Quantitative models on corrosion fatigue crack growth rates in metals: Part II. application of fatigue crack growth rate modeling for nickel-based superalloys at elevated temperatures

1998 ◽  
Vol 4 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Sang Shik Kim ◽  
Seung Joo Choe ◽  
Kwang Seon Shin
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Growth Rates ◽  
Elevated Temperatures ◽  
Corrosion Fatigue Crack ◽  
Corrosion Fatigue Crack Growth ◽  
Crack Growth Rates

Fatigue Crack Growth Behavior of Titanium Alloy Ti-6Al-4V and Weldment

2001 ◽  
Vol 123 (3) ◽  
pp. 141-146 ◽  
Author(s):  
Mamdouh M. Salama
Keyword(s):  
Growth Rate ◽  
Titanium Alloy ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Titanium Alloys ◽  
Crack Growth ◽  
Growth Rates ◽  
Offshore Structures ◽  
Crack Growth Rates

Optimization of weight, cost, and performance of deepwater offshore structures demands the increased utilization of high strength, light weight, and corrosion resistant materials such as titanium alloys. Titanium alloy Ti-6Al-4V has been considered for several critical components such as risers and taper joints. Because of the novelty of use of titanium alloys in the offshore industry, there is currently no standard governing design of titanium components for offshore structures. Since these structural components are subjected to a complex spectrum of environmental loading, assessment of defect tolerance using fatigue crack growth analysis is generally considered an important design parameter. In this paper, more than 60 crack growth data sets from 20 independent laboratories were collected and analyzed to develop crack growth rate equations for use in defect assessment. These data include the results of fatigue testing of both base material and welded joints in air and seawater with and without cathodic protection and at different R-ratios and test frequencies. The results suggest that for crack growth rates above 10−7 in./cycle, crack growth of Ti-6Al-4V appears to be independent of testing condition and materials processing. At the low crack growth rate (below 10−7 in./cycle), the review revealed that data are very limited. These limited data, however, suggest that the crack growth threshold is dependent on the R-ratio and slightly dependent on material processing. Comparison between crack growth rates of steel and titanium alloy (Ti-6Al-4V) showed that the two materials have very similar behavior.

Fatigue Crack Growth in Type 316 Stainless Steel at High Temperature

1971 ◽  
Vol 93 (4) ◽  
pp. 976-980 ◽  
Author(s):  
P. Shahinian ◽  
H. H. Smith ◽  
H. E. Watson
Keyword(s):  
Growth Rate ◽  
Stainless Steel ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Growth Rates ◽  
316 Stainless Steel ◽  
Arrhenius Relation ◽  
Crack Growth Rates

The dependence of fatigue crack growth rates on range of stress intensity factor (ΔK) in Type 316 stainless steel was investigated over the temperature range of 75 to 1100 deg F. The data for the most part could be described by a power law relationship. An increase in temperature generally increased crack growth rate for a given ΔK and decreased fatigue life. The dependence of crack growth rate on temperature is not described adequately by an Arrhenius relation over the range investigated. On the other hand, by normalizing ΔK with respect to Young’s modulus, E, the crack growth rates for the various temperatures tend to fall within a single band.

Characteristics of Corrosion Fatigue Crack Growth in Salt Water of Aluminum Alloys for Hydrogen Gas Containers

2013 ◽  
Author(s):  
Takeshi Ogawa ◽  
Yuki Sugiyama ◽  
Toshihiko Kanezaki ◽  
Noboru Hayashi
Keyword(s):  
Fatigue Crack ◽  
Aluminum Alloys ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Growth Rates ◽  
Salt Water ◽  
Hydrogen Gas ◽  
Corrosion Fatigue Crack ◽  
Corrosion Fatigue Crack Growth ◽  
Crack Growth Rates

A hydrogen gas container is one of the critical components for fuel cell vehicles (FCV), which is expected for CO2-free personal transportation. In the early stage of commercial FCV, the major container structure will be a compressed hydrogen gas cylinder, which consists of metal or plastic linear with metal boss and carbon fiber reinforced plastics (CFRP). In order to choose an appropriate material for the metal boss and metal liner, corrosion resistance should be evaluated for various aspects such as corrosion fatigue crack growth (CFCG) and stress corrosion cracking (SCC) in the high pressure hydrogen as well as in salt water environment for the purpose of vehicle use. In the present study, CFCG characteristics were evaluated for several aluminum alloys in air and in salt waters with various concentrations. The results showed that the crack growth rates were accelerated in salt water for all the materials and their environmental sensitivities were compared. The concentrations of the salt water exhibited minor effect on the fatigue crack growth rates. These CFCG characteristics were compared with the corrosion test results based on the ISO 7866 Annex A [1]. A basic idea was proposed for the evaluation of compressed hydrogen gas containers and the important material properties were suggested.

Experimental Study on Fatigue Crack Growth and Residual Strength of Steel 30CrMnSiNi2A under Mixed Corrosive Environments

2008 ◽  
Vol 33-37 ◽  
pp. 261-266
Author(s):  
Sheng Nan Wang ◽  
Yi Li ◽  
Jian Bo Qin ◽  
Ya Long Liu ◽  
Yue Quan Zhou
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Residual Strength ◽  
Growth Rates ◽  
Critical Crack Length ◽  
Corrosive Environments ◽  
Crack Growth Rates

The effects of five single and three mixed corrosive environments on the fatigue crack growth and residual strength of steel 30CrMnSiNi2A were experimentally studied. The crack growth rates in corrosive environments, obtained by using Paris equation, were compared with crack growth rate in lab air. The results showed that the interactions of aggressive environments with fatigue loads caused the accelerations of fatigue crack growth rates in steel 30CrMnSiNi2A. But the effects of various environments on the fatigue crack growth rate are different. Among the environments the most detrimental one was oil-box zone, followed by cookroom&washroom, tank seeper, 3.5%NaCl, moist air, high altitude and dried air. Also, the test data showed the less effect of various corrosive environments on critical crack length, that is, no direct infection of corrosive environments on residual strength capability dominated by fracture toughness.

scholarly journals Orientation Dependence of Hydrogen Accelerated Fatigue Crack Growth Rates in Pipeline Steels

2018 ◽  
Author(s):  
Eun Ju Song ◽  
Joseph A. Ronevich
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Growth Rates ◽  
Orientation Dependence ◽  
Gaseous Hydrogen ◽  
Crack Growth Rates

One of the most efficient methods for supplying gaseous hydrogen long distances is by using steel pipelines. However, steel pipelines exhibit accelerated fatigue crack growth rates in gaseous hydrogen relative to air. Despite conventional expectations that higher strength steels would be more susceptible to hydrogen embrittlement, recent testing on a variety of pipeline steel grades has shown a notable independence between strength and hydrogen assisted fatigue crack growth rate. It is thought that microstructure may play a more defining role than strength in determining the hydrogen susceptibility. Among the many factors that could affect hydrogen accelerated fatigue crack growth rates, this study was conducted with an emphasis on orientation dependence. The orientation dependence of toughness in hot rolled steels is a well-researched area; however, few studies have been conducted to reveal the relationship between fatigue crack growth rate in hydrogen and orientation. In this work, fatigue crack growth rates were measured in hydrogen for high strength steel pipeline with different orientations. A significant reduction in fatigue crack growth rates were measured when cracks propagated perpendicular to the rolling direction. A detailed microstructural investigation was performed, in an effort to understand the orientation dependence of fatigue crack growth rate performance of pipeline steels in hydrogen environments.

Influence of Environment and Creep on Fatigue Crack Growth in a High Temperature Aluminum Alloy 8009

1994 ◽  
Vol 116 (1) ◽  
pp. 45-53 ◽  
Author(s):  
K. V. Jata ◽  
D. Maxwell ◽  
T. Nicholas
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Growth Rates ◽  
Hold Time ◽  
Maximum Load ◽  
Frequency Effects ◽  
Crack Growth Rates

Frequency effects on fatigue crack growth rates are examined in aluminum alloy 8009 in sheet and extruded product forms. The investigations show that frequency effects on the fatigue crack growth rates are pronounced in the sheet but minimal in the extrusion. The influence of creep cracking on fatigue crack growth rate is studied through tests with a 60 s hold-time at maximum load at several stress intensity ranges. A 60 s hold-time at maximum load at 315°C tends to retard fatigue crack growth in both the sheet and the extrusion. The mechanism by which this retardation occurs is attributed to stress relaxation at the crack tip. At 204°C a 60 s hold at Pmax accelerates crack growth rate in the sheet but not in the extrusion. Vacuum and laboratory air tests show that fatigue crack growth rates in vacuum are lower than in air by about a factor of four. A 60 s hold-time at minimum load has only a minor effect on the fatigue crack growth rates at 315°C and no effect at 204°C, confirming the absence of any strong environmental contribution to crack growth rate. Fracture modes in fatigue, creep crack growth and hold-time at Pmax are significantly different. The fractographic results are discussed in relation to the mechanical property data.

Fatigue crack growth of rails for railways

2003 ◽  
Vol 217 (2) ◽  
pp. 89-97 ◽  
Author(s):  
L F M da Silva ◽  
D J Stewardson ◽  
F M F de Oliveira ◽  
P M S T de Castro
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Statistical Analysis ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Growth Rates ◽  
The European Union ◽  
Significant Difference ◽  
Crack Growth Rates

Fatigue crack growth rates of rails from four European rail manufacturers are presented. The tests performed, on which the present paper is based, are part of the contribution to a project on the fatigue crack growth rate qualifying criteria of rails for railways—SMT4-CT98-2240—part-funded by the European Union. Six different laboratories were involved in measuring the scatter in fatigue crack growth rates. The tests were carried out under a stress ratio of 0.5, with test temperature and relative humidity recorded but not controlled beyond the ambient laboratory condition. The cyclic test frequency was either 10 or 15 Hz. The crack length was measured manually (optical microscope) which requires interruptions to the test overnight. Statistical analysis revealed that interruptions to tests may cause interference with the results. The data were analysed by three procedures: formal methods used were the secant method and the seven-point incremental polynomial technique; in addition, statistical analysis of a more investigative type using running regressions was utilized. It was found that there was no significant difference between the crack growth rate in samples from four different manufacturers.

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