Radiation and Temper Embrittlement Processes in Advanced Reactor Weld Metals

1972 ◽  
Vol 94 (3) ◽  
pp. 807-814 ◽  
Author(s):  
J. R. Hawthorne ◽  
E. Fortner
Keyword(s):  
High Resistance ◽  
Copper Content ◽  
Temper Embrittlement ◽  
Radiation Sensitivity ◽  
Composition Series ◽  
Strength Increase ◽  
Radiation Embrittlement ◽  
Weld Deposit ◽  
Weld Metals ◽  
Filler Metals

Experimental weld filler metals having high resistance to radiation embrittlement at ≃550 F (288 C) have been developed for quenched and tempered A543 and A542 steel. The filler metals are from a special 2-1/4 Cr-1 Mo-0.40Si-0.10C composition series formulated to study the effects of variable copper, nickel, and manganese contents on weld performance. This report presents an advanced evaluation of weld deposit performance based on new Charpy-V (Cv) and tension data and an analysis of temper embrittlement and radiation embrittlement processes. High fluence assessments confirm the high resistance to radiation embrittlement of the low copper content filler metal group. A 530 F (277 C) irradiation of one typical submerged arc weld deposit to a fluence of 3.8 × 1020 n/cm2 > 1 MeV did not elevate its Cv 30 ft-lb transition temperature to above 275 F (135 C) or reduce its Cv shelf energy level to below 50 ft-lb. Radiation embrittlement saturation was not evident. Temper embrittlement and radiation embrittlement development and the probable mechanisms of copper and phosphorus influences on radiation embrittlement sensitivity are analyzed with the aid of experimental data for the weld metals and A543 plate. Temper embrittlement and radiation embrittlement are shown to be additive effects which can occur simultaneously or sequentially. A separate component of irradiation effects, manifested as a strength increase without embrittlement, is revealed. The enhancement of radiation sensitivity by high copper content (≧0.16–0.27 percent Cu) is related to a copper influence on the radiation elevation of yield strength; the enhancement of radiation sensitivity of phosphorus is ascribed to a detrimental effect similar to that of temper embrittlement. It is proposed that copper acts to pin radiation-induced defect aggregates and dislocation arrays in the matrix and that phosphorus segregates during irradiation to weaken the interface of ferrite platelets and carbides.

Radiation Embrittlement of PWR Reactor Vessel Weld Metals : Nickel and Copper Synergism Effects

2009 ◽  
pp. 392-392-20 ◽  
Author(s):  
C Guionnet ◽  
B Houssin ◽  
D Brasseur ◽  
A Lefort ◽  
D Gros ◽  
...  
Keyword(s):  
Reactor Vessel ◽  
Radiation Embrittlement ◽  
Weld Metals

Further Observations on A533-B Steel Plate Tailored for Improved Radiation Embrittlement Resistance

1976 ◽  
Vol 98 (2) ◽  
pp. 111-117 ◽  
Author(s):  
J. R. Hawthorne
Keyword(s):  
Radiation Resistance ◽  
Test Performance ◽  
Copper Content ◽  
Radiation Embrittlement ◽  
Copper Addition ◽  
Melt Composition ◽  
Impurity Elements ◽  
Irradiation Behavior ◽  
Embrittlement Resistance ◽  
Primary Melt

A series of advanced investigations on the radiation performance of four 6-in-thick plates from a large (30-ton) commercial melt of A533-B steel is described. The melt represented the first commercial scale demonstration test of improved radiation embrittlement resistance through the control (minimization) of selected residual impurity elements. Melt specifications emphasized the attainment of a low copper and phosphorus content; one half of the melt was modified, however, by a copper addition (0.03 percent Cu increased to 0.13 percent Cu). Initial plate tests described superior 550 F (288 C) radiation resistance, in terms of notch ductility retention, for the primary melt composition and verified the detrimental influence of impurity copper on irradiation behavior. Promising capability of the primary melt composition for very high fluence (∼2.5 × 1020 n/cm2 > 1 MeV) service is shown by the current investigations. In addition, a significant influence of copper content on radiation resistance is revealed for a broad range of exposure temperatures. A dependence of 650 F (343 C) postirradiation heat treatment response (notch ductility recovery) on copper content was also found. Charpy-V versus dynamic tear test performance and tensile strength trends with temperature are examined for low (<450 F, 121 C) and elevated (550 to 585 F, 288 to 307 C) temperature irradiation conditions.

Creep Strength of Welds in Hydrogen Reformer Outlet Manifolds

2009 ◽  
Author(s):  
Carl E. Jaske
Keyword(s):  
High Temperature ◽  
Creep Strength ◽  
Welded Joints ◽  
Piping System ◽  
Weld Metals ◽  
Alloy 800 ◽  
High Nickel ◽  
Rupture Data ◽  
Internal Pressures ◽  
Filler Metals

This paper reviews the creep strength of welds of the type typically used in hot outlet manifolds of hydrogen reformers. These manifolds can be visualized as a high-temperature piping system that collects the reformed gas from the outlets of the catalyst tubes. The catalyst tube outlet usually is connected to the manifold by means of a flexible pigtail. The pigtail is connected to the manifold via welded fittings, and the components of the manifold assembly are connected by welded joints. These hot manifolds operate under internal pressures in the range of 2000 to 3500 kPa and at temperatures in the range of 800 to 900 °C. The components are typically made of wrought Alloy 800, 800H or 800HT or similar cast 20Cr-32Ni-1Nb alloys. The welds are made using filler metals or electrodes of similar compositions or high-nickel alloy compositions. Creep-rupture data that have been developed for weld metals are reviewed and compared. Problems that have been encountered with failures of welds in this application are discussed. The current recommended materials for welding these manifolds are outlined.

Effects of Chemical Composition and Welding Process on Fracture Resistance of Type 347 Stainless Steel Weld

2007 ◽  
Vol 353-358 ◽  
pp. 1970-1973
Author(s):  
Ji Hyun Yoon ◽  
Bong Sang Lee ◽  
Eui Pak Yoon
Keyword(s):  
Fracture Resistance ◽  
Welding Process ◽  
Systematic Investigation ◽  
Low Carbon ◽  
High Carbon Content ◽  
Weld Metals ◽  
Aisi Type ◽  
Gtaw Process ◽  
Welding Processes ◽  
Filler Metals

The present study is a systematic investigation of the effects of microstructural changes, which have originated from the variations of filler metals and welding processes, on the J-R properties of simulated welds. Two AISI Type 347 weld metals, with different carbon contents, deposited by a GTAW process and two AISI Type 347 weld metals, with different carbon contents, deposited by a SMAW process were used in this study. The J-R tests were conducted at 316oC (600oF). The welds deposited by the GTAW process showed higher fracture resistances when compared to the welds deposited by the SMAW process. The J-R fracture resistance of the Type 347-GTAW processed weld with high carbon content was remarkably low when compared to the weld with low carbon. The J-R fracture resistances were decreased by coarse Nb(C, N) precipitates in the Type 347 weld deposited by the GTAW process. In the case of the SMAW welds, mainly coarse Ti-rich particles which had originated from the shielding of the welding rods deteriorated the fracture resistances.

scholarly journals Creep property of the Hastelloy X weld metals obtained by filler metals with minor elements.

1986 ◽  
Vol 4 (2) ◽  
pp. 371-377 ◽  
Author(s):  
Akiyoshi Kikuchi ◽  
Tsuneo Nakanishi ◽  
Shigeo Shin ◽  
Tamao Takatsu ◽  
Teiichiro Saitoh
Keyword(s):  
Creep Property ◽  
Hastelloy X ◽  
Minor Elements ◽  
Weld Metals ◽  
Filler Metals

On the radiation embrittlement of materials of support structures for WWER RPV. Part 1. Experimental studies

2019 ◽  
pp. 175-192
Author(s):  
B. Z. Margolin ◽  
E. V. Yurchenko ◽  
V. I. Kostylev ◽  
A. M. Morozov ◽  
A. Ya. Varovin ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Experimental Studies ◽  
Irradiation Temperature ◽  
Radiation Embrittlement ◽  
Support Structures ◽  
Metal Structures ◽  
Weld Metals ◽  
Sem Investigation ◽  
Low Irradiation

The features of the radiation embrittlement of materials of support structures for WWER RPV are considered. These features are connected with low irradiation temperature no exceeding90°Cand also with a use of the steels which are usually applied for building of the metal structures and have not a high resistance to the radiation embrittlement. It has been shown that support structure (SS) of WWER-440 of V-179, V-230 types may cause the operation life limit. The experimental data on the standard mechanical properties and fracture toughness are presented for different steels and weld metals in the initial and irradiation conditions. SEM investigation of fracture surface of broken specimens and atomic tomography have been performed.

Evaluation on the Corrosion and Wear Resistance of Welding Zone Welded with Plasma Transferred Arc Welding Method

2016 ◽  
Vol 723 ◽  
pp. 230-236 ◽  
Author(s):  
Jae Hyun Jeong ◽  
Kyung Man Moon ◽  
Sung Yul Lee ◽  
Myeong Hoon Lee
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Base Metal ◽  
Inconel 625 ◽  
Wear Loss ◽  
Stellite 6 ◽  
Weld Metals ◽  
Plasma Transferred Arc ◽  
Nimonic 80A ◽  
Filler Metals

There are many welding methods which have been currently performed to prolong the life time of exhaust valve of marine engine from an economic point of view. In this study, one of these welding methods, plasma transferred arc (PTA) welding was performed at the base metal of Nimonic 80A which would be used as the material of exhaust valve with three kinds of filler metals such as Stellite 6, Inconel 625 and Inconel 718. The mechanical and corrosion characteristics were investigated with electrochemical and wear loss test methods. The Nimonic 80A as the base metal had a better corrosion resistance than those of the weld metals welded with three types of the filler metals. However, after post weld heat treatment, all these weld metals mentioned above exhibited better corrosion resistance compared to the base metal, shifting the corrosion potential to the noble direction, and pitting corrosion was more or less observed at the surface of Nimonic 80A after post weld heat treatment. In particular, Inconel 625 showed the best corrosion resistance among the filler metals after heat treatment. The wear ratio of Stellite 6 showed the lowest value due to its highest hardness among the filler metals, however, its ratio by cavitation test exhibited the highest value. It is considered that increasing of embrittlement with increasing the hardness was resulted in increasing the wear loss by cavitation test.

Amelioration of Microcracking in Multipass Weld Metal of Alloy 690 by Adding Rare Earth Metals

2009 ◽  
Author(s):  
Kazutoshi Nishimoto ◽  
Kazuyoshi Saida ◽  
Yasuyuki Fujiya
Keyword(s):  
Rare Earth ◽  
Weld Metal ◽  
Rare Earth Metals ◽  
Boundary Segregation ◽  
Solidification Cracking ◽  
Scavenging Effect ◽  
Weld Metals ◽  
Alloy 690 ◽  
Multipass Weld ◽  
Filler Metals

The effect of the addition of rare earth metals (REM) to the weld metal on the microcracking susceptibility in the multipass welds of alloy 690 was examined by using the La or Ce containing filler metals. The amounts of the La and Ce in the filler metal were varied in several levels. The microcracking susceptibility of the reheated weld metal was evaluated by the spot and transverse-Varestraint tests using pre-welded specimens made by GTAW. The augmented strain levels were varied from 0.50–2.44%. Cracks that occurred in the reheated weld metal evaluated by the Varestraint test could be classified into three types; ductility-dip, liquation and solidification cracking. The ductility-dip cracking susceptibility could be significantly improved by adding 0.01–0.025mass%REM to the weld metal. Adversely, the excessive REM addition led to the liquation and/or solidification cracking in the weld metal. Microstructural analyses revealed that phosphide and sulphide of La or Ce were formed in the REM containing weld metals, and Ni-La or Ni-Ce intermetallic compound was additionally identified in the excessively REM containing weld metals. High temperature tensile test indicated that hot ductility of the weld metal was ameliorated by adding 0.01–0.03mass%REM, implying that the ductility-dip cracking susceptibility was decreased as a result of lowering the grain boundary segregation of impurity elements such as P and S due to the scavenging effect of REM. The liquation and solidification cracking in the excessively REM containing weld metals were considered to be due to the formation of liquefiable intermetallic compounds of Ni and REM. The multipass welding test confirmed that microcracks in the multipass welds of alloy 690 were completely prevented by using the filler metals containing approx. 0.03mass%REM.

Effects of copper content on the microstructure and brazing properties of Al-Si-Cu-Zn-Re filler metals

2015 ◽  
Vol 60 (1) ◽  
pp. 109-116
Author(s):  
S. Y. Chang ◽  
Y. H. Lei ◽  
L. C. Tsao ◽  
T. Y. Li
Keyword(s):  
Copper Content ◽  
Filler Metals
Sign in / Sign up

Export Citation Format

Share Document