Creep Rupture Life Prediction for Heat Resistant Steel Weld Metal

2017 ◽  
Vol 86 (2) ◽  
pp. 76-78
Author(s):  
Kensaku NISHIHARA
Keyword(s):  
Weld Metal ◽  
Life Prediction ◽  
Rupture Life ◽  
Creep Rupture ◽  
Resistant Steel ◽  
Steel Weld ◽  
Heat Resistant Steel ◽  
Heat Resistant ◽  
Steel Weld Metal

Rupture Behavior of Multi-Pass Welded Joints of Heat Resistant Steel Subjected to Creep Loading

2007 ◽  
Author(s):  
Masayoshi Yamazaki ◽  
Hiromichi Hongo ◽  
Takashi Watanabe
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Welded Joints ◽  
Stress Condition ◽  
Welded Joint ◽  
Creep Rupture ◽  
Resistant Steel ◽  
Heat Resistant Steel ◽  
Heat Resistant ◽  
Type Iv

By Conducting long-term creep rupture tests for ferritic (2.25Cr-1Mo and 9Cr-1Mo-VNb) and austenitic (18Cr-8Ni and 16Cr-12Ni-2Mo-0.01C-0.07N) heat resistant steel multi-pass welded joints, creep rupture behavior and microstructures were examined. Constant-load creep rupture tests were conducted at 550 and 600 °C up to about 30,000h. Viewpoint in this study was centered on the influence of microstructure on the fracture location of welded joints in heat resistant steels. The results obtained are as follows; 1. The rupture location of the welded joint in austenitic heat resistant steel was found to shift from the base metal at the higher stress condition to the weld metal at lower stress condition at 550 and 600 °C. 2. In the welded joint of austenitic heat resistant steels, the last layer of weld metal showed considerably lager creep strain than the central layers of weld metal. 3. The rupture location of the welded joint in ferritic heat resistant steel was found to shift from the base metal or weld metal at the higher stress condition to the fine-grained HAZ adjacent to the base metal at lower stress condition at 550 and 600 °C. 4. Type IV creep crack initiation occurred in the fine grained HAZ region adjacent to the base metal for the weld metal pass overlap regions of multi-pass large welded joints specimen in 2.25Cr-1Mo steel. 5. Type IV creep crack of the 9Cr-1Mo-V-Nb welded joint nucleated in the curved part of the groove angle and propagated to the top part of the V-groove. It was found that the voids and cracks were initiated inside the plate thickness.

Novel Concept of Creep Strengthening Mechanism using Grain Boundary Fe2Nb Laves Phase in Austenitic Heat Resistant Steel

2011 ◽  
Vol 1295 ◽  
Author(s):  
Imanuel Tarigan ◽  
Keiichi Kurata ◽  
Naoki Takata ◽  
Takashi Matsuo ◽  
Masao Takeyama
Keyword(s):  
Grain Boundary ◽  
Strengthening Mechanism ◽  
Local Deformation ◽  
Creep Rupture ◽  
Laves Phase ◽  
Resistant Steel ◽  
Heat Resistant Steel ◽  
Heat Resistant ◽  
Term Creep

ABSTRACTThe creep behavior of a new type of austenitic heat-resistant steel Fe-20Cr-30Ni-2Nb (at.%), strengthened by intermetallic Fe2Nb Laves phase, has been examined. Particular attention has been given to the role of grain boundary Laves phase in the strengthening mechanism during long-term creep. The creep resistance increases with increasing area fraction (ρ) of grain boundary Laves phase according to equation ε/ε = (1−ρ), where ε0 is the creep rate at ρ = 0. In addition, the creep rupture life is also extended with increasing ρ without ductility loss, which can yield up to 77% of elongation even at ρ = 89%. Microstructure analysis revealed local deformation and well-developed subgrains formation near the grain boundary free from precipitates, while dislocation pile-ups were observed near the grain boundary Laves phase. Thus, the grain boundary Laves phase is effective in suppressing the local deformation by preventing dislocation motion, and thereby increases the long-term creep rupture strength. This novel creep strengthening mechanism was proposed as “grain boundary precipitation strengthening mechanism” (GBPS).

scholarly journals PM-08Microstructure analysis of MX precipitates in weld metal for heat resistant steel

Microscopy ◽  
2018 ◽  
Vol 67 (suppl_2) ◽  
pp. i39-i39
Author(s):  
Hiroya Yasui ◽  
Kouichi Shida ◽  
Shinji Takahashi ◽  
Toshiaki Okabe ◽  
Hiroyuki Takeda ◽  
...  
Keyword(s):  
Weld Metal ◽  
Resistant Steel ◽  
Heat Resistant Steel ◽  
Heat Resistant

scholarly journals Creep-Rupture Life Prediction for 9Cr-1Mo-Nb-V Weld Metal

2015 ◽  
Vol 55 (10) ◽  
pp. 2189-2197
Author(s):  
Ayumu Miyakita ◽  
Ken Yamashita ◽  
Genichi Taniguchi ◽  
Tetsuo Suga
Keyword(s):  
Weld Metal ◽  
Life Prediction ◽  
Rupture Life ◽  
Creep Rupture

Growth Kinetics of Laves Phase and Its Effect on Creep Rupture Behavior in 9Cr Heat Resistant Steel

2016 ◽  
Vol 23 (7) ◽  
pp. 685-691 ◽  
Author(s):  
Zhi-xin Xia ◽  
Chuan-yang Wang ◽  
Chen Lei ◽  
Yun-ting Lai ◽  
Yan-fen Zhao ◽  
...  
Keyword(s):  
Growth Kinetics ◽  
Creep Rupture ◽  
Laves Phase ◽  
Resistant Steel ◽  
Heat Resistant Steel ◽  
Heat Resistant ◽  
Kinetics Of ◽  
Rupture Behavior

scholarly journals Creep Rupture Behavior in Dissimilar Weldment between FB2 and 30Cr1Mo1V Heat-Resistant Steel

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jiankun Xiong ◽  
Jianping Yang ◽  
Haiyan Zhao ◽  
Lin Yang ◽  
Yang Guo ◽  
...  
Keyword(s):  
Subgrain Size ◽  
Fracture Initiation ◽  
Creep Rupture ◽  
Transgranular Fracture ◽  
Resistant Steel ◽  
Laves Phases ◽  
Heat Resistant Steel ◽  
Heat Resistant ◽  
Fracture Character ◽  
Rupture Behavior

Creep rupture behavior of dissimilar weldments between FB2 and 30Cr1Mo1V heat-resistant steel by multipass welding at 783 K (510°C) under different stresses (260 to 420 MPa) was researched. The fitted creep rupture exponent is 14.53, and the 10,000 h extrapolating strength values predicted by the power law and Larson-Miller parameter show good agreement with experimental data. The samples exhibit a ductile fracture character and fracture in the weld fusion zone, which has a highly heterogeneous microstructure and grains with different morphologies and sizes and an obvious softening. There exist a decrease in the dislocation and precipitate density and an increase in the subgrain size in the weld metal after creep. The rupture is a transgranular fracture characterized by dimples as a result of microvoid coalescence. Laves phases along with copper-rich precipitates are observed in the vicinity of fracture surface, which creates a stress concentration that can cause transgranular fracture initiation.

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