共查询到20条相似文献,搜索用时 15 毫秒
1.
Dieter Hirschfeld Hans Busch Ingo Stellfeld Norbert Arlt Emil Michel Dieter Grimme Gregor Steinbeck 《国际钢铁研究》1993,64(8-9):461-465
Unexpected failures on 18/8 CrNi and 17/12/2 CrNiMo steels in indoor swimming pool atmospheres made it necessary to reinvestigate chloride induced stress corrosion cracking (SCC). SCC in the active state was investigated on stainless steels 1.3974, 1.4301, 1.4303, 1.4439, 1.4462, 1.4522, 1.4539 and 1.4571 by testing under constant load at temperatures up to 50°C. Selected tests were performed on the material with the highest SCC susceptibility, 1.4301, in solutions with different concentrations of hydrochloric acid and sodium chloride. SCC was only observed in critical ranges of hydrogen-ion concentration and only in conjunction with pronounced general corrosion. In a solution with c(HCl) = 1.0 mol/l and c(NaCl) = 0.5 mol/l, which had proved to be highly SCC-inducing, the effects of different parameters on SCC behaviour were studied. Temperature, stress level and degree of cold deformation exerted only a secondary influence, in contrast to alloy composition: austenitic steels containing about 10% nickel (1.4301, 1.4303, 1.4571) exhibited very pronounced SCC. The other materials with nickel contents distinctively higher or lower proved, respectively, to be less susceptible or resistant to SCC. Thus, the same effect of nickel content was observed as is known for resistance to chloride induced SCC in the passive state. All materials were prone to pronounced general corrosion. The corrosion phenomena observed were completely different from the swimming pool failures reported. 相似文献
2.
A. Chambreuil-Paret Ph.D. T. Magnin 《Metallurgical and Materials Transactions A》1999,30(5):1327-1331
Austenitic stainless steels are known to be sensitive to stress corrosion cracking (SCC) in hot chloride solutions. The aim
of the present study is to find improvements in the SCC behavior of 316L-type austenitic stainless steels in 117°C MgCl2 solutions. Previously, the authors have proposed the “corrosion-enhanced plasticity model” (CEPM) to describe the discontinuous
cracking process which occurs in SCC. This model is based on localized corrosion (anodic dissolution, and hydrogen absorption)-deformation
(dislocations) interactions (CDI). From the framework of this model, it is proposed that a prestraining in fatigue at saturation
decreases the SCC sensitivity. This idea is experimentally confirmed for both crack initiation and crack propagation, through
the analysis of the SCC behavior by slow-strain-rate tests of single and polycrystals after different prestraining conditions. 相似文献
3.
Markus O. Speidel 《Metallurgical and Materials Transactions A》1981,12(5):779-789
The metallurgical influences on the stress corrosion resistance of many commercial stainless steels have been studied using
the fracture mechanics approach. The straight-chromium ferritic stainless steels, two-phase ferritic-austenitic stainless
steels and high-nickel solid solutions (like alloys 800 and 600) investigated are all fully resistant to stress corrosion
cracking at stress intensity (K1) levels ≤ MN • m-3/2 in 22 pct NaCl solutions at 105 °C. Martensitic stainless steels, austenitic stainless steels and precipitation hardened
superalloys, all with about 18 pct chromium, may be highly susceptible to stress corrosion cracking, depending on heat treatment
and other alloying elements. Molybdenum additions improve the stress corrosion cracking resistance of austenitic stainless
steels significantly. The fracture mechanics approach to stress corrosion testing of stainless steels yields results which
are consistent with both the service experience and the results from testing with smooth specimens. In particular, the well
known “Copson curve” is reproduced by plotting the stress corrosion threshold stress intensity (ATISCC) vs the nickel content of stainless steels with about 18 pct chromium.
Formerly with the BBC Brown Boveri Company, Baden, Switzerland 相似文献
4.
P. Muraleedharan H. S. Khatak J. B. Gnanamoorthy P. Rodriguez 《Metallurgical and Materials Transactions A》1985,16(1):285-289
The influence of cold work (prestraining) in the range 2.3 to 56 pct on stress corrosion cracking (SCC) properties of types
304 and 316 stainless steels in boiling MgCl2 solution at 154 °C was investigated using a constant load method. In both materials,
SCC initiation was in transgranular mode. Transition in stress corrosion cracking mode from transgranular to intergranular,
as the crack proceeds, was observed at all cold work levels in 316 stainless steel and at cold work levels of 26 pct and 56
pct in 304 stainless steel. Both prestraining and increase in the initial applied stress facilitated the transition in crack
morphology to intergranular mode. Increased tendency to intergranular SCC at high applied stresses and in cold worked specimens
appears to be mechanistically analogous. 相似文献
5.
P. Muraleedharan H. S. Khatak J. B. Gnanamoorthy P. Rodriguez 《Metallurgical and Materials Transactions A》1985,16(2):285-289
The influence of cold work (prestraining) in the range 2.3 to 56 pct on stress corrosion cracking (SCC) properties of types
304 and 316 stainless steels in boiling MgCl2 solution at 154 °C was investigated using a constant load method. In both materials,
SCC initiation was in transgranular mode. Transition in stress corrosion cracking mode from transgranular to intergranular,
as the crack proceeds, was observed at all cold work levels in 316 stainless steel and at cold work levels of 26 pct and 56
pct in 304 stainless steel. Both prestraining and increase in the initial applied stress facilitated the transition in crack
morphology to intergranular mode. Increased tendency to intergranular SCC at high applied stresses and in cold worked specimens
appears to be mechanistically analogous. 相似文献
6.
Initiation of stress corrosion cracking for pipeline steels in a carbonate-bicarbonate solution 总被引:1,自引:0,他引:1
The linearly increasing stress test (LIST) was used to study the stress corrosion cracking (SCC) behavior of a range of pipeline
steels in carbonate-bicarbonate solution under stress rate control at different applied potentials. Stress corrosion cracking,
at potentials below -800 mV(SCE), was attributed to hydrogen embrittlement. Stress corrosion cracking, in the potential range
from about-700 to -500 mV(SCE), was attributed to an anodic dissolution mechanism. In the anodic potential region, the SCC
initiation stress was larger than the yield stress and was associated with significant plastic deformation at the cracking
site. The relative SCC initiation resistance decreased with in-creasing yield strength. In the cathodic potential region,
the SCC initiation stress was smaller than the yield stress of steel; it was approximately equal to the stress at 0.1 pct
strain(@#@ Σ0.1pct) for all the steels. The original surface was more susceptible to SCC initiation than the polished surface. 相似文献
7.
Younghwan Jang Sangshik Kim Jehyun Lee 《Metallurgical and Materials Transactions A》2005,36(5):1229-1236
The tensile and corrosion behaviors of CD4MCU cast duplex stainless steels with different Mo contents of 0, 2, and 4 pct,
respectively, were examined in the present study. The polarization and the in-situ slow-strain-rate (SSR) tests were conducted in a 3.5 pct NaCl+5 pct H2SO4 aqueous solution to quantify the resistances to pitting corrosion and stress corrosion cracking (SCC) with different Mo contents.
The addition of Mo, which is a strong ferrite stabilizer, affected the microstructure of the present alloy and, eventually,
the tensile and corrosion behaviors in a complex manner. The tensile properties of CD4MCU cast duplex stainless steel, for
example, were found to be determined by the volume fraction of hard ferritic phase, the presence of the second precipitates
of soft austenitic phase in the ferrite matrix, and the shape of the austenitic phase. The addition of 2 pct Mo was detrimental
to the corrosion properties of CD4MCU cast duplex stainless steel due to the significant increase in the volume fraction of
ferritic phase. With the addition of 4 pct Mo, however, the resistances to pitting corrosion and SCC recovered to those of
the specimen without Mo. The relationship between the microstructural evolution and the tensile and corrosion behavior of
CD4MCU cast duplex stainless steels with different Mo contents was discussed based on the micrographic and fractographic observations. 相似文献
8.
R. F. Hehemann 《Metallurgical and Materials Transactions A》1985,16(11):1909-1923
The similarities and differences in the stress corrosion cracking response of ferritic and austenitic stainless steels in
chloride solutions will be examined. Both classes of materials exhibit a cracking potential: similar transient response (to
loading) of the potential in open circuit tests or the current in potentiostatic tests and similar enrichment of chromium
and depletion of iron in the film associated with localized corrosion processes. The ferritic steels are more resistant to
localized corrosion than are the austenitic steels, which is responsible for the difference in the influence of prior thermal
and mechanical history on cracking susceptibility of the two types of steel. Similarities in the fractography of stress corrosion
cracks and those produced by brittle delayed failure during cathodic charging of the ferritic steels indicate that hydrogen
embrittlement is involved in the failure process. 相似文献
9.
Younghwan Jang Jinil Son Sanghik Kim Jehyun Lee Byunghak Choi 《Metallurgical and Materials Transactions A》2004,35(11):3431-3438
The tensile and corrosion behaviors of 0.13 pct N-containing CD4MCU cast duplex stainless steels with different Cr contents
ranging from 23 to 28 pct were examined in the present study. The polarization tests were conducted in 3.5 pct NaCl + 5 pct
H2SO4 aqueous solution for general corrosion resistance, and the in-situ slow strain rate (SSR) tests were also conducted in air and 3.5 pct NaCl + 5 pct H2SO4 aqueous solution to quantify the resistance to stress corrosion cracking (SCC) of the three materials. A substantial microstructural
change in 0.13 pct N-containing CD4MCU cast duplex stainless steel was observed with different Cr contents, which in turn
affected the tensile and corrosion behaviors significantly. Tensile behavior of 0.13 pct N-containing CD4MCU cast duplex stainless
steel, for example, varied in a nonlinear manner with different Cr contents due to the volume change of hard ferritic phase
and the presence of the second precipitates of soft austenitic phase in the ferrite matrix. The beneficial effect of Cr for
improving the general corrosion and the SCC resistances was largely overshadowed by this variation in microstructural characteristics.
The relationship between the microstructural evolution and the tensile and corrosion behavior of 0.13 pct N-containing CD4MCU
cast duplex stainless steels with different Cr contents was discussed based on the optical microscopy and scanning electron
microscopy (SEM) micrographic and fractographic observations. 相似文献
10.
Jinil Son Sangshik Kim Jehyun Lee Byunghak Choi 《Metallurgical and Materials Transactions A》2003,34(8):1617-1625
The effect of N addition on the microstructure, tensile, and corrosion behaviors of CD4MCU (Fe-25Cr-5Ni-2.8Cu-2Mo) cast duplex
stainless steel was examined in the present study. The slow strain rate tests were also conducted at a nominal strain rate
of 1 × 10−6/s in air and 3.5 pct NaCl+5 pct H2SO4 solution for studying the stress corrosion cracking (SCC) behavior. It was observed that the volume fraction of austenitic
phase in CD4MCU alloy varied from 38 to 59 pct with increasing nitrogen content from 0 to 0.27 wt. pct. The tensile behavior
of CD4MCU cast duplex stainless steels, which tended to vary significantly with different N contents, appeared to be strongly
related to the volume changes in ferritic and austenitic phases, rather than the intrinsic N effect. The improvement in the
resistance to general corrosion in 3.5 pct NaCl+5 pct H2SO4 aqueous solution was notable with 0.13 pct N addition. The further improvement was not significant with further N addition.
The resistance to SCC of CD4MCU cast duplex stainless steels in 3.5 pct NaCl+5 pct H2SO4 aqueous solution, however, increased continuously with increasing N content. The enhancement in the SCC resistance was believed
to be related to the volume fraction of globular austenitic colonies, which tended to act as barriers for the development
of initial pitting cracks in the ferritic phase into the sharp ones. 相似文献
11.
用U形弯试样浸泡和慢应变速率拉伸实验研究了3Cr17Ni7Mo2SiN和00Cr22Ni5Mo3N(2205)不锈钢在硫化氢介质中的应力腐蚀开裂(SCC)行为.2205不锈钢的SCC萌生孕育期较长,在pH较低的饱和H2S溶液中具有明显的SCC敏感性,其SCC敏感性随溶液pH值的升高或H2S含量的降低而迅速降低.3Cr17Ni7Mo2SiN的SCC孕育期均低于2205不锈钢,在pH ≤ 4.5、H2S的质量浓度 ≥ 103mg·L-1的H2S介质中均具有明显的SCC敏感性,其SCC敏感性受pH值和H2S含量变化影响较小.3Cr17Ni7Mo2SiN的SCC以沿晶裂纹萌生,扩展后转变为穿晶应力腐蚀开裂;2205不锈钢近表面处首先发生奥氏体-铁素体相间氢致开裂,并促进SCC萌生,其SCC为穿晶应力腐蚀开裂. 相似文献
12.
《Acta Metallurgica Materialia》1995,43(11):4001-4006
A synergistic effect of hydrogen and stress on a corrosion rate was analyzed with thermodynamics. The results showed that an interaction of stress and hydrogen could increase the corrosion rate remarkably. Stress corrosion cracking (SCC) of austenitic stainless steel (ASS) was investigated in boiling chloride solution to confirm the analysis. Hydrogen could be introduced into the specimen and concentrated at the crack tip during SCC in boiling LiCl solution (143°C). The concentrating factor is about 3 which is consistent with calculated results according to stress induced diffusion. 相似文献
13.
Hydrogen-facilitated corrosion and stress corrosion cracking of austenitic stainless steel of type 310 总被引:2,自引:0,他引:2
Qiao Lijie Chu Wuyang Miao Huijun Xiao Jimei Guo Peixin 《Metallurgical and Materials Transactions A》1993,24(4):959-962
The effects of hydrogen précharge and stress on anodic dissolution for Type 310 austenitic stainless steel (ASS) have been
investigated. An experiment determining the effect of hydrogen on stress corrosion cracking (SCC) was carried out in a boiling
42 pct MgCl2 solution and in a 2.5 mo/L H2SO4 + 1 mol/L HC1 solution. The results showed that both hydrogen and stress would increase the dissolution rate, and the effects
of hydrogen and stress on the dissolution rate were synergistic rather than simply additive. Hydrogen lowered the threshold
stress and the shortened fracture time of SCC in a boiling MgCl2 solution by a factor of 1/5 and 10, respectively. 相似文献
14.
Susceptibility of steel to cracking ‐either by contact with gas in wet H2S environments or near neutral solutions‐ is a dominant factor for residual life of gas‐line pipes. Three different phenomena are concerned with cracking, namely hydrogen induced cracking (HIC), sulphide stress cracking (SSC) and stress orientated hydrogen induced cracking (SOHIC). Whereas laboratory test methods for HIC are established the situation is different in combination with stress. If the coating is damaged and a near neutral liquid medium is penetrating the pipe surface a strain induced crack might occur. This type of corrosion is named near neutral SCC (NNSCC). A qualified test method with simulated cyclic loading conditions was not available. A test stand including pulsating tension on a high level qualified for high strength steels, wet environments with pH‐values between 2.7 (sour gas) and 8,3 (synthetic seawater) and bubbling several gases such as H2S, CO2 or N2 through the test solution with controlled room temperature was developed. The test‐method enables to qualify steels and pipes for line pipes in tests of short duration compared to lifecycles of line pipes. 相似文献
15.
Denny A. Jones 《Metallurgical and Materials Transactions A》1985,16(6):1133-1141
A mechanism of stress corrosion cracking (SCC) is outlined in which anodic dissolution at film rupture sites relieves strain
hardening and reduces the fracture stress at the crack tip. Experimental evidence is cited to suggest that relief of strain
hardening occurs by interaction of subsurface dislocations with divacancies generated by the anodic dissolution. A transgranular
crack propagates by accumulation of divacancies on prismatic planes which then separate by cleavage under plane strain conditions
at the crack tip. At appropriate metallurgical and chemical conditions, anodic dissolution and/or divacancy migration may
be enhanced at grain boundaries, leading to an intergranular failure mode. Evidence is also available to indicate that cyclic
loading relieves strain hardening. Relief of strain hardening by combined cyclic loading and corrosion accounts for the higher
incidence of corrosion fatigue cracking (CFC) without the requirement of any critical dissolved species. Data on fatigue of
stainless steel at elevated temperature in both vacuum and air provide additional support for the proposed mechanism. 相似文献
16.
This paper reports a study of grain boundary segregation, intergranular corrosion, and intergranular stress corrosion cracking
in austenitic stainless steels. The results show that phosphorus, nitrogen, and sulfur all segregate to grain boundaries in
these materials and that they can affect one another's segregation through site compctition. In particular, the results demonstrate
that phosphorus segregation can be lowered by the presence of nitrogen and sulfur in the steel. Also, if manganese is present
in the steel, sulfur segregation will be greatly decreased as a result of formation of manganese sulfides. Phosphorus, sulfur,
and nitrogen will not initiate intergranular corrosion in the modified Strauss test, although if corrosion is initiated by
chromium depletion, these elements might enhance the corrosion process. Phosphorus segregation does enhance corrosion in the
Huey test, even in steels that have not undergone grain boundary chromium depletion, although there does not appear to be
a precise correlation between the depth of corrosion penetration and phosphorus segregation. Intergranular stress corrosion
cracking in 288 °C water at a pH of 2.5 and electrochemical potential of OVSHE can occur in these steels even in the absence of chromium depletion if sulfur is present on the grain boundaries. Phosphorus
segregation appears to have very little effect. 相似文献
17.
Chuan-Ming Tseng Wen-Ta Tsai Horng-Yih Liou 《Metallurgical and Materials Transactions A》2003,34(1):95-103
The effect of nitrogen content on the stress corrosion cracking (SCC) behavior of 22 pct Cr duplex stainless steel (DSS) in
chloride solutions was investigated in this study. Slow strain rate testing (SSRT) was employed to evaluate the SCC susceptibility.
The experimental results showed that the tensile strength and ductility of 22 pct Cr DSS increased with increasing amount
of nitrogen (in the range of 0.103 to 0.195 wt pct). Slow strain rate testing results indicated that 22 pct Cr DSSs were resistant
to SCC in 3.5 wt pct NaCl solution at 80 °C. However, environmentally assisted cracking occurred in 40 wt pct CaCl2 solution at 100 °C and in boiling 45 wt pct MgCl2 solution at 155 °C, respectively. The effects of environment and nitrogen content in DSS on the cracking susceptibility are
discussed in this article. Selective dissolution of ferrite phase was found to participate in the SCC process for tests in
CaCl2 solution. At temperatures above 80 °C, dynamic strain aging was found to occur in various environments at a strain beyond
plastic deformation. 相似文献
18.
Hans Jürgen Grabke 《国际钢铁研究》1987,58(10):477-482
In steels produced and utilized in the Fed. Rep. of Germany the elements P and Sn may occur as impurities. Both these elements tend to enrich (segregate) at grain boundaries. The equilibria of grain boundary segregation in iron and the effects of alloying elements have been studied for P and Sn by Auger-electron-spectroscopy and were thermodynamically described. For a 3.5% NiCrMoV-turbine steel the grain boundary segregation of P and its effect on ductility have been studied in detail, with the results that the long-term embrittlement of this steel during application at temperatures around 400°C can be predicted and the maximum bulk concentration of P can be given. The effect of Sn on the creep of a 1% CrMoNiV steel at 550°C has been investigated, Sn favours cavity nucleation and growth, therefore tertiary creep starts earlier and premature failure occurs with increasing Sn content. Therefore, the Sn content should be kept as low as possible in heat resistant steels. Since carbon also segregates to grain boundaries and can displace P and Sn if there is enough free C in a steel, plain carbon steels are not subjected to embrittlement by P and Sn. The susceptibility to intergranular stress corrosion cracking in nitrates and other electrolytes is somewhat enhanced by P, however, only in a restricted range of potentials. In the range of maximum susceptibility the impurities have no effect, all carbon steels are susceptible to IGSCC, independently of their purity. So stress corrosion cracking cannot be suppressed by diminishing the content of phosphorus – only by avoiding the critical corrosion conditions concerning electrolyte and potential. 相似文献
19.
奥氏体不锈钢焊接构件在浓氯化物溶液中的应力腐蚀开裂 总被引:3,自引:1,他引:2
观察了18—8Ti奥氏体不锈钢焊接构件在浓氯化物溶液中的应力腐蚀,并对焊接接头各区应力腐蚀开裂敏感性进行了分析。 相似文献
20.
The stress corrosion cracking (SCC) behavior of PH13-8Mo precipitation hardening stainless steel (PHSS) in neutral NaCl solutions was investigated through slow-strain-rate tensile (SSRT)test at various applied potentials.Fracture morphology,elongation ratio,and percentage reduction of area were measured to evaluate the SCC susceptibility.A critical concentration of 1.0mol/L neutral NaCl existed for SCC of PH13-8Mo steel.Significant SCC emerged when the applied potential was more negative than-0.15 VSCE,and the SCC behavior was controlled by an anodic dissolution (AD) process.When the applied potential was lower than-0.55 VSCE,an obvious hydrogen-fracture morphology was observed,which indicated that the SCC behavior was controlled by hydrogen-induced cracking (HIC).Between-0.15 and-0.35 VSCE,the applied potential exceeded the equilibrium hydrogen evolution potential in neutral NaCl solutions and the crack tips were of electrochemical origin in the anodic region;thus,the SCC process was dominated by the AD mechanism. 相似文献