Acoustic Emission Study of Corrosion Fatigue and Fatigue for API 5L X70 Gas Pipeline Steel

2011 ◽  
Vol 138-139 ◽  
pp. 635-639
Author(s):  
Z.H. Hanafi ◽  
Nordin Jamaludin ◽  
Shahrum Abdullah ◽  
M.F.M. Yusof ◽  
M.S.M. Zain
Keyword(s):  
Acoustic Emission ◽  
Fatigue Test ◽  
Corrosion Fatigue ◽  
Pipeline Steel ◽  
Petroleum Industry ◽  
Fatigue Behaviour ◽  
Pressure Vessels ◽  
Uniform Corrosion ◽  
Smooth Specimen ◽  
Steel Pipeline

Acoustic emission is a very important test among non-destructive tests, and it has been applied for the detection of failures in various types of equipment in the petroleum industry, such as pressure vessels, tanks and pipelines. In this study, the effect of pre-existing uniform corrosion on the corrosion fatigue specimen and smooth specimen on fatigue behaviour of API 5L X70 steel pipeline in long life range was investigated by using acoustic emission in fatigue test. The presence of pre-existing uniform corrosion specimen, produces by 4 month immersion in sulphuric acid, H2SO4 (concentration 0.2 ml H2SO4 in 5000 ml deionized water ). Fully reverse (R = -1) constant amplitude fatigue test were done in corrosion fatigue and smooth specimen in different stress amplitudes. It was found that, effect of pre-existing uniform corrosion significantly reduced the fatigue life of the steel pipeline. The correlations of accumulative AE counts for corrosion fatigue higher than fatigue test because of the mechanisms of possible AE sources due to corrosion.

Acoustic Emission Behavior during Fatigue Crack of API5LX70 Gas Pipeline Steel

2011 ◽  
Vol 80-81 ◽  
pp. 148-152 ◽  
Author(s):  
M.F.M. Yusof ◽  
C.K.E. Nizwan ◽  
Nordin Jamaludin ◽  
S. Abdullah
Keyword(s):  
Acoustic Emission ◽  
Crack Initiation ◽  
Fatigue Test ◽  
Slip Plane ◽  
Pipeline Steel ◽  
Gas Pipeline ◽  
Crack Initiation And Propagation ◽  
Formation Stage ◽  
Initiation And Propagation ◽  
Propagation Stage

This paper present Acoustic Emission (AE) generated during fatigue mechanism of API5LX70 steel which was widely use as gas pipeline materials. Fully reverse (R=-1) constant amplitude fatigue test were done with four different stress amplitudes which were 437.5MPa, 406.25Mpa, 390.6MPa and 359.4MPa respectively. An observation from those tests shows that AE Count gives a significant value during cyclic softening and bauschinger effect. Crack initiation indicated by rapid increase of AE count values at positive peak stress and followed by high AE count values around zero stress which indicate crack closure phenomena. Among all four tests, it was show that AE activity from fatigue test with amplitude of 359.4MPa can be significantly divided into 3 region which correspond to crack incubation stage, microplastic and slip plane formation stage and crack initiation and propagation stage. Further analysis was done by separating AE signals from those 3 regions into 6 different groups. Ten AE signatures from each group were selected to calculate AE RMS and AE kurtosis. Analyses on AE RMS which correspond to overall energy of the signal were useful to indicate the microplastic and slip plane formation stage and crack initiation and propagation stage while AE kurtosis was useful in indicating crack stage including initiation, propagation and closure stage.

Effect of Sulfuric Acid Concentration on Acoustic Emission Signals in Uniform-Corrosion

2006 ◽  
Vol 321-323 ◽  
pp. 553-556 ◽  
Author(s):  
Asa Prateepasen ◽  
Chalermkiat Jirarungsatean ◽  
Pongsak Tuengsook
Keyword(s):  
Acoustic Emission ◽  
Sulfuric Acid ◽  
Inorganic Compounds ◽  
Petroleum Industry ◽  
Sulfuric Acid Concentration ◽  
Steel Structures ◽  
Life Time ◽  
Corrosion Mechanism ◽  
Uniform Corrosion ◽  
Ae Signals

In petroleum industry, corrosion failures of steel structures are common. The severity of corrosion in oil distillery inorganic compounds is higher than in those of organic compounds. Inorganic compounds such as sulfur are the most influential corrosive activators inside oil or chemical storage tanks. They normally have the tanks inspected and repaired along their life time. In addition the concentration of sulfur compound increases due to the accumulation of the residuals inside the tank, and so does the corrosive rate. In this paper, Acoustic Emission (AE) has been chosen to study the characteristic of AE signals received from the uniform corrosion mechanism of mild steel (A36) in various concentrations of Sulfuric acid (H2SO4) solution. AE signals were captured using a wide band sensor (WD) and recorded by AE system model LOCAN 320. The relationship between AE signals and sulfur concentrations as well as pH were exhibited.

Detection of Corrosion Damage on Pressure Equipment with Acoustic Emission

2006 ◽  
Vol 13-14 ◽  
pp. 127-132 ◽  
Author(s):  
Gerold Lackner ◽  
Peter Tscheliesnig
Keyword(s):  
Acoustic Emission ◽  
Test Procedure ◽  
Corrosion Damage ◽  
Practical Experience ◽  
Pressure Vessels ◽  
Destructive Testing ◽  
Widespread Application ◽  
Traditional Procedure ◽  
Emission Testing ◽  
Service Period

Acoustic emission testing (AT) is in Europe an already well established non-destructive testing (NDT) method. Qualification requirements as well as certification of testing personnel are laid down in European standard EN 473. A widespread application of AT deals with testing of unfired pressure vessels for re-qualification after a certain period of service (repetition test). The advantages of applying AT compared to the traditional procedure of hydrostatic test plus visual inside inspection are numerous. Just to name the most important: reduction of downtime, omitting of residual humidity and no risk of product contamination with water. It is a fact that AT provides much more useful information concerning the condition of the pressure vessel under test than a simple ‘passed’ or ‘not passed’ obtained usually by a hydrostatic test. This contribution gives two examples of practical experience, where severe corrosion defects have been detected by AT. The defects have been found in both cases on the vessel’s shell under the thermal insulation, where they have been hidden undetected for years. It can be assumed that even the vessel with the most severe damage (loss of more than 50% of the nominal wall thickness) would have passed the traditional repetition test procedure and that failure within the following service period would have occurred. In contrary to this scenario, AT enabled the vessel operator to perform appropriate repair in time.

Evaluation of High Cycle Fatigue Properties of Double Side Welded AISI 321 Plates Using GTAW Process for Pressure Vessels

2021 ◽  
Author(s):  
Mohan Kumar S ◽  
A. Rajesh Kannan ◽  
Pramod R. ◽  
Pravin Kumar N ◽  
Nallathambi Siva Shanmugam ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Fatigue Behavior ◽  
Fatigue Behaviour ◽  
Pressure Vessels ◽  
Fatigue Properties ◽  
Dendritic Microstructure ◽  
Gas Tungsten Arc ◽  
Gtaw Process ◽  
Fatigue Rupture ◽  
Aisi 321

Abstract Titanium stabilized AISI 321 material (UNS S32100) is generally preferred in the pressure vessel industry as they are not sensitive to intergranular corrosion. In critical applications, the fatigue behaviour of weld seams are amongst the most stringent requirements. The microstructural characteristics and fatigue performance of double side welded AISI 321 plate having 6 mm thickness were evaluated in this work. AISI 321 was welded with Double side-gas tungsten arc welding (DS-GTAW) process. The fatigue behavior was examined under a loading ratio of 0.1 for two different specimens: Base metal (BM) and Weld metal (WM). Monotonic tensile results show the improved tensile properties of WM compared to BM samples. The fatigue strength of WM (332.6 MPa) was 25% higher than that of BM (265.7 MPa) specimen and is attributed to the increase in ferrite volume along with dendritic microstructure. The change in the fraction of low angle grain boundaries (LABs) and high angle grain boundaries (HABs) improved the tensile and fatigue properties. The stress amplitudes influenced the degree of striations in the BM and WM. Final fracture surfaces were characterized with dimples and micro-voids, revealing the ductile mode of fatigue fracture. The fatigue rupture surfaces of BM and WM samples at different stress regimes are discussed.

INFORMATION AND KINETIC APPROACH TO THE EVALUATION OF STRESS STATE OF VESSELS OPERATING UNDER PRESSURE IN HYDROGEN ENVIRONMENTS

2021 ◽  
pp. 30-45
Author(s):  
V. V. Nosov ◽  
A. R. Yamilova
Keyword(s):  
Acoustic Emission ◽  
Pressure Vessels ◽  
Maximum Activity ◽  
The State ◽  
Material Structure ◽  
Diagnostic Efficiency ◽  
Active Volume ◽  
And Control ◽  
Non Destructive ◽  
Altitude Level

Separation of the influence of various factors on the strength of the material and control parameters is the basis for increasing the diagnostic efficiency. The article describes methods for assessing the state of pressure vessels, features of their damage under conditions of hydrogen absorption, presents data from acoustic emission and ultrasonic testing, compares them, sets out an approach to non-destructive assessment of the strength state of technical objects, based on a multilevel model of time dependences of acoustic emission parameters (AE), the kinetic concept of strength, micromechanics of fracture of discrete media, their relationship with the resource, parameters of fatigue curves and characteristics of the material structure, the problems of the influence of strength and metrological heterogeneity on the information content of control, the sequence of assessing the indicators of the strength state and resource of vessels, the model of strength and metrological heterogeneity of the AE are presented control, explaining the maximum activity of AE during tests in the first periods of operation, a methodology for assessing the strength state of pressure vessels is presented. Demonstration of the effectiveness of the technique is shown as an example of AE testing of an absorber for purifying hydrogen sulfide with a monoethanolamine solution by predicting the resource of its components and comparing the prediction results with the coordinate-altitude level of the adsorber belt, which correlates with the average internal hydrostatic stresses. Approbation of the approach has shown its versatility on the example of effective application for objects with defects of both fatigue and chemical origin under conditions of hydrogenation. Using the example of assessing the state of the most damaged lower belt, it is shown that an increase in the AE activity during hydrogenation of the material occurs mainly due to the growth of the acoustically active volume of the controlled zone, which is not unambiguously associated with the resource, and therefore the activity and energy intensity of the AE should not be considered sufficient a sign of the danger of a defect formed under the influence of hydrogen-containing media.

Sign in / Sign up

Export Citation Format

Share Document