J0310301 Creep Strength of Dissimilar Weld Joint for A-USC Boiler

2015 ◽  
Vol 2015 (0) ◽  
pp. _J0310301--_J0310301-
Author(s):  
Masaaki TABUCHI ◽  
Hiromichi HONGO ◽  
Tetsuya MATSUNAGA ◽  
Fujio ABE
Keyword(s):  
Creep Strength ◽  
Weld Joint ◽  
Dissimilar Weld

Comparison of Creep Behavior of 2.25Cr-1.6W/Mod. 9Cr-1Mo Dissimilar Weld Joint with Each Matching Filler Metal

2005 ◽  
Vol 297-300 ◽  
pp. 1452-1457
Author(s):  
Jong Jin Park ◽  
Cheol Hong Joo ◽  
Jeong Tae Kim ◽  
Hyu Sun Yu
Keyword(s):  
Creep Behavior ◽  
Creep Strength ◽  
Weld Joint ◽  
Filler Metal ◽  
Welded Joint ◽  
Creep Damage ◽  
Creep Rupture ◽  
Dissimilar Weld ◽  
Weld Joints ◽  
Carbon Migration

This paper describes the evaluation of the creep behavior with two types of matching filler metals for 2.25Cr-1.6W(T23)/Mod. 9Cr-1Mo(T91) dissimilar weld joint. Through the welding procedure qualification tests prior to the creep tests, optimum PWHT holding times at 745±5oC were determined as 30minutes for T23 matching filler metal and 60minutes for T91 matching filler metal. It was also confirmed that carbon migration across the weld interfaces and the softened area at HAZ occurred during PWHT. Creep rupture tests were carried out at 575-650oC and 70-220MPa for two dissimilar metal welds manufactured by an optimum PWHT condition. From the comparison of creep rupture strength, it was shown that the creep strength of the welded joint including T23 matching filler metal was similar to that of T23 base material and somewhat higher than that of the welded joint including T91 matching filler metal. From metallurgical study on the crept specimen, the creep damage of T23/T91 dissimilar weld joints could occur at T23 side IC HAZ and near the T23/T91 weld interface simultaneously. However, the final failure locations seemed to depend on the filler metal and the cause of this phenomenon might be regarded as the additional effect of carbon migration across the weld interfaces. It is thought that the dissimilar weld including T91 filler metal which failures at T23 side CG HAZ subject to both metallurgical notch and carbon migration become more susceptible to creep damage than that including T23 filler metal in which the carbon depletion occurs at the T23 filler metal with higher creep strength than T23 HAZ. T23 filler metal can therefore be proposed for matching filler metal of T23/T91 dissimilar weld joints

scholarly journals Residual Stress Analysis of Dissimilar Weld Joint between CastIron Pipe and Steel Flange

2020 ◽  
Vol 38 (2) ◽  
pp. 144s-148s
Author(s):  
Tomohiro MURATA ◽  
Shigetaka OKANO ◽  
Shimpei TSUTSUMI ◽  
Kenji SAWADA ◽  
Koji NAKAMOTO ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Analysis ◽  
Weld Joint ◽  
Dissimilar Weld ◽  
Residual Stress Analysis

Evaluation of Residual Stresses in Dissimilar Weld Joints

2011 ◽  
Vol 681 ◽  
pp. 182-187 ◽  
Author(s):  
Alix Bonaventur ◽  
Danièle Ayrault ◽  
Guillaume Montay ◽  
Vincent Klosek
Keyword(s):  
Residual Stresses ◽  
Weld Joint ◽  
Safety Issue ◽  
Austenitic Steels ◽  
Hole Drilling ◽  
Primary Coolant ◽  
Pressurized Water ◽  
Dissimilar Weld ◽  
Dissimilar Welds ◽  
Water Reactors

Dissimilar metal joints between pipes of ferritic and austenitic steels are present in primary coolant circuit of pressurized water reactors. Over the last years in particular in USA and Japan, stress corrosion cracks, often associated with weld repairs, have been observed for some dissimilar welds made with an Inconel filler metal. The integrity of this type of components is thus a major safety issue. In this context, the goal of this work is to evaluate the welding residual stresses field for a dissimilar weld joint. A representative bi-metallic tubular weld joint was fabricated and residual stresses profiles in the different weld zones were evaluated by means of the hole drilling and neutron diffraction methods.

Quantitative Evaluation of Secondary Phases in a Weld Joint Made of COST F and FB2 Creep Resistant Steels

2017 ◽  
Vol 270 ◽  
pp. 183-188
Author(s):  
Dagmar Jandová
Keyword(s):  
Quantitative Evaluation ◽  
Creep Strength ◽  
Weld Joint ◽  
Precipitate Size ◽  
Secondary Phases ◽  
Creep Tests ◽  
Transmission Electron ◽  
Creep Resistant Steels ◽  
Term Creep

Conventional (CCT) and accelerated (ACT) creep tests of a weld joint made of COST F and COST FB2 steels were carried out over a temperature range from 550 °C to 650 °C. Fracturing of the crept specimens was located in the heat affected zone (HAZ) of the F steel. Two specimens were selected after CCT and ACT for quantitative evaluation of the precipitates and compared to the weld joint in as-received conditions. Scanning and transmission electron micrographs were used to measure the precipitate size. Both methods were compared and the accuracy of the results was discussed. It was concluded that ACT can simulate the precipitation of chromium carbides and structure recovery during long term creep exposures. However, precipitation of Laves phase during CCT was not recorded after ACT. Therefore, it is difficult to use ACT in this experiment for estimating the long term creep strength.

Studies on Characteristics of Ti6Al4V/AA2024 Dissimilar Weld Joint Using Laser Beam Focusing from AA2024 Side

2017 ◽  
Vol 70 (8) ◽  
pp. 2147-2153 ◽  
Author(s):  
K. Kalaiselvan ◽  
A. Elango ◽  
N. M. Nagarajan ◽  
K. Sekar
Keyword(s):  
Laser Beam ◽  
Weld Joint ◽  
Dissimilar Weld ◽  
Beam Focusing

PWSCC Experience of Pressurizer Dissimilar Metal Welds at Tsuruga Unit-2

2004 ◽  
Author(s):  
Hiroyuki Kobayashi ◽  
Kimihito Takeuchi ◽  
Shohei Nakama ◽  
Masayuki Mukai ◽  
Takahiro Ohta
Keyword(s):  
Alloy Steel ◽  
Weld Joint ◽  
Repair Process ◽  
Visual Observation ◽  
Low Alloy Steel ◽  
Relief Valve ◽  
Metallographic Examination ◽  
Dissimilar Weld ◽  
Root Cause ◽  
Non Destructive

During the 13th refuel outage in September 2003, the small boric acid deposit was observed at one dissimilar weld joint between Relief Valve Nozzle and Safe End of Pressurizer in Tsuruga unit 2. The other four indications were also observed at the weld joint by non-destructive examination. Similar indications were also observed at Safety Valve Nozzle. Both Nozzles were under the steam condition at 345°C. As the first root cause investigation, the visual observation after etching was conducted at these weld joint on site. The observation revealed the repair weld print. Both weld joints with cracks were taken to conduct some investigations such as metallographic examination of fracture surface at hot laboratory. Hot laboratory examination results revealed that all cracks were extended axially in the Ni base metal weld joint, and there was no evidence of any cracks extending into the low alloy steel Nozzle and stainless steel Safe end. All cracks were interdendritic and branched. Metallographic examination results revealed that the crack growth mainly was caused by interdendritic stress corrosion cracking (IDSCC). These Nozzles including the weld joint with indications were repaired by jointing the spool piece as new Safe ends. The repair process includes the weld buttering on the low alloy steel Nozzle and joint welding between Nozzle and the spool piece. These welding were conducted by GTAW using alloy 52. It took twenty days to complete the repair works.

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