Please wait a minute...
Acta Metall Sin  2012, Vol. 48 Issue (6): 753-758    DOI: 10.3724/SP.J.1037.2011.00668
论文 Current Issue | Archive | Adv Search |
EFFECT OF THE PRECIPITATION OF Cu-RICH CLUSTERS ON THE DBTT OF RPV SIMULATED STEEL
XU Gang1, CAI Linling1, FENG Liu1, ZHOU Bangxin1,2,WANG Jun'an1,2,ZHANG Haisheng3
1. Institute of Materials, Shanghai University, Shanghai 200072
2. Laboratory for Microstructures, Shanghai University, Shanghai 200444
3. National Key Laboratory for Nuclear Fuel and Materials, Nuclear Power Institute of China, Chengdu 610041
Download:  PDF(1181KB) 
Export:  BibTeX | EndNote (RIS)      
Abstract  Reactor pressure vessels (RPVs) are usually made of low alloy ferritic steels, among which A508-III steel is a typical one. The long--term neutron irradiation can induce the embrittlement of RPV steels, and the embrittlement may lead to a reduction of the RPV service life. Generally, this behavior of the embrittlement is well established and is typically assessed by the increase in the ductile-to-brittle transition temperature (DBTT) of the RPV steels. For many years, extensive studies have revealed that irradiation-induced ultrafine Cu-rich clusters (CRCs) play an important role and CRCs with high number density cause hardening and embrittlement of the RPV steels. In order to investigate the effect of the precipitation of CRCs on DBTT of RPV steels by thermal aging, it is necessary to increase the Cu content in RPV steel. A 40 kg ingot of RPV simulated steel based on the composition of A508--III steel with higher Cu content (0.6% in mass fraction) was prepared by vacuum induction melting, and it was forged and hot rolled to a plate with 7 mm in thickness. Specimens with a dimension of 7 mm×12 mm×60 mm were cut from the hot--rolled plate. The heat treatment routes of the specimens consists of a soaking at 880℃ for 0.5 h, a water quenching, a tempering at 660℃ for 10 h, and a final aging at 370℃ for various times. The effect of the precipitation of CRCs on the DBTT of the RPV simulated steel was investigated by Charpy impact tests, as well as the microstructure analysis was carried out by TEM and atom probe tomography (APT). According to ASME 23 standard, Charpy-V specimens with a dimension of 5 mm×10 mm×55 mm were prepared and tested by TINIUS OLSEN 84 impact test machine. The TEM analysis shows that CRCs precipitate on dislocations in the specimen aged at 370 ℃ for 3000 h, and the clusters become a little coarsened when the aging time is extended to 13200 h. For the specimens aged for 1150 h, CRCs were on the stage of the nucleation assessed by TEM as well as APT analysis, and they did not have an effect on the DBTT of the RPV simulated steel. For the specimens aged for 3000 h, CRCs precipitated with an average equivalent diameter of 1.5 nm and a number density of 4.2×1022 m-3, and it results in the increase of the DBTT from -100 ℃ to -60 ℃. For the specimens aged for 13200 h, CRCs slightly coarsened to 2.4 nm of the average equivalent diameter, while the number density is similar to that of the specimens aged for 3000 h. In this case the DBTT rose to -45 ℃. Therefore, the present work shows the precipitation of CRCs induced by thermal aging reveals a smaller impact on the DBTT than that by neutron irradiation. From the thermal aging aspect, the much lower number density of CRCs and the absence of the defects induced by neutron irradiation in the matrix could account for this phenomenon.
Key words:  reactor pressure vessel simulated steel      ductile-to-brittle transformation temperature      Cu-rich cluster      atom probe tomography     
Received:  25 October 2011     
ZTFLH: 

TL341

 

Cite this article: 

XU Gang, CAI Linling, FENG Liu, ZHOU Bangxin,WANG Jun'an,ZHANG Haisheng. EFFECT OF THE PRECIPITATION OF Cu-RICH CLUSTERS ON THE DBTT OF RPV SIMULATED STEEL. Acta Metall Sin, 2012, 48(6): 753-758.

URL: 

https://www.ams.org.cn/EN/10.3724/SP.J.1037.2011.00668     OR     https://www.ams.org.cn/EN/Y2012/V48/I6/753

[1] Toyama T, Nagai Y, Tang Z, Hasegawa M, Almazouzi A, van Walle E,Gerard R.  Acta Mater, 2007; 55: 6852

[2] Auger P, Pareige P, Welzel S, van Duysen J C.  J Nucl Mater,2000; 280: 331

[3] Miller M K, Russell K F, Sokolov M A, Nanstad R K.  J Nucl Mater,2007; 361: 248

[4] Miller M K, Russell K F, Sokolov M A, Nanstad R K.  J Nucl Mater,2003; 320: 177

[5] Miller M K, Nanstad P K, Sokolov M A, Russell K F.  J Nucl Mater,2006; 351: 216

[6] Phythian W J, English C A.  J Nucl Mater, 1993; 205: 162

[7] Carter R G, Soneda N, Dohi K, Hyde J M, English C A, Server W L. J Nucl Mater, 2001; 298: 211

[8] Miller M K, Chernobaeva A A, Shtrombakh Y I, Russell K F, Nanstad R K,Erak D Y, Zabusov O O.  J Nucl Mater, 2009; 385: 615

[9] Miller M K, Russell K F.  J Nucl Mater, 2007; 371: 145

[10] Hornbogen E, Glenn, R C.  Trans Metall Soc AIME, 1960; 218: 1064

[11] Zhang R Q, Hong X F, Peng Q.  Nucl Power Eng, 2010; 31(1): 4

     (张瑞谦, 洪晓峰, 彭倩. 核动力工程. 2010; 31(1): 4)

[12] Goodman S R, Brenners S S, Low J R.  Metall Trans,1973; 4: 2363

[13] Pizzini S, Roberts K J, Phythian W J, English C A, Greaves G N. Philos Mag Lett, 1990; 61: 223

[14] Othen P J, Jenkins M L, Smith G D W, Phythian W J.  Philos Mag Lett,1991; 64: 383

[15] Speich G R, Oriani R A.  Trans Metall Soc AIME, 1965; 233: 623

[16] Othen P J, Jenkins M L, Smith G D W.  Philos Mag, 1994; A70: 1

[17] Styman P D, Hyde J M, Wilford K, Morley A, Smith G D W.Prog Nucl Energ, 2011, doi:10.1016/j.pnucene.2011.10.010

[18] Chu D F, Xu G, Wang W, Peng J C, Wang J A, Zhou B X. Acta Metall Sin, 2011; 47: 269

     (楚大锋, 徐刚, 王伟, 彭剑超, 王均安, 周邦新. 金属学报,2011; 47: 269)

[19] Xu G, Cai L L, Feng L, Zhou B X, Wang W, Peng J C.  Acta Metall Sin,2011; 47: 906

     (徐刚, 蔡琳玲, 冯柳, 周邦新, 王伟, 彭剑超. 金属学报,2011; 47: 906)

[20] Miller M K.  Atom Probe Tomography: Analysis at the Atomic Level.New York: Kliwer Academic/Plenum Publishers, 2000: 25

[21] Yong Q L.  Secondary Phase in Steel. Beijing: Metallurgical Industry Press, 2006: 127

     (雍岐龙. 钢铁材料中的第二相. 北京: 冶金工业出版社, 2006: 127)

[22] Xu G, Cai L L, Feng L, Zhou B X, Liu W Q, Wang J A. Acta Metall Sin, 2012; 48: 407

     (徐刚, 蔡琳玲, 冯柳, 周邦新, 刘文庆, 王均安. 金属学报,2012; 48: 407)

[23] Buswell J T, English C A, Herherington M G, Phythian W J, Smith G D W, Worral G M. In: Steele L E ed.,  Proc 14th Int Symp Effects of Radiation on Materials, Vol. 2, Andover, Massachusseetts:The American Society for Testing and Materials, 1990: 127

[24] Brown L M, Ham R K. In: Kelly A, Nicholson R B, eds.,  Strengthening Methods in Crystals. London:Applied Science Publishers; 1965: 9

[25] Friedel J.  Disloctions. London: Pergamon Press; 1964: 1

[26] Russell K C, Brown L M.  Acta Metall, 1972; 20: 969

[27] Harry T, Bacon D J.  Acta Mater, 2002; 50: 195

[28] Harry T, Bacon D J.  Acta Mater, 2002; 50: 209
[1] Qin SHEN,Xiaojiao WANG,Anyu ZHAO,Yifeng HE,Xulei FANG,Jiarong MA,Wenqing LIU. EFFECTS OF Mn ON MULTI-PRECIPITATES EVOLUTION OF Cu-RICH AND NiAl PHASE IN STEELS[J]. 金属学报, 2016, 52(5): 513-518.
[2] WANG Bo, WANG Xiaojiao, SONG Hui, YAN Jujie, QIU Tao, LIU Wenqing, LI Hui. STRENGTHENING EFFECTS OF MICROSTRUCTURE EVOLUTION DURING EARLY AGEING PROCESS IN Al-Mg-Si ALLOY[J]. 金属学报, 2014, 50(6): 685-690.
[3] WANG Xiaojiao, SHEN Qin, YAN Jujie, QIU Tao, WANG Bo, LI Hui, LIU Wenqing. PRECIPITATION CHARACTERIZATION OF NiAl AND Cu-RICH PHASES IN DUAL-PHASE REGION OF PRECIPITATION STRENGTHENING STEEL[J]. 金属学报, 2014, 50(11): 1305-1310.
[4] LIU Wenqing, LIU Qingdong, GU Jianfeng. DEVELOPMENT AND APPLICATION OF ATOM PROBE TOMOGRAPHY[J]. 金属学报, 2013, 49(9): 1025-1031.
[5] XU Gang, CAI Linling, FENG Liu, ZHOU Bangxin,LIU Wenqing, WANG Jun'an. STUDY ON THE PRECIPITATION OF Cu-RICH CLUSTERS IN THE RPV MODEL STEEL BY APT[J]. 金属学报, 2012, 48(4): 407-413.
[6] XU Gang CHU Dafeng CAI Linling ZHOU Bangxin WANG Wei PENG Jianchao. INVESTIGATION ON THE PRECIPITATION AND STRUCTURAL EVOLUTION OF Cu-RICH NANOPHASE IN RPV MODEL STEEL[J]. 金属学报, 2011, 47(7): 905-911.
[7] CHU Dafeng XU Gang WANG Wei PENG Jianchao WANG Jun’an ZHOU Bangxin. APT AND EXTRACTION REPLICA CHARACTERIZATION OF Cu–RICH CLUSTERS PRECIPITATED IN PRESSURE VESSEL MODEL STEELS[J]. 金属学报, 2011, 47(3): 269-274.
No Suggested Reading articles found!