Showing papers on "Stress corrosion cracking published in 1976"
TL;DR: Precipitation reactions that occur in Inconel Alloy 600 were studied and correlated with corrosion behavior in nitric acid and stress corrosion cracking (SCC) susceptibility in polythionic...
Abstract: Precipitation reactions that occur in Inconel Alloy 600 were studied and correlated with corrosion behavior in nitric acid and stress corrosion cracking (SCC) susceptibility in polythionic...
55 citations
TL;DR: In this article, the authors studied the stress corrosion cracking behavior at room temperature of amorphous Fe-Cr-Ni-P-C alloys subjected to constant strain rates in some acidic solutions containing Cl− ions.
47 citations
TL;DR: In this article, the kinetics of sustained load subcritical crack growth for 18 Ni maraging steels in high purity hydrogen are examined using crack-tip stress intensity,K, as a measure of crack driving force.
Abstract: The kinetics of sustained-load subcritical crack growth for 18 Ni maraging steels in high purity hydrogen are examined using crack-tip stress intensity,K, as a measure of crack driving force. Crack growth rate as a function of stress intensity exhibited a clearly definedK-independent stage (Stage II). Crack growth rates in an 18 Ni (250) maraging steel are examined for temperatures from -60°C to 100°C. A critical temperature was observed above which crack growth rates became diminishingly small. At lower temperatures the activation energy for Stage II crack growth was found to be 16.7 ± 3.3 kJ/mole. Temperature and hydrogen partial pressure are shown to interact in a complex manner to determine the apparentK
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and the crack growth behavior. Comparison of results on ‘250’ and ‘300’ grades of 18 Ni maraging steel indicate a significant influence of alloy composition and/or strength level on the crack growth behavior. These phenomenological observations are discussed in terms of possible underlying controlling processes.
47 citations
TL;DR: In this paper, a study has been conducted of the terrace-like fracture morphology of gaseous hydrogen-induced crack growth in acicular alpha-beta titanium alloys in terms of specimen configuration, magnitude of applied stress intensity, test temperature, and hydrogen pressure.
Abstract: A study has been conducted of the terrace-like fracture morphology of gaseous hydrogen-induced crack growth in acicular alpha-beta titanium alloys in terms of specimen configuration, magnitude of applied stress intensity, test temperature, and hydrogen pressure. Although the overall appearance of the terrace structure remained essentially unchanged, a distinguishable variation is found in the size of the individual terrace steps, and step size is found to be inversely dependent upon the rate of hydrogen-induced slow crack growth. Additionally, this inverse relationship is independent of all the variables investigated. These observations are quantitatively discussed in terms of the formation and growth of a thin hydride film along the alpha-beta boundaries and a qualitative model for hydrogen-induced slow crack growth is presented, based on the film-rupture model of stress corrosion cracking.
46 citations
Journal Article•
01 Jan 1976-Science reports of the Research Institutes, Tohoku University. Ser. A, Physics, chemistry and metallurgy
TL;DR: In this article, the authors studied the stress corrosion cracking behavior at room temperature of amorphous Fe-Cr-Ni-P-C alloys subjected to constant strain rates in some acidic solutions containing Cl− ions.
Abstract: The stress corrosion cracking behaviour at room temperature of amorphous Fe-Cr-Ni-P-C alloys subjected to constant strain rates was studied in some acidic solutions containing Cl− ions. Hydrogen embrittlement of the alloys occurred in the potential region lower than −300 mV relative to the corrosion potential in acidic solutions regardless of Cl− concentration. In the passive potential region no embrittlement was observed during tests in neutral NaCl solutions and in acidic solutions with low concentrations of Cl− ions. Only when tensile stress was applied to the specimen in relatively strong acidic solutions containing a certain amount of Cl− ions, fracture stress decreased in this potential region. The lowering of the fracture stress can also be attributed to hydrogen embrittlement.
46 citations
01 Aug 1976
TL;DR: In this paper, the feasibility of measuring the degree of sensitization (DOS) in thermally treated Type-304 stainless steel by using an electrochemical technique was evaluated using the ASTM Procedure A262-Practice E (A262-E)) for laboratory evaluation of welded and as-received conditions.
Abstract: A study was completed to determine the feasibility of measuring the degree of sensitization (DOS) in thermally treated Type-304 stainless steel by using an electrochemical technique Additionally, extensive work is in progress to develop a data base for evaluating sensitization and subsequent intergranular stress corrosion cracking (IGSCC) susceptibility of welded components in the field The technique is considered viable and superior to the presently used chemical method (ASTM Procedure A262-Practice E (A262-E)) for laboratory evaluation of welded and as-received conditions The data developed to date indicate good correlation between DOS, as measured electrochemically, and IGSCC resistance of mill-annealed, furnace sensitized, and as-welded material Additional study needs to be performed, however, to better establish safe limits of DOS for as-welded Type-304 stainless steel These limits are necessary before a unit capable of evaluating welds in the field nondestructively is developed and used The success of this latter objective will be enhanced using the optimized electrochemical test parameters established during the present investigation 36 figures, 25 tables
33 citations
TL;DR: In this paper, a technique for embossing an orthogonal array of lines (grid) on prepared metal surfaces was described, and workpieces of oxygen-free high conductivity copper and 18% nickel maraging steel were machined orthogonally under dry unlubricated conditions.
30 citations
TL;DR: In this paper, the authors reviewed the phenomena of branching and blunting of stress corrosion cracks and their effects demonstrated for a martensitic steel, and a simple procedure was outlined for converting apparent stress intensities to effective stress intensity, so eliminating anomalous effects due to crack branching.
Abstract: The phenomena of branching and blunting of stress corrosion cracks are reviewed and their effects demonstrated for a martensitic steel. The stress intensity that a crack can sustain is proportional to the square root of its tip radius, so that blunt cracks require a higher apparent stress intensity. A simple procedure is outlined for converting apparent stress intensities to effective stress intensities, so eliminating anomalous effects due to crack branching and blunting.
29 citations
TL;DR: In this paper, a correlation with susceptibility to stress corrosion cracking was found for low carbon steels in carbonate/bicarbonate solutions at 70°C, by means of a.c. impedance measurements.
26 citations
23 citations
TL;DR: In this article, the modern outlook on the mechanism of cracking in high strength steel in the case of stress corrosion cracking (SCC) is given, and it is shown that numerous experimental data c...
Abstract: An analysis is given of the modern outlook on the mechanism of cracking in high strength steel in the case of stress corrosion cracking (SCC). It is shown that numerous experimental data c...
TL;DR: In this article, a fracture mechanics approach to interpret iodine-vapor stress-corrosion cracking in unirradiated Zircaloy-4 tubing is presented in which crack velocities are related to the fourth power on the stress intensity factor, K I.
TL;DR: Admiralty brass (Cu-Zn-Sn) is shown to be susceptible to stress corrosion cracking (SCC) in copper sulfate solutions as mentioned in this paper, and fracture surfaces of the resultant transgranular cracks are characteri...
Abstract: Admiralty brass (Cu-Zn-Sn) is shown to be susceptible to stress corrosion cracking (SCC) in copper sulfate solutions. Fracture surfaces of the resultant transgranular cracks are characteri...
TL;DR: Stress corrosion tests have been conducted on martensitic, ferritic, and austenitic steels and nickel-base alloys as discussed by the authors, and the results are discussed with reference to stress, alloy composition, and structure.
Abstract: Stress corrosion tests have been conducted on martensitic, ferritic, and austenitic steels and nickel-base alloys. The tests were conducted on stressed U-bend specimens cut from sheet and tubing and on C-ring specimens cut from tubing. The deoxygenated environments were 10% NaOH at 600 and 630 F (316 and 332 C) and 50% NaOH at 600 F (316 C). The effects of temper embrittlement and sensitization on applicable alloys were studied. It was found that U-bend specimens cracked more readily than C-ring specimens, and that the choice of specimen can affect the relative ranking of some alloys. Temper embrittlement was found to be deleterious to the ferritic alloys, and sensitization was not found to be damaging to the austenitic alloys. The results are discussed with reference to stress, alloy composition, and structure.
TL;DR: A review of the work done to elucidate the mechanism of stress-corrosion cracking of austenitic stainless steels is presented in this article, where the major emphasis is placed on the cracking which occurs in chloride environments, although other environments are mentioned.
Abstract: A review of the work done to elucidate the mechanism of stress-corrosion cracking of austenitic stainless steels is presented. The major emphasis is placed on the cracking which occurs in chloride environments, although other environments are mentioned. This paper is intended to update earlier reviews and is concerned mainly with works published in the period 1960-1971. The various studies on the effects of environmental and metallurgical factors on the kinetics of the cracking process are reviewed in detail. Variables such as temperature, chloride concentration, pH, stress, and metallurgical state are discussed. Also, the various studies on the electrochemistry of the system are reviewed. The major theories on the mechanism of the cracking process are divided into two groups: The electrochemical theories postulate that the effect of tensile stress is to accelerate the localization of the corrosion process at crack sites. These theories include stress assisted segregation of damaging elements in the steel to the crack region, moving crystal imperfections including dislocations, and slip steps. The hydrogen entry theories, such as the formation of an easily corroded hydride phase or eta martensite formation, also fall into this category. The quasi-mechanical theories involve a mechanical fracture step in addition to corrosion. Tunnel pitting, corrosion produced wedging, and reduction of stress energy required to propagate a crack through chemical adsorption are examples of these theories. Finally, some areas of future work are discussed, and questions which need to be resolved are delineated.
TL;DR: In this paper, a new stress corrosion cracking phenomenon of mild and low alloy steels in a CO/CO2 environment was described and these incidents of cracking were reproduced by laboratory tests.
Abstract: This paper is related to the new stress corrosion cracking phenomenon of mild and low alloy steels in a CO/CO2 environment. The incidents of cracking are described and these were reproduced by laboratory tests. The results obtained are as follows: (1) No stress corrosion cracking of mild steel was found to occur in water containing just CO or CO2. (2) The transgranular stress corrosion cracking occurred only in CO/CO2 environment with water. (3) Stress corrosion cracking occurred in a wide range of CO/CO2 ratios in water. (4) The susceptibility to stress corrosion cracking of mild steel decreases with increasing temperature. (5) No stress corrosion cracking was found to occur on 18Cr-10Ni stainless steel. (6) From the study of electrochemical measurements, the mechanism has been proposed that this form of cracking is stress corrosion cracking rather than hydrogen embrittlement. (7) Prevention of stress corrosion cracking in these environments is discussed.
TL;DR: Inconel-600 and Incoloy-800 cracks intergranularly at mildly anodic potentials and transgranularally at reduced potentials at open circuit potentials, respectively.
Abstract: High-temperature electrochemical tests have resulted in the stress corrosion cracking of Inconel-600 and Incoloy-800 (registered trademarks, International Nickel Company), and Type 304 stainless steel in caustic solutions. Results show that stress corrosion cracking of these alloys can be prevented or accelerated by varying their electrochemical potential. To a certain extent, the same effect can be achieved by altering the gas atmosphere above the test solution from a pure nitrogen cover gas to a mixture of 5 percent H$sub 2$ and 95 percent N$sub 2$. The effect of the cover gas can then be negated by adjusting the specimen's electrochemical potential either to cause or to inhibit stress corrosion cracking. Some specifics of the test results reveal that in deoxygenated caustic solutions, Inconel-600 cracks intergranularly at mildly anodic potentials; Incoloy-800 cracks transgranularly at reduced potentials (at or near the open circuit potential) and intergranularly at highly oxidizing potentials; and cracking is mixed (transgranular/intergranular) for Type 304 stainless steel at or near the open circuit potential. The severity of cracking for both Inconel-600 and Incoloy-800 in deoxygenated caustic solutions is reduced by giving the materials a simulated post-weld heat treatment (1150$sup 0$F for 18 h). Test results on Inconel-600 show that high-carbonmore » (0.06 percent) material cracks less severely than low-carbon (0.02 percent) material, in both the simulated post-weld heat-treated condition and the mill-annealed condition. (auth)« less
TL;DR: In this article, the authors measured the stress corrosion resistance of nonmagnetic austenitic chromium-maganese steels using fracture mechanics techniques and found that the resulting crack velocity-stress intensity curves resemble those observed with other material-environment combinations.
Abstract: The stress corrosion resistance of austenitic chromium-maganese steels has been measured using fracture mechanics techniques. The resulting crack velocity-stress intensity curves resemble those observed with other material-environment combinations. High strength, nonmagnetic austenitic steels of the 18% Mn-5% Cr-0.5% C variety exhibit both intergranular and transgranular stress corrosion cracking (SCC) in distilled water at room temperature. Important mechanical and environmental effects on stress corrosion crack growth are measured and discussed.
Patent•
26 Aug 1976
TL;DR: An aluminum alloy having a high mechanical strength and elongation and resistant to stress corrosion cracking is disclosed which comprises 5 to 15% by weight of Zn, 0.3 to 1.5% by value of Mg and 0.1 to 0.
Abstract: An aluminum alloy having a high mechanical strength and elongation and resistant to stress corrosion cracking is disclosed which comprises 5 to 15% by weight of Zn, 0.3 to 1.5% by weight of Mg, 0.1 to 1.0% by weight of Zr, 0.1 to 1.0% by weight an alloying metal selected from the group consisting of Cu and Ag, and the remainder of Al and impurities normally present therein.
TL;DR: In this paper, the authors assessed the SCC behavior of mild steel in ammonium carbonate test solution at 70 C and the potential range measured within which minimum time to failure occurs.
Abstract: Stress corrosion cracking (SCC) behavior of mild steel is assessed in ammonium carbonate test solution at 70 C and the potential range measured within which minimum time to failure occurs. The effects of cold rolling and of alloyed carbon, silicon, nickel, chromium, and molybdenum are included. Results are compared with similar data previously reported in a nitrate test solution.
TL;DR: In this article, the stress corrosion cracking of mild steel in saturated ammonia vapor was studied by slow straining of a hollow specimen, which could be heated or cooled in relation to the temperature of the liquid.
Abstract: The stress corrosion cracking (SCC) of mild steel in saturated ammonia vapor was studied by slow straining of a hollow specimen, which could be heated or cooled in relation to the temperature of the liquid. SCC was effectively prevented if the specimen was heated 1 to 2 C above the temperature of the liquid, but SCC did occur on the cooled specimen, where condensation took place. Water inhibition of the liquid ammonia (with 0.2% water) did not prevent SCC in vapor of a strongly cooled specimen, where condensation was rapid.
Patent•
11 Aug 1976
TL;DR: In this paper, a solution treatment while generating the compressive residual stress at the inner surface of the stainless steel pipe and to prevent the occurrence of the stress corrosion cracking was carried out.
Abstract: PURPOSE:To carry out the solution treatment while generating the compressive residual stress at the inner surface of the stainless steel pipe and to prevent the occurrence of the stress corrosion cracking, by heating the area sensitized by welding of the austenitic stainless steel pipe to the solution treatment temperature and then by quenching the inner surface of the pipe.
TL;DR: Some electrochemical aspects of the stress corrosion cracking (SCC) behavior of ASTM A517 Grade F steel in liquid ammonia environments at 25 C have been studied in this article, where the electrode potentials were analyzed.
Abstract: Some electrochemical aspects of the stress corrosion cracking (SCC) behavior of ASTM A517 Grade F steel in liquid ammonia environments at 25 C have been studied. Electrode potentials were ...
TL;DR: The effects of environmental factors, aqueous HCl, anhydrous HCl and water, on stress corrosion cracking (SCC) and anodic polarization of annealed zirconium in methanol-HCl solutions were studied in this paper.
Abstract: The effects of the environmental factors, aqueous HCl, anhydrous HCl, and water, on stress corrosion cracking (SCC) and anodic polarization of annealed zirconium in methanol-HCl solutions ...
TL;DR: The threshold stress intensities for stress corrosion crack propagation in beta titanium alloy 38-6-44, Ti-3AI-8V-6Cr-4Mo-4Zr, has been determined in salt water and methanolic solutions as mentioned in this paper.
Abstract: The threshold stress intensities for stress corrosion crack propagation in beta titanium alloy 38-6-44, Ti-3AI-8V-6Cr-4Mo-4Zr, has been determined in salt water and methanolic solutions The alloy was immune to stress corrosion cracking (SCC) in aqueous sodium chloride solutions (marine atmosphere) However, in methanolic solutions, the alloy was very susceptible to SCC This marked susceptibility in methanolic solutions can be mitigated by the addition of an inhibitor: sodium nitrate Crack extension in the alloy was transgranular and failure occurred by brittle quasi-cleavage in methanolic solutions
TL;DR: In this article, the authors investigated the SCC properties of 17-4 PH steel over a wide range of yield strengths and applied cathodic potentials and found that increased applied cathode potentials increase SCC susceptibility of the alloy significantly.
Abstract: Recent unexpected occurrences of stress-corrosion cracking (SCC) with 17-4 PH structural components indicated a need for improved characterization of the alloy and application of more advanced analytical procedures for reliably predicting structural performance. Accordingly, the purpose of the present studies was to establish systematically the SCC properties of 17-4 PH steel over a wide range of yield strengths and applied cathodic potentials. Six different heat treatments were selected for the SCC studies. The data, when analyzed in terms of ratio analysis procedures, are immediately useful for predictions of service reliability of the steel in marine structures. The results show that 17-4 PH steel is moderately sensitive to SCC at high-strength levels, less sensitive to SCC at intermediate strength levels, and relatively insensitive to SCC in the metallurgically overaged, low yield strength condition. Increased applied cathodic potentials increase the SCC susceptibility of the alloy significantly which strongly suggests the involvement of hydrogen in the SCC mechanism. The minimum specimen thickness required for determining a thickness-independent K I s c c for steels by the cantilever method appears to be considerably less than for a standard K I c test.
TL;DR: In this paper, it was shown that during the preparation of Al alloy specimens, and during the spontaneous first step of S.c., sensitisation is brought about by diffusion of Al+3 causing structural disorder on immobile Al +3 and hence loss of cohesion.
Abstract: In Part I (BCJ, 1976, 11, 143) using aluminium specimens electrolytically notched (e.n.) by anodic dissolution, it was demonstrated that these specimens reached failure in s.c.c. in a shorter time than did mechanically notched (m.n.) specimens, tested under the same conditions. Similar results were obtained on e.n. and m.n. specimens after mechanical ‘denotching’. These results, combined with the fact that, for Al alloys, the rate determining stepfor s.c.c. is the solid state diffusion of mobile Al+3, were taken to provide evidence that during the e.n. preparation of Al alloy specimens, and during the spontaneous first step of S.c.c., sensitisation is brought about by diffusion of Al+3 causing structural disorder on immobile Al+3 and hence loss of cohesion. The results also provide indirect evidence that sensitisation is due to active path formation.Exactly similar experiments, now carried out on m.n. and e.n. and ‘denotched’ steel specimens (in which the rate determining step is diffusion of corr...
TL;DR: In this article, a study of the stress corrosion cracking susceptibility of quenched and tempered specimens of 13%Cr martensitic stainless steel, in aerated 3%NaCl at room temperature was made with concurrent in situ microscopical observation.