Residual Stresses in Bent Tubes for Nuclear Steam Generators

CORROSION ◽  
1976 ◽  
Vol 32 (9) ◽  
pp. 357-364 ◽  
Author(s):  
Ph. BERGE ◽  
H. D. BUI ◽  
J. R. DONATI ◽  
D. VILLARD
Keyword(s):  
Stainless Steel ◽  
Residual Stresses ◽  
Stress Corrosion ◽  
Strain Gauge ◽  
Corrosion Test ◽  
Steam Generators ◽  
Steel Tubes ◽  
Inconel 600 ◽  
Stress Relieving ◽  
Very High

Abstract Residual stresses in Inconel 600 tubes for PWR steam generators were measured using the strain gauge technique, and the results were checked by a stress corrosion test in boiling MgCl2 performed on stainless steel tubes manufactured according to the same process as the Inconel 600 tubes. It was shown that very high tensile stresses, equal to or even exceeding the yield stress, could exist as a result of the straightening, bending or roll expanding operations. The efficiency of possible stress relieving treatments was also investigated.

Stress Corrosion Cracking of Iron and Nickel Base Alloys in Sulfate Solutions at 289 C

CORROSION ◽  
1973 ◽  
Vol 29 (11) ◽  
pp. 442-450 ◽  
Author(s):  
DAVID A. VERMILYEA
Keyword(s):  
Stainless Steel ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Chromium Depletion ◽  
Reaction Products ◽  
Inconel 600 ◽  
Sulfate Solutions ◽  
Cold Worked ◽  
Nickel Base

Abstract Stress corrosion cracking (SCC) of iron and nickel base alloys in aqueous solutions at 289 C (552 F) has been studied using a straining electrode apparatus. Cracking susceptibility decreases in the order sensitized stainless steel, cold worked stainless steel containing martensite, sensitized Inconel 600, annealed stainless steel, and annealed or cold worked Inconel 600 and alloy AL 326. High cracking susceptibility usually occurs when conditions result in the development of thick reaction products. Acid conditions and chromium depletion favor thick reaction products and enhance susceptibility.

Microstructure and Microchemistry of Inconel 600 STEAM Generator Tubing

2000 ◽  
Vol 6 (S2) ◽  
pp. 356-357
Author(s):  
V. Perovic ◽  
A. Perovic ◽  
G.C. Weatherly ◽  
A.M. Brennenstuhl
Keyword(s):  
Grain Boundary ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Analytical Electron Microscopy ◽  
Corrosion Cracking ◽  
Steam Generators ◽  
Intergranular Stress Corrosion ◽  
Candu Reactors ◽  
Inconel 600 ◽  
Water Reactors

Inconel 600 is an austenitic Ni-Cr-Fe alloy which is extensively used for tubing in steam generators of pressurized light water reactors (PWR) and CANDU heavy water reactors, because of its excellent mechanical properties and corrosion resistance. However, there have been instances of intergranular stress corrosion cracking of tubes in operating steam generators. The chemistry and the structure of grain boundaries and grain boundary precipitation have emerged as factors of prime importance in understanding stress corrosion cracking and intergranular attack of nickel-base alloys (see e.g. ref. l).In this study analytical electron microscopy was used to determine the microstructure of grain boundary and matrix precipitates, grain boundary chromium content and dislocation substructure of selected steam generating tubes of CANDU reactors. The results of the in-service materials are compared with as-received material. Two JEOL 2010 STEM instruments were used in this study.

scholarly journals A Study on Microstructure, Residual Stresses and Stress Corrosion Cracking of Repair Welding on 304 Stainless Steel: Part I-Effects of Heat Input

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2416
Author(s):  
Yun Luo ◽  
Wenbin Gu ◽  
Wei Peng ◽  
Qiang Jin ◽  
Qingliang Qin ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Heat Input ◽  
Corrosion Cracking ◽  
304 Stainless Steel ◽  
Sensitivity Index ◽  
Repair Welding

In this paper, the effect of repair welding heat input on microstructure, residual stresses, and stress corrosion cracking (SCC) sensitivity were investigated by simulation and experiment. The results show that heat input influences the microstructure, residual stresses, and SCC behavior. With the increase of heat input, both the δ-ferrite in weld and the average grain width decrease slightly, while the austenite grain size in the heat affected zone (HAZ) is slightly increased. The predicted repair welding residual stresses by simulation have good agreement with that by X-ray diffraction (XRD). The transverse residual stresses in the weld and HAZ are gradually decreased as the increases of heat input. The higher heat input can enhance the tensile strength and elongation of repaired joint. When the heat input was increased by 33%, the SCC sensitivity index was decreased by more than 60%. The macroscopic cracks are easily generated in HAZ for the smaller heat input, leading to the smaller tensile strength and elongation. The larger heat input is recommended in the repair welding in 304 stainless steel.

scholarly journals A Study on Microstructure, Residual Stresses and Stress Corrosion Cracking of Repair Welding on 304 Stainless Steel: Part II-Effects of Reinforcement Height

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2434 ◽  
Author(s):  
Xiaodong Hu ◽  
Hao-Yong Jiang ◽  
Yun Luo ◽  
Qiang Jin ◽  
Wei Peng ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Residual Stresses ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Structural Integrity ◽  
Great Influence ◽  
Steel Part ◽  
Corrosion Cracking ◽  
304 Stainless Steel ◽  
Repair Welding

The repair reinforcement height is an important parameter of repair welding, which may have a great influence on structural integrity. In this paper, the effects of repair welding reinforcement height on the microstructure, microhardness, residual stresses and stress corrosion cracking (SCC) behavior of a 304 stainless steel-repaired joint were investigated by experimentation and simulation. With an increase of the repair weld reinforcement height, the δ ferrite content in weld and fusion zone is obviously reduced, and the ferrite shape is gradually changed from the skeleton to the worm shape. With the increase of repair welding reinforcement height, the microhardness and residual stresses decrease gradually. The tensile strength and elongation for higher repair weld reinforcement height are larger than those with lower repair weld reinforcement height. The higher the repair weld reinforcement height, the harder it is for SCC to occur. The repair welding in 304 stainless steel is recommended to be repaired no more than two times.

Investigation of Transformation Induced Plasticity and Residual Stress Analysis in Stainless Steel Welds

2010 ◽  
Author(s):  
H. Dai ◽  
R. Moat ◽  
A. F. Mark ◽  
P. J. Withers
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Base Plate ◽  
Element Model ◽  
Image Correlation ◽  
Fe Model ◽  
Transformation Induced Plasticity ◽  
Stress Relieving ◽  
Steel Welds

The aim of this paper is to investigate the implications for weld residual stresses of martensitic transformation induced plasticity (TRIP) in stainless steel filler metal. The TRIP strains occurring during cooling under different uniaxial load levels have been obtained using digital image correlation (DIC) for a residual stress relieving low transformation temperature weld filler known to show little variant selection on cooling as a function of stress. In order to investigate the efficacy of current FE transformation plasticity models of different levels of sophistication in simulating TRIP strains, a finite element model, incorporating the so-called Greenwood-Johnson effect was used to simulate these constrained dilatometry measurements. To assess the implications of the different approaches to modelling TRIP for weld residual stresses, the TRIP coefficients determined from the above experiments were incorporated into an FE model simulating the residual stresses that are generated when a single weld bead is deposited on to a stainless steel base plate. It was found that including TRIP had a significant influence on the weld stresses, while the differences between the models were much smaller.

Stress-Corrosion Cracking of Steels In Agricultural Ammonia

CORROSION ◽  
1962 ◽  
Vol 18 (8) ◽  
pp. 299t-309t ◽  
Author(s):  
A. W. LOGINOW ◽  
E. H. PHELPS
Keyword(s):  
Carbon Dioxide ◽  
Carbon Steel ◽  
Residual Stresses ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Air Contamination ◽  
Stress Relieving ◽  
Steel Tanks ◽  
Cause Of Failure

Abstract Stress-corrosion cracking has been determined as the cause of failure of carbon steel tanks in agricultural ammonia service. Effects of ammonia contaminants, such as air, water, carbon dioxide, oil, etc on failure rates were studied. In general, air contamination increased stress-corrosion cracking and water in small amounts inhibited the attack. For prevention of such failures, it was recommended that high residual stresses in ammonia vessels be avoided by the use of stress relieving treatments, that air be eliminated from agricultural ammonia systems and that the ammonia should have a minimum water content of 0.20 percent. 3.5.8

Sign in / Sign up

Export Citation Format

Share Document