Microstructure evolution, creep damage and fracture mechanism of deposited weld metal in muclear class 316H Pipe were studied based on uniaxial creep tests at 525℃ under various stress. The results showed that creep curves consist of three typical stages, including:transient stage, steady-creep stage and accelerated creep regime. Power-law creep dominates the creep deformation behavior of the deposited weld metal. After creep, three types of precipitates can be observed in fractured samples. The Laves phase is considered as the main strengthening phase, which precipitated inside the δ ferrite; the σ phase and the chain-like M23C6 precipitated around the interface between the δ ferrite and the austenite, facilitating the formation and growth of cavities, which caused the failure for the weld metals. Uniform equiaxed dimples are found in fracture surfaces, indicating that the ductile fracture mechanism occurs in deposited weld metal after creep rupture.
ZHANG Bojun
,
YU Huajin
,
JING Hongyang
,
XU Lianyong
,
ZHAO Lei
. Study on creep properties of deposited weld metal in nuclear class 316H pipe[J]. Transactions of The China Welding Institution, 2019
, 40(12)
: 97
-101
.
DOI: 10.12073/j.hjxb.2019400320
[1] 雷玉成, 张 鑫, 陈 玲, 等. 中国低活化马氏体钢TIG焊焊接接头的高温蠕变性能分析[J]. 焊接学报, 2016, 37(3):5-8
Lei Yucheng, Zhang Xin, Chen Ling, et al. Analysis on creep properties of TIG welding joints of China low activation martensitic steel[J]. Transactions of the China Welding Institution, 2016, 37(3):5-8
[2] 田志凌, M·Steen. X20CrMoV12·1钢焊接接头的蠕变行为[J]. 焊接学报, 1992, 13(2):79-84
Tian Zhiling, M·Steen. Creep behavior of X20CrMoV12·1 welded joint[J]. Transactions of the China Welding Institution, 1992, 13(2):79-84
[3] Sakthivel T, Vasudevan M, Laha K, et al. Comparison of creep rupture behaviour of type 316L(N) austenitic stainless-steel joints welded by TIG and activated TIG welding processes[J]. Materials Science & Engineering A, 2011, 528(22-23):6971-6980.
[4] Vijayanand V D, Laha K, Parameswaran P, et al. Microstructural evolution during creep of 316LN stainless steel multi-pass weld joints[J]. Materials Science and Engineering:A, 2014, 607:138-144.
[5] Vlastimil V. Creep behaviour and microstructural evolution in AISI 316LN + Nb steels at 650℃[J]. Materials Science & Engineering A, 2011, 528(12):4232-4238.
[6] Zhang Y, Jing H, Xu L, et al. Microstructure and texture study on an advanced heat-resistant alloy during creep[J]. Materials Characterization, 2017, 130:156-172.
[7] Xiao B, Xu L, Zhao L, et al. Microstructure evolution and fracture mechanism of a novel 9Cr tempered martensite ferritic steel during short-term creep[J]. Materials Science and Engineering:A, 2017, 707:466-477.
[8] Zhang Y, Jing H, Xu L, et al. High-temperature deformation and fracture mechanisms of an advanced heat resistant Fe-Cr-Ni alloy[J]. Materials Science and Engineering:A, 2017, 686:102-112.
[9] 杨 滨. CrMoV-9%Cr转子钢窄间隙埋弧焊焊接接头的蠕变行为研究[D]. 上海:华东理工大学, 2017.
[10] Zhang Y, Jing H, Xu L, et al. Design and performance of weld filler metal to match an advanced heat-resistant Fe-Cr-Ni alloy[J]. Materials Science & Engineering A, 2018, 721:103-116.
