No Cover Image

E-Thesis 50 views 31 downloads

Use of the environmentally controlled scanning vibrating electrode technique for the investigation of localised corrosion in pipeline steel. / Jim Boughton

Swansea University Author: Jim Boughton

Abstract

The aim of this project was to explore the design criterion for a scanning vibrating electrode technique (SVET) assembly with partial environmental control. To facilitate this goal an SVET has been designed which incorporates an enclosed sample chamber equipped with a means of gas purging. The desig...

Full description

Published: 2002
Institution: Swansea University
Degree level: Master of Philosophy
Degree name: M.Phil
URI: https://cronfa.swan.ac.uk/Record/cronfa42542
Tags: Add Tag
No Tags, Be the first to tag this record!
first_indexed 2018-08-02T18:54:57Z
last_indexed 2019-10-21T16:48:01Z
id cronfa42542
recordtype RisThesis
fullrecord <?xml version="1.0"?><rfc1807><datestamp>2018-08-16T14:39:02.9105634</datestamp><bib-version>v2</bib-version><id>42542</id><entry>2018-08-02</entry><title>Use of the environmentally controlled scanning vibrating electrode technique for the investigation of localised corrosion in pipeline steel.</title><swanseaauthors><author><sid>68d1df10658deb2a0435ad14d51cce4a</sid><ORCID>NULL</ORCID><firstname>Jim</firstname><surname>Boughton</surname><name>Jim Boughton</name><active>true</active><ethesisStudent>true</ethesisStudent></author></swanseaauthors><date>2018-08-02</date><abstract>The aim of this project was to explore the design criterion for a scanning vibrating electrode technique (SVET) assembly with partial environmental control. To facilitate this goal an SVET has been designed which incorporates an enclosed sample chamber equipped with a means of gas purging. The design allows for prepurging of electrolyte prior to sample immersion since corrosion initiated prior to stabilising the atmosphere is likely to dominate the corrosion profile. In addition, dosing of the electrolyte with prepurged solution such as corrosion inhibitor is possible through injection ports. The apparatus has been built and rigorously calibrated using a point current source as described in Chapter 3. The apparatus has a spatial resolution of ~220mum at 100mum scan height, this is slightly larger than the theoretical value due to the finite size of the SVET tip. The use of the point current source enabled a calibration factor 1 of 5445 Am-2V-1 to be obtained in 0.1% NaC1. This acts as a means of converting SVET voltages to current densities and is also a routine calibration check. The first use of the equipment described in chapter 4 has been to analyse the efficiency of a commercial filming amine inhibitor on the kinetics and mechanisms of corrosion. The addition of inhibitor to the electrolyte served to reduce the levels of corrosion of the pipeline material. However low concentrations (&lt;5ppm) did, whilst reducing the overall corrosion levels, cause the formation of intense localised pits. Measurement of the Ecorr showed an increase on addition of the inhibitor implying partial anodic inhibition. Total metal loss (TML) for varying levels of inhibitor concentration and atmospheric conditions were calculated over a three hour period; under normal atmospheric conditions the TML for a l0mm2 area was 24.8mug, under CO2 purged conditions this decreased to 12.1mug, the addition of 5 parts per million inhibitor solution reduced the TML further to 4.65mug and finally the addition of 10ppm inhibitor yielded the lowest total metal loss figure of 2.84mug. Due to the fact that the inhibitor is a positively charged species the inhibitor solution served to actually increase crevice corrosion activity by a factor of three in the crevice region whilst reducing corrosion across the bulk surface. In the second application, described in chapter 5, the environmental SVET has been used to visualise galvanic coupling between weld metal and base materials in a field failure supplied by Total Elf Fina. The weld and the heat affected zones are anodic to the tube base metal and this is related to their lower chromium level and elevated aluminium content. Comparing total metal loss values of the welded sample in a CO2 saturated atmosphere with a single metal material under the same conditions; the galvanic corrosion effectively doubles the corrosion activity, bringing it back up to the levels found with samples corroding in air saturated sodium chloride solution. Further more the corrosion is focused on the small area of the weld metal, and in the field the ratio of areas between the cathodic pipeline and anodic welded joints will be significantly greater therefore accelerating time to failure.</abstract><type>E-Thesis</type><journal/><journalNumber></journalNumber><paginationStart/><paginationEnd/><publisher/><placeOfPublication/><isbnPrint/><issnPrint/><issnElectronic/><keywords>Electrical engineering.</keywords><publishedDay>31</publishedDay><publishedMonth>12</publishedMonth><publishedYear>2002</publishedYear><publishedDate>2002-12-31</publishedDate><doi/><url/><notes/><college>COLLEGE NANME</college><department>Engineering</department><CollegeCode>COLLEGE CODE</CollegeCode><institution>Swansea University</institution><degreelevel>Master of Philosophy</degreelevel><degreename>M.Phil</degreename><apcterm/><lastEdited>2018-08-16T14:39:02.9105634</lastEdited><Created>2018-08-02T16:24:29.6186062</Created><path><level id="1">Faculty of Science and Engineering</level><level id="2">School of Engineering and Applied Sciences - Uncategorised</level></path><authors><author><firstname>Jim</firstname><surname>Boughton</surname><orcid>NULL</orcid><order>1</order></author></authors><documents><document><filename>0042542-02082018162502.pdf</filename><originalFilename>10805291.pdf</originalFilename><uploaded>2018-08-02T16:25:02.7070000</uploaded><type>Output</type><contentLength>10909486</contentLength><contentType>application/pdf</contentType><version>E-Thesis</version><cronfaStatus>true</cronfaStatus><embargoDate>2018-08-02T16:25:02.7070000</embargoDate><copyrightCorrect>false</copyrightCorrect></document></documents><OutputDurs/></rfc1807>
spelling 2018-08-16T14:39:02.9105634 v2 42542 2018-08-02 Use of the environmentally controlled scanning vibrating electrode technique for the investigation of localised corrosion in pipeline steel. 68d1df10658deb2a0435ad14d51cce4a NULL Jim Boughton Jim Boughton true true 2018-08-02 The aim of this project was to explore the design criterion for a scanning vibrating electrode technique (SVET) assembly with partial environmental control. To facilitate this goal an SVET has been designed which incorporates an enclosed sample chamber equipped with a means of gas purging. The design allows for prepurging of electrolyte prior to sample immersion since corrosion initiated prior to stabilising the atmosphere is likely to dominate the corrosion profile. In addition, dosing of the electrolyte with prepurged solution such as corrosion inhibitor is possible through injection ports. The apparatus has been built and rigorously calibrated using a point current source as described in Chapter 3. The apparatus has a spatial resolution of ~220mum at 100mum scan height, this is slightly larger than the theoretical value due to the finite size of the SVET tip. The use of the point current source enabled a calibration factor 1 of 5445 Am-2V-1 to be obtained in 0.1% NaC1. This acts as a means of converting SVET voltages to current densities and is also a routine calibration check. The first use of the equipment described in chapter 4 has been to analyse the efficiency of a commercial filming amine inhibitor on the kinetics and mechanisms of corrosion. The addition of inhibitor to the electrolyte served to reduce the levels of corrosion of the pipeline material. However low concentrations (<5ppm) did, whilst reducing the overall corrosion levels, cause the formation of intense localised pits. Measurement of the Ecorr showed an increase on addition of the inhibitor implying partial anodic inhibition. Total metal loss (TML) for varying levels of inhibitor concentration and atmospheric conditions were calculated over a three hour period; under normal atmospheric conditions the TML for a l0mm2 area was 24.8mug, under CO2 purged conditions this decreased to 12.1mug, the addition of 5 parts per million inhibitor solution reduced the TML further to 4.65mug and finally the addition of 10ppm inhibitor yielded the lowest total metal loss figure of 2.84mug. Due to the fact that the inhibitor is a positively charged species the inhibitor solution served to actually increase crevice corrosion activity by a factor of three in the crevice region whilst reducing corrosion across the bulk surface. In the second application, described in chapter 5, the environmental SVET has been used to visualise galvanic coupling between weld metal and base materials in a field failure supplied by Total Elf Fina. The weld and the heat affected zones are anodic to the tube base metal and this is related to their lower chromium level and elevated aluminium content. Comparing total metal loss values of the welded sample in a CO2 saturated atmosphere with a single metal material under the same conditions; the galvanic corrosion effectively doubles the corrosion activity, bringing it back up to the levels found with samples corroding in air saturated sodium chloride solution. Further more the corrosion is focused on the small area of the weld metal, and in the field the ratio of areas between the cathodic pipeline and anodic welded joints will be significantly greater therefore accelerating time to failure. E-Thesis Electrical engineering. 31 12 2002 2002-12-31 COLLEGE NANME Engineering COLLEGE CODE Swansea University Master of Philosophy M.Phil 2018-08-16T14:39:02.9105634 2018-08-02T16:24:29.6186062 Faculty of Science and Engineering School of Engineering and Applied Sciences - Uncategorised Jim Boughton NULL 1 0042542-02082018162502.pdf 10805291.pdf 2018-08-02T16:25:02.7070000 Output 10909486 application/pdf E-Thesis true 2018-08-02T16:25:02.7070000 false
title Use of the environmentally controlled scanning vibrating electrode technique for the investigation of localised corrosion in pipeline steel.
spellingShingle Use of the environmentally controlled scanning vibrating electrode technique for the investigation of localised corrosion in pipeline steel.
Jim Boughton
title_short Use of the environmentally controlled scanning vibrating electrode technique for the investigation of localised corrosion in pipeline steel.
title_full Use of the environmentally controlled scanning vibrating electrode technique for the investigation of localised corrosion in pipeline steel.
title_fullStr Use of the environmentally controlled scanning vibrating electrode technique for the investigation of localised corrosion in pipeline steel.
title_full_unstemmed Use of the environmentally controlled scanning vibrating electrode technique for the investigation of localised corrosion in pipeline steel.
title_sort Use of the environmentally controlled scanning vibrating electrode technique for the investigation of localised corrosion in pipeline steel.
author_id_str_mv 68d1df10658deb2a0435ad14d51cce4a
author_id_fullname_str_mv 68d1df10658deb2a0435ad14d51cce4a_***_Jim Boughton
author Jim Boughton
author2 Jim Boughton
format E-Thesis
publishDate 2002
institution Swansea University
college_str Faculty of Science and Engineering
hierarchytype
hierarchy_top_id facultyofscienceandengineering
hierarchy_top_title Faculty of Science and Engineering
hierarchy_parent_id facultyofscienceandengineering
hierarchy_parent_title Faculty of Science and Engineering
department_str School of Engineering and Applied Sciences - Uncategorised{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Engineering and Applied Sciences - Uncategorised
document_store_str 1
active_str 0
description The aim of this project was to explore the design criterion for a scanning vibrating electrode technique (SVET) assembly with partial environmental control. To facilitate this goal an SVET has been designed which incorporates an enclosed sample chamber equipped with a means of gas purging. The design allows for prepurging of electrolyte prior to sample immersion since corrosion initiated prior to stabilising the atmosphere is likely to dominate the corrosion profile. In addition, dosing of the electrolyte with prepurged solution such as corrosion inhibitor is possible through injection ports. The apparatus has been built and rigorously calibrated using a point current source as described in Chapter 3. The apparatus has a spatial resolution of ~220mum at 100mum scan height, this is slightly larger than the theoretical value due to the finite size of the SVET tip. The use of the point current source enabled a calibration factor 1 of 5445 Am-2V-1 to be obtained in 0.1% NaC1. This acts as a means of converting SVET voltages to current densities and is also a routine calibration check. The first use of the equipment described in chapter 4 has been to analyse the efficiency of a commercial filming amine inhibitor on the kinetics and mechanisms of corrosion. The addition of inhibitor to the electrolyte served to reduce the levels of corrosion of the pipeline material. However low concentrations (<5ppm) did, whilst reducing the overall corrosion levels, cause the formation of intense localised pits. Measurement of the Ecorr showed an increase on addition of the inhibitor implying partial anodic inhibition. Total metal loss (TML) for varying levels of inhibitor concentration and atmospheric conditions were calculated over a three hour period; under normal atmospheric conditions the TML for a l0mm2 area was 24.8mug, under CO2 purged conditions this decreased to 12.1mug, the addition of 5 parts per million inhibitor solution reduced the TML further to 4.65mug and finally the addition of 10ppm inhibitor yielded the lowest total metal loss figure of 2.84mug. Due to the fact that the inhibitor is a positively charged species the inhibitor solution served to actually increase crevice corrosion activity by a factor of three in the crevice region whilst reducing corrosion across the bulk surface. In the second application, described in chapter 5, the environmental SVET has been used to visualise galvanic coupling between weld metal and base materials in a field failure supplied by Total Elf Fina. The weld and the heat affected zones are anodic to the tube base metal and this is related to their lower chromium level and elevated aluminium content. Comparing total metal loss values of the welded sample in a CO2 saturated atmosphere with a single metal material under the same conditions; the galvanic corrosion effectively doubles the corrosion activity, bringing it back up to the levels found with samples corroding in air saturated sodium chloride solution. Further more the corrosion is focused on the small area of the weld metal, and in the field the ratio of areas between the cathodic pipeline and anodic welded joints will be significantly greater therefore accelerating time to failure.
published_date 2002-12-31T03:53:10Z
_version_ 1763752637059039232
score 11.013686

Similar Items