Crude Oil Corrosion Fatigue of L485MB Pipeline Steel

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Ľ. Gajdoš ◽  
M. Šperl ◽  
J. Bystrianský
Keyword(s):  
Crude Oil ◽  
Strain Rate ◽  
Corrosion Fatigue ◽  
Pipeline Steel ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Oil Pipeline ◽  
Oil Processing ◽  
Tension Loading ◽  
Aggressive Effect

An investigation was made into the fatigue properties of L485MB (X70) pipeline steel after 13 yr of exploitation as a crude oil pipeline material. Fatigue tests in zero-to-tension loading were carried out (i) in air, (ii) in crude oil, (iii) in a mixture of crude oil with rainwater, and (iv) in water separated from the crude oil phase. The aim of the investigation was to assess the degree of degradation of the fatigue properties of this steel due to the action of environments typical for crude oil processing and transport. The results are not directly comparable to any corrosion fatigue experienced by the crude oil pipeline, since the strain rate for the tests was higher by an order of five than the strain rate observed in typical loading cycles. The results showed that crude oil and a mixture of crude oil with rainwater had no aggressive effect on the steel in the sense of reducing its fatigue characteristics, while the separated water had an aggressive effect.

Corrosion Fatigue Tests of Micro-Sized Specimens

2000 ◽  
Vol 657 ◽  
Author(s):  
Y. Mizutani ◽  
Y. Higo ◽  
Y. Ichikawa ◽  
A. Morita ◽  
K. Takashima ◽  
...  
Keyword(s):  
Fatigue Test ◽  
Corrosion Fatigue ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Fatigue Tests ◽  
Test Method ◽  
Fatigue Properties ◽  
Mems Devices ◽  
Problems And Solutions ◽  
Beam Type

ABSTRACTCorrosion fatigue properties of micro-sized materials are extremely important to design MEMS devices and micro-machines used in corrosive environments. However, there have been few studies that investigate corrosion fatigue properties of micro-sized materials. Thus, it is necessary to develop a corrosion fatigue test method for micro-sized materials. However, there are several difficulties in corrosion fatigue tests on micro-sized specimens. It is also necessary to clarify the problems for the method and to find their solutions. In this investigation, a corrosion fatigue test method for micro-sized specimens has been developed and corrosion fatigue tests for micro-sized Ni-P amorphous alloy specimens have been carried out in a 0.9% NaCl solution. Specimens of cantilever-beam-type with dimensions of 10 × 12 × 50 μm3 were prepared from a Ni-P amorphous thin film by focused ion beam machining. Corrosion fatigue tests on the micro-sized specimens were succeeded, and environmental effects on fatigue properties of micro-sized specimens were clearly observed. Several problems and solutions for the method were described.

The Influence of Air Humidity on Fatigue Properties of an AA2524－T34 Aluminum Alloy

2011 ◽  
Vol 213 ◽  
pp. 311-314
Author(s):  
Tang Li ◽  
Jun Lin Tao ◽  
Qing Yuan Wang
Keyword(s):  
Relative Humidity ◽  
Fatigue Behavior ◽  
Rolling Direction ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Al Alloy ◽  
Coarse Particles ◽  
Point Bend ◽  
Tension Loading ◽  
Cycles To Failure

Self-aligning four-point bend fatigue tests were conducted to investigate the influence of humid air on the fatigue behavior of an AA2524-T34 Al alloy. Test specimens of the alloy along the rolling direction was cycled at room temperature and frequency of 15 Hz, tension-tension loading(R = 0.1), in 15% relative humidity (RH) and 95% RH up to 107 cycles to failure. The S-N data shows continuous reduction tendency. It was found that with the increase of test relative humidity, the fatigue properties of the alloy is decreased, the fatigue limit in 95% RH was nearly 20% reduction of that in 15% RH, only 67% of its yield strength. Meanwhile, the S-N data is much more scattered than it in lower relative humidity. In 15% and 95% RH, cracks were initiated predominantly at coarse particles but partly at grain boundaries on the surface in 95%RH. SEM results show the characteristics of intergranular fracture in high humidity circumstance.

scholarly journals Usability of Ultrasonic Frequency Testing for Rapid Generation of High and Very High Cycle Fatigue Data

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2245
Author(s):  
Michael Fitzka ◽  
Bernd M. Schönbauer ◽  
Robert K. Rhein ◽  
Niloofar Sanaei ◽  
Shahab Zekriardehani ◽  
...  
Keyword(s):  
Strain Rate ◽  
High Cycle Fatigue ◽  
Fatigue Properties ◽  
Ultrasonic Frequency ◽  
Cycle Fatigue ◽  
Reinforced Polymer ◽  
Very High Cycle Fatigue ◽  
Ultrasonic Fatigue ◽  
Fibre Reinforced Polymer ◽  
Very High

Ultrasonic fatigue testing is an increasingly used method to study the high cycle fatigue (HCF) and very high cycle fatigue (VHCF) properties of materials. Specimens are cycled at an ultrasonic frequency, which leads to a drastic reduction of testing times. This work focused on summarising the current understanding, based on literature data and original work, whether and how fatigue properties measured with ultrasonic and conventional equipment are comparable. Aluminium alloys are not strain-rate sensitive. A weaker influence of air humidity at ultrasonic frequencies may lead to prolonged lifetimes in some alloys, and tests in high humidity or distilled water can better approximate environmental conditions at low frequencies. High-strength steels are insensitive to the cycling frequency. Strain rate sensitivity of ferrite causes prolonged lifetimes in those steels that show crack initiation in the ferritic phase. Austenitic stainless steels are less prone to frequency effects. Fatigue properties of titanium alloys and nickel alloys are insensitive to testing frequency. Limited data for magnesium alloys and graphite suggest no frequency influence. Ultrasonic fatigue tests of a glass fibre-reinforced polymer delivered comparable lifetimes to servo-hydraulic tests, suggesting that high-frequency testing is, in principle, applicable to fibre-reinforced polymer composites. The use of equipment with closed-loop control of vibration amplitude and resonance frequency is strongly advised since this guarantees high accuracy and reproducibility of ultrasonic tests. Pulsed loading and appropriate cooling serve to avoid specimen heating.

scholarly journals Geophysical investigations for stability and safety mitigation of regional crude-oil pipeline near abandoned coal mines

2021 ◽  
Vol 18 (1) ◽  
pp. 145-162
Author(s):  
B Butchibabu ◽  
Prosanta Kumar Khan ◽  
P C Jha
Keyword(s):  
High Resolution ◽  
Crude Oil ◽  
Seismic Refraction ◽  
High Resolution Imaging ◽  
Weak Zone ◽  
Near Surface ◽  
Oil Pipeline ◽  
Refraction Tomography ◽  
Geophysical Investigations ◽  
Resolution Imaging

Abstract This study aims for the protection of a crude-oil pipeline, buried at a shallow depth, against a probable environmental hazard and pilferage. Both surface and borehole geophysical techniques such as electrical resistivity tomography (ERT), ground penetrating radar (GPR), surface seismic refraction tomography (SRT), cross-hole seismic tomography (CST) and cross-hole seismic profiling (CSP) were used to map the vulnerable zones. Data were acquired using ERT, GPR and SRT along the pipeline for a length of 750 m, and across the pipeline for a length of 4096 m (over 16 profiles of ERT and SRT with a separation of 50 m) for high-resolution imaging of the near-surface features. Borehole techniques, based on six CSP and three CST, were carried out at potentially vulnerable locations up to a depth of 30 m to complement the surface mapping with high-resolution imaging of deeper features. The ERT results revealed the presence of voids or cavities below the pipeline. A major weak zone was identified at the central part of the study area extending significantly deep into the subsurface. CSP and CST results also confirmed the presence of weak zones below the pipeline. The integrated geophysical investigations helped to detect the old workings and a deformation zone in the overburden. These features near the pipeline produced instability leading to deformation in the overburden, and led to subsidence in close vicinity of the concerned area. The area for imminent subsidence, proposed based on the results of the present comprehensive geophysical investigations, was found critical for the pipeline.

scholarly journals Fatigue Properties of AZ31B Magnesium Alloy Processed by Equal-Channel Angular Pressing

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1191
Author(s):  
Ryuichi Yamada ◽  
Shoichiro Yoshihara ◽  
Yasumi Ito
Keyword(s):  
Magnesium Alloy ◽  
Equal Channel Angular Pressing ◽  
Low Cycle Fatigue ◽  
Annealed Sample ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Angular Pressing ◽  
Fundamental Research ◽  
Number Of Cycles ◽  
Biodegradable Magnesium

A stent is employed to expand a narrowed tubular organ, such as a blood vessel. However, the persistent presence of a stainless steel stent yields several problems of late thrombosis, restenosis and chronic inflammation reactions. Biodegradable magnesium stents have been introduced to solve these problems. However, magnesium-based alloys suffer from poor ductility and lower than desired fatigue performance. There is still a huge demand for further research on new alloys and stent designs. Then, as fundamental research for this, AZ31 B magnesium alloy has been investigated for the effect of equal-channel angular pressing on the fatigue properties. ECAP was conducted for one pass and eight passes at 300 °C using a die with a channel angle of 90°. An annealed sample and ECAP sample of AZ31 B magnesium alloy were subjected to tensile and fatigue tests. As a result of the tensile test, strength in the ECAP (one pass) sample was higher than in the annealed sample. As a result of the fatigue test, at stress amplitude σa = 100 MPa, the number of cycles to failure was largest in the annealed sample, medium in the ECAP (one pass) sample and lowest in the ECAP (eight passes) sample. It was suggested that the small low cycle fatigue life of the ECAP (eight passes) sample is attributable to severe plastic deformation.

scholarly journals Data Analysis and Discussion on the Reliability of the Control Principle of a Sealed Crude Oil Pipeline

2021 ◽  
Vol 1927 (1) ◽  
pp. 012021
Author(s):  
Junjiang Liu ◽  
Liang Feng ◽  
Dake Yang ◽  
Xianghui Li
Keyword(s):  
Data Analysis ◽  
Crude Oil ◽  
Oil Pipeline ◽  
Control Principle

Experimental study on the wax removal physics of foam pig in crude oil pipeline pigging

2021 ◽  
Vol 205 ◽  
pp. 108881
Author(s):  
Xuedong Gao ◽  
Qiyu Huang ◽  
Xun Zhang ◽  
Yu Zhang ◽  
Xiangrui Zhu ◽  
...  
Keyword(s):  
Experimental Study ◽  
Crude Oil ◽  
Oil Pipeline ◽  
Wax Removal
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