifugally applying the liner to straight pipe, for casting the liner in pipe fittings, and for closure of field joints. Physical properties of the liner materials were measured. Compressive strengths of up to 165.8 MPa (24,045 psi) and splitting tensile strengths of 23.5 MPa (3408 psi) were measured at ambient temperature. Compressive strengths of 24 MPa (3490 psi) and splitting tensile strengths of 2.5 MPa (366 psi) were measured at about 150/sup 0/C (302/sup 0/F). A full-scale production plant is described which would be capable of producing about 950 m (3120 ft) of lined 305-mm-diam (12 in.) pipe per day. Capital cost of the plant is estimated to be about $8.6 million with a calculated return on investment of 15.4%. Cost of piping a geothermal plant with PC and PC-lined steel pipe is calculated to be $1.21 million, which compares favorably with a similar plant piped with alloy steel piping at a cost of $1.33 million. Life-cycle cost analysis indicates that the cost of PC-lined steel pipe would be 82% of that of carbon steel pipe over a 20-year plant operating life.

  7. Speed of Sound in Metal Pipes: An Inexpensive Lab

    Science.gov (United States)

    Huggins, Elisha

    2008-01-01

    Our favorite demonstration for sound waves is to set up a compressional pulse on a horizontally stretched Slinky[TM]. One can easily watch the pulse move back and forth at a speed of the order of one meter per second. Watching this demonstration, it occurred to us that the same thing might happen in a steel pipe if you hit the end of the pipe with…

  8. Corrosion of CANDU outlet feeder pipes

    Energy Technology Data Exchange (ETDEWEB)

    Burrill, K.A.; Cheluget, E.L

    1999-02-01

    Recent inspections have indicated that carbon steel outlet feeder pipes in some CANDU reactors are experiencing wall loss near the exit from the reactor core. This phenomenon is not observed in inlet feeder pipes. Examination of a sample of pipe removed from a CANDU 6 reactor has indicated that the mechanism causing the wall loss is flow-accelerated corrosion (FAC), at rates higher than expected, but two orders of magnitude lower than those typically observed in secondary circuits of nuclear and conventional power plants. Although the CANDU reactor outlet feeder operating temperatures and the use of LiOH at a high pH should have ensured low corrosion rates, use of SA 106 Grade B carbon steel with a low chromium content resulted in some susceptibility to FAC. The main parameter influencing the rate of wall loss is the coolant velocity, with the bend angle playing a secondary role. A solubility-based mathematical model describing the effects of water chemistry and coolant hydrodynamics on the rate of FAC has been developed and has been recently improved by the empirical incorporation of the effect of electrochemical potential on the solubility of magnetite. Experiment and theory have indicated that the corrosion rates are lower at lower pH values within the permissible operating range. Experiments are being conducted to obtain more information on the effects of water chemistry and material composition on FAC. Current results support the predicted effects of pH and carbon steel chromium content on the FAC rate. Remedial measures implemented include operation of existing reactors at the lower end of the specified pH range and the specification of a minimum of 0.20 wt% Cr in the carbon steel of feeder pipes of future CANDU reactors. (author)

  9. Three-dimensional atom probe microscopy study of interphase precipitation and nanoclusters in thermomechanically treated titanium–molybdenum steels

    International Nuclear Information System (INIS)

    Mukherjee, S.; Timokhina, I.B.; Zhu, C.; Ringer, S.P.; Hodgson, P.D.

    2013-01-01

    Atom probe microscopy was used to generate tomographic analyses of solute clustering and precipitation reactions in a Ti–Mo added microalloyed steel under simulated strip-rolling conditions. It was observed that the interphase row spacing of precipitates was reduced with the application of a pre-strain. The atom probe data also revealed the coexistence of nanoclusters and precipitate particles, even after isothermal holding for 3600 s. These microstructural features occurred both within 3-D interphase precipitate sheets, and in randomly selected fields of view. A bimodal distribution of larger (∼8–10 nm) precipitates coexisted with smaller nanoclusters (∼3 nm) within the interphase sheets/rows. Both the nanoclusters and the precipitates possessed a disc morphology, although nanoclusters with less than ∼30 atoms were more irregular in shape. The size of the nanoclusters and the precipitates was expressed as a Guinier radius, and this varied between 0.5 and 8 nm for both strain conditions, with the average size ∼1.8 nm. The composition of the nanoclusters varied over a wide range, yet was mostly rich in C. All of the nanoclusters and precipitates consisted of a mixture of Ti, Mo and C and the average precipitate composition was close to that of MC carbide stoichiometry, where M represents a mixture of Ti and Mo. In the majority of cases, the Ti/Mo ratio in the MC carbides was > 1. As the Guinier radius increased above 2.5 nm, the composition range became narrower, towards the MC carbide stoichiometry, with a small amount of Fe (∼3–12 at.%)

  10. EXPERIMENTAL AND NUMERICAL INVESTIGATION OF FLEXIBLE BURIED PIPE DEFORMATION BEHAVIOR UNDER VARIOUS BACKFILL CONDITIONS

    Directory of Open Access Journals (Sweden)

    Niyazi Uğur TERZİ

    2009-01-01

    Full Text Available Deformation characteristics of polyethylene based flexible pipes are different than rigid pipes such as concrete and iron pipes. Deflection patterns and stress-strain behaviors of flexible pipes have strict relation between the engineering properties of backfill and its settlement method. In this study, deformation behavior of a 100 mm HDPE flexible pipe under vertical loads is investigated in laboratory conditions. Steel test box, pressurized membrane, raining system, linear position transducers and strain gauge rosettes are used in the laboratory tests. In order to analyze the buried pipe performance; Masada Derivation Formula which is mostly used by designers is employed. According to the test and mathematical studies, it is understood that relative density of backfill and its settlement method is a considerable effect on buried pipe performance and Masada Derivation method is very efficient for predicting the pipe performance.

  11. 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.

  12. Laser-treated stainless steel mini-screw implants: 3D surface roughness, bone-implant contact, and fracture resistance analysis.

    Science.gov (United States)

    Kang, He-Kyong; Chu, Tien-Min; Dechow, Paul; Stewart, Kelton; Kyung, Hee-Moon; Liu, Sean Shih-Yao

    2016-04-01

    This study investigated the biomechanical properties and bone-implant intersurface response of machined and laser surface-treated stainless steel (SS) mini-screw implants (MSIs). Forty-eight 1.3mm in diameter and 6mm long SS MSIs were divided into two groups. The control (machined surface) group received no surface treatment; the laser-treated group received Nd-YAG laser surface treatment. Half in each group was used for examining surface roughness (Sa and Sq), surface texture, and facture resistance. The remaining MSIs were placed in the maxilla of six skeletally mature male beagle dogs in a randomized split-mouth design. A pair with the same surface treatment was placed on the same side and immediately loaded with 200 g nickel-titanium coil springs for 8 weeks. After killing, the bone-implant contact (BIC) for each MSI was calculated using micro computed tomography. Analysis of variance model and two-sample t test were used for statistical analysis with a significance level of P titanium alloy MSIs. © The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  13. Effect of torsion moment on failure bending moment for circumferentially cracked pipe

    International Nuclear Information System (INIS)

    Li, Yinsheng; Hasegawa, Kunio; Ida, Wataru; Hoang, Phuong H.; Bezensek, Bostjan

    2010-01-01

    When a crack is detected in a stainless steel pipe during in-service inspection, the limit load criterion given in the codes such as JSME Rules on Fitness-for-Service for Nuclear Power Plants or ASME Boiler and Pressure Vessel Code Section XI can be applied to evaluate the integrity of the pipe. However, in the current codes, the limit load criterion is only provided considering pressure and bending moment. The torsion moment is not considered, although torsion moment does exist in the nuclear power piping system. In this paper, finite element analyses are carried out for stainless steel pipe containing a circumferential surface crack under the combination of bending moment and torsion moment, considering different pipe dimensions and flaw sizes. Based upon the analysis results, a plastic collapse estimation method is proposed considering the existence of the torsion moment and its magnitude, and this method make it possible to evaluate the integrity of the pipe for general loading conditions. (author)

  14. Identification and reduction of piping-vibrations in plants

    International Nuclear Information System (INIS)

    Kerkhof, K.

    2012-01-01

    Safe operation, availability and lifetime assessment of piping systems are of utmost concern for plant operators. The use of tuned mass dampers is a rather new approach for reducing vibrations to avoid high cycle fatigue in a large chemical piping system. The investigated piping system is supported by a tall structure fixed at the base. As a result, the steel building stiffness decreases with height. Furthermore large piping-elbow forces act at the top of the building, which lead to large vibration amplitudes. Since both piping system and supporting structure exhibited these large vibration amplitudes, dampers or shock absorbers placed between them would prove ineffective. Therefore, special vibration absorbers were developed for such piping systems. The paper presents the design process, starting with an extensive system investigation up to the passive multi-axial vibration absorber design parameters. This includes: Laboratory tests with a mock-up pipe system, where the first design ideas for new passive vibration absorbers were investigated. Vibration measurements were carried out to investigate the current state of the vibration behaviour. The piping system was inspected; strain gauges were used to identify stress concentrations at welds and other notches due to ovalization. Finite element calculations were performed, first as a combined beam and shell model for the pipe without the support structure. A detailed model for the combined steel construction and pipe system was created. Model-updating was done to fit the calculated model to the experimental modal analysis data. Loading assumptions describing excitation forces from the mass flow were checked. Harmonic frequency analysis was performed. On the basis of these calculations design parameters for the passive vibration absorber were determined. Finally, a solution for the design of two passive vibration absorbers will be presented.

  15. Application of Leak Before Break concept in 316LN austenitic steel pipes welded using 316L; Aplicação do conceito 1vazamento antes da falha' (Leak Before Break) em tubulações de aço 316LN soldado com metal de adição 316L

    Energy Technology Data Exchange (ETDEWEB)

    Cunto, Gabriel Giannini de

    2017-07-01

    This work presents a study of application of the Leak Before Break (LBB) concept, usually applied in nuclear power plants, in a pipe made from steel AISI type 316LN welded a coated electrode AISI type 316L. LBB concept is a criterion based on fracture mechanics analysis to show that a crack leak, present in a pipe, can be detected by leak detection systems, before this crack reaches a critical size that results in pipe fail. In the studied pipe, tensile tests and Ramberg-Osgood analyses were performed, as well as fracture toughness tests for obtaining the material resistance curve J-R. The tests were performed considering the base metal, weld and heat affected zone (HAZ), at the same operating temperatures of a nuclear power plant. For the mechanical properties found in these tests, load limit analyses were performed in order to determine the size of a crack which could cause a detectable leakage and the critical crack size, considering failure by plastic collapse. For the critical crack size found in the weld, which is the region that presented the lowest toughness, Integral J and tearing modulus T analyses were performed, considering failure by tearing instability. Results show a well-defined behavior between the base metal, HAZ and weld zones, where the base metal has a high toughness behavior, the weld has a low toughness behavior and the HAZ showed intermediate mechanical properties between the base metal and the weld. Using the PICEP software, the leak rate curves versus crack size and also the critical crack size were determined by considering load limit analysis. It was observed that after a certain crack size, the leak rate in base metal is much higher than for the HAZ and the weld, considering the same crack length. This occurs because in the base metal crack, it is expected that the crack grows in a more rounded form due to its higher toughness. The lowest critical crack size was found for the base metal presenting circumferential cracks. For the

  16. Ductile fracture behaviour of primary heat transport piping material ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Heat transport piping material of nuclear reactors. 169. Table 1. Chemical composition of. SA333, Grade 6 steel in wt%. C. Mn. Si. S. P. 0·18 0·90 0·25 0·02 0·02 room temperature. The tensile flow curve of the steel exhibited prominent yield-point effect accompanied by non-hardening strain propagation (Lüders strain) of ...

  17. Formation of structure and properties in welded joints of oil line pipes

    Science.gov (United States)

    Vyboishchik, L. M.; Ioffe, A. V.

    2013-01-01

    The effect of welding and heat treatment modes on mechanical properties and corrosion resistance of welded joints of oil line pipes is studied. It is shown that high-frequency welding followed by high-temperature annealing provides strength and corrosion properties in welds of pipes from low-carbon low-alloy steels at the level of the welded metal.

  18. Spinning pipe gas lens aberrations along the axis and in the boundary layer

    CSIR Research Space (South Africa)

    Mafusire, C

    2013-11-01

    Full Text Available When the walls of an open-ended horizontal steel pipe are heated before the pipe is rotated along its axis, the exchange of the expelled heated air with the incoming cooler air, sucked in along the axis, results in a medium capable of focusing a...

  19. Arc Welding-Pipe, 3-25. Military Curriculum Materials for Vocational and Technical Education.

    Science.gov (United States)

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This instructor guide and text for a secondary-postsecondary level course in arc welding-pipe comprise one of a number of military-developed curriculum packages selected for adaptation to vocational instruction and curriculum development in a civilian setting. Purpose of the course is to teach students to weld 5-inch mild steel schedule 80 pipe,…

  20. WIND project tests and analysis on the integrity of small size pipe under severe accident condition

    International Nuclear Information System (INIS)

    Nakamura, Naohiko; Hashimoto, Kazuichiro; Maruyama, Yu; Igarashi, Minoru; Hidaka, Akihide; Sugimoto, Jun

    1996-01-01

    In a severe accident of a light water reactor(LWR), fission products (FPs) released from fuel rods will be transported to the primary cooling system piping as aerosol and some of them will be deposited on the inner surface of piping. In such conditions the primary cooling system piping might be subjected to both of elevated temperature load due to decay heat of FPs and pressure load, and as a consequence the integrity of piping might be threatened. The WIND (Wide Range Piping Integrity Demonstration) Project is being performed at Japan Atomic Energy Research Institute (JAERI) to investigate the FP aerosol behavior in reactor piping and the integrity of reactor piping under severe accident condition (K. Hashimoto et al., 1994, K. Hashimoto et al., 1995). In order to meet these two objectives, the Project comprises two test series: an aerosol behavior test series and a piping integrity test series. In the piping integrity test a straight stainless steel pipe is used to simulate a partial fraction of reactor piping under severe accident conditions. In parallel with conducting the tests, test analyses are performed with ABAQUS code (Hibbitt, Karlsson and Sorensen Inc. 1989) using the test conditions to investigate the behavior of straight pipe against thermal and pressure loads. This paper describes the comparison of the scoping piping integrity test results and the analysis results with ABAQUS

  1. Non destructive testing for seamless pipes steel inspection of Vallourec and Mannesmann of Brazil: innovation, quality and satisfaction of their clients; Ensaios nao destrutivos para inspecao de tubos de aco sem costura da Vallourec e Mannesmann do Brasil: inovacao, qualidade e satisfacao de seus clientes

    Energy Technology Data Exchange (ETDEWEB)

    Eufrasio, Edson; Pawellwtz, Reinhard [V e M do Brasil S.A., Belo Horizonte, MG (Brazil)

    2004-07-01

    Seamless steel pipes presents wide application in many areas, which require high levels of quality , requirements and security of the product are guaranteed. In face to these requirements, V and M do Brazil is always in the vanguard of the technological innovation, in order to offer products with high level of quality and uniformity to the customers requirements. To guarantee the quality of its products, V and M do Brazil uses an ample variety of destructive and nondestructive testings, systems of measurement and inspection, which are distributed throughout all the productive process, in different production lines. Pioneering in the development of new techniques of inspection, mainly with relation to the non destructive testings, has been a constant mark of V and M do Brazil; assuring of this form, the improvement and expansion of the non destructive testings in the inspection of its products from the use of new techniques, as well as the improvement of the quality. (author)

  2. Impact of Si on Microstructure and Mechanical Properties of 22MnB5 Hot Stamping Steel Treated by Quenching & Partitioning (Q&P)

    Science.gov (United States)

    Linke, Bernd M.; Gerber, Thomas; Hatscher, Ansgar; Salvatori, Ilaria; Aranguren, Iñigo; Arribas, Maribel

    2018-01-01

    Based on 22MnB5 hot stamping steel, three model alloys containing 0.5, 0.8, and 1.5 wt pct Si were produced, heat treated by quenching and partitioning (Q&P), and characterized. Aided by DICTRA calculations, the thermal Q&P cycles were designed to fit into industrial hot stamping by keeping partitioning times ≤ 30 seconds. As expected, Si increased the amount of retained austenite (RA) stabilized after final cooling. However, for the intermediate Si alloy the heat treatment exerted a particularly pronounced influence with an RA content three times as high for the one-step process compared to the two-step process. It appeared that 0.8 wt pct Si sufficed to suppress direct cementite formation from within martensite laths but did not sufficiently stabilize carbon-soaked RA at higher temperatures. Tensile and bending tests showed strongly diverging effects of austenite on ductility. Total elongation improved consistently with increasing RA content independently from its carbon content. In contrast, the bending angle was not impacted by high-carbon RA but deteriorated almost linearly with the amount of low-carbon RA.

  3. Introduction to Heat Pipes

    Science.gov (United States)

    Ku, Jentung

    2015-01-01

    This is the presentation file for the short course Introduction to Heat Pipes, to be conducted at the 2015 Thermal Fluids and Analysis Workshop, August 3-7, 2015, Silver Spring, Maryland. NCTS 21070-15. Course Description: This course will present operating principles of the heat pipe with emphases on the underlying physical processes and requirements of pressure and energy balance. Performance characterizations and design considerations of the heat pipe will be highlighted. Guidelines for thermal engineers in the selection of heat pipes as part of the spacecraft thermal control system, testing methodology, and analytical modeling will also be discussed.

  4. Piping engineering and operation

    International Nuclear Information System (INIS)

    1993-01-01

    The conference 'Piping Engineering and Operation' was organized by the Institution of Mechanical Engineers in November/December 1993 to follow on from similar successful events of 1985 and 1989, which were attended by representatives from all sectors of the piping industry. Development of engineering and operation of piping systems in all aspects, including non-metallic materials, are highlighted. The range of issues covered represents a balance between current practices and implementation of future international standards. Twenty papers are printed. Two, which are concerned with pressurized pipes or steam lines in the nuclear industry, are indexed separately. (Author)

  5. Failure mode and fracture behavior evaluation of pipes with local wall thinning subjected to bending load

    International Nuclear Information System (INIS)

    Ahn, Seok Hwan; Nam, Ki Woo; Kim, Seon Jin; Kim, Jin Hwan; Kim, Hyun Soo; Do, Jae Yoon

    2003-01-01

    Fracture behaviors of pipes with local wall thinning are very important for the integrity of nuclear power plant. In pipes of energy plants, sometimes, the local wall thinning may result from severe Erosion-Corrosion (E/C) damage. However, the effects of local wall thinning on strength and fracture behaviors of piping system were not well studied. In this paper, the monotonic bending tests were performed of full-scale carbon steel pipes with local wall thinning. A monotonic bending load was applied to straight pipe specimens by four-point loading at ambient temperature without internal pressure. From the tests, fracture behaviors and fracture strength of locally thinned pipe were manifested systematically. The observed failure modes were divided into four types; ovalization, crack initiation/growth after ovalization, local buckling and crack initiating/growth after local buckling. Also, the strength and the allowable limit of piping system with local wall thinning were evaluated

  6. Seismic design evaluation guidelines for buried piping for the DOE HLW Facilities

    International Nuclear Information System (INIS)

    Lin, Chi-Wen; Antaki, G.; Bandyopadhyay, K.; Bush, S.H.; Costantino, C.; Kennedy, R.

    1995-01-01

    This paper presents the seismic design and evaluation guidelines for underground piping for the Department of Energy (DOE) High-Level-Waste (HLW) Facilities. The underground piping includes both single and double containment steel pipes and concrete pipes with steel lining, with particular emphasis on the double containment piping. The design and evaluation guidelines presented in this paper follow the generally accepted beam-on-elastic-foundation analysis principle and the inertial response calculation method, respectively, for piping directly in contact with the soil or contained in a jacket. A standard analysis procedure is described along with the discussion of factors deemed to be significant for the design of the underground piping. The following key considerations are addressed: the design feature and safety requirements for the inner (core) pipe and the outer pipe; the effect of soil strain and wave passage; assimilation of the necessary seismic and soil data; inertial response calculation for the inner pipe; determination of support anchor movement loads; combination of design loads; and code comparison. Specifications and justifications of the key parameters used, stress components to be calculated and the allowable stress and strain limits for code evaluation are presented

  7. Piping inspection activities at the EPRI NDE Center

    International Nuclear Information System (INIS)

    Ammirato, F.V.

    1990-01-01

    The dominant reliability issue for nuclear plant piping systems for nearly 15 years has been intergranular stress corrosion cracking (IGSCC) in BWR plants. IGSCC has been found in most stainless steel welds in BWR coolant piping. Initial concerns existed regarding the effectiveness of ultrasonic examination techniques for detecting and sizing IGSCC in either unrepaired or repaired piping. These concerns have been resolved through extensive EPRI programs directed toward developing and evaluating adequate techniques and providing operator training and qualification. In recent years, significantly improved examination techniques; automated examination equipment; signal processing and pattern recognition techniques; and extensive operator training have been developed, evaluated, and applied to the IGSCC detection and sizing problem. Cast stainless steel (CSS) piping and components are used extensively in nuclear plant primary coolant systems, particularly in PWR main coolant piping. No degradation has been reported. Periodic in-service inspection (ISI) of CSS primary piping components is nonetheless required; effective examination techniques, however, have not been conclusively demonstrated. The major NDE Center focus in 1989 has been evaluation of the adequacy of ultrasonic examination techniques for CSS. Another major activity in 1989 was helping utilities to resolve field problems associated with IGSCC detection and sizing. These activities are described

  8. Investigation on size tolerance of pore defect of girth weld pipe

    Science.gov (United States)

    Shuai, Jian; Xu, Kui

    2018-01-01

    Welding quality control is an important parameter for safe operation of oil and gas pipes, especially for high-strength steel pipes. Size control of welding defect is a bottleneck problem for current pipe construction. As a key part of construction procedure for butt-welding of pipes, pore defects in girth weld is difficult to ignore. A three-dimensional non-linear finite element numerical model is established to study applicability of size control indices based on groove shape and softening phenomenon of material in heat-affected zone of practical pipe girth weld. Taking design criteria of pipe as the basis, basic tensile, extremely tensile and extremely compressive loading conditions are determined for pipe stress analysis, and failure criteria based on flow stress is employed to perform stress analysis for pipe girth weld with pore defect. Results show that pipe girth welding stresses of pores at various radial locations are similar. Whereas, stress for pores of different sharpness varied significantly. Besides, tolerance capability of API 5L X90 grade pipe to pore defect of girth weld is lower than that of API 5L X80 grade pipe, and size control index of 3 mm related to pore defect in current standards is applicable to API 5L X80 and X90 grade girth welded pipes with radially non-sharp pore defects. PMID:29364986

  9. Piping research program plan

    International Nuclear Information System (INIS)

    1988-09-01

    This document presents the piping research program plan for the Structural and Seismic Engineering Branch and the Materials Engineering Branch of the Division of Engineering, Office of Nuclear Regulatory Research. The plan describes the research to be performed in the areas of piping design criteria, environmentally assisted cracking, pipe fracture, and leak detection and leak rate estimation. The piping research program addresses the regulatory issues regarding piping design and piping integrity facing the NRC today and in the foreseeable future. The plan discusses the regulatory issues and needs for the research, the objectives, key aspects, and schedule for each research project, or group of projects focussing of a specific topic, and, finally, the integration of the research areas into the regulatory process is described. The plan presents a snap-shot of the piping research program as it exists today. However, the program plan will change as the regulatory issues and needs change. Consequently, this document will be revised on a bi-annual basis to reflect the changes in the piping research program. (author)

  10. Transients in pipes

    International Nuclear Information System (INIS)

    Marchesin, D.; Paes-Leme, P.J.S.; Sampaio, R.

    1981-01-01

    The motion of a fluid in a pipe is commonly modeled utilizing the one space dimension conservation laws of mass and momentum. The development of shocks and spikes utilizing the uniform sampling method is studied. The effects of temperature variations and friction are compared for gas pipes. (Author) [pt

  11. Oscillating heat pipes

    CERN Document Server

    Ma, Hongbin

    2015-01-01

    This book presents the fundamental fluid flow and heat transfer principles occurring in oscillating heat pipes and also provides updated developments and recent innovations in research and applications of heat pipes. Starting with fundamental presentation of heat pipes, the focus is on oscillating motions and its heat transfer enhancement in a two-phase heat transfer system. The book covers thermodynamic analysis, interfacial phenomenon, thin film evaporation,  theoretical models of oscillating motion and heat transfer of single phase and two-phase flows, primary  factors affecting oscillating motions and heat transfer,  neutron imaging study of oscillating motions in an oscillating heat pipes, and nanofluid’s effect on the heat transfer performance in oscillating heat pipes.  The importance of thermally-excited oscillating motion combined with phase change heat transfer to a wide variety of applications is emphasized. This book is an essential resource and learning tool for senior undergraduate, gradua...

  12. Studies on ductile unstable fracture of piping materials in light water reactors, (2)

    International Nuclear Information System (INIS)

    Yasuda, Yuji; Shibata, Katsuyuki; Ohba, Toshihiro; Kawamura, Takaichi; Onizawa, Kunio; Miyazono, Shohachiro

    1986-07-01

    A pipe fracture test program has been conducted in Japan Atomic Energy Research Institute (JAERI) using austenitic stainless steel pipes and carbon steel pipes to investigate fracture behavior of the cracked pipe and to demonstrate the validity of the ''Leak Before Break'' concept for nuclear pressure boundary piping. This report describes the results of the laboratory-scale tests on center-cracked-tension (CCT) specimens machined from the 12-inch diameter Type 304 Nuclear Grade stainless steel pipe under tensile loading condition at room temperature. The program approach includes two efforts. The first phase develops J-R curve data for CCT specimens to characterize crack growth resistance. Furthermore, the flow stress obtained from these tests was applied to predict the collapse load of stainless steel pipe with a through-wall circumferential crack, based on the net-section collapse criterion. In the second phase of this program, unstable fracture experiments were conducted using compliant disc spring device. J-based tearing instability criterion was compared with the test results, and the validity of this criterion was discussed. (author)

  13. LHCb celebrates completion of its beam pipe

    CERN Multimedia

    2007-01-01

    Members of the LHCb collaboration and of the AT and TS Departments are ready to pop open the champagne bottles and celebrate the complete installation and commissioning of the LHCb experiment’s beam pipe. Members of the LHCb collaboration and of the AT and TS Departments gather near the newly completed beam pipe in the foreground. All four sections of LHCb’s beam pipe have been installed, interconnected, pumped down and baked out.. Three of the conical tubes are made of beryllium in order to minimize the level of background in the experiment, while the fourth and largest section is composed of stainless steel. The first of the beryllium sections, an important connection to the Vertex Locator vacuum vessel (VELO) was installed in August 2006 (see Bulletin No. 37/2006). One of the more challenging tasks was the installation of the longest (6 m) piece of beryllium beam pipe through the 2.4 m long RICH2 detector in January 2006. Deli...

  14. Application of LBB to high energy piping systems in operating PWR

    Energy Technology Data Exchange (ETDEWEB)

    Swamy, S.A.; Bhowmick, D.C. [Westinghouse Nuclear Technology Division, Pittsburgh, PA (United States)

    1997-04-01

    The amendment to General Design Criterion 4 allows exclusion, from the design basis, of dynamic effects associated with high energy pipe rupture by application of leak-before-break (LBB) technology. This new approach has resulted in substantial financial savings to utilities when applied to the Pressurized Water Reactor (PWR) primary loop piping and auxiliary piping systems made of stainless steel material. To date majority of applications pertain to piping systems in operating plants. Various steps of evaluation associated with the LBB application to an operating plant are described in this paper.

  15. Assessment of cracked pipes in primary piping systems of PWR nuclear reactors

    International Nuclear Information System (INIS)

    Jong, Rudolf Peter de

    2004-01-01

    Pipes related to the Primary System of Pressurized Water Reactors (PWR) are manufactured from high toughness austenitic and low alloy ferritic steels, which are resistant to the unstable growth of defects. A crack in a piping system should cause a leakage in a considerable rate allowing its identification, before its growth could cause a catastrophic rupture of the piping. This is the LBB (Leak Before Break) concept. An essential step in applying the LBB concept consists in the analysis of the stability of a postulated through wall crack in a specific piping system. The methods for the assessment of flawed components fabricated from ductile materials require the use of Elasto-Plastic Fracture Mechanics (EPFM). Considering that the use of numerical methods to apply the concepts of EPFM may be expensive and time consuming, the existence of the so called simplified methods for the assessment of flaws in piping are still considered of great relevance. In this work, some of the simplified methods, normalized procedures and criteria for the assessment of the ductile behavior of flawed components available in literature are described and evaluated. Aspects related to the selection of the material properties necessary for the application of these methods are also discussed. In a next .step, the methods are applied to determine the instability load in some piping configurations under bending and containing circumferential through wall cracks. Geometry and material variations are considered. The instability loads, obtained for these piping as the result of the application of the selected methods, are analyzed and compared among them and with some experimental results obtained from literature. The predictions done with the methods demonstrated that they provide consistent results, with good level of accuracy with regard to the determination of maximum loads. These methods are also applied to a specific Study Case. The obtained results are then analyzed in order to give

  16. Uniaxial Fatigue of HDPE-100 Pipe. Experimental Analysis

    Directory of Open Access Journals (Sweden)

    A. Aid

    2014-04-01

    Full Text Available In this paper, an experimental analysis for determining the fatigue strength of PE-100, one of the most used High Density Polyethylene (HDPE materials for pipes, under cyclic axial loadings is presented. HDPE is a thermoplastic material used for piping systems, such as natural gas distribution systems, sewer systems and cold water systems, which provides a good alternative to metals such as cast iron or carbon steel. One of the causes for failures of HDPE pipes is fatigue which is the result of pipes being subjected to cyclic loading, such as internal pressure, weight loads or external loadings on buried pipes, which generate stress in different directions: circumferential, longitudinal and radial. HDPE pipes are fabricated using an extrusion process, which generates anisotropic properties. By testing in the Laboratory a series of identical specimens obtained directly from PE-100 HDPE pipes in longitudinal directions, the relationships between amplitude stress and number of cycles (S-N curve test frequency 2 Hz and stress ratio R = 0.0 are established.

  17. Non-metallic structural wrap systems for pipe

    International Nuclear Information System (INIS)

    Walker, R.H.; Wesley Rowley, C.

    2001-01-01

    The use of thermoplastics and reinforcing fiber has been a long-term application of non-metallic material for structural applications. With the advent of specialized epoxies and carbon reinforcing fiber, structural strength approaching and surpassing steel has been used in a wide variety of applications, including nuclear power plants. One of those applications is a NSWS for pipe and other structural members. The NSWS is system of integrating epoxies with reinforcing fiber in a wrapped geometrical configuration. This paper specifically addresses the repair of degraded pipe in heat removal systems used in nuclear power plants, which is typically caused by corrosion, erosion, or abrasion. Loss of structural material leads to leaks, which can be arrested by a NSWS for the pipe. The technical aspects of using thermoplastics to structurally improve degraded pipe in nuclear power plants has been addressed in the ASME B and PV Code Case N-589. Using the fundamentals described in that Code Case, this paper shows how this technology can be extended to pipe repair from the outside. This NSWS has already been used extensively in non-nuclear applications and in one nuclear application. The cost to apply this NSWS is typically substantially less than replacing the pipe and may be technically superior to replacing the pipe. (author)

  18. Influence of heat treatment on mechanical property of steel hollow sphere and its sheet construction

    Science.gov (United States)

    Yoshida, Yoshinori; Ozawa, Sho

    2017-10-01

    Heat treatments, water quenching and annealing, are performed on the metallic hollow spheres (MHS) made from steel with 4.0 mm in outer diameter. They are pierced then put on a piece of tungsten alloy wire for making a MHS thread. The thread is set in between two neighboring warps of the tungsten alloy and the thread is placed in a reticular pattern. The MHS fabric sheet which has plain weave structure is produced by the weaving process. Furthermore, a sandwich construction of the sheet with 2 sheets of aluminum plate. The influence of the heat treatments on difference of mechanical and energy absorption property are evaluated by mean of compression test for the sheet along with the thickness direction. In addition, an aluminum pipe is filled with a heat treated MHS sheet and compression test is performed for the pipe along the radial direction. Its difference of compression load and energy consumption property is investigated.

  19. Bending of pipes with inconel cladding; Curvamento de tubos revestidos com inconel

    Energy Technology Data Exchange (ETDEWEB)

    Nachpitz, Leonardo; Menezes, Carlos Eduardo B.; Vieira, Carlos R. Tavares [PROTUBO, Macae, RJ (Brazil)

    2008-07-01

    The pipes used in offshore equipment, such as wet Christmas trees, sub sea manifolds and rigid platform risers, as well as some pipes for refineries and ships, must have mechanical resistance to high pressure and also be resistant to corrosion from acids. Some special materials, such as stainless steel, duplex and super duplex steel are used to resolve this problem, but the cost is very high. Besides the problem of cost, these materials have other drawbacks, such as the difficulty of welding them, a technology mastered in few countries. As a better alternative, the use has been increasing of carbon steel and API pipes coated internally with inconel by welding deposition. This groundbreaking technology, of proven efficiency, has a far superior cost-benefit relation. Carbon steel and API pipes, besides having better mechanical resistance to high pressure and corrosion resistance, can be fabricated with technology mastered worldwide. Nickel alloys, such as inconel, are highly resistant to corrosion and temperature, and in these aspects are better than stainless steels. The pipes for transportation equipment and for refining hydrocarbons, as mentioned above, require various turns and special geometries, which generally are solved by the use of bends and spools made by high-frequency induction. This technology, already well established for various carbon and stainless steels, was developed to work with pipes coated internally with inconel (inconel cladding). Therefore, our work describes the process of fabricating bends from API steel pipes with inconel cladding, demonstrating the efficacy of this technology along with its quality gains and cost reduction. (author)

  20. Pipe drafting and design

    CERN Document Server

    Parisher, Roy A

    2011-01-01

    Pipe Drafting and Design, Third Edition provides step-by-step instructions to walk pipe designers, drafters, and students through the creation of piping arrangement and isometric drawings. It includes instructions for the proper drawing of symbols for fittings, flanges, valves, and mechanical equipment. More than 350 illustrations and photographs provide examples and visual instructions. A unique feature is the systematic arrangement of drawings that begins with the layout of the structural foundations of a facility and continues through to the development of a 3-D model. Advanced chapters

  1. Application of ultrasonic NDT technique for butt fusion joints of plastic pipes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Gyung; Lim, Hyung Taik; Choi, Jeong Guen; Lee, Jae Myung [ANSCO, Daejeon (Korea, Republic of)

    2016-05-15

    The long term-durability and the soundness of the plastic pipe have been sufficiently verified through use of the plastic pipe during the past several decades. Recently, as the pipe material have been constantly developed, the application of the plastic pipe is expanded to various industrial fields, such as an increase of a use pressure, the bigger diameter of the pipe, etc. In a nuclear power plant where a carbon steel pipe and a stainless steel pipe are mainly used as a safety class III buried pipe, safety in an operation is seriously threatened by abrasion, heat deterioration or the like, frequently generated in a metal pipe. Therefore, in order to provide an alternate to this problem there is a rising interest on using high-density polyethylene (HDPE) pipes which are known to provide much enhanced corrosion, abrasion and impact resistant properties. With polyethylene piping, one of the issue that is being looked into is the integrity of butt-fusion joint. At the present time the Referencing Code and Standard for the NDT technology of for butt fusion joint of the plastic pipe have not yet established. An optimum inspection parameters were determined according to the thickness of the HDPE pipe. It was also confirmed that most of the detection results of two techniques have matched with each other. In the PAUT, it is easy to distinguish signals with from the flaws made by the thin plate and the void. Also the resolving power of PAUT on the detection in the depth direction has been demonstrated to be satisfactory.

  2. Estudo da soldagem de tubos de aço inoxidável duplex e superduplex na posição 5G Study of the welding of duplex and superduplex stainless steel pipes in the 5G position

    Directory of Open Access Journals (Sweden)

    Pedro Ivo Guimarães de Vasconcellos

    2010-09-01

    Full Text Available Os aços inoxidáveis duplex e superduplex possuem uma microestrutura austeno-ferrítica com fração média de cada fase de cerca 50%. A microestrutura duplex é responsável pelas excelentes propriedades mecânicas, especialmente o limite de escoamento e a tenacidade, e pela elevada resistência a corrosão por pites e sob tensão em meios contendo cloretos. A soldagem destes aços é frequentemente uma operação crítica. Neste trabalho, um tubo de superduplex SAF 2207 foi soldado pelo processo TIG (GTAW no passe de raiz e eletrodo revestido (SMAW nos passes de enchimento, e um tubo de duplex SAF 2205 foi todo soldado pelo processo GTAW. A microestrutura do metal base, zona afetada termicamente (ZTA e metal de solda foi caracterizada e quantificada. As propriedades de tenacidade, resistência a corrosão e composição química foram avaliadas e correlacionadas. Os valores de tenacidade ao impacto Charpy-V foram considerados adequados. Não foi observada a precipitação de intermetálicos, carbonetos e nitretos. O melhor resultado no teste de corrosão da junta soldada de aço inox superduplex, comparado ao duplex, foi atribuído ao baixo teor de ferrita delta na solda e ZTA, e composição química da solda enriquecida em Cr, Mo, W e N.The duplex and superduplex stainless steels have an austenitic-ferritic microstructure with an average fraction of each phase of approximately 50%. This duplex microstructure is responsible for the excellent mechanical properties, specially the yield strength and toughness, and for the improved pitting and stress corrosion cracking resistance in chloride environments. Welding of these steels is often a critical operation. In this work, a superduplex stainless steel SAF 2507 pipe was welded by the GTAW process in the root pass and by SMAW process on filler passes, and one pipe of duplex SAF 2205 was entirely welded by the GTAW process. The microstructure of the base metal, heat affected zone (HAZ and weld

  3. Flexible ultrasonic pipe inspection apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, C.F.; Howard, B.D.

    1994-01-01

    Pipe crawlers, pipe inspection {open_quotes}rabbits{close_quotes} and similar vehicles are widely used for inspecting the interior surfaces of piping systems, storage tanks and process vessels for damaged or flawed structural features. This paper describes the design of a flexible, modular ultrasonic pipe inspection apparatus.

  4. 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.

  5. 77 FR 2318 - Certain Circular Welded Pipe and Tube From Brazil, India, Korea, Mexico, Taiwan, Thailand, and...

    Science.gov (United States)

    2012-01-17

    ..., Taiwan, Thailand, and Turkey; Scheduling of Full Five-Year Reviews AGENCY: United States International... Turkey, the antidumping duty orders on welded carbon steel pipe and tube from India, Thailand, and Turkey...

  6. Improved Thin, Flexible Heat Pipes

    Science.gov (United States)

    Rosenfeld, John H.; Gernert, Nelson J.; Sarraf, David B.; Wollen, Peter J.; Surina, Frank C.; Fale, John E.

    2004-01-01

    Flexible heat pipes of an improved type are fabricated as layers of different materials laminated together into vacuum- tight sheets or tapes. In comparison with prior flexible heat pipes, these flexible heat pipes are less susceptible to leakage. Other advantages of these flexible heat pipes, relative to prior flexible heat pipes, include high reliability and greater ease and lower cost of fabrication. Because these heat pipes are very thin, they are highly flexible. When coated on outside surfaces with adhesives, these flexible heat pipes can be applied, like common adhesive tapes, to the surfaces of heat sinks and objects to be cooled, even if those surfaces are curved.

  7. PPOOLEX experiments with a modified blowdown pipe outlet

    International Nuclear Information System (INIS)

    Laine, J.; Puustinen, M.; Raesaenen, A.

    2009-08-01

    This report summarizes the results of the experiments with a modified blowdown pipe outlet carried out with the PPOOLEX test facility designed and constructed at Lappeenranta University of Technology. Steam was blown into the dry well compartment and from there through a vertical DN200 blowdown pipe to the condensation pool. Four reference experiments with a straight pipe and ten with the Forsmark type collar were carried out. The main purpose of the experiment series was to study the effect of a blowdown pipe outlet collar design on loads caused by chugging phenomena (rapid condensation) while steam is discharged into the condensation pool. The PPOOLEX test facility is a closed stainless steel vessel divided into two compartments, dry well and wet well. During the experiments the initial temperature level of the condensation pool water was either 20-25 or 50-55 deg. C. The steam flow rate varied from 400 to 1200 g/s and the temperature of incoming steam from 142 to 185 deg. C. In the experiments with 20-25 deg. C pool water, even 10 times higher pressure pulses were measured inside the blowdown pipe in the case of the straight pipe than with the collar. In this respect, the collar design worked as planned and removed the high pressure spikes from the blowdown pipe. Meanwhile, there seemed to be no suppressing effect on the loads due to the collar in the pool side in this temperature range. Registered loads in the pool were approximately in the same range (or even a little higher) with the collar as with the straight pipe. In the experiments with 50-55 deg. C pool water no high pressure pulses were measured inside the blowdown pipe either with the straight pipe or with the collar. In this case, more of the suppressing effect is probably due to the warmer pool water than due to the modified pipe outlet. It has been observed already in the earlier experiments with a straight pipe in the POOLEX and PPOOLEX facilities that warm pool water has a diminishing effect on

  8. Ultrasonic Device Would Open Pipe Bombs

    Science.gov (United States)

    El-Raheb, Michael S.; Adams, Marc A.; Zwissler, James G.

    1991-01-01

    Piezoelectric ultrasonic transducer, energized by frequency generator and power supply, vibrates shell of pipe bomb while hardly disturbing explosive inner material. Frequency-control circuitry senses resonance in shell and holds generator at that frequency to induce fatigue cracking in threads of end cap. In addition to disarming bombs, ultrasonically induced fatigue may have other applications. In manufacturing, replaces some machining and cutting operations. In repair of equipment, cleanly and quickly disassembles corroded parts. In demolition of buildings used to dismember steel framework safely and controllably.

  9. 78 FR 25253 - Seamless Carbon and Alloy Steel Standard, Line, and Pressure From the People's Republic of China...

    Science.gov (United States)

    2013-04-30

    ... International Trade Administration Seamless Carbon and Alloy Steel Standard, Line, and Pressure From the People... seamless carbon and alloy steel standard, line, and pressure pipe ] (``seamless pipe'') from the People's... Act of 1930, as amended, and 19 CFR 351.213(d)(4). Dated: April 22, 2013. Christian Marsh, Deputy...

  10. Study of residual stresses generated in P91 pipe steel welded by MCAW / FCAW processes; Estudo das tensoes residuais geradas na soldagem de tubulacao de aco P91 pelos processos MCAW/FCAW

    Energy Technology Data Exchange (ETDEWEB)

    Chuvas, Tatiane C.; Pardal, Juan M.; Garcia, Pedro P.; Souza, Guttemberg C. de; Fonseca, Maria P. Cindra, E-mail: chuvas@vm.uff.br [Universidade Federal Fluminense (PGMEC/UFF), Niteroi, RJ (Brazil). Departamento de Engenharia Mecanica; Cardote, Ismael [UTC Engenharia S/A, Niteroi, Rio de Janeiro, RJ (Brazil)

    2014-07-01

    The welding is one of the main industrial manufacturing processes structures and piping, knowledge of residual stress from this process is of paramount importance because the mechanical properties of welded components are not only determined by the microstructures present in the joint, but also by residual stresses heterogeneous introduced by thermal cycling during the process. The aim of this work is the characterization ASTM P91 joints welded by MCAW / FCAW (Metal Cored Arc Welding / Flux Cored Arc Welding) processes through the residual stresses evaluating associated with welding and post-weld heat treatments. Residual stresses were measured using X-rays diffraction sin2psi method, with Crκα radiation and they presented tensile at the root joints with larger magnitudes in the weld metal region and compressive on the surface. The post weld heat treatment resulted relief of residual stresses at the root of the joints. However, the same effect was observed in compressive surface stresses, which could adversely affect the service life of the pipe, reducing the fatigue and stress corrosion cracking resistances. (author)

  11. Corroded scale analysis from water distribution pipes

    Directory of Open Access Journals (Sweden)

    Rajaković-Ognjanović Vladana N.

    2011-01-01

    Full Text Available The subject of this study was the steel pipes that are part of Belgrade's drinking water supply network. In order to investigate the mutual effects of corrosion and water quality, the corrosion scales on the pipes were analyzed. The idea was to improve control of corrosion processes and prevent impact of corrosion on water quality degradation. The instrumental methods for corrosion scales characterization used were: scanning electron microscopy (SEM, for the investigation of corrosion scales of the analyzed samples surfaces, X-ray diffraction (XRD, for the analysis of the presence of solid forms inside scales, scanning electron microscopy (SEM, for the microstructural analysis of the corroded scales, and BET adsorption isotherm for the surface area determination. Depending on the composition of water next to the pipe surface, corrosion of iron results in the formation of different compounds and solid phases. The composition and structure of the iron scales in the drinking water distribution pipes depends on the type of the metal and the composition of the aqueous phase. Their formation is probably governed by several factors that include water quality parameters such as pH, alkalinity, buffer intensity, natural organic matter (NOM concentration, and dissolved oxygen (DO concentration. Factors such as water flow patterns, seasonal fluctuations in temperature, and microbiological activity as well as water treatment practices such as application of corrosion inhibitors can also influence corrosion scale formation and growth. Therefore, the corrosion scales found in iron and steel pipes are expected to have unique features for each site. Compounds that are found in iron corrosion scales often include goethite, lepidocrocite, magnetite, hematite, ferrous oxide, siderite, ferrous hydroxide, ferric hydroxide, ferrihydrite, calcium carbonate and green rusts. Iron scales have characteristic features that include: corroded floor, porous core that contains

  12. The pipes of pan.

    Science.gov (United States)

    Chalif, David J

    2004-12-01

    The pipes of pan is the crowning achievement of Pablo Picasso's neoclassical period of the 1920s. This monumental canvas depicts a mythological Mediterranean scene in which two sculpted classical giants stare out, seemingly across the centuries, toward a distant and lost Arcadia. Picasso was influenced by Greco-Roman art during his travels in Italy, and his neoclassical works typically portray massive, immobile, and pensive figures. Pan and his pipes are taken directly from Greek mythological lore by Picasso and placed directly into 20th century art. He frequently turned to various mythological figures throughout his metamorphosing periods. The Pipes of Pan was also influenced by the painter's infatuation with the beautiful American expatriate Sara Murphy, and the finished masterpiece represents a revision of a previously conceived neoclassical work. The Pipes of Pan now hangs in the Musee Picasso in Paris.

  13. Heat Pipe Systems

    Science.gov (United States)

    1993-01-01

    The heat pipe was developed to alternately cool and heat without using energy or any moving parts. It enables non-rotating spacecraft to maintain a constant temperature when the surface exposed to the Sun is excessively hot and the non Sun-facing side is very cold. Several organizations, such as Tropic-Kool Engineering Corporation, joined NASA in a subsequent program to refine and commercialize the technology. Heat pipes have been installed in fast food restaurants in areas where humid conditions cause materials to deteriorate quickly. Moisture removal was increased by 30 percent in a Clearwater, FL Burger King after heat pipes were installed. Relative humidity and power consumption were also reduced significantly. Similar results were recorded by Taco Bell, which now specifies heat pipe systems in new restaurants in the Southeast.

  14. Mechanical properties of API X80 steel pipe joints welded by Flux Core Arc Weld Process; Propriedades mecanicas de juntas de tubos de aco API X80 soldadas com arame tubulares

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez, Robert E. Cooper; Silva, Jose Hilton F.; Trevisan, Roseana E. [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Engenharia de Fabricacao

    2003-07-01

    Flux Core Arc Welding processes (FCAW) are beginning to be applied in pipeline welds, however, very limited experimental data regarding mechanical properties of pipeline weld joints with these processes are available in the literature. In this paper, the effects of preheat temperature and type of FCAW on mechanical properties (microhardness and tensile strength) of API X80 weld joint steel are presented. FCAW processes with gas protection and self-shielded were used. Multipasses welding were applied in 30'' diameter and 0,625'' thickness tubes. Influence factors were: FCAW type and preheat temperature. Acceptance criteria of welded joints were evaluated by API 1104 standard for tensile strength test and ASTM E384-99 for microhardness test. The results obtained showed that FCAW type and preheat temperature have no influence on mechanical properties of API X80 joint steel. (author)

  15. Development of intelligent pipe locator

    Science.gov (United States)

    Miyamoto, Y.; Wasa, Y.

    1986-08-01

    An inductive pipe locator was developed, so that the position and depth of an underground gas pipe can be accurately located by passing an ac current to the pipe and measuring the generated magnetic field. An ac current (several to 100 kHz) of several tens of mA is transmitted to the underground pipe, and a magnetic sensor above the ground catches the induced magnetic field to estimate the position and depth of the pipe.

  16. Stuck pipe prediction

    KAUST Repository

    Alzahrani, Majed

    2016-03-10

    Disclosed are various embodiments for a prediction application to predict a stuck pipe. A linear regression model is generated from hook load readings at corresponding bit depths. A current hook load reading at a current bit depth is compared with a normal hook load reading from the linear regression model. A current hook load greater than a normal hook load for a given bit depth indicates the likelihood of a stuck pipe.

  17. Methods of making bainitic steel materials

    Energy Technology Data Exchange (ETDEWEB)

    Bakas, Michael Paul; Chu, Henry Shiu-Hung; Zagula, Thomas Andrew; Langhorst, Benjamin Robert

    2018-01-16

    Methods of making bainitic steels may involve austenitizing a quantity of steel by exposing the quantity of steel to a first temperature. A composition of the quantity of steel may be configured to impede formation of non-bainite ferrite, pearlite, and Widmanstatten ferrite. The quantity of steel may be heat-treated to form bainite by exposing the quantity of steel to a second, lower temperature. The second, lower temperature may be stabilized by exposing the quantity of steel to the second, lower temperature in the presence of a thermal ballast.

  18. Development and Manufacture of Cost-Effective Composite Drill Pipe

    Energy Technology Data Exchange (ETDEWEB)

    James C. Leslie

    2008-12-31

    Advanced Composite Products and Technology, Inc. (ACPT) has developed composite drill pipe (CDP) that matches the structural and strength properties of steel drill pipe, but weighs less than 50 percent of its steel counterpart. Funding for the multiyear research and development of CDP was provided by the U.S. Department of Energy Office of Fossil Energy through the Natural Gas and Oil Projects Management Division at the National Energy Technology Laboratory (NETL). Composite materials made of carbon fibers and epoxy resin offer mechanical properties comparable to steel at less than half the weight. Composite drill pipe consists of a composite material tube with standard drill pipe steel box and pin connections. Unlike metal drill pipe, composite drill pipe can be easily designed, ordered, and produced to meet specific requirements for specific applications. Because it uses standard joint connectors, CDP can be used in lieu of any part of or for the entire steel drill pipe section. For low curvature extended reach, deep directional drilling, or ultra deep onshore or offshore drilling, the increased strength to weight ratio of CDP will increase the limits in all three drilling applications. Deceased weight will reduce hauling costs and increase the amount of drill pipe allowed on offshore platforms. In extreme extended reach areas and high-angle directional drilling, drilling limits are associated with both high angle (fatigue) and frictional effects resulting from the combination of high angle curvature and/or total weight. The radius of curvature for a hole as small as 40 feet (12.2 meters) or a build rate of 140 degrees per 100 feet is within the fatigue limits of specially designed CDP. Other properties that can be incorporated into the design and manufacture of composite drill pipe and make it attractive for specific applications are corrosion resistance, non-magnetic intervals, and abrasion resistance coatings. Since CDP has little or no electromagnetic force

  19. Small pipe characterization system (SPCS) conceptual design

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, M.O.; Ferrante, T.A.; McKay, M.D.

    1995-01-01

    Throughout the Department of Energy (DOE) complex there are many facilities that have been identified for Decontamination and Decommissioning (D&D). As processes are terminated or brought off-line, facilities are placed on the inactive list, and facility managers and site contractors are required to assure a safe and reliable decommissioning and transition of these facilities to a clean final state. Decommissioning of facilities requires extensive reliable characterization, decontamination and in some cases dismantlement. Characterization of piping systems throughout the DOE complex is becoming more and more necessary. In addition to decommissioning activities, characterization activities are performed as part of surveillance and maintenance (S&M). Because of the extent of contamination, all inactive facilities require some type of S&M. These S&M activities include visual assessment, equipment and material accounting, and maintenance. The majority of the inactive facilities have piping systems 3 inches or smaller that are inaccessible because they are contaminated, imbedded in concrete, or run through hot cells. Many of these piping systems have been inactive for a number of years and there exists no current system condition information or the historical records are poor and/or missing altogether. Many of these piping systems are placed on the contaminated list, not because of known contamination, but because of the risk of internal contamination. Many of the piping systems placed on the contamination list may not have internal contamination. Because there is a potential however, they are treated as such. The cost of D&D can be greatly reduced by identifying and removing hot spot contamination, leaving clean piping to be removed using conventional methods. Accurate characterization of these piping systems is essential before, during and after all D&D activities.

  20. Small pipe characterization system (SPCS) conceptual design

    International Nuclear Information System (INIS)

    Anderson, M.O.; Ferrante, T.A.; McKay, M.D.

    1995-01-01

    Throughout the Department of Energy (DOE) complex there are many facilities that have been identified for Decontamination and Decommissioning (D ampersand D). As processes are terminated or brought off-line, facilities are placed on the inactive list, and facility managers and site contractors are required to assure a safe and reliable decommissioning and transition of these facilities to a clean final state. Decommissioning of facilities requires extensive reliable characterization, decontamination and in some cases dismantlement. Characterization of piping systems throughout the DOE complex is becoming more and more necessary. In addition to decommissioning activities, characterization activities are performed as part of surveillance and maintenance (S ampersand M). Because of the extent of contamination, all inactive facilities require some type of S ampersand M. These S ampersand M activities include visual assessment, equipment and material accounting, and maintenance. The majority of the inactive facilities have piping systems 3 inches or smaller that are inaccessible because they are contaminated, imbedded in concrete, or run through hot cells. Many of these piping systems have been inactive for a number of years and there exists no current system condition information or the historical records are poor and/or missing altogether. Many of these piping systems are placed on the contaminated list, not because of known contamination, but because of the risk of internal contamination. Many of the piping systems placed on the contamination list may not have internal contamination. Because there is a potential however, they are treated as such. The cost of D ampersand D can be greatly reduced by identifying and removing hot spot contamination, leaving clean piping to be removed using conventional methods. Accurate characterization of these piping systems is essential before, during and after all D ampersand D activities

  1. Process research into metallic pipe wear of hot chamber die casting machines and methods ofincreasing wear resistance

    Science.gov (United States)

    Mukhametzyanova, G. F.; Kolesnikov, MS; Mukhametzyanov, I. R.; Astatshenko, V. I.

    2017-09-01

    The kinetics and reasons for metallic pipe wear of hot chamberzinc alloy die casting machines are established.Increasing metallic pipe wear components wear resistance is being achieved by means of die steelДИ - 22 with electroslag remelting modification and electron-beamremelting modification and after the processes of nitriding and boriding besides.

  2. Experimental investigation of coarse particles-water mixture flow in horizontal and inclined pipes

    Directory of Open Access Journals (Sweden)

    Vlasák Pavel

    2014-09-01

    Full Text Available The effect of solid concentration and mixture velocity on the flow behaviour, pressure drops, and concentration distribution of coarse particle-water mixtures in horizontal, vertical, and inclined smooth stainless steel pipes of inner diameter D = 100 mm was experimentally investigated. Graded basalt pebbles were used as solid particles. The study revealed that the coarse-grained particle-water mixtures in the horizontal and inclined pipes were significantly stratified. The solid particles moved principally in a layer close to the pipe invert; however for higher and moderate flow velocities, particle saltation became the dominant mode of particle conveyance. Frictional pressure drops in the horizontal pipe were found to be markedly higher than in the vertical pipe, while the frictional pressure drops in the ascending pipe increased with inclination angle up to about 30°.

  3. Wall Thickness Measurement Of Insulated Pipe By Tangential Radiography Technique Using Ir 192

    International Nuclear Information System (INIS)

    Soedarjo

    2000-01-01

    Insulation pipe wall thickness by tangential radiography technique has been carried out using 41 Curie Iridium 192 source has activity for two carbon steel pipes. The outer diameter of the first pipe is 90 mm, wall thickness is 75.0 mm, source film film distance is 609.5 mm, source tangential point of insulation is 489.5 mm and exposure time 3 minute and 25 second. From the calculation, the first pipe thickness is found to be 12.54 mm and for the second pipe is 8.42 mm. The thickness is due to inaccuracy in reading the pipe thickness on radiography film and the geometry distortion radiation path

  4. Corrosion and deposit evaluation in large diameter pipes using radiography

    International Nuclear Information System (INIS)

    Boateng, A.

    2012-01-01

    The reliability and safety of industrial equipment in the factories and processing industries are substantially influenced by degradation processes such as corrosion, erosion, deposits and blocking of pipes. These might lead to low production, unpredictable and costly shutdowns due to repair and replacement and sometimes combined environmental pollution and risk of personnel injuries. Only periodic inspection for the integrity of pipes and equipment can reduce the risk in connection with other maintenance activities. The research explored two methods of radiographic inspection techniques, the double wall technique and the tangential radiographic technique using Ir-192 for evaluating deposits and corrosion attacks across the inner and outer walls of steel pipes with diameter greater than 150 mm with or without insulation. The application of both techniques was conducted depending on pipe diameter, wall thickness, radiation source (Ir-92) and film combination. The iridium source was positioned perpendicular with respect to the pipe axis projecting the double wall of the pipe on the plated radiographic film. With the tangential radiographic technique, the source was placed tangential to the pipe wall and because of its large diameter, the source was collimated to prevent backscatter and also to focus the beam at the target area of interest. All measurements were performed on special designed test pieces to simulate corrosion attack and deposits on industrial pipes. Pitting corrosion measurements based on Tangential Radiographic Technique were more sophisticated, and therefore magnification factor and correction were used to establish the estimated pit depth on the film. The insulating material used to conserve the thermodynamic properties of the transported media had relatively negligible attenuation coefficient compared to the concrete deposit. The two explored techniques were successful in evaluating corrosion attack and deposit on the walls of the pipe and the risk

  5. Characterization of thermal aging of duplex stainless steel by SQUID

    International Nuclear Information System (INIS)

    Isobe, Y.; Kamimura, A.; Aoki, K.; Nakayasu, F.

    1995-01-01

    Thermal aging is a growing concern for long-term-aged duplex stainless steel piping in nuclear power plants. Superconducting QUantum Interference Device (SQUID) was used for the detection of thermal aging of SUS329 rolled duplex stainless steel and SCS16 cast duplex stainless steel. It was found that the SQUID output signal pattern in the presence of AC magnetic field applied to the specimen was sensitive to the changes in electromagnetic properties due to thermal aging

  6. Effects of chemistry on corrosion-erosion of steels in water and wet steam

    International Nuclear Information System (INIS)

    Berge, P.; Ducreux, J.; Saint-Paul, P.

    1981-01-01

    In steam production plants, numerous cases of degradation of steels occur when in contact with water or wet steam circulating at high velocity: in feed or discharge pumps, water reheaters, etc. When the phenomenon occurs without any mechanical wear of the metal or the oxide from the impact of solid particles (abrasion) or droplets (erosion), it is called corrosion-erosion. The phenomenon usually occurs between 100 and 250 0 C, as has been confirmed by an empirical study of the thermal and hydraulic factors which govern it. Corrosion rates can reach 1 to 2 mm/year, for a carbon steel pipe where water treated with ammonia circulates at about pH 9, at 200 0 C, and at a velocity of 5 to 10 m/s. This study evaluates the part played by the factors solely connected to the chemistry of water, with respect to the kinetics of the corrosion-erosion phenomenon. (author)

  7. Real-time corrosion control system for cathodic protection of buried pipes for nuclear power plant

    International Nuclear Information System (INIS)

    Kim, Ki Tae; Kim, Hae Woong; Kim, Young Sik; Chang, Hyun Young; Lim, Bu Taek; Park, Heung Bae

    2015-01-01

    Since the operation period of nuclear power plants has increased, the degradation of buried pipes gradually increases and recently it seems to be one of the emerging issues. Maintenance on buried pipes needs high quality of management system because outer surface of buried pipe contacts the various soils but inner surface reacts with various electrolytes of fluid. In the USA, USNRC and EPRI have tried to manage the degradation of buried pipes. However, there is little knowledge about the inspection procedure, test and manage program in the domestic nuclear power plants. This paper focuses on the development and build-up of real-time monitoring and control system of buried pipes. Pipes to be tested are tape-coated carbon steel pipe for primary component cooling water system, asphalt-coated cast iron pipe for fire protection system, and pre-stressed concrete cylinder pipe for sea water cooling system. A control system for cathodic protection was installed on each test pipe which has been monitored and controlled. For the calculation of protection range and optimization, computer simulation was performed using COMSOL Multiphysics (Altsoft co.)

  8. An investigation of wall temperature characteristics to evaluate thermal fatigue at a T-junction pipe

    International Nuclear Information System (INIS)

    Miyoshi, Koji; Nakamura, Akira; Utanohara, Yoichi; Takenaka, Nobuyuki

    2014-01-01

    Thermal fatigue cracking may initiate at a T-junction pipe where high and low temperature fluids mix. In this study, wall temperature characteristics at a T-junction pipe were investigated to improve the evaluation method for thermal fatigue. The stainless steel test section consisted of a horizontal main pipe (diameter, 150 mm) and a T-junction connected to a vertical branch pipe (diameter, 50 mm). The inlet flow velocities in the main and branch pipes were set to 0.99 m/s and 0.66 m/s respectively to produce a wall jet pattern in which the jet from the branch pipe was bent by the main pipe flow and made to flow along the pipe wall. The temperature difference was 34.1 K. A total of 148 thermocouples were installed to measure the wall temperature on the pipe inner surface in the downstream region. The maximum of temperature fluctuation intensity on the pipe inner surface was measured as 5% of the fluid temperature difference at the inlets. The dominant frequency of the large temperature fluctuations in the region downstream from z = 0.5D m was equal to 0.2 of the Strouhal number, which was equal to the frequency caused by the vortex streets generated around the jet flow. The large temperature fluctuation was also observed with the period of about 10 s. The fluctuation was caused by spreading of the heated region in the circumferential direction. (author)

  9. Pulsed Eddy Current Sensing for Critical Pipe Condition Assessment.

    Science.gov (United States)

    Ulapane, Nalika; Alempijevic, Alen; Vidal Calleja, Teresa; Valls Miro, Jaime

    2017-09-26

    Pulsed Eddy Current (PEC) sensing is used for Non-Destructive Evaluation (NDE) of the structural integrity of metallic structures in the aircraft, railway, oil and gas sectors. Urban water utilities also have extensive large ferromagnetic structures in the form of critical pressure pipe systems made of grey cast iron, ductile cast iron and mild steel. The associated material properties render NDE of these pipes by means of electromagnetic sensing a necessity. In recent years PEC sensing has established itself as a state-of-the-art NDE technique in the critical water pipe sector. This paper presents advancements to PEC inspection in view of the specific information demanded from water utilities along with the challenges encountered in this sector. Operating principles of the sensor architecture suitable for application on critical pipes are presented with the associated sensor design and calibration strategy. A Gaussian process-based approach is applied to model a functional relationship between a PEC signal feature and critical pipe wall thickness. A case study demonstrates the sensor's behaviour on a grey cast iron pipe and discusses the implications of the observed results and challenges relating to this application.

  10. Defect Depth Measurement of Straight Pipe Specimen Using Shearography

    International Nuclear Information System (INIS)

    Chang, Ho Seob; Kim, Kyung Suk

    2012-01-01

    In the nuclear industry, wall thinning defect of straight pipe occur the enormous loss in life evaluation and safety evaluation. To use non-destructive technique, we measure deformation, vibration, defect evaluation. But, this techniques are a weak that is the measurement of the wide area is difficult and the time is caught long. In the secondary side of nuclear power plants mostly used steel pipe, artificiality wall thinning defect make in the side and different thickness make to the each other, wall thinning defect part of deformation measure by using shearography. In addition, optical measurement through deformation, vibration, defect evaluation evaluate pipe and thickness defects of pressure vessel is to evaluate quantitatively. By shearography interferometry to measure the pipe's internal wall thinning defect and the variation of pressure use the proposed technique, the quantitative defect is to evaluate the thickness of the surplus. The amount of deformation use thickness of surplus prediction of the actual thickness defect and approximately 7 percent error by ensure reliability. According to pressure the amount of deformation and the thickness of the surplus through DB construction, nuclear power plant pipe use wall thinning part soundness evaluation. In this study, pressure vessel of thickness defect measure proposed nuclear pipe of wall thinning defect prediction and integrity assessment technology development. As a basic research defected theory and experiment, pressure vessel of advanced stability and soundness and maintainability is expected to contribute foundation establishment

  11. OTEC Cold Water Pipe-Platform Subsystem Dynamic Interaction Validation

    Energy Technology Data Exchange (ETDEWEB)

    Varley, Robert [Lockheed Martin Corporation, Manassas, VA (United States); Halkyard, John [John Halkyard and Associates, Houston, TX (United States); Johnson, Peter [BMT Scientific Marine Services, Inc., Houston, TX (United States); Shi, Shan [Houston Offshore Engineering, Houston, TX (United States); Marinho, Thiago [Federal Univ. of Rio de Janeiro (Brazil). LabOceano

    2014-05-09

    A commercial floating 100-megawatt (MW) ocean thermal energy conversion (OTEC) power plant will require a cold water pipe (CWP) with a diameter of 10-meter (m) and length of up to 1,000 m. The mass of the cold water pipe, including entrained water, can exceed the mass of the platform supporting it. The offshore industry uses software-modeling tools to develop platform and riser (pipe) designs to survive the offshore environment. These tools are typically validated by scale model tests in facilities able to replicate real at-sea meteorological and ocean (metocean) conditions to provide the understanding and confidence to proceed to final design and full-scale fabrication. However, today’s offshore platforms (similar to and usually larger than those needed for OTEC applications) incorporate risers (or pipes) with diameters well under one meter. Secondly, the preferred construction method for large diameter OTEC CWPs is the use of composite materials, primarily a form of fiber-reinforced plastic (FRP). The use of these material results in relatively low pipe stiffness and large strains compared to steel construction. These factors suggest the need for further validation of offshore industry software tools. The purpose of this project was to validate the ability to model numerically the dynamic interaction between a large cold water-filled fiberglass pipe and a floating OTEC platform excited by metocean weather conditions using measurements from a scale model tested in an ocean basin test facility.

  12. Experimental study of plastic responses of pipe elbows

    International Nuclear Information System (INIS)

    Greenstreet, W.L.

    1978-01-01

    Load-deflection responses were determined experimentally for sixteen 152.4-mm (6-in.) (nominal) commercial carbon steel pipe elbows and four 152.4-mm (6-in.) stainless steel elbows. Each specimen was loaded with an external force of sufficient magnitude to produce predominantly plastic response. The influences of bend radius and wall thickness were studied, as well as the effect of internal prssure on load-deflection behavior. Comparisons of results from stainless steel and from carbon steel elbows indicate differences in responses attributable to material differences. The results were interpreted in terms of limit analysis concepts, and collapse loads were determined. Trends given by the collapse loads are identified and discussed

  13. Coated 4340 Steel

    Science.gov (United States)

    2013-08-26

    NAWCADPAX/TR-2013/252 4 MECHANICAL TEST Single edge notched, square-bar ( Charpy ) specimens, bare or coated, were tested under four-point bending at...Treated 4340 Steel Tested in Air NAWCADPAX/TR-2013/252 APPENDIX 100 150 200 250 300 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08 M ax . S tr es s ( ks i...Fatigue Life, N (cycle) Bare No. 1 ST No. 3 ST Figure 10: Stress-Life Fatigue Curves for Bare and Surface-Treated 4340 Steel Tested in 3.5% NaCl

  14. Pipe whip and impact

    International Nuclear Information System (INIS)

    Attwood, G.J.

    1987-01-01

    Over the past few years changes in economic and safety considerations in nuclear power plants have resulted in a need to examine the problem of pipe whip in greater detail. Consequently, experimental programmes were set up in France, North America and Britain. Results from these tests combined with analytical work indicate that pipe whip followed by impact with surrounding pipework and structures may not be as serious as had been believed. Impact loads have been found to be much less (at least five times) than those predicted to the appropriate design regulations. Hence, the use of pipe whip restraints may have been overconservative. The use of fewer, better designed restraints, would result in greater accessibility of pipework, a reduced need for inspection of restraints, and a considerable financial saving. (author)

  15. Steel making

    CERN Document Server

    Chakrabarti, A K

    2014-01-01

    "Steel Making" is designed to give students a strong grounding in the theory and state-of-the-art practice of production of steels. This book is primarily focused to meet the needs of undergraduate metallurgical students and candidates for associate membership examinations of professional bodies (AMIIM, AMIE). Besides, for all engineering professionals working in steel plants who need to understand the basic principles of steel making, the text provides a sound introduction to the subject.Beginning with a brief introduction to the historical perspective and current status of steel making together with the reasons for obsolescence of Bessemer converter and open hearth processes, the book moves on to: elaborate the physiochemical principles involved in steel making; explain the operational principles and practices of the modern processes of primary steel making (LD converter, Q-BOP process, and electric furnace process); provide a summary of the developments in secondary refining of steels; discuss principles a...

  16. Heat pipes and use of heat pipes in furnace exhaust

    Science.gov (United States)

    Polcyn, Adam D.

    2010-12-28

    An array of a plurality of heat pipe are mounted in spaced relationship to one another with the hot end of the heat pipes in a heated environment, e.g. the exhaust flue of a furnace, and the cold end outside the furnace. Heat conversion equipment is connected to the cold end of the heat pipes.

  17. EPR method for the detection of sensitization in stainless steels

    International Nuclear Information System (INIS)

    Clarke, W.L.; Cowan, R.L.

    1980-01-01

    The overall objective of the program was to improve the reliability of reactor system piping by increasing knowledge of failure causing mechanisms and by enhancing the capability for design evaluation and analysis. Toward the attainment of that objective, a technique has been developed to measure the degree of sensitization quantitatively in thermally treated AISI-304, -304L, -316 and 316L stainless steels. The Electrochemical Potentiokinetic Reactivation (EPR) test was developed because of an industrial need for a rapid, nondestructive, quantitative field test which could be used for assessing sensitization in reactor components. The EPR method consists of developing potentiokinetic curves on a polarized sample obtained by controlled potential sweep from the passive to the active region (reactivation) in a specific electrolyte; details of the test technique have been reported

  18. PE 100 pipe systems

    CERN Document Server

    Brömstrup, Heiner

    2012-01-01

    English translation of the 3rd edition ""Rohrsysteme aus PE 100"". Because of the considerably increased performance, pipe and pipe systems made from 100 enlarge the range of applications in the sectors of gas and water supply, sewage disposal, industrial pipeline construction and in the reconstruction and redevelopment of defective pipelines (relining). This book applies in particular to engineers, technicians and foremen working in the fields of supply, disposal and industry. Subject matters of the book are all practice-relevant questions regarding the construction, operation and maintenance

  19. Performance of buried pipe installation.

    Science.gov (United States)

    2010-05-01

    The purpose of this study is to determine the effects of geometric and mechanical parameters : characterizing the soil structure interaction developed in a buried pipe installation located under : roads/highways. The drainage pipes or culverts instal...

  20. POSSIBILITIES OF THE USE OF GRP PIPING IN THE CONSTRUCTION AND RECONSTRUCTION OF ENGINEERING NETWORKS

    Directory of Open Access Journals (Sweden)

    ikitina Irina Nikolaevna

    2015-12-01

    Full Text Available Today in modern construction new technologies and materials are used for the manufacture of pipelines for water supply and sanitation. They are supposed to operate for at least 50 years. Unlike plastic pipes, fiberglass ones may be made of larger sizes — up to 3700 mm in diameter. They are produced using the technology of optical fiber winding, which is carried out according to modern international standards of quality. The basic raw materials — fiberglass and resin — are produced in Russia, but their production is limited, so they are purchased abroad, which increases the cost of manufacture of this type of piping. However, due to the necessity of laying pipelines of large diameter, which cannot be made with plastic pipes, the manufacture of GRP pipes will increase. The experience of laying and constructing this type of pipelines, for example, in the areas of hot water supply allows concluding that they are able to withstand the temperatures of up to 150 °C, while their weight is four times less than the weight of steel pipes (they are easily installed with the help of small lifting equipment and by a team of six people. It should be noted that the use of fiberglass pipes helps to reduce the costs of system operation, because this type of piping is not subject to corrosion and encrustation of the inner surface, since it has a low level of roughness, which, for example, is 0.013 for a steel pipe, and 0.01 for fiberglass pipe. Thus, it is not necessary to put protective corrosion-resistant coatings and to provide an expensive protection against electrochemical corrosion. Piping made of fiberglass pipes can be designed as underground, above-ground with stacking or raised on poles. It is possible to combine these options.

  1. Finite Element Analysis of Fluid-Conveying Timoshenko Pipes

    Directory of Open Access Journals (Sweden)

    Chih-Liang Chu

    1995-01-01

    Full Text Available A general finite element formulation using cubic Hermitian interpolation for dynamic analysis of pipes conveying fluid is presented. Both the effects of shearing deformations and rotary inertia are considered. The development retains the use of the classical four degrees-of-freedom for a two-node element. The effect of moving fluid is treated as external distributed forces on the support pipe and the fluid finite element matrices are derived from the virtual work done due to the fluid inertia forces. Finite element matrices for both the support pipe and moving fluid are derived and given explicitly. A numerical example is given to demonstrate the validity of the model.

  2. Microstructural Characterization and the Effect of Phase Transformations on Toughness of the UNS S31803 Duplex Stainless Steel Aged Treated at 850 °C

    Directory of Open Access Journals (Sweden)

    Zucato Igor

    2002-01-01

    Full Text Available Duplex stainless steels, with ferritic-austenitic microstructure, have excellent mechanical properties and corrosion resistance. However, when duplex stainless steels are exposed to temperatures between 600 and 1000 °C, some phase transformations can occur such as chromium nitrides precipitation, chromium carbides precipitation and the sigma phase formation. The formation of such compounds leads to loss in both corrosion resistance and fracture toughness. The negative effects of the formation of chromium nitrides, carbides and the sigma phase are due to the chromium depletion in the matrix. The phase transformations cited above occur initially at ferritic-austenitic interfaces and at the grain boundaries. The aim of this work is to identify and characterize the phase transformations, which occur when aging heat treatments are carried out at temperatures at which the kinetics is the fastest for the reactions mentioned. At first, the samples were annealed at 1100 °C for 40 min. The aging heat treatments were then carried out at 850 °C for 6, 40 e 600 min. Microstructural characterization was done by using optical microscopy with different etchings, in order to identify each phase formed in the duplex stainless steel during aging heat treatments. The toughness was also evaluated by using Charpy impact test. Impact tests show that loss of toughness was related to phase transformations.

  3. Development and testing of restraints for nuclear piping systems

    International Nuclear Information System (INIS)

    Kelly, J.M.; Skinner, M.S.

    1980-06-01

    As an alternative to current practice of pipe restraint within nuclear power plants it has been proposed to adopt restraints capable of dissipating energy in the piping system. The specific mode of energy dissipation focused upon in these studies is the plastic yielding of steels utilizing relative movement between the pipe and the base of the restraint, a general mechanism which has been proven as reliable in several allied studies. This report discusses the testing of examples of two energy-absorbing devices, the results of this testing and the conclusions drawn. This study concentrated on the specific relevant performance characteristics of hysteretic behavior and degradation with use. The testing consisted of repetitive continuous loadings well into the plastic ranges of the devices in a sinusoidal or random displacement controlled mode

  4. Dimensional control of buttwelding pipe fitting for nuclear power plant Class 1 piping systems

    International Nuclear Information System (INIS)

    Rodabaugh, E.C.; Moore, S.E.; Robinson, J.N.

    1976-11-01

    Dimensional controls of wrought steel buttwelding fittings are examined from the standpoint of design adequacy. A fairly large number of fittings were purchased from different manufacturers. The dimensions of each fitting were measured and correlated along with additional information obtained from the manufacturers in an effort to establish ''standard'' shapes. This information and a critical examination of the present ANSI standards is used to develop a ''Supplementary Standard.'' The Supplementary Standard is intended to provide improved dimensional control and more complete design information for fittings used in Class 1 nuclear power plant piping systems

  5. Safety catching device for pipes in missile shielding cylinders of nuclear power plants

    International Nuclear Information System (INIS)

    Hering, S.; Doll, B.

    1976-01-01

    The safety catching device consists of a steel wire passed in U-shape around the pipe to be caught and supported by two anchor ties embedded in the concrete of the missile shielding cylinder. This flexible catching device is to cause the energy released in case of a pipe rupture to be absorbed and no dangerous bending shesses to be transferred to the walls of the missile shielding cylinder. (UWI) [de

  6. Optimization of Pipe Networks

    DEFF Research Database (Denmark)

    Hansen, C. T.; Madsen, Kaj; Nielsen, Hans Bruun

    1991-01-01

    algorithm using successive linear programming is presented. The performance of the algorithm is illustrated by optimizing a network with 201 pipes and 172 nodes. It is concluded that the new algorithm seems to be very efficient and stable, and that it always finds a solution with a cost near the best...

  7. HPFRCC - Extruded Pipes

    DEFF Research Database (Denmark)

    Stang, Henrik; Pedersen, Carsten

    1996-01-01

    The present paper gives an overview of the research onHigh Performance Fiber Reinforced Cementitious Composite -- HPFRCC --pipes recently carried out at Department of Structural Engineering, Technical University of Denmark. The project combines material development, processing technique developme...... of the newly extruded material....

  8. Self-contained pipe cutting shear. Innovative technology summary report

    International Nuclear Information System (INIS)

    1998-11-01

    The US Department of Energy (DO) is in the process of decontaminating and decommissioning (D and D) many of its nuclear facilities throughout the country. Facilities have to be dismantled and demolition waste must be sized into manageable pieces for handling and disposal. Typically, the facilities undergoing D and D are contaminated, either chemically, radiologically, or both. In its D and D work, the DOE was in need of a tool capable of cutting steel and stainless steel pipe up to 6.4 cm in diameter. The self-contained pipe cutting shear was developed by Lukas Hydraulic GmbH and Co. KG to cut pipes up to 6.4 cm (2.5 in.) in diameter. This tool is a portable, hand-held hydraulic shear that is powered by a built-in rechargeable battery or a portable auxiliary rechargeable battery. Adding to its portability, it contains no hydraulic fluid lines or electrical cords, making it useful in congested areas or in areas with no power. Both curved and straight blades can be attached, making it adaptable to a variety of conditions. This tool is easy to set up, operates quietly, and cuts through pipes quickly. It is especially useful on contaminated pipes, as it crimps the ends while cutting and produces no residual cuttings. This shear is a valuable alternative to baseline technologies such as portable band saws, electric hacksaws, and other hydraulic shears. Costs using the innovative shear for cutting 2.5 cm (1-in.) pipe, for example, are comparable to costs using a conventional shear, approximately 80% of portable bandsaw costs and half of electric hacksaw costs

  9. Long-term Stability of 9- to 12 % Cr Steels

    DEFF Research Database (Denmark)

    Hald, John

    2004-01-01

    In the recent 25 years creep rupture strength of 9- to 12 %Cr steels for steam pipes and turbines has been doubled by development of new alloys. This development has formed a basis for improved efficiency of fossil fired steam power plants by introduction of advanced steam temperatures and pressu......In the recent 25 years creep rupture strength of 9- to 12 %Cr steels for steam pipes and turbines has been doubled by development of new alloys. This development has formed a basis for improved efficiency of fossil fired steam power plants by introduction of advanced steam temperatures...... and pressures. Newly developed steam pipe steels are based on modifications of well-established steels like the X 20CrMoV12 1. Balanced addition of V, Nb and N to a 9Cr 1 Mo steel led to the Modified 9 Cr steel P 91. Addition of 1% W to a 9Cr 1 MoVNbN base composition led to steel E 911 and partial replacement...... of Mo with 1.8 % W combined with a slight amount of Boron led to steel P 92. The creep rupture strength of these new alloys are now secured with long-term tests up to 100,000 hours, which demonstrate improvements of 50% (P 91), 75 % (E 911) and 100 % (P 92) in strength compared to X 20CrMoV12 1....

  10. Inclusion control in high-performance steels

    International Nuclear Information System (INIS)

    Holappa, L.E.K.; Helle, A.S.

    1995-01-01

    Progress of clean steel production, fundamentals of oxide and sulphide inclusions as well as inclusion morphology in normal and calcium treated steels are described. Effects of cleanliness and inclusion control on steel properties are discussed. In many damaging constructional and engineering applications the nonmetallic inclusions have a quite decisive role in steel performance. An example of combination of good mechanical properties and superior machinability by applying inclusion control is presented. (author)

  11. Corrosion damage examples and brittleness affecting containing carbon steel materials of the PWR type reactors

    International Nuclear Information System (INIS)

    Millet, L.; Dordonat, M.; Guttmann, D.; Calle, P.

    1993-01-01

    Intercrystalline corrosion has been observed in carbon steel heat exchanger tubes. Waterproof turbine boxes composed of graphite rings and carbon steel, some coated with a KANIGEN chemical nickel, may develop a galvanic coupling corrosion between the graphite rings and the carbon steel body. In a steam impulsion pipe circuit, fatigue corrosion and stress corrosion cracking may appear. Brittleness of carbon steel is linked to an anomalous composition with an excess content of phosphorus and nitrogen. Lamellar wrenchings are observed on steam pipes connection. 5 refs., 3 figs

  12. SEALING LARGE-DIAMETER CAST-IRON PIPE JOINTS UNDER LIVE CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kiran M. Kothari; Gerard T. Pittard

    2005-07-01

    Utilities in the U.S. operate over 75,000 km (47,000 miles) of old cast-iron pipes for gas distribution. Bell-and-spigot joints that connect pipe sections together tend to leak as these pipes age. Current repair practices are costly and highly disruptive. The objective of this program is to design, test and commercialize a robotic system capable of sealing multiple castiron bell and spigot joints from a single pipe entry point. The proposed system will perform repairs with the pipe in service by traveling through the pipe, cleaning each joint surface, and installing a stainless-steel sleeve lined with an epoxy-impregnated felt across the joint. This approach will save considerable time and labor, minimize excavation, avoid traffic disruption, and eliminate any requirement to interrupt service to customers (which would result in enormous expense to utilities). Technical challenges include: (1) repair sleeves must compensate for diametric variation and eccentricity of old cast-iron pipes; (2) the assembly must travel long distances through pipes containing debris; (3) the pipe wall must be effectively cleaned in the immediate area of the joint to assure good bonding of the sleeve; and (4) an innovative bolt-on entry fitting is required to conduct safe repair operations on live mains.

  13. Heat pipe applications workshop report

    International Nuclear Information System (INIS)

    Ranken, W.A.

    1978-04-01

    The proceedings of the Heat Pipe Applications Workshop, held at the Los Alamos Scientific Laboratory October 20-21, 1977, are reported. This workshop, which brought together representatives of the Department of Energy and of a dozen industrial organizations actively engaged in the development and marketing of heat pipe equipment, was convened for the purpose of defining ways of accelerating the development and application of heat pipe technology. Recommendations from the three study groups formed by the participants are presented. These deal with such subjects as: (1) the problem encountered in obtaining support for the development of broadly applicable technologies, (2) the need for applications studies, (3) the establishment of a heat pipe technology center of excellence, (4) the role the Department of Energy might take with regard to heat pipe development and application, and (5) coordination of heat pipe industry efforts to raise the general level of understanding and acceptance of heat pipe solutions to heat control and transfer problems

  14. Development of Structural Health Monitoring System for pipes in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Eom, H. S.; Choi, Y. C.; Shin, S. H.; Youn, D. B.; Park, J. H.

    2010-01-01

    Structural health monitoring (SHM) has becoming an important issue in the maintenance of various structures such as large steel plates, vessels, and pipes in nuclear power plants. There are important factors to be considered in developing an SHM system. With consideration of these factors, we have developed a computerized multi-channel ultrasonic system that can handle array transducers and generate a high-power pulse for online SHM of the plates and pipes. The proposed system is compact but has all the necessary functions for SHM of important structure such as pipes and plates in a NPP

  15. Experimental evaluation of J in cracked straight and curved pipes under bending

    International Nuclear Information System (INIS)

    Moulin, D.; Touboul, F.; Foucher, N.; Lebey, J.; Acker, D.

    1989-01-01

    An experimental program is being carried out at the CEA Saclay in collaboration with FRAMATOME and IPSN with a view to validate analysis methods applicable for evaluation of leak before break behavior in P.W.R. piping. A large experimental work was already performed in USA, Germany and Japan and cracked pipes made of stainless steel material under bending. The methods of analysis got same validations for straight pipes. However applicability to elbows and comparison with toughness values obtained on small specimens like CT specimens was not completely dealt with

  16. Evaluation of stresses in large diameter, thin walled piping at support locations

    International Nuclear Information System (INIS)

    Bryan, B.J.; Flanders, H.E. Jr.; Rawls, G.B. Jr.

    1992-01-01

    The highest stresses in many thin walled piping systems are the local stresses at the pipe supports. These secondary stresses are caused by saddles or other structural discontinuities that restrain pipe ovalization. A static analysis of a thin walled pipe supported on structural steel saddle under dead weight loading is presented. The finite element analysis is performed using a shell model with distributed gravity and hydrostatic pressure loading. Parametric studies on global and local stress are performed to determine the effect of the pipe diameter to thickness ratio. Two aspects of the saddle design are also investigated: the effect of saddle width, and the effect of saddle wrap angle. Additionally, the computed stresses are compared to closed form solutions

  17. Guided waves based diagnostic imaging of circumferential cracks in small-diameter pipe.

    Science.gov (United States)

    Liu, Kehai; Wu, Zhanjun; Jiang, Youqiang; Wang, Yishou; Zhou, Kai; Chen, Yingpu

    2016-02-01

    To improve the safety and reliability of pipeline structures, much work has been done using ultrasonic guided waves methods for pipe inspection. Though good for evaluating the defects in the pipes, most of the methods lack the capability to precisely identify the defects in the pipe features like welds or supports. Therefore, a novel guided wave based cross-sectional diagnostic imaging algorithm was developed to improve the ability of circumferential cracks identification in the pipe features. To ensure the accuracy of the imaging, an angular profile-based frequency selection method is presented. As validation, the approach was employed to identify the presence and location of a small circumferential crack with 1.13% cross sectional area (CSA) in the welding zone of a 48 mm diameter type 304 stainless steel pipe. Accurate identification results have demonstrated the effectiveness of the developed approach. Copyright © 2015. Published by Elsevier B.V.

  18. Imperfection analysis of flexible pipe armor wires in compression and bending

    DEFF Research Database (Denmark)

    Østergaard, Niels Højen; Lyckegaard, Anders; Andreasen, Jens H.

    2012-01-01

    The work presented in this paper is motivated by a specific failure mode known as lateral wire buckling occurring in the tensile armor layers of flexible pipes. The tensile armor is usually constituted by two layers of initially helically wound steel wires with opposite lay directions. During pipe...... laying in ultra deep waters, a flexible pipe experiences repeated bending cycles and longitudinal compression. These loading conditions are known to impose a danger to the structural integrity of the armoring layers, if the compressive load on the pipe exceeds the total maximum compressive load carrying...... ability of the wires. This may cause the wires to buckle in the circumferential pipe direction, when these are restrained against radial deformations by adjacent layers. In the present paper, a single armoring wire modeled as a long and slender curved beam embedded in a frictionless cylinder bent...

  19. 76 FR 15299 - Certain Hot-Rolled Carbon Steel Flat Products From India: Preliminary Rescission of...

    Science.gov (United States)

    2011-03-21

    ..., A507). Non-rectangular shapes, not in coils, which are the result of having been processed by cutting... December 31, 2010. \\4\\ See, e.g., Welded Carbon Steel Standard Pipe and Tube from Turkey: Notice of...

  20. The effect of cerium-based conversion treatment on the cathodic delamination and corrosion protection performance of carbon steel-fusion-bonded epoxy coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Ramezanzadeh, B., E-mail: ramezanzadeh@aut.ac.ir [Department of Surface Coatings and Corrosion, Institute for Color Science and Technology (ICST), 16765-654, Tehran (Iran, Islamic Republic of); Rostami, M. [Department of Nanomaterials and Nanocoatings, Institute for Color Science and Technology (ICST), 16765-654, Tehran (Iran, Islamic Republic of)

    2017-01-15

    Highlights: • Steel surface was treated by Ce and acid phosphoric solutions. • Ce treatment considerably enhanced the surface energy and produce nanoscale roughness. • Ce treated samples showed enhanced adhesion to FBE coating. • Ce treatment of steel significantly reduced the FBE cathodic delamination rate. • Ce treated sample showed enhanced corrosion resistance. - Abstract: The effect of surface pre-treatment of pipe surface by green cerium compound and phosphoric acid solution on the fusion-bonded epoxy (FBE) coating performance was studied. The composition and surface morphology of the steel samples treated by acid and Ce solutions were characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), equipped with energy dispersive spectroscopy (EDS). Also, the surface free energy was evaluated on these samples through contact angle measurements. In addition, the effect of Ce and acid washing procedures on the adhesion properties and corrosion protection performance of the FBE was examined by pull-off, salt spray and electrochemical impedance spectroscopy (EIS) tests. Results showed that compared to acid washing, the chemical treatment by Ce solution noticeably increased the surface free energy of steel, improved the adhesion properties of FBE, decreased the cathodic delamination rate of FBE, and enhanced the coating corrosion resistance compared to the acid washed samples.

  1. Nuclear piping and pipe support design and operability relating to loadings and small bore piping

    International Nuclear Information System (INIS)

    Stout, D.H.; Tubbs, J.M.; Callaway, W.O.; Tang, H.T.; Van Duyne, D.A.

    1994-01-01

    The present nuclear piping system design practices for loadings, multiple support design and small bore piping evaluation are overly conservative. The paper discusses the results developed for realistic definitions of loadings and loading combinations with methodology for combining loads under various conditions for supports and multiple support design. The paper also discusses a simplified method developed for performing deadweight and thermal evaluations of small bore piping systems. Although the simplified method is oriented towards the qualification of piping in older plants, this approach is applicable to plants designed to any edition of the ASME Section III or B31.1 piping codes

  2. Effect of Reheating Temperature and Cooling Treatment on the Microstructure, Texture, and Impact Transition Behavior of Heat-Treated Naval Grade HSLA Steel

    Science.gov (United States)

    Sk, Md. Basiruddin; Ghosh, A.; Rarhi, N.; Balamuralikrishnan, R.; Chakrabarti, D.

    2017-07-01

    In order to achieve the desired mechanical properties [YS > 390 MPa, total elongation >16 pct and Charpy impact toughness of 78 J at 213 K (-60 °C)] for naval application, samples from a low-carbon microalloyed steel have been subjected to different austenitization (1223 K to 1523 K) (950 °C to 1250 °C) and cooling treatments (furnace, air, or water cooling). The as-rolled steel and the sample air cooled from 1223 K (950 °C) could only achieve the required tensile properties, while the sample furnace cooled from 1223 K (950 °C) showed the best Charpy impact properties. Water quenching from 1223 K (950 °C) certainly contributed to the strength but affected the impact toughness. Overall, predominantly ferrite matrix with fine effective grain size and intense gamma-fiber texture was found to be beneficial for impact toughness as well as impact transition behavior. Small size and fraction of precipitates (like TiN, Nb, and V carbonitrides) eliminated the possibility of particle-controlled crack propagation and grain size-controlled crack propagation led to cleavage fracture. A simplified analytical approach has been used to explain the difference in impact transition behavior of the investigated samples.

  3. Seismic ratchet-fatigue failure of piping systems

    International Nuclear Information System (INIS)

    Severud, L.K.; Anderson, M.J.; Lindquist, M.R.; Weiner, E.O.

    1986-01-01

    Failures of piping systems during earthquakes have been rare. Those that have failed were either made of brittle material such as cast iron, were rigid systems between major components where component relative seismic motions tore the pipe out of the component, or were high pressure systems where a ratchet-fatigue fracture followed a local bulging of the pipe diameter. Tests to failure of an unpressurized 3-in. and a pressurized 6-in. diameter carbon steel nuclear pipe systems subjected to high level shaking have been accomplished. Failure analyses of these tests are presented and correlated to the test results. It was found that failure of the unpressurized system could be correlated well with standard ASME type fatigue analysis predictions. Moreover, the pressurized system failure occurred in significantly less load cycles than predicted by standard fatigue analysis. However, a ratchet-fatigue and ductility exhaustion analysis of the pressurized system did correlate very well. These findings indicate modifications to design analysis methods and the present ASME Code piping design rules may be appropriate to cover the ratchet-fatigue failure mode

  4. Heat pipe cooling system for underground, radioactive waste storage tanks

    International Nuclear Information System (INIS)

    Cooper, K.C.; Prenger, F.C.

    1980-02-01

    An array of 37 heat pipes inserted through the central hole at the top of a radioactive waste storage tank will remove 100,000 Btu/h with a heat sink of 70 0 F atmospheric air. Heat transfer inside the tank to the heat pipe is by natural convection. Heat rejection to outside air utilizes a blower to force air past the heat pipe condenser. The heat pipe evaporator section is axially finned, and is constructed of stainless steel. The working fluid is ammonia. The finned pipes are individually shrouded and extend 35 ft down into the tank air space. The hot tank air enters the shroud at the top of the tank and flows downward as it is cooled, with the resulting increased density furnishing the pressure difference for circulation. The cooled air discharges at the center of the tank above the sludge surface, flows radially outward, and picks up heat from the radioactive sludge. At the tank wall the heated air rises and then flows inward to comple the cycle

  5. Drill pipe protector development

    Energy Technology Data Exchange (ETDEWEB)

    Thomerson, C.; Kenne, R. [Regal International Corp., Corsicanna, TX (United States); Wemple, R.P. [Sandia National Lab., Albuquerque, NM (United States)] [ed.] [and others

    1996-03-01

    The Geothermal Drilling Organization (GDO), formed in the early 1980s by the geothermal industry and the U.S. Department of Energy (DOE) Geothermal Division, sponsors specific development projects to advance the technologies used in geothermal exploration, drilling, and production phases. Individual GDO member companies can choose to participate in specific projects that are most beneficial to their industry segment. Sandia National Laboratories is the technical interface and contracting office for the DOE in these projects. Typical projects sponsored in the past have included a high temperature borehole televiewer, drill bits, muds/polymers, rotary head seals, and this project for drill pipe protectors. This report documents the development work of Regal International for high temperature geothermal pipe protectors.

  6. Diffusion in flexible pipes

    Energy Technology Data Exchange (ETDEWEB)

    Brogaard Kristensen, S.

    2000-06-01

    This report describes the work done on modelling and simulation of the complex diffusion of gas through the wall of a flexible pipe. The diffusion and thus the pressure in annulus depends strongly on the diffusion and solubility parameters of the gas-polymer system and on the degree of blocking of the outer surface of the inner liner due to pressure reinforcements. The report evaluates the basis modelling required to describe the complex geometries and flow patterns. Qualitatively results of temperature and concentration profiles are shown in the report. For the program to serve any modelling purpose in 'real life' the results need to be validated and possibly the model needs corrections. Hopefully, a full-scale test of a flexible pipe will provide the required temperatures and pressures in annulus to validate the models. (EHS)

  7. LHCb: Beam Pipe portrait

    CERN Multimedia

    LHCb, Collaboration

    2005-01-01

    The proton beams circulate in the accelerator in Ultra High Vacuum to make them interact only with each other when colliding at the interaction point. A special beam pipe "holds" the vacuum where they pass through the LHCb detector: it has to be mechanically very strong to stand the difference in pressure between the vacuum inside it and the air in the cavern but also be as transparent as possible for the particles originating in the proton−proton collisions.

  8. LHCb: Beam Pipe

    CERN Multimedia

    LHCb, Collaboration

    2005-01-01

    The proton beams circulate in the accelerator in Ultra High Vacuum to make them interact only with each other when colliding at the interaction point. A special beam pipe "holds" the vacuum where they pass through the LHCb detector:it has to be mechanically very strong to stand the difference in pressure between the vacuum inside it and the air in the cavern but also be as transparent as possible for the particles originating in the proton−proton collisions.

  9. Effect of Carbonitriding on the Susceptibility of Medium-Carbon Alloy Steels to Temper Brittleness

    Science.gov (United States)

    Priymak, E. Yu.; Stepanchukova, A. V.; Yakovleva, I. L.; Tereshchenko, N. A.; Chirkov, E. Yu.

    2017-07-01

    The effect of carbonitriding as a finishing operation of hardening of the thread of drill pipes on the properties of the matrix metal, its temper brittleness in particular, is studied. The cold brittleness is evaluated with the help of tests for impact toughness. Steels for the production of drill pipe locks for operation at negative temperatures are recommended.

  10. Pipe clamp effects on thin-walled pipe design

    International Nuclear Information System (INIS)

    Lindquist, M.R.

    1980-01-01

    Clamp induced stresses in FFTF piping are sufficiently large to require structural assessment. The basic principles and procedures used in analyzing FFTF piping at clamp support locations for compliance with ASME Code rules are given. Typical results from a three-dimensional shell finite element pipe model with clamp loads applied over the clamp/pipe contact area are shown. Analyses performed to categorize clamp induced piping loads as primary or secondary in nature are described. The ELCLAMP Computer Code, which performs analyses at clamp locations combining clamp induced stresses with stresses from overall piping system loads, is discussed. Grouping and enveloping methods to reduce the number of individual clamp locations requiring analysis are described

  11. Pipe inspection using the pipe crawler. Innovative technology summary report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-01

    The US Department of Energy (DOE) continually seeks safer and more cost-effective remediation technologies for use in the decontamination and decommissioning (D and D) of nuclear facilities. In several of the buildings at the Fernald Site, there is piping that was used to transport process materials. As the demolition of these buildings occur, disposal of this piping has become a costly issue. Currently, all process piping is cut into ten-foot or less sections, the ends of the piping are wrapped and taped to prevent the release of any potential contaminants into the air, and the piping is placed in roll off boxes for eventual repackaging and shipment to the Nevada Test Site (NTS) for disposal. Alternatives that allow for the onsite disposal of process piping are greatly desired due to the potential for dramatic savings in current offsite disposal costs. No means is currently employed to allow for the adequate inspection of the interior of piping, and consequently, process piping has been assumed to be internally contaminated and thus routinely disposed of at NTS. The BTX-II system incorporates a high-resolution micro color camera with lightheads, cabling, a monitor, and a video recorder. The complete probe is capable of inspecting pipes with an internal diameter (ID) as small as 1.4 inches. By using readily interchangeable lightheads, the same system is capable of inspecting piping up to 24 inches in ID. The original development of the BTX system was for inspection of boiler tubes and small diameter pipes for build-up, pitting, and corrosion. However, the system is well suited for inspecting the interior of most types of piping and other small, confined areas. The report describes the technology, its performance, uses, cost, regulatory and policy issues, and lessons learned.

  12. Pipe inspection using the pipe crawler. Innovative technology summary report

    International Nuclear Information System (INIS)

    1999-05-01

    The US Department of Energy (DOE) continually seeks safer and more cost-effective remediation technologies for use in the decontamination and decommissioning (D and D) of nuclear facilities. In several of the buildings at the Fernald Site, there is piping that was used to transport process materials. As the demolition of these buildings occur, disposal of this piping has become a costly issue. Currently, all process piping is cut into ten-foot or less sections, the ends of the piping are wrapped and taped to prevent the release of any potential contaminants into the air, and the piping is placed in roll off boxes for eventual repackaging and shipment to the Nevada Test Site (NTS) for disposal. Alternatives that allow for the onsite disposal of process piping are greatly desired due to the potential for dramatic savings in current offsite disposal costs. No means is currently employed to allow for the adequate inspection of the interior of piping, and consequently, process piping has been assumed to be internally contaminated and thus routinely disposed of at NTS. The BTX-II system incorporates a high-resolution micro color camera with lightheads, cabling, a monitor, and a video recorder. The complete probe is capable of inspecting pipes with an internal diameter (ID) as small as 1.4 inches. By using readily interchangeable lightheads, the same system is capable of inspecting piping up to 24 inches in ID. The original development of the BTX system was for inspection of boiler tubes and small diameter pipes for build-up, pitting, and corrosion. However, the system is well suited for inspecting the interior of most types of piping and other small, confined areas. The report describes the technology, its performance, uses, cost, regulatory and policy issues, and lessons learned

  13. Studies on reactor piping integrity during severe accident in WIND project

    International Nuclear Information System (INIS)

    Maeda, Akio; Maruyama, Yu; Harada, Yuhei; Shibazaki, Hiroaki; Hidada, Akihide; Sugimoto, Jun; Nakamura, Naohiko

    1998-01-01

    In a severe accident of a light water reactor, the reactor coolant piping might be subjected to thermal loads resulted from decay heat release of the deposited fission products, and heat transfer from high temperature gases generated in the reactor core region in addition to an internal pressure load. Thermal and structural responses of the reactor coolant piping under elevated temperature and pressure conditions are being investigated in piping integrity tests in WIND (Wide Range Piping Integrity Demonstration) project at Japan Atomic Energy Research Institute. Four piping failure tests have been conducted using straight stainless steel pipes with a diameter of 114.3mm or 355.6mm which simulate a part of the reactor coolant piping. In a recent failure test in which a pipe with an outer diameter of 355.6mm and a wall thickness of 35.7mm was used and an internal pressure was kept at 10MPa, a failure of the pipe was observed when the maximum temperature of the pipe reached 1040degC after the temperature was sustained at 1000degC for about one hour. Several small openings were formed at the pipe failure in an area showing the maximum temperature. A history of the change in a vertical diameter was obtained from the measurement of displacement at the top and the bottom of the pipe at the center of heated area. An acceleration of piping ballooning was observed when the maximum temperature of the pipe became approximately 1000degC. It was confirmed in post-test observation that the pipe diameter in vertical and horizontal direction was remarkably enlarged and the pipe wall thickness was largely reduced. In parallel with the tests, a post-test analysis was performed using ABAQUS code. The results from 2D elasto-plastic creep analysis for a piping failure test with an outer diameter of 114.3mm and a wall thickness of 13.5mm qualitatively reproduced the final deformation including the diameter enlargement and the wall thinning. (author)

  14. Stress corrosion cracking (SCC) susceptibility of various stainless steels in oxygenated high temperature water

    International Nuclear Information System (INIS)

    Akashi, Masatsune; Kawamoto, Teruaki

    1978-01-01

    In order to evaluate new plant materials for their future applications to boiling water reactors (BWRs), the creviced bent beam SCC tests (CBB tests) were conducted on various sensitized stainless steels in oxygenated high temperature water. The results obtained are as follows. 1. Field SCC can be easily reproduced by the CBB test using the specimens taken from the 304 stainless steel pipe weld joints. 2. The SCC susceptibility of 18Cr-11Ni stainless steel in oxygenated high temperature water decreases markedly with the reduction of the carbon content. 3. The SCC susceptibility of low carbon stainless steels (304L, 316L) and stabilized stainless steels (321, 347) is significantly lower than that of the 304 and 316 stainless steels. 4. The addition of molybdenum causes the sensitization of stainless steels to delay at lower temperatures, improving the SCC resistance of the weld joints of BWR pipe materials. (auth.)

  15. Noncondensable gas accumulation phenomena in nuclear power plant piping

    International Nuclear Information System (INIS)

    Yamamoto, Yasushi; Aoki, Kazuyoshi; Sato, Teruaki; Shida, Akira; Ichikawa, Nagayoshi; Nishikawa, Akira; Inagaki, Tetsuhiko

    2011-01-01

    In the case of the boiling water reactor, hydrogen and oxygen slightly exist in the main steam, because these noncondensable gases are generated by the radiolytic decomposition of the reactor water. BWR plants have taken measures to prevent noncondensable gas accumulation. However, in 2001, the detonation of noncondensable gases occurred at Hamaoka-1 and Brunsbuttel, resulting in ruptured piping. The accumulation phenomena of noncondensable gases in BWR closed piping must be investigated and understood in order to prevent similar events from occurring in the future. Therefore, an experimental study on noncondensable gas accumulation was carried out. The piping geometries for testing were classified and modeled after the piping of actual BWR plants. The test results showed that 1) noncondensable gases accumulate in vertical piping, 2) it is hard for noncondensable gases to accumulate in horizontal piping, and 3) noncondensable gases accumulate under low-pressure conditions. A simple accumulation analysis method was proposed. To evaluate noncondensable gas accumulation phenomena, the three component gases were treated as a mixture. It was assumed that the condensation amount of the vapor is small, because the piping is certainly wrapped with heat insulation material. Moreover, local thermal equilibrium was assumed. This analysis method was verified using the noncondensable gas accumulation test data on branch piping with a closed top. Moreover, an experimental study on drain trap piping was carried out. The test results showed that the noncondensable gases dissolved in the drain water were discharged from the drain trap, and Henry's law could be applied to evaluate the amount of dissolved noncondensable gases in the drain water. (author)

  16. Pipe support program at Pickering

    International Nuclear Information System (INIS)

    Sahazizian, L.A.; Jazic, Z.

    1997-01-01

    This paper describes the pipe support program at Pickering. The program addresses the highest priority in operating nuclear generating stations, safety. We present the need: safety, the process: managed and strategic, and the result: assurance of critical piping integrity. In the past, surveillance programs periodically inspected some systems, equipment, and individual components. This comprehensive program is based on a managed process that assesses risk to identify critical piping systems and supports and to develop a strategy for surveillance and maintenance. The strategy addresses all critical piping supports. Successful implementation of the program has provided assurance of critical piping and support integrity and has contributed to decreasing probability of pipe failure, reducing risk to worker and public safety, improving configuration management, and reducing probability of production losses. (author)

  17. Thermo-Mechanical Analysis of a Single-Pass Weld Overlay and Girth Welding in Lined Pipe

    Science.gov (United States)

    Obeid, Obeid; Alfano, Giulio; Bahai, Hamid

    2017-08-01

    The paper presents a nonlinear heat-transfer and mechanical finite-element (FE) analyses of a two-pass welding process of two segments of lined pipe made of a SUS304 stainless steel liner and a C-Mn steel pipe. The two passes consist of the single-pass overlay welding (inner lap weld) of the liner with the C-Mn steel pipe for each segment and the single-pass girth welding (outer butt weld) of the two segments. A distributed power density of the moving welding torch and a nonlinear heat-transfer coefficient accounting for both radiation and convection have been used in the analysis and implemented in user subroutines for the FE code ABAQUS. The modeling procedure has been validated against previously published experimental results for stainless steel and carbon steel welding separately. The model has been then used to determine the isotherms induced by the weld overlay and the girth welding and to clarify their influence on the transient temperature field and residual stress in the lined pipe. Furthermore, the influence of the cooling time between weld overlay and girth welding and of the welding speed have been examined thermally and mechanically as they are key factors that can affect the quality of lined pipe welding.

  18. Water hammer in elastic pipes

    International Nuclear Information System (INIS)

    Gale, J.; Tiselj, I.

    2002-01-01

    One dimensional two-fluid six-equation model of two-phase flow, that can be found in computer codes like RELAP5, TRAC, and CATHARE, was upgraded with additional terms, which enable modelling of the pressure waves in elastic pipes. It is known that pipe elasticity reduces the propagation velocity of the shock and other pressure waves in the piping systems. Equations that include the pipe elasticty terms are used in WAHA code, which is being developed within the WAHALoads project of 5't'h EU research program.(author)

  19. The Electrochemical Investigation of the Corrosion Rates of Welded Pipe ASTM A106 Grade B

    Directory of Open Access Journals (Sweden)

    Trinet Yingsamphancharoen

    2016-08-01

    Full Text Available The aim of this work was to investigate the corrosion rate of welded carbon steel pipe (ASTM (American Society for Testing and Materials A106 Grade B by GTAW under the currents of 60, 70, and 80 A. All welded pipes satisfied weld procedure specifications and were verified by a procedure qualification record. The property of used materials was in agreement with the ASME standard: section IX. The welded pipe was used for schematic model corrosion measurements applied in 3.5 wt % NaCl at various flow rates and analyzed by using the electrochemical technique with Tafel’s equation. The results showed the correlation between the flow rate and the corrosion rate of the pipe; the greater the flow rate, the higher corrosion rate. Moreover, the welded pipe from the welding current of 70 A exhibited higher tensile strength and corrosion resistance than those from currents of 60 and 80 A. It indicated that the welding current of 70 A produced optimum heat for the welding of A106 pipe grade B. In addition, the microstructure of the welded pipe was observed by SEM. The phase transformation and crystallite size were analyzed by XRD and Sherrer’s equation. The results suggested that the welding current could change the microstructure and phase of the welded pipe causing change in the corrosion rate.

  20. Post-test creep analysis of piping failure tests in wind project

    International Nuclear Information System (INIS)

    Chino, E.; Maruyama, Y.; Yuchi, Y.; Shibazaki, H.; Nakamura, H.; Hidaka, A.; Kudo, T.; Hashimoto, K.

    2000-01-01

    Thermal and structural responses of the reactor coolant piping under elevated temperature and pressure conditions are being investigated in piping failure tests in WIND (Wide Range Piping Integrity Demonstration) project at JAERI (Japan Atomic Energy Research Institute). The elasto-plastic creep analysis was performed with ABAQUS code for the test using a nuclear grade type 316 stainless steel pipe, which had an outer diameter of 114.3 mm and a wall thickness of 13.5 mm. The major material properties at elevated temperature needed for the analysis were measured for specimen sectioned from the test pipe. Based on the measured creep data, a creep constitutive equation including the tertiary stage was developed and incorporated into ABAQUS code. We compared the results of the three-dimensional analysis with those of two-dimensional analysis and the piping failure test. The comparison showed that the piping failure timing and deformation of pipe obtained from the three dimensional analysis underestimated the test results, and that temperature history at the elevated temperature should be adequately considered. (author)

  1. Analytical and numerical calculations of resistive wall impedances for thin beam pipe structures at low frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Niedermayer, U., E-mail: u.niedermayer@gsi.de [Technische Universitaet Darmstadt, Institut fuer Theorie Elektromagnetischer Felder, Schlossgartenstrasse 8, 64289 Darmstadt (Germany); Boine-Frankenheim, O. [Technische Universitaet Darmstadt, Institut fuer Theorie Elektromagnetischer Felder, Schlossgartenstrasse 8, 64289 Darmstadt (Germany)

    2012-09-21

    The resistive wall impedance is one of the main sources for beam instabilities in synchrotrons and storage rings. The fast ramped SIS18 synchrotron at GSI and the projected SIS100 synchrotron for FAIR both employ thin (0.3 mm) stainless steel beam pipes in order to reduce eddy current effects. The lowest betatron sidebands are at about 100 kHz, which demands accurate impedance predictions in the low frequency (LF) range where the beam pipe and possibly also the structures behind the pipe are the dominating impedance sources. The longitudinal and transverse resistive wall impedances of a circular multi-layer pipe are calculated analytically using the field matching technique. We compare the impedances obtained from a radial wave model, which corresponds to the setup used in bench measurements, with the axial wave model, which corresponds to an actual beam moving with relativistic velocity. For thin beam pipes the induced wall current and the corresponding shielding properties of the pipe are important. In both models the wall current is obtained analytically. The characteristic frequencies for the onset of the wall current are calculated from equivalent lumped element circuits corresponding to the radial model. For more complex structures, like the SIS100 beam pipe, we use a numerical method, in which the impedance is obtained from the total power loss. The method is validated by the analytic expressions for circular beam pipes.

  2. Ultrasonic testing of austenitic stainless steel welds

    International Nuclear Information System (INIS)

    Nishino, Shunichi; Hida, Yoshio; Yamamoto, Michio; Ando, Tomozumi; Shirai, Tasuku.

    1982-05-01

    Ultrasonic testing of austenitic stainless steel welds has been considered difficult because of the high noise level and remarkable attenuation of ultrasonic waves. To improve flaw detectability in this kind of steel, various inspection techniques have been studied. A series of tests indicated: (1) The longitudinal angle beam transducers newly developed during this study can detect 4.8 mm dia. side drilled holes in dissimilar metal welds (refraction angle: 55 0 from SUS side, 45 0 from CS side) and in cast stainless steel welds (refraction angle: 45 0 , inspection frequency: 1 MHz). (2) Cracks more than 5% t in depth in the heat affected zones of fine-grain stainless steel pipe welds can be detected by the 45 0 shear wave angle beam method (inspection frequency: 2 MHz). (3) The pattern recognition method using frequency analysis technology was presumed useful for discriminating crack signals from spurious echoes. (author)

  3. Finding buried metallic pipes using a non-destructive approach based on 3D time-domain induced polarization data

    Science.gov (United States)

    Shao, Zhenlu; Revil, André; Mao, Deqiang; Wang, Deming

    2018-04-01

    The location of buried utility pipes is often unknown. We use the time-domain induced polarization method to non-intrusively localize metallic pipes. A new approach, based on injecting a primary electrical current between a pair of electrodes and measuring the time-lapse voltage response on a set of potential electrodes after shutting down this primary current is used. The secondary voltage is measured on all the electrodes with respect to a single electrode used as a reference for the electrical potential, in a way similar to a self-potential time lapse survey. This secondary voltage is due to the formation of a secondary current density in the ground associated with the polarization of the metallic pipes. An algorithm is designed to localize the metallic object using the secondary voltage distribution by performing a tomography of the secondary source current density associated with the polarization of the pipes. This algorithm is first benchmarked on a synthetic case. Then, two laboratory sandbox experiments are performed with buried metallic pipes located in a sandbox filled with some clean sand. In Experiment #1, we use a horizontal copper pipe while in Experiment #2 we use an inclined stainless steel pipe. The result shows that the method is effective in localizing these two pipes. At the opposite, electrical resistivity tomography is not effective in localizing the pipes because they may appear resistive at low frequencies. This is due to the polarization of the metallic pipes which blocks the charge carriers at its external boundaries.

  4. Large-bore pipe decontamination

    International Nuclear Information System (INIS)

    Ebadian, M.A.

    1998-01-01

    The decontamination and decommissioning (D and D) of 1200 buildings within the US Department of Energy-Office of Environmental Management (DOE-EM) Complex will require the disposition of miles of pipe. The disposition of large-bore pipe, in particular, presents difficulties in the area of decontamination and characterization. The pipe is potentially contaminated internally as well as externally. This situation requires a system capable of decontaminating and characterizing both the inside and outside of the pipe. Current decontamination and characterization systems are not designed for application to this geometry, making the direct disposal of piping systems necessary in many cases. The pipe often creates voids in the disposal cell, which requires the pipe to be cut in half or filled with a grout material. These methods are labor intensive and costly to perform on large volumes of pipe. Direct disposal does not take advantage of recycling, which could provide monetary dividends. To facilitate the decontamination and characterization of large-bore piping and thereby reduce the volume of piping required for disposal, a detailed analysis will be conducted to document the pipe remediation problem set; determine potential technologies to solve this remediation problem set; design and laboratory test potential decontamination and characterization technologies; fabricate a prototype system; provide a cost-benefit analysis of the proposed system; and transfer the technology to industry. This report summarizes the activities performed during fiscal year 1997 and describes the planned activities for fiscal year 1998. Accomplishments for FY97 include the development of the applicable and relevant and appropriate regulations, the screening of decontamination and characterization technologies, and the selection and initial design of the decontamination system

  5. Prediction of the hardness profile of an AISI 4340 steel cylinder heat-treated by laser - 3D and artificial neural networks modelling and experimental validation

    Energy Technology Data Exchange (ETDEWEB)

    Hadhri, Mahdi; Ouafi, Abderazzak El; Barka, Noureddine [University of Quebec, Rimouski (Canada)

    2017-02-15

    This paper presents a comprehensive approach developed to design an effective prediction model for hardness profile in laser surface transformation hardening process. Based on finite element method and Artificial neural networks, the proposed approach is built progressively by (i) examining the laser hardening parameters and conditions known to have an influence on the hardened surface attributes through a structured experimental investigation, (ii) investigating the laser hardening parameters effects on the hardness profile through extensive 3D modeling and simulation efforts and (ii) integrating the hardening process parameters via neural network model for hardness profile prediction. The experimental validation conducted on AISI4340 steel using a commercial 3 kW Nd:Yag laser, confirm the feasibility and efficiency of the proposed approach leading to an accurate and reliable hardness profile prediction model. With a maximum relative error of about 10 % under various practical conditions, the predictive model can be considered as effective especially in the case of a relatively complex system such as laser surface transformation hardening process.

  6. Prediction of the hardness profile of an AISI 4340 steel cylinder heat-treated by laser - 3D and artificial neural networks modelling and experimental validation

    International Nuclear Information System (INIS)

    Hadhri, Mahdi; Ouafi, Abderazzak El; Barka, Noureddine

    2017-01-01

    This paper presents a comprehensive approach developed to design an effective prediction model for hardness profile in laser surface transformation hardening process. Based on finite element method and Artificial neural networks, the proposed approach is built progressively by (i) examining the laser hardening parameters and conditions known to have an influence on the hardened surface attributes through a structured experimental investigation, (ii) investigating the laser hardening parameters effects on the hardness profile through extensive 3D modeling and simulation efforts and (ii) integrating the hardening process parameters via neural network model for hardness profile prediction. The experimental validation conducted on AISI4340 steel using a commercial 3 kW Nd:Yag laser, confirm the feasibility and efficiency of the proposed approach leading to an accurate and reliable hardness profile prediction model. With a maximum relative error of about 10 % under various practical conditions, the predictive model can be considered as effective especially in the case of a relatively complex system such as laser surface transformation hardening process

  7. Inter granular stress corrosion cracking of Ignalina NPP austenitic piping of outside diameter 325 mm

    International Nuclear Information System (INIS)

    Nedzinskas, L.; Klimasauskas, A.

    2003-01-01

    The Inter Granular Stress Corrosion Cracking (IGSCC) of Ignalina NPP main circulation circuit piping, produced from austenitic stainless steel is presented covering current performances and further 'Ageing Management' related actions and plans as well as experience (lessons learned) on solving IGSCC phenomenon, which is currently under investigations and no yet comprehensive answer how to avoid it. (author)

  8. Evaluation of conjugate, radial heat transfer in an internally insulated composite pipe

    NARCIS (Netherlands)

    Reurings, C.; Koussios, S.; Bergsma, O.K.; Vergote, K.

    2015-01-01

    In order to compete with steel, a fibre-reinforced composite exhaust wall with a general-purpose resin system requires an effective but lightweight insulation layer. However a lack of experimental methods for heat transfer from turbulent gas flow to pipe walls lined with a porous insulation layer

  9. 76 FR 38691 - Certain Pipe and Tube From Brazil, India, Korea, Mexico, Taiwan, Thailand, and Turkey

    Science.gov (United States)

    2011-07-01

    ..., Thailand, and Turkey Institution of five-year review concerning the countervailing duty order on welded... Brazil, India, Korea, Mexico, Taiwan, Thailand, and Turkey. AGENCY: United States International Trade... duty orders on welded carbon steel pipe and tube from India, Thailand, and Turkey, the antidumping duty...

  10. Heat pipe and method of production of a heat pipe

    International Nuclear Information System (INIS)

    Kemp, R.S.

    1975-01-01

    The heat pipe consists of a copper pipe in which a capillary network or wick of heat-conducting material is arranged in direct contact with the pipe along its whole length. Furthermore, the interior space of the tube contains an evaporable liquid for pipe transfer. If water is used, the capillary network consists of, e.g., a phosphorus band network. To avoid contamination of the interior of the heat pipe during sealing, its ends are closed by mechanical deformation so that an arched or plane surface is obtained which is in direct contact with the network. After evacuation of the interior space, the remaining opening is closed with a tapered pin. The ratio wall thickness/tube diameter is between 0.01 and 0.6. (TK/AK) [de

  11. Leak-thight seals got high pressure testing of pipes, tanks, valves

    International Nuclear Information System (INIS)

    Estrade, J.

    1985-01-01

    Leak-tight seals ensure quick, safe and efficient testing of pipes with plain-ended or flanged openings, valves with flanged or welded edges, manifields, recipients, etc. They are inserted into the pipe end manually then simply a slight turn of the seal treated wheel commences the pressure test. Hydraulic pressure is supplied by a pump through the inlet seal and air is purged through the outlet seal which then closes. The higher the pressure, the greater the sealing strength of the seal which prevents accidental unplugging. There are different types of seals: for interior plain-ended openings, for pipes with plain-ended opening, for flanged pipes. (author)

  12. Modeling of heat transfer into a heat pipe for a localized heat input zone

    International Nuclear Information System (INIS)

    Rosenfeld, J.H.

    1987-01-01

    A general model is presented for heat transfer into a heat pipe using a localized heat input. Conduction in the wall of the heat pipe and boiling in the interior structure are treated simultaneously. The model is derived from circumferential heat transfer in a cylindrical heat pipe evaporator and for radial heat transfer in a circular disk with boiling from the interior surface. A comparison is made with data for a localized heat input zone. Agreement between the theory and the model is good. This model can be used for design purposes if a boiling correlation is available. The model can be extended to provide improved predictions of heat pipe performance

  13. Piping Failure Probability Assessments on Material Types, Temperatures and Leak Rates for a RI-ISI Program

    International Nuclear Information System (INIS)

    Bae, Yoonho; Kim, Dongwook

    2015-01-01

    Inservice Inspection (ISI) of piping elements is performed to identify pipe degradation mechanisms that may lead to leaks or ruptures. Risk-informed ISI (RIISI) is presently being applied as an alternative approach to the traditional method for establishing ISI requirements. The RI-ISI process is described in detail in WCAP-14572, Revision 1-NP-A. As a part of this process, an assessment of the piping failure probabilities is made in order to support the segment risk ranking and change in risk tasks. The piping failure probability assessment is performed by using Structural Reliability and Risk Assessment (SRRA) software developed specifically for piping RI-ISI. For each piping segment, information is gathered from various sources to provide the input for the SRRA model. The SRRA input is used to calculate the failure probabilities with and without the effects of inservice inspection for each piping segment. The calculated failure probabilities are then combined with the consequences of failure to develop the segment risk ranking and determine required inspection locations in accordance with the WCAP-14572, Revision 1-NP-A. One of the SRRA inputs is a type of piping material. It has 3 standard values: 304 stainless steel, 316 stainless steel, and carbon steel. To have a better understanding of effects of the types of piping material, a set of sensitivity assessment of SRRA software is performed. In developing of a RI-ISI program, there are material differences depending on the nuclear power plants between 304 St and 316 St on segments of the same location. To have a better understanding of effects of the types of piping material, a set of sensitivity assessment using SRRA software is performed. To find the effects of NPS changes, temperature at pipe weld and leak rates, the assessments are performed for NPS: 2, 5, 16; temperature at pipe weld: 150 .deg. F, 350 .deg. F, 550 .deg. F; and leak rate: Small Leak(SL) and Large Leaks(LL: 2, 30, 300, 1500 gpm). For NPS 2

  14. Thermomechanical and Heat Hardening of Building Steels

    Science.gov (United States)

    Odesskii, P. D.; Rudchenko, A. V.; Shabalov, I. P.

    2005-03-01

    Hardening treatment of steels used in welded metal structures like steelwork of industrial and civil buildings, towers, poles, reservoirs, railway bridge girders, cranes, construction machines, truck bodies, etc. is considered. The structures mentioned are produced from rolled stock supplied by metallurgy in an annual amount of tens of million of tons. In the first turn these are plates, shapes, rolled bars and sections, and pipes with different wall thickness and cross section. A classification of steels for metallic structures with respect to chemical composition and microstructure is presented.

  15. Corrosion and deposit determination in large diameter pipes by radiography

    International Nuclear Information System (INIS)

    Harara, W.

    2006-08-01

    Two steel reference pipes with outer diameters of 8 and 12 inches were machined to make artificial defects on each of them, such as inside and outside steps of different wall thicknesses, inside and outside flat bottomed holes (FBH) of different diameters and depths on steps, flat area (FA), and ground patch (GP). The artificial defect were made to simulate natural corrosion attack as regular corrosion and pitting. The two reference pipes were tested according to tangential radiography technique and double wall single image technique. Tangential radiography technique had been applied using Co-60 radio-isotope to determine the steps thicknesses, the FBH, the remaining wall thickness under the FA, the remaining wall thickness above the GP, and the minimum detectable thickness of the artificial cement deposit on the two reference pipes, with and without insulation. Double wall single image technique had also been applied on the two reference pipes with and without insulation using Ir-192 radio-isotope to measure the flat bottomed holes depths, GP depth, and FA depth by density measurement. The measurement results obtained from the radiographs confirm that, tangential radiography technique can be applied to detect and evaluate the inside and outside regular corrosion attack in the large diameter pipes. It can also be applied to detect and evaluate the outside FBH with depth equal or greater than 10%. Inside 10% FBH and inside 20% FBH can not be detected if their diameters are not larger than certain value related to diameter and wall thickness of the pipe under test. Increasing the film density up to 5 outside the pipe did not provide any detection improvement of 10% and 20% inside FBH. Tangential radiography technique can also be applied to detect and measure the deposit inside the pipes. Double wall technique can be applied as an alternative method of the tangential radiography technique to detect and to evaluate the shallow and small diameter, 10% and 20% inside FBH

  16. Investigation of guided waves propagation in pipe buried in sand

    International Nuclear Information System (INIS)

    Leinov, Eli; Cawley, Peter; Lowe, Michael J.S.

    2014-01-01

    The inspection of pipelines by guided wave testing is a well-established method for the detection of corrosion defects in pipelines, and is currently used routinely in a variety of industries, e.g. petrochemical and energy. When the method is applied to pipes buried in soil, test ranges tend to be significantly compromised because of attenuation of the waves caused by energy radiating into the soil. Moreover, the variability of soil conditions dictates different attenuation characteristics, which in-turn results in different, unpredictable, test ranges. We investigate experimentally the propagation and attenuation characteristics of guided waves in pipes buried in fine sand using a well characterized full scale experimental apparatus. The apparatus consists of an 8 inch-diameter, 5.6-meters long steel pipe embedded over 3 meters of its length in a rectangular container filled with fine sand, and an air-bladder for the application of overburden pressure. Longitudinal and torsional guided waves are excited in the pipe and recorded using a transducer ring (Guided Ultrasonics Ltd). Acoustic properties of the sand are measured independently in-situ and used to make model predictions of wave behavior in the buried pipe. We present the methodology and the systematic measurements of the guided waves under a range of conditions, including loose and compacted sand. It is found that the application of overburden pressure modifies the compaction of the sand and increases the attenuation, and that the measurement of the acoustic properties of sand allows model prediction of the attenuation of guided waves in buried pipes with a high level of confidence

  17. Failure rates in piping manufactured to different standards

    International Nuclear Information System (INIS)

    Barnes, R.W.; Cooper, G.D.

    1995-11-01

    Most non-nuclear process piping systems in Canada and the United States are constructed to the requirements of the piping codes of the American Society of Mechanical Engineers (ASME B31.1 and B31.3). Section III of the ASME Boiler and Pressure Vessel Code, has additional requirements for piping that are expected to provide further assurance of pressure boundary integrity. This project attempted to determine if the additional requirements of Section III were beneficial in preventing failure of the pressure boundary. The approach taken in the study was to determine the causes of failure of non-nuclear piping subjected to service similar to that experienced by piping in CANDU nuclear power plants. The study examined information on carbon steel piping systems filled with water/steam which operate up to a maximum temperature of 600 F and a maximum pressure of 1600 psi. The failure mechanisms were identified and analysed to determine whether application of the requirements of Section III would have prevented the failure. Through a process of interviews and literature search, 186 failures were identified and assembled into a reference database. Many of the records were incomplete; therefore, the reference database was trimmed to include a subset of 65 failure points supported by complete data. This subset formed the basis for this study. The results from the study of other databases assembled for similar purposes were reviewed and compared to the conclusions reached in this study. These reviews confirmed the conclusions reached in this study. (author). 48 refs., 20 tabs

  18. Mechanical Behaviour of Lined Pipe

    NARCIS (Netherlands)

    Hilberink, A.

    2011-01-01

    Installing lined pipe by means of the reeling installation method seems to be an attractive combination, because it provides the opportunity of eliminating the demanding welds from the critical time offshore and instead preparing them onshore. However, reeling of lined pipe is not yet proven

  19. Brittle fracture in casing pipes; Sproeda brott i mantelroer

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Stefan; Thoernblom, Kristian; Saellberg, Sven-Erik; Bergstroem, Gunnar [Swedish National Testing and Research Inst., Goeteborg (Sweden)

    2005-05-01

    Rapid Crack Propagation (RCP) has been observed in the casing pipe of large diameter district heating pipes on several occasions. An RCP crack is driven by hoop stresses in the casing pipe wall. It is a problem during installation work in cold weather. The casing pipe material is more brittle in low temperatures, and a temperature decrease will cause a hoop stress build-up since the thermal contraction of the casing pipe is constrained by the steel pipe and the PUR foam. RCP fracture has been documented at temperatures around -18 deg C but has likely, at some instances, occurred already at few degrees below 0 deg C. Three different polyethylene materials were evaluated with respect to the risk for brittle fracture of the casing pipe. One unimodal material of PE80 quality which have been used in casing to a large extent previously, one modern unimodal PE80 material which is used today and, finally, a bimodal PE80 material of a quality which currently is the dominant choice among pipe producers. Modern materials are in general much more resistant to brittle fracture, since it is an important design property for the raw material producers. Tests were done on casing of both large (up to 630 mm in diameter) and small (160 mm) dimension. A handling test was made where the pipes were cooled down and worked on with power tools in a manner similar to actual field work. An RCP fracture occurred at -25 deg C during cutting with angle grinder on a pipe with a diameter of 500 mm on the modern unimodal PE80 material. The same material also fractured during impact testing according to EN 253 at -20 deg C on both small and large diameter pipes. The bimodal PE80 resin passed both tests without fracture. A series of impact tests were done on pipes with diameter 160 mm with the purpose of determining critical temperatures and temperature stress levels with respect to brittle fracture. The results show that the bimodal material is so resistant that there is no real risk for RCP in

  20. SEALING LARGE-DIAMETER CAST-IRON PIPE JOINTS UNDER LIVE CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kiran M. Kothari, Gerard T. Pittard

    2004-01-01

    Utilities in the U.S. operate over 75,000 km (47,000 miles) of old cast-iron pipes for gas distribution. The bell-and-spigot joints that connect pipe sections together tend to leak as these pipes age. Current repair practices are costly and highly disruptive. The objective of this program is to design, test and commercialize a robotic system capable of sealing multiple cast iron bell and spigot joints from a single pipe entry point. The proposed system will perform repairs while the pipe remains in service by traveling through the pipe, cleaning each joint surface, and installing a stainless-steel sleeve lined with an epoxy-impregnated felt across the joint. This approach will save considerable time and labor, avoid traffic disruption, and eliminate any requirement to interrupt service to customers (which would result in enormous expense to utilities). Technical challenges include: (1) repair sleeves must compensate for diametric variation and eccentricity of cast-iron pipes; (2) the assembly must travel long distances through pipes containing debris; (3) the pipe wall must be effectively cleaned in the immediate area of the joint to assure good bonding of the sleeve; and (4) an innovative bolt-on entry fitting is required to conduct repair operations on live mains. The development effort is divided into eleven tasks. Task 1--Program Management and Task 2--were completed in prior quarters while Task 3--Design and Fabricate Ratcheting Stainless-Steel Repair Sleeves has progressed to installing prototype sleeves in cast iron test pipe segments. Efforts in this quarter continued to focus on Tasks 4--8, with significant progress made in each. Task 4 (Design, Fabricate and Test Patch Setting Robotic Train) progressed to the design of the control electronics and pneumatic system to inflate the bladder robotic patch setting module. Task 5 (Design & Fabricate Pipe-Wall Cleaning Robot Train with Pan/Zoom/Tilt Camera) continued with additional in-pipe testing required to