摘要
在核电一回路系统中,存在许多连接核压力容器接管嘴与安全端的异种金属焊接接头。由于设计及使用的要求,这种焊接接头一般是在低合金高强钢管嘴焊接坡口面上预堆焊多层镍基合金后,再用镍基合金焊材将之与奥氏体不锈钢安全端焊接在一起而得到的。核电站运行历史表明,这种多材料构成的焊接接头是发生失效的薄弱环节,因而属于核安全重点关注的部位。为发展适合于这种复杂多材料接头的完整性设计和评价的先进技术,需要对接头局部力学性能和微观组织,不同位置与不同尺寸裂纹的局部断裂行为进行深入系统的研究及理解。本文以新一代压水堆核电站系统中的Alloy52M异种金属焊接接头为研究对象,对这些问题开展了研究,所做工作和得到的主要结论如下：
(1)通过微观组织观察和小尺寸平板试样拉伸试验,表征了Alloy52M异种金属焊接接头区不同位置的微观组织和局部力学性能(强度、塑性、应力-应变行为,硬度)。研究表明,在异种金属焊接接头多材料组合的界面区域,存在复杂的微观组织及急剧的力学性能变化。由焊接过程中的热流动和元素迁移导致了这些复杂组织及局部力学性能分布。非均匀的力学性能分布造成接头局部位置的性能失配,这将影响裂尖断裂力学参数、塑性变形行为、局部断裂阻力和裂纹扩展行为,需要在结构完整性评定中予以考虑。
(2)采用含GTN模型的有限元法,数值模拟研究了简化四材料异种金属焊接接头不同位置及不同深度裂纹的三点弯曲试样的延性扩展行为。结果显示,初始裂纹位于异种金属焊接接头不同位置时,得到的裂纹扩展阻力及裂纹扩展路径不同。当初始裂纹位于焊缝及隔离层中心时,裂纹尖端塑性及损伤区基本是对称的,裂纹扩展路径基本沿着初始裂纹面向前扩展。当初始裂纹位于不同材料的界面或近界面区,裂尖塑性和损伤区是非对称的,裂纹扩展路径有显著偏转现象。裂纹倾向于向界面两侧低屈服应力一侧材料扩展。异种金属焊接接头不同初始裂纹位置、不同裂纹深度及不同材料间的强度失配影响裂纹尖端三轴应力及塑性应变的分布,导致不同的延性裂纹扩展阻力及扩展路径。
(3)采用原位观察拉伸试验,研究了异种金属焊接接头微单边缺口拉伸试样的裂纹起裂及扩展过程。结果显示,异种金属焊接接头缺口尖端一般经历大范围塑性变形,主导性的断裂机制为局部孔洞型延性断裂,在个别位置出现局部脆断现象。裂纹通常在低屈服强度材料内起裂并扩展。初始缺口位于异种金属焊接接头的不同位置时,试样呈现不同的承载能力及表观韧性。这主要由缺口尖端局部力学性能、强度失配及材料裂纹扩展阻力不同导致。
(4)通过Alloy52M异种金属焊接接头三点弯曲试样的断裂试验,研究了十三个局部位置的裂纹扩展行为。确定了局部断裂阻力曲线及裂纹扩展路径,标定得到了十三个位置的GTN损伤参数,分析了局部强度失配对局部断裂阻力、裂纹扩展路径及结构完整性评定的影响。结果进一步表明,裂纹总是向低屈服强度材料一侧偏转,裂纹扩展路径主要由强度失配控制,而非韧性失配控制。具有较大裂纹路径偏转的裂纹扩展阻力曲线反映沿裂纹扩展区域的表观断裂阻力,而非初始裂纹尖端区域材料的本质断裂阻力。如不考虑热影响区、界面区及近界面区的局部断裂阻力,使用母材或焊材的裂纹扩展阻力去评价异种金属焊接接头局部位置缺陷的安全性,将不可避免的得到非保守(危险)或保守的评定结果。且大多数情况下,评价结果为潜在的非安全。
(5)通过断裂试验及微观组织观察,研究了Alloy52M异种金属焊接接头的断裂机制,分析了局部断裂机制与局部断裂阻力的关系。得出,母材A508和316L区及316L热影响区的断裂是典型的微孔洞形核、生长及聚合为特征的延性断裂,三个区域不同的裂纹扩展阻力与局部微观组织有关。具有板条马氏体组织的A508热影响区及A508/52Mb界面区呈现延性和脆性混合的断裂模式,具有低的裂纹扩展阻力。相对于主裂纹扩展方向,奥氏体柱状晶位向显著影响隔离层Alloy52Mb和焊缝Alloy52Mw的断裂机制和断裂阻力。隔离层Alloy52Mb中的裂纹扩展跨过柱状晶,产生高的裂纹扩展阻力。焊缝Alloy52Mw中的裂纹沿着薄弱的柱状晶界扩展,呈现脆性断裂模式,形成低的裂纹扩展阻力。
(6)局部力学性能及其失配显著影响裂纹尖端塑性变形行为、局部断裂阻力、裂纹扩展路径及断裂机制。对于异种金属焊接接头中显著的局部失配情况,需要得到局部力学性能及断裂阻力,并用于其完整性评定。并且也需要发展基于局部损伤和断裂模型的异种金金焊接接头完整性评定新方法。
Dissimilar metal welded joints (DMWJs) are widely used to join the ferritic steel pipe nozzles of the pressure vessels to the austenitic stainless steel safe-end pipes in primary water systems of Pressurized water reactors (PWRs). Based on the requirements of design and use for the DMWJs, multilayers Nickel-base alloy are generally pre-deposited on the ferritic nozzle face firstly, then welding is carried out between the buttering layer and the austenitic safe-end pipe with Nickel-base alloy. The running history of PWRs shows that the DMWJs are weak components in the primary water systems. As a result, the DMWJs are regarded to be the key attention structure. In order to develop the advanced technique on integrity design and assessment for the complicated multi materials welded joint, local fracture behavior for the cracks in different position and for different depth cracks, local mechanical properties and local microstructures of the DMWJ should be investigated and understood. In this paper, Alloy52M DMWJ of the new generation PWR was studied on these issues above. The main work and conclusion were as follows:
(1) The microstructures and local mechanical properties (strength, ductility, stress-strain behavior and hardness) were characterized by the microstructure observation and tensile tests of mini-sized flat specimens. The results show that in the interface regions between materials, there exist complex microstructures and drastic change in local mechanical properties. The heat flow and element migration during welding process leads to these complex microstructures and local distributions in mechanical properties. The heterogeneous mechanical distributions cause local mechanical mismatches, and which will affect the crack-tip fracture mechanics parameter, plastic deformation behavior, local fracture resistance and crack growth behavior. This needs to be considered in the integrity assessment of the DMWJs.
(2) The finite element method (FEM) based on GTN model was used to investigate the ductile crack growth behavior in three-point bending specimens of a simplified DMWJ composed of four materials. Results show that the initial cracks with different locations and different depths in the DMWJ have different crack growth resistances and growth paths. When the initial crack lies in the centers of the buttering and weld, the crack-tip plastic and damage zones are symmetrical, and the crack grow path is nearly straight along the initial crack plane. While for the interface cracks between materials and near interface crack, the crack tip plastic and damage zones are asymmetric, and the crack growth path has significant deviation phenomenon. The crack growth tends to deviate into the material whose yield stress is lower between the two materials on both side of the interface. The different initial crack locations, crack depths and strength mismatches between different materials in the DMWJ affect the local stress triaxiality and plastic strain distributions in front of crack tips, and lead to different ductile crack growth resistances and growth paths.
(3)The crack initiation and growth process in notched specimens made from a nuclear dissimilar metal welded joint (DMWJ) were investigated and analyzed by using in-situ tensile tests via SEM. The fracture is dominated by ductile void fracture mechanism, but there exists local brittle fracture in a few locations. The cracks in the specimens with inhomogenous material generally initiate and propagate in the materials with lower yield stress. There is great difference in the load-carrying capacity and toughness for the specimens with different initial notch locations in the DMWJ. This is caused by the local mechanical properties, the strength mismatch and crack growth resistance of the material ahead of notches.
(4) An experimental investigation on the local fracture resistance and crack growth behavior in an Alloy52M DMWJ has been carried out by using three-point bending specimens. The local J-resistance curves and crack growth paths of13cracks located at various positions in the DMWJ were determined, and GTN parameters were calibrated for the13cracks. The effects of the local strength mismatch on local fracture resistance, crack growth paths and integrity assessment for the DMWJ were analyzed. The results show that the cracks always deviate to the materials with lower strength, and the crack path deviations are mainly controlled by the strength mismatch, rather than toughness mismatch. The crack extension resistance curve with larger crack path deviation only reflect the apparent fracture resistance along the crack growth region, rather than the intrinsic fracture resistance of the material at the initial crack-tip region. Without considering the local fracture resistance properties of heat affected zone (HAZ), interface and near interface zone, the use of the J-resistance curves of base metals or weld metals following present codes will unavoidably produce non-conservative (unsafe) or excessive conservative assessment results. In most cases, the assessment results will be potentially unsafe.
(5) Both fracture tests and microscopic observations were carried out to investigate the fracture mechanism of different regions within the DMWJ, and the relationship between fracture mechanism in local microstructures and local fracture resistance of the DMWJ was analyzed. The results show the fracture mechanism of A508and316L base metals and heat-affected-zone (HAZ) of316L is typical ductile fracture of nucleation, growth and coalescence of voids, and different crack growth resistance is mainly related to microstructures of them. The fracture mode in A508HAZ and A508/52Mb interface region with predominant martensite microstructure is mixed brittle and ductile fracture, which leads to lower crack growth resistance. The columnar austenite crystal orientation relative to main crack growth direction apparently affects fracture mechanism and crack growth resistance of buttering Alloy52Mb and weld Alloy52Mw. The cracks in Alloy52Mb propagate across columnar crystal boundaries in a ductile mode, and higher fracture resistance is produced. While the cracks in weld Alloy52Mw propagate along the weak columnar crystal boundaries in a brittle mode, which leads to lower crack growth resistance.
(6) The plastic deformation behavior, local fracture resistance, crack growth path and fracture mechanism were remarkably affected by the local mechanical properties and their mismatches. It is recommended to obtain and use local mechanical and fracture properties of all regions of the DMWJ if the complex local mismatch situation is a concern. And new integrity assessment methods based on local damage and fracture models also need to be developed for the DMWJs.
引文
[1]Li GF, Li GJ, Fang KW, et al. Stress Corrosion Cracking Behavior of Dissimilar Metal Weld A508/52M/316L in simulated PWR Primary Water Environment.2nd International Symposium on Materials and Reliability in Nuclear Power Plants. Shengyang, China. April 11-14,2011,137-144
[2]Riess R, Ford FP, Lundgren K. LCC-2 Annual Report. Advanced nuclear technology international Krongjutarvagen 2C, SE-730 50 SKULTUNA, Sweden.2006
[3]Bowerman BS, Czajkowski CJ, Roberts TC, Neal C. Metallurgical Evaluation of a Feedwater Nozzle to Safe-End Weld. Materials characterization.1999, (43):347-353
[4]Rudland D, Zhang T, Wilkowski G, Csontos A. Welding Residual Stress Solutions for Dissimilar Metal Surge Line Nozzles Welds. Proceedings of 2008 ASME Pressure Vessels and Piping Division Conference. Chicago, Illinois, USA. July 27-31,2008. PVP2008-61285
[5]PWR Material Reliability Project, Interim Alloy 600 safety Assessment for US PWR Plant, Part 1:Alloy82/182 Pipe Butt Welds," EPRI Report TP-1001491, April 2001
[6]Gorman J, Hunt S, Riccardella P. PWR Reactor Vessel Alloy 600 Issues. Chapter 44. Companion guide to the ASME boiler & Pressure vessel code.2009
[7]White GA, Nordmann NS, Hickling J, Harrington CD. Development of crack growth rate disposition curves for primary water stress corrosion cracking (PWSCC) of Alloy82,182, and 132 weldments. Proceedings of the 12th International Conference on Environmental Degradation of Materials in Nuclear Power System-Water Reactors-Edited by T.R. Allen, P.J. King, and L. Nelson TMS (The Minerals, Metals & Materials Society),2005
[8]刘全印.核电站稳压器设备安全端焊接技术.压力容器.2009,26(6)：34-37
[9]张茂龙,核电设备典型镍基合金焊接接头力学性能评定及焊缝金属热裂纹敏感性分析.上海交通大学,硕士学位论文,2003
[10]Yoon B, Yang S, Kim Y. Development of an Ultrasonic Performance Demonstration System for Dissimilar Metal Welds in Korean Nuclear Power Plants. Journal of nuclear science and technology.2011,48(11):1403-1411
[11]Chhibber R, Arora N, Gupta SR, Dutta BK. Use of bimetallic welds in nuclear reactors: associated problems and structural integrity assessment issues. Proceedings of the Institution of Mechanical Engineers, Part C:Journal of Mechanical Engineering Science.2006,220: 1121-1133
[12]Bhaduri AK, Venkadesan S, Rodriguez P, Mukunda PG. Transition metal joints for steam generators-An overview. International Journal of Pressure Vessels and Piping.1994,58: 251-265
[13]Faidy C. EDF(France). Overview of EDF ageing management program of safety class components. Autorite desurete nucleaire nupeer. Recueil de contributions collection of papers. 2005
[14]Celin R. Tehovnik F. Degradation of a Ni-Cr-Fe alloy in a pressurized water nuclear power plant. ISSN 1580-2949, MTAEC9.2011,45(2):151-157
[15]Kim MW, Kim YJ, Kim BC. Crack growth analysis in Alloy82/182 butt weld by using the finite element alternating method. Proceedings of the ASME 2009 Pressure Vessels and Piping Division Conference, Prague, Czech Republic. July 26-30,2009. PVP2009-78039
[16]Mendonc MM, Quinan SM, Lourenc WR. Stress corrosion cracking of the AISI 316L stainless steel HAZ in a PWR nuclear reactor environment. Welding International.2011,25(1): 15-23
[17]Chung WC, Huang JY, Tsay LW, Chen C. Stress corrosion cracking in the heat-affected zone of A508 steel welds under high-temperature water. Journal of Nuclear Materials.2011, 408:125-128
[18]Ljungberg LG, Ortnas A, Stahle P, Nelson JL. Stress corrosion cracking initiation in alloys 600 and 182. In sixth International symposium on Environmental Degradation of Materials in Nuclear Power systems-Water Reactors.1993,379-386
[19]Brust FW, Zhang T, Shim DJ, Kalyanam SK, Wilkowski G, Smith M, Goodfellow A. Summary of weld residual stress analyses for Dissimilar metal weld nozzles. Proceedings of the ASME 2010 Pressure Vessels & Piping Division/K-PVP Conference. Bellevue, Washington, USA. July 18-22,2010. PVP2010-26106
[20]Brust FW, Scott PM. Weld residual stresses and primary water stress corrosion cracking in bimetal nuclear pipe welds. Proceedings of 2007 ASME Pressure Vessels and Piping Division Conference. San Antonio, Texas. July 22-26,2007. PVP2007-26297
[21]Seifert HP, Ritter S, Shoji T, Peng QJ, Takeda Y, Lu ZP. Environmentally-assisted cracking behaviour in the transition region of an Alloy182/SA 508 C1.2 dissimilar metal weld joint in simulated boiling water reactor normal water chemistry environment. Journal of Nuclear Materials.2008,378:197-210
[22]Seifert HP, Ritter S. Review and Assessment of SCC Experiments with RPV Steels in Oskarshamn 2 and 3 (ABB Report SBR 99-020). SKI Report.2005,61
[23]Shim DJ, Kalysnam S, Punch E, Zhang T, Brust F, Wilkowski G. Advanced finite element analysis evaluation for circumferential and axial PWSCC defects. Proceedings of the ASME 2010 Pressure Vessels & Piping Division/K-PVP Conference. Bellevue, Washington, USA. July 18-22,2010. PVP2010-25162
[24]White G, Broussard J, Collin J. Klug M. Advanced FEA Modeling of PWSCC Crack Growth in PWR Dissimilar Metal Piping Butt Welds and Application to the Industry Inspection and Mitigation Program. Proceedings of 2008 ASME Pressure Vessels and Piping Division Conference. Chicago, Illinois, USA. July 27-31,2008. PVP2008-61616
[25]Lima LI. Influencia da comcentracao de hidrogenio na suscetibilidade a corrosao sob tensao de Junta soldada com metains dissimilaares em ambiente do circuito primario de reator nuclear. Universidade federal de minas gerais. Programa de pos-graduacao em engenharia mecanica. Belo Horizonte,07 de Julho de 2011
[26]杨敏,米小琴,罗英,王小彬.反应堆压力容器接管与安全端对接焊缝焊接材料的选择及其对焊缝性能的影响.第四届中国核学会省市“三核”论坛.2007,25-29
[27]Sireesha M, Albert SK, Shankar V, Sundaresan S. A comparative evaluation of welding consumables for dissimilar welds between 316LN austenitic stainless steel and Alloy 800. Journal of Nuclear Materials.2000,279:65-76
[28]Busboom H. Ring PJ. Dissimilar-weld failure analysis and development-comparative behavior of similar and dissimilar welds, EPRI report CS64666, July 1986
[29]Scott P, Francini RS, Rosenfield A, Wilkoski G. Fracture evaluations of fusion line cracks in nuclear pipe bimetallic welds, NUREG report/CR-6297, April 1995
[30]Faidy C. Structural integrity of bi-metallic welds in piping fracture testing and analysis. Proceedings of 2008 ASME Pressure Vessels and Piping Division Conference. Chicago, Illinois, USA. July 27-31,2008. PVP2008-61912
[31]Wu WT, Tsai CH. Hot Cracking Susceptibility of Fillers 52 and 82 in Alloy 690 Welding. Metallurgical and materials transactions A.1999, (30A):417-425
[32]丁训慎,核电厂蒸汽发生器制造中的安全问题.核安全.2006,1：16-22
[33]Joseph A, Rai SK, Jayakumar T, Murugan N. Evaluation of residual stresses in dissimilar weld joints. International Journal of Pressure Vessels and Piping.2005,82:700-705
[34]Lee J, Jang Ch, Kim JS, Jin TE. Mechanical Properties Evaluation in Inconel 82/182 Dissimilar Metal Welds. Transactions, SMiRT 19, Toronto. August 2007. Paper#G04/4
[35]Jang Ch, Lee J, Kim JS, Jin TE. Mechanical property variation within Inconel 82/182 dissimilar metal weld between low alloy steel and 316 stainless steel. International Journal of Pressure Vessels and Piping.2008,85:635-646
[36]Iglesias L, Lima L, Silva GM, Chilque AR. Characterization of Dissimilar Metal Weld between Low Alloy Steel ASTM A508 and 316L Stainless Steel. Soldagem Insp. Sao Paulo. Abr/Jun2010,15(2):112-120
[37]Doctor SR, chuster GJS. Assessing primary water stress corrosion crack morphology and nondestructive evaluation reliability.18th international Conference on structure mechanics in reactor technology (SMiRT 18). Beijing, China. August 7-12,2005. SMiRT 18-005-2
[38]Yoshida K, Kojima M, Iida M, Takahashi I. Fracture toughness of Weld Metals in Steel Piping for Nuclear Power Plants. International Journal of Pressure Vessels and Piping.1990, 43:273-284
[39]Hou J, Peng QJ, Takeda Y, Kuniya J, Shoji T. Microstructure and stress corrosion cracking of the fusion boundary region in an alloy 182-A533B low alloy steel dissimilar weld joint. Cossosion Science.2010,52:3949-3954
[40]Faidy C, Chas G, Bhandari S, Valeta MP, Hurst R, Youtsos A, Nevasmaa P, Brocks W, Lidbury D, Wiesner C. BIMET:structural integrity of bi-metallic components. Nuclear Engineering and Design.2001,209:79-85
[41]Schwalbe KH, Cornec A, Lidbury D. Fracture mechanics analysis of the BIMET welded pipe tests. International Journal of Pressure Vessels and Piping.2004,81:251-277
[42]Gilles P, Brosse A. Pignol M. Simulation of ductile tearing in a dissimilar material weld up to pipe wall break through. Proceedings of the ASME 2010 Pressure Vessels & Piping Division/K-PVP Conference. Bellevue. Washington. USA. July 18-22.2010. PVP2010-25706
[43]Faidy C. Structural integrity of dissimilar welds ADIMEW project overview. Flaw Evaluation. Service Experience, and Materials for Hydrogen Service. San Diego, California. USA. July 25-29,2004. PVP2004-2540
[44]Faidy C, Martin G, Taylor N, Youtsos A, Katsareas D, Keinanen H, Laukkanen A, Wintle J, Sherry A, Lidbury D, Assurance S. Nuclear science and technology:Assessment of aged piping dissimilar metal weld integrity (ADIMEW), European commission, Final report EUR 23315,2008
[45]Talor N, Faidy C, Gilles P. ADIMEW "Assessment of dissimilar weld integrity:Final Report of the NESC-Ⅲ Project", Network for evaluating structural components. European commission directorate general joint research center. EUR 22510 EN, Printed in Italy.2006
[46]STYLE "Structural integrity for lifetime management-non RPV components", grant agreement no 249648,2010
[47]Laukkanen A, Nevasmaa P, Ehrnst'en U, Rintamaa R. Characteristics relevant to ductile failure of bimetallic welds and evaluation of transferability of fracture properties. Nuclear Engineering and Design.2007,237:1-15
[48]Blouin A, Chapuliot S, Marie S, Bergheau JM. Brittle fracture analysis of dissimilar metal weld joints. Proceedings of the ASME 2012 Pressure Vessels & Piping Conference., Toronto, Ontario, CANADA. July 15-19,2012. PVP2012-78696
[49]Kim JW, Lee K, Kim JS, Byun TS. Local mechanical properties of Alloy 82/182 dissimilar weld joint between SA508Gr.la and F316 SS at RT and 320℃. Journal of Nuclear Materials.2009,384:212-221
[50]Uyulgan B, Cetinel H, Aksoy T. Effect of constraint on fracture behavior of welded 17MN4 and AISI304 steels. Journal of Mechanical Science and Technology.2011,25 (9): 2171-2177
[51]Itatani M, Saito T, Hayashi T, Narazaki C, Kazuo. Ogawa, Masaaki K. Evaluation of fracture characteristics of ni-base weld metal for BWR components. Proceedings of ASME Pressure Vessels and Piping Division Conference. Prague, Czech Republic. July 26-30,2009. PVP2009-77720
[52]Ogawa T, Itatani M, Saito T, Hayashi T, Narazaki C, Tsuchihashi K. Fracture assessment for a dissimilar metal weld of low alloy steel and Ni-base alloy. International Journal of Pressure Vessels and Piping.2012,90-91:61-68
[53]Samal MK, Seidenfuss M, Roos E, Balani K. Investigation of failure behavior of ferritic-austenitic type of dissimilar steel welded joints. Engineering Failure Analysis.2011, 18:999-1008
[54]Devaux J, Mottet G, Bergheau JM, Bhandari S, Faidy C. Evaluation of the integrity of PWR Bimetallic welds. Journal of Pressure vessel Technology.2000,122:386-373
[55]Gilles Ph. Devaux J, Faidy C. ADIMEW project:Prediction of the ductile tearing of a cracked 16" dissimilar welded junction. Proc of ASME 2004 Pressure Vessel and Piping Conference, USA.2004
[56]Blouin A, Chapuliot S. Marie S. A method to characterize the fracture resistance of dissimilar metal welds. Proceedings of the ASME 2012 Pressure Vessels & Piping Conference. Toronto, Ontario, CANADA. July 15-19,2012. PVP2012-78697
[57]Ancelet O, Matheron PH. Development of a new measurement system for tensile testing. ASME 2010 Pressure Vessels & Piping Division Conference.2010
[58]Bourgeois M, Ancelet O, Marie S. Mechanical characterization for a large test design of a dissimilar metals welding with a narrow gap nickel alloy weld:experimental and numerical analysis on specimens. Proceedings of the ASME 2012 Pressure Vessels & Piping Conference. Toronto, Ontario, CANADA. July 15-19,2012. PVP2012-78139
[59]Dzugan J, Viehrig HW. Application of the normalization method for the determination of J-R curves. Materials Science and Engineering A.2004,387-389:307-311
[60]Faidy C. "BIMET:Structural Integrity of Bi-Metallic Components", In Proceedings of FISA 1999 Conference. Luxembourg,1999
[61]Samal MK, Balani K, Seidenfuss M, Roos E. An experimental and numerical investigation of fracture resistance behaviour of a dissimilar metal welded joint. Proceedings of the Institution of Mechanical Engineers, Part C:Journal of Mechanical Engineering Science.2009,223:1507-1523
[62]Wilkowski G, Xu H, Shim DJ, Rudland DL. Determination of the Elastic-Plastic Fracture Mechanics Z-factor for Alloy 182 Weld Metal Flaws for Use in the ASME Section XI Appendix C Flaw Evaluation Procedures. Proceedings of 2007 ASME Pressure Vessels and Piping Division Conference. San Antonio, Texas. July 22-26,2007. PVP2007-26733
[63]Nicak T, Schendzielorz H, Keim E, Meier G. STYLE:study on transferability of fracture material properties from small scale specimens to a real component. Proceedings of the ASME 2011 Pressure Vessels & Piping Division Conference. Baltimore, Maryland, USA. Julyl7-21,2011. PVP2011-57613
[64]Kolednik O. The yield stress gradient effect in inhomogeneous materials. International Journal of Solids and Structures.2000,37:781-808
[65]Castelluccio GM, Cravero S, Bravo R, Ernst H. Mismatch effect on fracture driving force in mismatched girth welded pipes. Proceedings of the ASME 2011 Pressure Vessels & Piping Division Conference, Baltimore, Maryland, USA. July 17-21,2011. PVP2011-58044
[66]Beremin FM, Cavity formation from inclusions in ductile fracture of A508 steel. Metallurgical Transactions A.1981,12A:723-731
[67]Beremin FM. A local criterion for cleavage fracture of a nuclear pressure vessel steel. Metallurgical Transactions A.1983,14A:2277-2287
[68]Gurson AL. Continuum theory of ductile rupture by void nucleation and growth. Part I: yield criteria and flow rules for porous ductile media. Journal of Engineering Materials and Technology.1977,99:2-15
[69]Tvergaard V. Meterial failure by void growth to coalescence. Advances in Applied Mechanics.1990,27:83-151
[70]Rousselier G. Ductile fracture models and their potential in local approach of fracture. Nuclear Engineering and Design.19877105:97-111
[71]Yin SJ. Williams PT. Klasky HB. BV. Analysis of Ductile Crack Growth in Pipe Test in STYLE Project. Proceedings of the ASME 2012 Pressure Vessels & Piping Conference. Toronto, Ontario, CANADA. July 15-19,2012. PVP2012-78518
[72]Daly M, Sherry AH. Advanced assessment of the integrity of ductile components. Proceedings of the ASME 2012 Pressure Vessels & Piping Conference. Toronto, Ontario, CANADA. July 15-19,2012. PVP2012-78774
[73]Besson J, Madi Y, Motarjemi A. Crack initiation and propagation close to the interface in a ferrite-austenite joint. Materials Science and Engineering A.2005,397:84-91
[74]Harrington C. Materials Reliability Program:"Materials Reliability Program:Advanced FEA Evaluation of Growth of Postulated Circumferential PWSCC Flaws in Pressurizer Nozzle Dissimilar Metal Welds, " MRP-216 Revision 1, August 2007
[75]Ogawa K, Chidwick LO, Kingston EJ, Muroya I, Iwamoto Y, Smith DJ. Measurement of residual stresses in the dissimilar metal weld joint of a safe end nozzle component. Proceedings of ASME 2009 Pressure Vessels and Piping Division Conference. Prague, Czech Republic. July 26-30,2009. PVP2009-77830
[76]Dike J, Cadden C, Corderman C, Schultz C, Mcaninch M. Finite element modeling of multi-pass GMA welds in steel plates. In:International Trends in welding Research. ASM International, Materials Park, ohio.1996,57-66
[77]Killian DE, Mahmoud SH. Development and validation of analysis method for simulating residual stresses in dissimilar metal pipe butt welds. Proceedings of 2008 ASME Pressure Vessels and Piping Division Conference. Chicago, Illinois, USA. July 27-31,2008. PVP2008-61642
[78]Lee KS, Kim W, Lee JG, Park CY, Yang JS, Kim TR, Park JH. Finite element analysis and measurement for residual stress of dissimilar metal weld in pressurizer safety nozzle mockup. Journal of Mechanical Science and Technology.2009,23:2948-2955
[79]Ogawa N, Muroya I, Iwamoto Y, Hojo K, Ogawa K, Kingston Ed, Smith DJ. Residual stress evaluation of dissimilar weld joint using reactor vessel outlet nozzle mock-up model (report-2). Proceedings of ASME 2009 Pressure Vessels and Piping Division Conference. Prague, Czech Republic. July 26-30,2009. PVP2009-77269
[80]Muroya I, Iwamoto Y, Ogawa N, Hojo K, Ogawa K. Residual stress evaluation of dissimilar weld joint using reactor vessel outlet nozzle mock-up model (Report-1). Proceedings of 2008 ASME Pressure Vessels and Piping Division Conference. Chicago, Illinois, USA. July 27-31,2008. PVP2008-61829
[81]Deng D, Ogawa K. Kiyoshima S, Yanagida N, Saito K. Prediction of residual stresses in a dissimilar metal welded pipe with considering cladding, buttering and post weld heat treatment. Computational Materials Science.2009,47:398-408
[82]Deng D, Ogawa K. Finite element analyses of residual stresses in typical welded joints used in nuclear power plants and comparisons with experiments. Proceedings of the ASME 2010 Pressure Vessels & Piping Division/K-PVP Conference. Bellevue, Washington, USA. July 18-22.2010. PVP2010-25321
[83]Deng D. Kiyoshima S, Ogawa K. Yanagida N. Saito K. Predicting welding residual stresses in a dissimilar metal girth welded pip using 3D finite element model with a simplified heat source. Nuclear Engineering and Design.2011.241:46-54
[84]Na MG, Kim JW, Lim DH, Kang YJ. Residual stress prediction of dissimilar metals welding at NPPs using support vector regression. Nuclear Engineering and Design.2008, 238:1503-1510
[85]Ting K. The evaluation of intergranular stress corrosion cracking problems of stainless steel piping in Taiwan BWR-6 nuclear power plant. Nuclear Engineering and Design.1999, 191:245-254
[86]ASME BPVC Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components. In:ASME Boiler and Pressure Vessel Code. New York:American Society of Mechanical Engineers.2002
[87]Kim YJ, Schwalbe KH, Ainsworth RA. Simplified J-estimations based on the engineering treatment model for homogeneous and mismatched structures. Engineering Fracture Mechanics.2001,68(1):9-27
[88]Schwalbe KH, Zerbst U. The Engineering treatment model. International Journal of Pressure Vessels and Piping.2000,77(14-15):905-918
[89]Kim YJ, Schwalbe KH. Numerical analyses of strength mis-match effect on local stresses for ideally plastic materials. Engineering Fracture Mechanics.2004,71 (7-8):1177-1199
[90]Zerbst U, Primas R, Schindler HJ, Heerens J, Schwalbe KH. The fracture behaviour of a welded tubular joint-an ESIS TCI-3 round robin on failure assessment methods. Part4: application of the ETM 97/1. Engineering Fracture Mechanics.2002,69(10):1129-1148
[91]Kim YJ, Schwalbe KH. Compendium of yield load solutions for strength mis-matched DE(T), SE(B) and C(T) specimens. Engineering Fracture Mechanics.2001,68(9):1137-1151
[92]Kim YJ, Schwalbe KH. Mismatch effect on plastic yield loads in idealized weldments:I. weld centre cracks. Engineering Fracture Mechanics.2001,68(2):163-182
[93]R6:assessment of the integrity of structures containing defects, British energy generation report R/H/R6, revision 4.British Energy Ltd, Gloucester, UK.2007
[94]SINTAP. Structural assessment procedures for European industry, final procedure, project BE95-1426. British Steel Report, Rotherham.1999
[95]RSE-M, "Surveillance and in-service inspection rules for mechanical components of PWR nuclear inlands" edition 1997,1998 and addenda, AFCEN
[96]Gilles P, Brosse A. Large ductile tearing in dissimilar material welds and transferability issues. Proceedings of the ASME 2011 Pressure Vessels & Piping Division Conference. Baltimore, Maryland, USA. July 17-21,2011. PVP2011-57898
[97]Hertele S, Waele WD, Denys R, Verstraete M, Minnebruggen KV, Horn A. Weld strength mismatch in strain based flaw assessment:which definition to use? Proceedings of the ASME 2012 Pressure Vessels & Piping Conference. Toronto, Ontario, CANADA. July 15-19,2012. PVP2012-78306
[98]Itatani M, Ogawa T, Saito T, Narazaki C Ogawa K. Fracture assessment for butt welded plate of Ni-based alloy. Proceedings of the ASME 2010 Pressure Vessels & Piping Division/ K-PVP Conference. Bellevue, Washington, USA. July 18-22,2010. PVP2010-25645
[99]Cox AJ, Olson RJ. Young BA. Scott PM. Rudland DL. Dissimilar metal weld pipe fracture testing:experimental procedures and results. Proceedings of the ASME 2012 Pressure Vessels & Piping Conference. Toronto, Ontario, CANADA. July 15-19,2012. PVP2012-78353
[100]Khana IA, Bhasin V, Vaze KK, Kushwaha HS, Srivastava R, Gupta SR. An estimation procedure to evaluate limit loads of bi-metallic specimens. PART-1. International Journal of Pressure Vessels and Piping.2004,81:451-462
[101]Shim DJ, Wilkowski GM, Rudland DL, Brust FW, Ogawa K. Development of Z-factor for circumferential part-through surface cracks in dissimilar metal welds. Proceedings of ASME 2008 Pressure Vessels and Piping Division Conference. Chicago, Illinois, USA. July 27-31,2008. PVP2008-61110
[102]Shim DJ, Gery M, Wilkowski GM, Rudland DL. Determination of the Elastic plastic Fracture mechanics Z-factor for Alloy 182 weld Metal Flaws. International Journal of Pressure Vessels and Piping.2011,88:231-238
[103]Kim JS, Hwang SS, Kim HP. PWSCC Assessment of dissimilar weld on steam generator drain nozzle in PWR. Proceedings of ASME Pressure Vessels and Piping Division Conference. Prague, Czech Republic. July 26-30,2009. PVP2009-77715
[104]Yu YJ, Yoon KS, Park SH, Park KB, Kim YJ. Extended applications of LBB piping evaluation diagrams for a new plant design. Nuclear Engineering and Design.1997,174:101-110
[105]Focht EM, DeBoo G. Development of initial input parameters for a probabilistic pipe rupture assessment code for nuclear reactor coolant pressure boundary leak-before-break analyses. Proceedings of the ASME 2010 Pressure Vessels & Piping Division/K-PVP Conference. Bellevue, Washington, USA. July 18-22,2010. PVP2010-26021
[106]Gong N, Wang G.Z, Xuan FZ, Tu ST. Leak-before-break analysis of a dissimilar metal welded joint for connecting pipe-nozzle in nuclear power plants. Nuclear Engineering and Design.2013,255:1-8
[107]Gong N, Wang GZ, Xuan FZ, Tu ST. Effects of Initial Crack Location on Failure Assessment Curves in Dissimilar Metal Weld Joints in Nuclear Power Plants. Journal of Pressure Vessel Technology.2012,134:1-7
[108]Rudland D, Lukes R, Scott P, Olson R, Cox A. Dissimilar Metal Weld Pipe Fracture Testing:Analysis of Results and their Implications. Proceedings of the ASME 2012 Pressure Vessels & Piping Conference. Toronto. Ontario, CANADA. July 15-19,2012. PVP2012-78140
[109]French DN. High nickel joints unite dissimilar steels. Welding Design and Fabrication. 1981,54(5):92-93
[110]Wilson DW. Test results on dissimilar metal pipe welds prove favourable. Welding Journal.1990,69(1):71-72
[111]Farley S. An Overview of Non Destructive Inspection Service in Nuclear Power Plants. International Conference Nuclear Energy for New Europe. Portoraz. Slovenia,2004, 811.1-811.9
[112]Jenssen A, Norrgard K, Lagerstron J. Tice DR. Assessment of cracking in dissimilar metal welds. Proc. of Tenth Int. Symp. On Envionmental Degradation of Materials in Nuclear Power Systems-Water Reactors. USA:NACE International. CD-ROM. Aug.2001
[113]Bamford WH, Foster J, Hsu KR, Sanjur LT, Mcilree A. Alloy 182 weld crack growth and its impact on service-induced cracking in operating PWR plant piping, Proc. of Tenth Int. Symp. On Environmental Degradation of Materials in Nuclear Power Systems-Water Reactors. USA:NACE International. CD-ROM. Aug.2001
[114]Cam G, Yeni C, Erim S, Ventzke V, Kocak M. Investigation into properties of laser welded similar and dissimilar steel joints. Science and Technology of welding and joining. 1998,3(4):177-189
[115]Cam G. Bohm KH, Mullauer J, Kocak M. The Fracture behavior of Diffusion-bonded Duplex Gamma TiAl. JOM.1996,11:66-68
[116]Keller C, Hug E, Chateigner D. On the origin of the stress decrease for nickel polycrystals with few grains across the thickness. Materials Science and Engineering A.2009, 500:207-215
[117]Keller C, Hug E, Habraken AM, Duchene L. Finite element analysis of the free surface effects on the mechanical behavior of thin nickel polycrystals. International Journal of Plasticity.2012,29:155-172
[118]Keller C, Hug E, Feaugas X. Microstructural size effects on mechanical properties of high purity nickel. International Journal of Plasticity.2011,27:635-654
[119]Naffakh H, Shamanian M, Ashrafizadeh F. Dissimilar welding of AISI 310 austenitic stainless steel to nickel-based alloy inconel 657. Journal of Materials Processing Technology. 2009,209(7):3628-3639
[120]Nelson TW, Lippold JC, Mills MJ. Investigation of boundaries and structures in dissimilar metal welds. Science and Technology of welding and Joining.1998,3(5):249-255
[121]Asami K, Sakai T. Hydrogen induced cracking at interface between stainless steel overlay weld metal and base metal in pressure vessel. Transactions of the Iron and Steel Institute of Japan.1981,21:B269
[122]Schwalbe KH, Kim YJ, Hao S, Cornec A, Kocak M. EFAM ETM-MM96-The ETM method for assessing the significance of crack like defects in joints with mechanical heterogeneity (strength mismatch), GKSS Report 97/E/9-ETM-MM, GKSS-Forschungszentr-um Geesthacht Gmbh,Geesthacht, Germany.1997
[123]Kocak M. Fitness for service analysis of structures using the FITNET procedure:an overview.24th International conference on offshore mechanics and arctic engineering. Halkidiki, Greece. June 12-17,2005
[124]Kocak M. Structural Integrity of welded structures:Process-Property-Performance (3P) Relationship.63rd Annual Assembly & International Conference of the International Institute of Welding. Istanbul, Turkey.2010
[125]Wang GZ, Wang YL. Effects of loading rate, notch geometry and loading mode on the local cleavage fracture stress of a C-Mn steel. International Journal of Fracture.2007. 146:105-121
[126]Younise B. Sedmak A. Rakin M. Gubeljak N, Medjo B. Burzic M. Zrilic M. Micromechanical analysis of mechanical heterogeneity effect on the ductile tearing of weldments. Materials and Design.2012,37:193-201
[127]Tvergaard V. On localization in ductile materials containing spherical voids. International Journal of Fracture.1982,18:157-169
[128]Tvergaard V, Needleman A. Anlysis of the cup-cone fracture in a round tensile bar. Acta metallurgica.1984,32:157-169
[129](?)stby E, Thaulow C, Zhang ZL. Numerical simulation of specimen size and mismatch effects in ductile crack growth-Part I:Tearing resistance and crack growth paths. Engineering Fracture Mechanics.2007,74:1771-1791
[130]Negre P, Steglich D, Brocks W. Crack extension at an interface:prediction of fracture toughness and simulation of crack path deviation. International Journal of Fracture.2005, 134:209-229
[131]Penuelas I, Betegon C, Rodriguez C. A ductile failure model applied to the determination of the fracture toughness of welded joints. Numerical simulation and experimental validation. Engineering Fracture Mechanics.2006,73:2756-2773
[132]Sun HM, Wang GZ, Xuan FZ. Numerical simulation of the ductile crack growth in a weld joint. In:Proceeding of 12th International Conference on Pressure Vessel Technology, Jeju, Korea. September 20-23,2009
[133]Negre P, Steglich D, Brocks W. Crack extension in aluminium welds:a numerical approach using the Gurson-Tvergaard-Needleman model. Engineering Fracture Mechanics. 2004,71:2365-2383
[134]Rakin M, Gubeljak N. Modelling of ductile fracture initiation in strength mismatched welded joint. Engineering Fracture Mechanics.2008,75:3499-3510
[135]Tanguy B, Besson J, Piques R. Ductile to brittle transition of A508 steel characterized by Charpy impact test Part II:modeling of the Charpy transition curve. Engineering Fracture Mechanics.2005,72:413-434
[136]Itatani M, Saito T, Hayashi T. Evaluation of Fracture Characteristics of Ni-base weld metal for BWR components. In:2009 ASME Pressure Vessels and Piping Division Conference. Vancoucer. BC, Canada. July23-27,2009. PVP2009-77710. CD ROM
[137]Blandford RK, Morton DK, Snow SD. Tensile stress-strain results for 304L and 316L stainless steel plate at temperature. In:2007 ASME Pressure Vessels and Piping Division Conference. San Antonio, TX. July 22-26,2007. PVP2007-16096. CD ROM
[138]Rudland D, Brust F. Shim DJ. Further welding residual stress and flaw tolerance assessment of Dissimilar metal welds with Alloy52 inlays. In:2010 ASME Pressure Vessels and Piping Division Conference. Bellevue, Washington, USA. July 18-22,2010. PVP2010-25433. CD ROM
[139]Ogawa K. Deng D. Investigations on welding resisdual stresses in penetration nozzles by means of 3D thermal elastic plastic FEM and experiment. Computational Materials Science.2009,45:1031-1042
[140]Benseddiq N, Imad AA. ductile fracture analysis using a local damage model. International Journal of Pressure Vessels and Piping.2008,85:219-227
[141]ASTM E1820-08a. Standard test method for measurement of fracture toughness. Philadelphia:American Society for Testing and Materials.2008
[142]Zhu XK, Lam PS, Chao YJ. Application of normalization method to fracture resistance testing for stora tank A285 carbon steel. International Journal of Pressure Vessels and Piping, 2009,86:669-676
[143]Zhu XK, Brian N. Application of Constraint Corrected J-R Curves to Fracture Analysis of Pipelines. Journal of Pressure Vessel Technology.2006,128:581-582
[144]Bertolino G, Meyer G, Ipina JP. In situ crack growth observation and fracture toughness measurement of hydrogen charged Zircaloy-4. Journal of Nuclear Materials 2003,322:57-65
[145]Lin TS, Jia DC, He PG, Wang MR. In situ crack growth observation and fracture behavior of short carbon fiber reinforced geopolymer matrix composites. Materials Science and Engineering A.2010, (A527):2404-2407
[146]Li BS, Shang JL, Guo JJ, Fu HZ. In situ observation of fracture behavior of in situ TiBw/Ti composites. Materials Science and Engineering.2004, A383:316-322
[147]Zhu XK, Joyce JA. J-resistance curve testing of HY80 steel using SE(B) specimens and normalization mechod. Engineering Fracture Mechanics.2007,74:2263-2281
[148]Chhibber R, Biswas P, Arora N, Gupta RS, Dutta BK. Micromechanical modeling of weldments using GTN model. International Journal of fracture.2011,167:71-82
[149]Faleskog J, Gao XS, Shih CF. Cell model for nonlinear fracture analysis-Ⅰ. Micromechanics calibration. International Journal of fracture.1998,89:355-373
[150]Gao XS, Faleskog J, Shih CF. cell model for nonlinear fracture analysis-Ⅱ. Fracture-process calibration and verufucation. International Journal of fracture.1998,89: 375-398
[151]Dutta BK, Guin S, Sahu MK, Samal MK. A phenomenological form of the q2 parameter in the Gurson model. International Journal of Pressure Vessels and Piping.2008,85:199-210
[152]Lei YP, Shi YW, Murakawa H, Luo Y. The effect of mechanical heterogeneity and limit load of a weld joint with longitudinal weld crack on the J-integral and failure assessment curve. International Journal of Pressure Vessels and Piping.1998,75:625-632
[153]Zhang M, Shi YW, Zhang XP. Influence of strength mis-matching on crack driving force and failure assessment curve of weldment. International Journal of Pressure Vessels and Piping.1997,70:33-41
[154]Song TK, Kim YJ, Kim JS, Jin TE. Mismatch limit loads and approximate J estimates for tensile plates with constant-depth surface cracks in the center of welds. International Journal of Fracture.2007,148:343-360
[155]Hao S, Schwalbe KH, Comec A. The effect of yield strength mis-match on the fracture analysis of the welded joints:slip-line field solutions for pure bending. International Journal of Solids and Structures.2000.37:5385-5411