Showing papers on "Stress corrosion cracking published in 1971"
60 citations
TL;DR: In this article, the authors showed that increasing the thickness of epoxy joints with either tetraethylenepentamine (TEPA) or hexahydrophthalic anhydride (HHPA) was associated with a marked increase in macroroughness, and showed that an upper limit of joint thickness and hence toughness occurred because very thick joints could not be produced because residual stresses developed during cooling from the curing temperature caused the latter to separate at the interface.
Abstract: Increasing joint thickness was shown to increase the toughness of epoxy joints hardened with either tetraethylenepentamine (TEPA) or hexahydrophthalic anhydride (HHPA) The increased toughness was associated with a marked increase in macroroughness An upper limit of joint thickness and hence toughness occurred because very thick joints could not be produced Residual stresses developed during cooling from the curing temperature caused the latter to separate at the interface Stress corrosion cracking resistance was also found to depend on bond thickness For the TEPA-hardened system, bond thickness had only a minor influence for thicknesses up to 25 mils; and for the HHPA-hardened system, this persisted to bond thickness of 50 mils Further increases in bond thickness for both systems caused an abrupt rise in resistance to stress corrosion cracking
48 citations
TL;DR: In this paper, the limiting long time static load carrying capability of an epoxy joint was found to depend on its ability to resist crack extension in the presence of water, and this resistance to crack extension was shown to be independent of the epoxy resistance to water.
Abstract: The limiting long time static load carrying capability of an epoxy joint was found to depend on its ability to resist crack extension in the presence of water. This resistance to crack extension in...
46 citations
TL;DR: In this article, the causes of loss of corrosion resistance and ductility of AISI Type 446 steel with high chromium content have been investigated and changes in composition and heat treatment that would improve their material properties.
Abstract: The ferritic alloys, particularly AISI Type 446 steel with its high chromium content, have desirable properties of corrosion resistance, low raw material cost, and resistance to stress corrosion cracking (SCC); yet they are not widely used in construction work because of the damaging effects of high temperature exposures (such as welding) on their corrosion resistance and ductility. This work describes the causes for their loss of corrosion resistance and ductility, and defines changes in composition and heat treatment that would improve their material properties.
45 citations
TL;DR: In this paper, the dependence of cracking rate on applied stress intensity factor, K a, was measured in either salt water, or distilled water for the following steels: 300M, 250 grade maraging and the 9 Ni-4 Co-0.45 C, all heat treated to tensile strengths between 200 and 250 ksi.
44 citations
01 Feb 1971
TL;DR: In this paper, the second-phase particles are located in grain boundaries and interdendritic sites, and their concentration was varied by thermal-mechanical processing, and empirical results were presented and discussed.
Abstract: The mechanical behavior of a wrought high strength aluminum alloy is examined as a function of the concentration of second-phase microconstituents. These second-phase particles are located in grain boundaries and interdendritic sites. Their concentration was varied by thermal-mechanical processing. In the areas of strengths, ductility, crack toughness, fatigue, and stress corrosion cracking, empirical results are presented and discussed. Observations are made on changes in the anisotropic character of this category of material with lower concentrations of second phases.
39 citations
TL;DR: In this paper, an 18Ni (280) maraging steel has been tested in 3.5% NaCl solution under various modes of loading and the most severe condition was plane strain loading of fatigue precracked samples.
Abstract: An 18Ni (280) maraging steel has been tested in 3.5% NaCl solution under various modes of loading. The most severe condition was plane strain loading of fatigue precracked samples. The severity of stress corrosion cracking (SCC) of unnotched samples decreased in the sequence: plane strain bending, tension, plane stress bending, and torsion. The most consistent explanation for the various observations is that SCC results from hydrogen embrittlement. Under certain circumstances anodic dissolution processes can result in beneficial crack blunting effects rather than SCC failure.
34 citations
TL;DR: In this paper, the failure of notched and annealed rods of 304L austenitic steel stressed in tension in an aqueous solution of MgCl2 boiling at 154 C (309 F) was studied.
Abstract: Studies have been conducted on the failure of notched and annealed rods of 304L austenitic steel stressed in tension in an aqueous solution of MgCl2 boiling at 154 C (309 F). The phases pr...
31 citations
TL;DR: In this article, the failure was caused by a significant depletion in the chromium content in the weld metal, and the lack in the compositional balance was found to have originated at the overlaying of the first layer on the dissimilar base metal.
29 citations
TL;DR: Since the phenomena of stress corrosion cracking (of austenitic stainless steels) were first reported about 30 years ago, there has been a snowballing of costly failures in stainless steel.
Abstract: Since the phenomena of stress corrosion cracking (of austenitic stainless steels) were first reported about 30 years ago, there has been a snowballing of costly failures in stainless steel...
27 citations
TL;DR: Stress corrosion cracking of Cu-29.38 zinc in Mattsson's ammoniacal solution has been studied over the pH range 5.9 to 8.0 in this paper, where electron diffraction studies conducted on the actual stress corr...
Abstract: Stress corrosion cracking of Cu-29.38 zinc in Mattsson's ammoniacal solution has been studied over the pH range 5.9 to 8.0. Electron diffraction studies conducted on the actual stress corr...
01 Sep 1971
TL;DR: In this article, the effect of hydrogen concentration on the critical strain at which plastic instability along pure shear directions occurs was investigated in the case of Ti-8Al-lMo-lV and Ti-5Al-2.5Sn.
Abstract: The effect of hydrogen on the properties of metals, including titanium and its alloys, was investigated. The basic theories of stress corrosion of titanium alloys are reviewed along with the literature concerned with the effect of absorbed hydrogen on the mechanical properties of metals. Finally, the basic modes of metal fracture and their importance to this study is considered. The experimental work was designed to determine the effects of hydrogen concentration on the critical strain at which plastic instability along pure shear directions occurs. The materials used were titanium alloys Ti-8Al-lMo-lV and Ti-5Al-2.5Sn.
TL;DR: The susceptibility of 18% Ni (250) maraging steel to stress corrosion cracking in 3.5% NaCl solution has been investigated in this paper, where Metallographic and fractographic examinations show distinct diff...
Abstract: The susceptibility of 18% Ni (250) maraging steel to stress corrosion cracking in 3.5% NaCl solution has been investigated. Metallographic and fractographic examinations show distinct diff...
01 Apr 1971
TL;DR: In this article, the effects of a number of elements (C, Mn, Cr, Mo, Ni, Co, P, and S) on the stress-corrosion cracking (SCC) resistance in salt water of some quenched-and-tempered steels were investigated.
Abstract: The effects of a number of elements (C, Mn, Cr, Mo, Ni, Co, P, and S) on the stress-corrosion cracking (SCC) resistance in salt water of some quenched-and-tempered steels were investigated Values of the threshold stress intensity for crack growth in salt water (K
Iscc) were measured using the cantilever beam test and precracked specimens Values of the fracture toughness parameterK
Ix (an approximation ofK
Ic) were also determined The steels were either Fe-C alloys to which alloying elements were added, or basically of AISI 4340-type composition in which alloying elements were varied All steels in a series to show the effects of a given element were heat treated to the same yield strength, and generally the effects of an element were determined at two yield strength levels The results show that only carbon and manganese are definitely harmful to SCC resistance
01 Sep 1971
TL;DR: In this paper, the authors examined the nature of slip interaction with the grain boundaries on the polished surface of Inconel-600 pulled in tension at 370°C and at the initial strain rate of 1.65 × 10−6 sec−1.
Abstract: The nature of slip interaction with the grain boundaries was examined on the polished surface of Inconel-600 pulled in tension at 370°C and at the initial strain rate of 1.65 × 10−6 sec−1. It was shown that the grain boundaries could not always accommodate slip taking place at the boundary regions. This led to the separation of grains at the boundary. Depending on the detailed morphology of the carbides, these intergranular cracks could form at axial strains as low as 10 pet. Since the cracking takes place in the inert atmosphere, it is concluded that the grain boundaries are inherently embrittled by the formation of carbides and/or by solute segregation. There was no evidence of grain boundary sliding, but when carbides were absent highly localized slip in the boundary region gave the appearance of grain boundary offsets. The implications of these observations to stress corrosion cracking are discussed.
TL;DR: In this paper, a single crystal specimens of a Type 316 stainless steel was stressed in bending, using a self relieving loading system, and the variations of load during crack propagation were recorded and analyzed to obtain a relation between the crack propagation rate and other parameters.
Abstract: Crystallography, morphology, and kinetics of stress corrosion cracking (SCC) in austenitic stainless steels exposed to boiling, aqueous 45% magnesium chloride solution were studied on single crystal specimens of a Type 316 stainless steel. Notched specimens of selected orientations were stressed in bending, using a self relieving loading system. The variations of load during crack propagation were recorded and analyzed to obtain a relation between the crack propagation rate and other parameters. A single surface analysis of crack traces on the specimen sides and a two surface trace analysis on sections through flat regions of fracture surfaces were used in the determination of the crystallographic orientation of the cracking plane. Fracture surface topography and corrosion attack on slip steps were examined in a scanning electron microscope. The results of the crystal lographic analysis show that the stress corrosion cracks propagated on (210) oriented crystal planes. After an initial period, the...
TL;DR: In this paper, the mechanism of stress corrosion cracking of annealed zirconium in CH 3 OH + 04%HCl solution electrochemical studies such as the variation of potential with time, cracking behaviour under controlled potentials and effect of stress on cathodic and anodic polarization curves were carried out.
TL;DR: In this article, the effect of Mo, applied stress, and testing temperature on the fracture mode of stainless steels in stress corrosion cracking in MgCl2 and CaCl2 solution was investigated fractographically by scanning electron microscopy.
Abstract: Fracture surface of several austenitic stainless steels in stress corrosion cracking (SCC) in MgCl2 and CaCl2 solution was investigated fractographically by scanning electron microscopy. Effect of Mo, applied stress, and testing temperature on the fracture mode was studied. Type 304 steel and 310 steel fractured transgranularly in MgCl2 solution boiling at 143 C (289 F). Transgranular fracture was characterized by a fine parallel pleat pattern. This pattern seemed to be traces of dissolution of metals. Intergranular SCC occurred in Type 316 steel and 16Cr-15Ni-2~4Mo steels, and it was also observed in Type 304 steel fractured at temperatures lower than 125 C (257 F). Intergranular fracture tended to occur with increasing Mo content, applied stress, and lowering testing temperature.
01 Oct 1971
TL;DR: In this paper, a review of pertinent analytical fracture mechanics considerations and of basic test methods, the implications for test corrosion cracking studies of the time-to-failure determining kinetics of crack growth and life are examined.
Abstract: Discussion of some of the precaution needs the development of fracture-mechanics based test methods for studying stress corrosion cracking involves Following a review of pertinent analytical fracture mechanics considerations and of basic test methods, the implications for test corrosion cracking studies of the time-to-failure determining kinetics of crack growth and life are examined It is shown that the basic assumption of the linear-elastic fracture mechanics analyses must be clearly recognized and satisfied in experimentation and that the effects of incubation and nonsteady-state crack growth must also be properly taken into account in determining the crack growth kinetics, if valid data are to be obtained from fracture-mechanics based test methods
TL;DR: In this article, the authors compared the known behavior of hydrogen embrittled high-strength steel to the characteristics of environmentally induced failure where hydrogen is continuously generated at the specimen surface.
TL;DR: In this paper, 18Ni 180 and 18Ni 200 maraging steels have shown high resistance to stress corrosion cracking in sea water and 3-1/2% NaCl.
Abstract: 18Ni 180 and 18Ni 200 maraging steels have shown high resistance to stress corrosion cracking in sea water. U-bends had no cracks after exposure for over three years. 18Ni 180 welds also had good resistance, but welds in the 18Ni 200 grade suffered stress corrosion cracking. Cathodic protection of U-bends was beneficial, although a sensitivity to hydrogen was observed at very negative potentials. Fracture toughness measurements in sea water and 3-1/2% NaCl gave KISCC values of 130 ksi (in)1/2 for the 18 Ni 180 steel and 94 ksi (in)1/2 for 18Ni 200. The corresponding values for welds were 122 ksi (in)1/2 and 70 ksi (in)1/2. Fracture toughness decreased when the precracked cantilever bars were coupled to zinc or, in the case of welds, held at −0.85 volt vs SCE. General corrosion rates of maraging steels in sea water and marine atmospheres were approximately half those of HY-80 and 4340 low alloy steels.
TL;DR: In this article, the rate-controlling step of stress-corrosion cracking corresponds to the slip step formation, where the rate controlling mechanism requires the activation energy of about 18·7 Kcal/mol.
TL;DR: In this paper, the deformation twinning accompanied the formation of a stress corrosion fracture surface and opposite faces of a crack contained matching faceted (stepped) topography, consistent with their origin being associated with underlying deformation twins formed prior to the passage of the crack tip.
Abstract: Transgranular stress corrosion cracking of notched, solution treated and quenched Mg-8.6 wt % Al alloy rods tested in both salt solution and distilled water environments at 20 C (68 F) has been studied by direct electron diffraction techniques conducted on actual stress corrosion fracture surfaces, optical fractography, scanning electron fractography, and replica electron fractography. The studies revealed that considerable deformation twinning accompanied the formation of a stress corrosion fracture surface and that opposite faces of a stress corrosion crack contained matching faceted (stepped) topography. The detailed faceted topographical patterns were consistent with their origin being associated with underlying deformation twins formed prior to the passage of the crack tip and, frequently, deformation twins were observed adjacent and parallel to the stress corrosion fracture surface. All observations were consistent with a stress corrosion crack propagation process involving the formation of...
01 Nov 1971-Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science
TL;DR: In this paper, a study has been made of the dissolution and stress-corrosion cracking of copper and a series of α-brasses in nontarnishing 15 N ammoniacal solutions containing various concentrations of cupric complex ions.
Abstract: A study has been made of the dissolution and stress-corrosion cracking of copper and a series of α-brasses in nontarnishing 15 N ammoniacal solutions containing various concentrations of cupric complex ions Corrosion studies under open-circuit conditions indicated that the dissolution process is controlled by the cathodic reduction of the cupric complexes or, more specifically, by the transport of these ions to the metal surface Stress-corrosion tests confirmed earlier reports that failure of Cu-30 Zn under open-circuit conditions requires the presence in solution of cupric complexes in excess of a critical concentration However, potentiostatic experiments demonstrated that cracking occurs in theabsence of significant cupric complex-ion concentrations provided that the dissolution rate of the specimens exceeds a critical value Thus it is concluded that in stress-corrosion tests under open-circuit conditions the role of the cupric complex ions is simply to provide an efficient cathodic reaction, permitting rapid anodic dissolution These observations are discussed in terms of the mechanism of cracking in these solutions
TL;DR: In this paper, the mechanism of failure of aluminum/epoxide joints was investigated and a critical concentration of A-1100 silane was found to inhibit stress corrosion cracking, as well as evidence of plastic deformation at a crack tip.
Abstract: Scanning electron microscopy has supplied information concerning the mechanism of failure of aluminium/epoxide joints: (1) evidence for a critical concentration of A-1100 silane that inhibits stress corrosion cracking; (2) evidence of plastic deformation at a crack tip; (3) observation of aluminum corrosion products.
TL;DR: In this paper, the initiation and propagation of stress corrosion cracking (SCC) of austenitic stainless steels in boiling 35% magnesium chloride solution, with the pH adjusted to 3.0, were investigated.
Abstract: The initiation and propagation of stress corrosion cracking (SCC) of austenitic stainless steels in boiling 35% magnesium chloride solution, with the pH adjusted to 3.0, were investigated ...
TL;DR: In this paper, the effect of the carbide forming nature of a series of addition elements upon the location within the material of the interstitial elements contained in the alloys was studied.
TL;DR: In this article, a wide range of electrochromatic and electromechanical conditions were investigated for the AISI 4340 STEEL (200-KSI YIELD STRENGTH level) in DEAERATED 3.5 percent SODIUM CHLORIDE SOLUTION.
Abstract: STRESS CORROSION CRACK GROWTH RATES (DA/DT) AS A FUNCTION OF STRESS INTENSITY FACTOR (K) WERE DETERMINED OVER A WIDE RANGE OF ELECTRODE POTENTIALS FOR AISI 4340 STEEL (200-KSI YIELD STRENGTH LEVEL) IN DEAERATED 3.5 PERCENT SODIUM CHLORIDE SOLUTION BUFFERED TO PH 3.8. PARTICULAR EMPHASIS WAS PLACED ON CONDUCTING THE STRESS CORROSION TESTS UNDER WELL DEFINED ELECTROCHEMICAL AND MECHANICAL CONDITIONS. AT INTERMEDIATE K LEVELS, DA/DT WAS ESSENTIALLY INDEPENDENT OF K, SUGGESTING THAT CRACK GROWTH IS LIMITED BY MASS TRANSPORT. CRACK GROWTH IS APPARENTLY DOMINATED BY LOCALIZED MECHANICAL RUPTURING AT HIGH K LEVELS WHERE DA/DT INCREASED RAPIDLY WITH INCREASING K. EXCEPT AT A VERY CATHODIC POTENTIAL, DA/DT AT INTERMEDIATE K LEVELS WAS ALSO INDEPENDENT OF POTENTIAL, IMPLYING THAT THE ELECTROCHEMICAL CONDITIONS AT THE TIP OF THE STRESS CORROSION CRACK ARE NOT THE SAME AS THOSE OUTSIDE THE CRACK. THE TENDENCY FOR THE STRESS CORROSION CRACKS TO BRANCH WAS FOUND TO BE ELECTROCHEMICALLY, AS WELL AS MECHANICALLY, CONTROLLED.