scholarly journals Effect of aging on the general corrosion and stress corrosion cracking of uranium--6 wt % niobium alloy

1975 ◽  
Author(s):  
J.W. Koger ◽  
A.M. Ammons ◽  
J.E. Ferguson
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Niobium Alloy ◽  
Corrosion Cracking ◽  
General Corrosion

Surface Chemical Factors in the Stress-Corrosion Cracking off Alpha Brass

CORROSION ◽  
1966 ◽  
Vol 22 (6) ◽  
pp. 178-179 ◽  
Author(s):  
H. E. JOHNSON ◽  
J. LEJA
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Absolute Temperature ◽  
Corrosion Cracking ◽  
General Corrosion ◽  
Linear Relationships ◽  
Energy Lowering ◽  
Cracking Mechanisms ◽  
Ph Range ◽  
Alpha Brass

Abstract Stress corrosion cracking of alpha brass in ammonia solutions containing copper-ammonia complexes is most rapid in the pH range 6 to 7, where weight loss corrosion is insignificant, Linear relationships were found for (a) log 1/tc (tc = cracking time) vS log Cu++ (initial copper concentration) and (b) l/tc vs 1/T (T = absolute temperature). Oxygen appears necessary for general corrosion and cracking at pH values above 8. Rapid cracking is interpreted in terms of a drastic surface free energy decrease caused by the adsorption of an intermediate copper-zinc- ammonia complex (not yet identified) which is catalytically formed at the brass/solution interface and is surface active. It is suggested also that linear relationships like (a) and (b) above may be distinguishing features of stress corrosion cracking mechanisms which involve surface energy lowering.

Role of Mexican Clay Soils on Corrosiveness and Stress Corrosion Cracking of Low-Carbon Pipeline Steels: A Case Study

CORROSION ◽  
10.5006/3515 ◽  
2020 ◽  
Vol 76 (10) ◽  
pp. 967-984
Author(s):  
A. Contreras ◽  
L.M. Quej ◽  
H.B. Liu ◽  
J.L. Alamilla ◽  
E. Sosa
Keyword(s):  
Corrosion Rate ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
The State ◽  
Clay Soils ◽  
Corrosion Mechanism ◽  
General Corrosion ◽  
Southern Mexico ◽  
Gauge Section

This work analyzed the physicochemical effect of different types of Mexican clay soils on corrosion and stress corrosion cracking (SCC) behavior in contact with X60 and X65 steels. Four soils were obtained from the right of way land in southern Mexico at 1.5 m depth close to pipelines. Two soils were from the state of Oaxaca (SO1 and SO2), and two others from the state of Veracruz (SV1 and SV2). Physicochemical and textural analysis of soils was performed and correlated to SCC susceptibility and corrosion mechanism. It was observed that soil texture might be related to corrosivity. A texture index (ratio between sand and silt + clay), which was seen to have a relationship with the corrosive tendency of soils, was estimated. It showed that soil with a higher index (SV1) has a higher corrosion rate. Electrochemical impedance spectroscopy and polarization curves were performed and correlated to the corrosion rate and the SCC susceptibility of steels. Steels exposed to SV1 soil exhibited a higher corrosion rate related to a higher content of chlorides and acid pH than those seen in other soils, which resulted in the pitting of such steels. Two types of corrosion were observed. Soils from SV1 and SV2 generated pitting, and soils from SO1 and SO2 produced general corrosion. Inclusions caused pitting in the gauge section of X60 and X65 steels exposed to SV1 soil by anodic dissolution. Galvanic coupling between inclusions and the base metal and dissolution of the inclusions might have enhanced the nucleation of pits at these sites. SCC susceptibility was evaluated using slow strain rate tests (SSRT). After SSRT, the fracture surfaces were analyzed through scanning electron microscopy. The SCC index obtained from SSRT indicates that X60 and X65 steels exhibited good resistance to SCC. A highly corrosive soil, such as SV1, causes the formation of pits instead of cracks, which is attributed to the dissolution process; however, lower SCC indexes were obtained for this system. The higher corrosion resistance of X60 steel is related to a more homogenous microstructure and a higher content of elements, such as Ni and Cr, than those of X65 steel that decrease the corrosion rate.

Corrosion and Stress Corrosion Cracking Susceptibility of Type 347H Stainless Steel in Supercritical Water

CORROSION ◽  
10.5006/2459 ◽  
2017 ◽  
Vol 74 (1) ◽  
pp. 83-95 ◽  
Author(s):  
Xianglong Guo ◽  
Wenhua Gao ◽  
Kai Chen ◽  
Zhao Shen ◽  
Lefu Zhang
Keyword(s):  
Stainless Steel ◽  
Stress Corrosion ◽  
Oxygen Content ◽  
Supercritical Water ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
General Corrosion ◽  
Scattered Electron ◽  
Intergranular Cracking ◽  
Exposure Test

The corrosion resistance and stress corrosion cracking (SCC) susceptibility of Type 347H stainless steel (SS) in supercritical water (SCW) were investigated. The general corrosion behavior was investigated by exposure test and the specimens after testing were characterized utilizing scanning electron microscopy (SEM), Auger and x-ray diffraction analysis, optical microscopy, and energy dispersive spectroscopy (EDS). The results show that with the increase of testing temperature, the corrosion rate of the materials is greatly enhanced. The corrosion process is analyzed and the formation of oxide islands on the surface of the corroded sample is attributed to the higher diffusion rate of Cr along the grain boundary. The effects of temperature and dissolved oxygen on SCC susceptibility were investigated by slow strain rate tensile test. The fractographs were characterized by SEM and the cross-section morphologies were characterized with back-scattered electron imaging, SEM, and EDS. The results indicate that, as temperature is increased, the tensile strength and strain of materials is greatly reduced, while the oxygen content in SCW has a limited effect on the mechanical properties. Intergranular cracking and ductile fracture are the main fracture modes for Type 347H SS tested in SCW, independent of temperature and oxygen content. The implications of the results to the mechanisms of SCC are discussed.

Action of Carbon in Stress Corrosion Cracking of Mild Steel in Nitrate Solutions

CORROSION ◽  
1973 ◽  
Vol 29 (1) ◽  
pp. 37-46 ◽  
Author(s):  
J. FLIS
Keyword(s):  
Carbon Content ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Intergranular Corrosion ◽  
Corrosion Cracking ◽  
Total Carbon ◽  
General Corrosion ◽  
Low Carbon ◽  
Total Carbon Content ◽  
Protective Properties

Abstract The effect of total carbon content on susceptibility of iron to stress corrosion cracking (SCC), on the depth of intergranular corrosion without stresses, anodic polarization curves, and the general corrosion rate was examined on decarburized Armco iron and its ferritic or martensitic alloys with carbon up to 1.4% in 5N NH4NO3 and 5N Ca(NO3)2, pH 5.0, at 75 and 100 C (167 and 212 F). The susceptibility to SCC and intergranular corrosion increased with the carbon content increasing up to about 0.009% or above, and it diminished with further increase in the carbon content. Carbon decreased the ability of iron to passivate (depassivating action), but it also promoted deposition of magnetite and enhanced its protective properties (impeding action). It is suggested that the observed effect of carbon on SCC and intergranular corrosion results from the predominance of the depassivating action at low carbon contents, and the predominance of the impeding action at higher carbon contents.

scholarly journals The Effect of the pH of Ammonum Nitrate Solution on the Susceptability of Mild Steel to Stress Corrosion Cracking (SCC) and General Corrosion

2010 ◽  
Vol 01 (04) ◽  
pp. 191-198
Author(s):  
Fathia S. Mohammed ◽  
Alyaa G. Elramady ◽  
Salheddin E. Abu Yahya
Keyword(s):  
Mild Steel ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Nitrate Solution ◽  
Corrosion Cracking ◽  
General Corrosion

Influence of Changes in Pressure and Temperature of Supercritical Water on the Susceptibility to Stress Corrosion Cracking of 316L Austenitic Stainless Steel

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Alberto Sáez-Maderuelo ◽  
Dolores Gómez-Briceño ◽  
César Maffiotte
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Stress Corrosion ◽  
Supercritical Water ◽  
Stress Corrosion Cracking ◽  
High Efficiency ◽  
Austenitic Stainless Steels ◽  
Corrosion Cracking ◽  
General Corrosion ◽  
316L Austenitic Stainless Steel

The supercritical water reactor (SCWR) is one of the Generation IV designs. The SCWR is characterized by its high efficiency, low waste production, and simple design. Despite the suitable properties of supercritical water as a coolant, its physicochemical properties change sharply with pressure and temperature in the supercritical region. For this reason, there are many doubts about how changes in these variables affect the behavior of the materials to general corrosion or to specific types of corrosion such as stress corrosion cracking (SCC). Austenitic stainless steels are candidate materials to build the SCWR due to their optimum behavior in the light water reactors (LWRs). Nevertheless, their behavior under the SCWR conditions is not well known. First, the objective of this work was to study the SCC behavior of austenitic stainless steel 316 type L in deaerated supercritical water at 400°C/25  MPa and 30 MPa and 500°C/25  MPa to determine how variations in pressure and temperature influence its behavior with regard to SCC and to make progress in the understanding of mechanisms involved in SCC processes in this environment. Second, the oxide layer formed at 400°C/30  MPa/<10  ppb O2 was analyzed to gain some insight into these processes.

A New Probabilistic Model for High-pH Stress Corrosion Cracking

2006 ◽  
Author(s):  
Andrew Francis ◽  
Chas Jandu
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Probabilistic Model ◽  
Corrosion Cracking ◽  
Time Dependent ◽  
Management Tool ◽  
Soil Conditions ◽  
General Corrosion ◽  
High Ph ◽  
Integrity Management

Stress corrosion cracking (SCC) poses a threat to integrity of buried pipelines in many parts of the world. In North America there is now a requirement that integrity management plans should address SCC and a direct assessment methodology, SCCDA, for managing the threat due to SCC, is now becoming established. Like general corrosion or fatigue, SCC is a time dependent deterioration process that leads to progressive weakness of the pipe wall eventually causing failure as a leak or rupture, if not managed. There are indeed two known forms of SCC; High-pH and near neutral-pH SCC. The focus of this paper is on High-pH SCC. High-pH SCC involves a number of phases including incubation, initiation, anodic growth, coalescence, mechanical growth and final failure. Factors affecting these processes include temperature, static and cyclic stress, soil conditions, type of coating and level of Cathodic Protection. Some of these factors may vary seasonally. The temporal development of SCC damage is thus both complex and subject to significant uncertainty. The purpose of this paper is to describe a detailed probabilistic model that addresses the various phases of High-pH SCC taking account of uncertainty in the relevant influencing factors. The model determines the likely times to coalescence and to grow to a critical size thus providing a time dependent probability of failure. The model gives a clear indication of which parameters should be managed in order to reduce the likelihood of failure to an acceptable level. The model provides the basis of a powerful decision making tool for the purpose of managing High pH SCC. Consequently, the model can be used in conjunction with relevant in-line inspection data and/or above ground survey data to provide an effective SCC integrity management tool. The model is illustrated through a numerical example and the use of the model as an integrity management tool is clearly demonstrated.

scholarly journals Potential for Stress Corrosion Cracking of A537 Carbon Steel Nuclear Waste Tanks Containing Highly Caustic Solutions

2010 ◽  
Author(s):  
Poh-Sang Lam ◽  
Craig S. Stripling ◽  
Donald L. Fisher ◽  
James B. Elder
Keyword(s):  
Carbon Steel ◽  
Stress Corrosion ◽  
Nuclear Waste ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Welding Residual Stress ◽  
Caustic Solution ◽  
Experimental Program ◽  
General Corrosion ◽  
Waste Tanks

The evaporator recycle streams of nuclear waste tanks may contain waste in a chemistry and temperature regime that exceeds the current corrosion control program, which imposes temperature limits to mitigate caustic stress corrosion cracking (CSCC). A review of the recent service history found that two of these A537 carbon steel tanks were operated in highly concentrated hydroxide solution at high temperature. Visual inspections, experimental testing, and a review of the tank service history have shown that CSCC has occurred in uncooled/un-stress relieved tanks of similar construction. Therefore, it appears that the efficacy of stress relief of welding residual stress is the primary corrosion-limiting mechanism. The objective of this experimental program is to test A537 carbon steel small scale welded U-bend specimens and large welded plates (30.48 × 30.38 × 2.54 cm) in a caustic solution with upper bound chemistry (12 M hydroxide and 1 M each of nitrate, nitrite, and aluminate) and temperature (125 °C). These conditions simulate worst-case situations in these nuclear waste tanks. Both as-welded and stress-relieved specimens have been tested. No evidence of stress corrosion cracking was found in the U-bend specimens after 21 days of testing. The large plate test was completed after 12 weeks of immersion in a similar solution at 125 °C except that the aluminate concentration was reduced to 0.3 M. Visual inspection of the plate revealed that stress corrosion cracking had not initiated from the machined crack tips in the weld or in the heat affected zone. NDE ultrasonic testing also confirmed subsurface cracking did not occur. Based on these results, it can be concluded that the environmental condition of these tests was unable to develop stress corrosion cracking within the test periods for the small welded U-bends and for the large plates, which were welded with an identical procedure as used in the construction of the actual nuclear waste tanks in the 1960s. The absence of evidence of stress corrosion cracking and general corrosion in the laboratory-scaled specimens indicate that this type of nuclear waste tank is not susceptible to highly caustic solutions up to 12 M hydroxide at 125 °C when sufficient nitrite inhibitor is present.

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