Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Manufacturing of Welded Rings: Evaluation of Post-Weld Operations
Karlstad University, Faculty of Health, Science and Technology (starting 2013).
2019 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesisAlternative title
Tillverkning av svetsade ringämnen : Utvärdering av svetsfogsoperationer (Swedish)
Abstract [en]

Pipe and ring blanks can be produced in several different ways. Today's focus on environmental effects motivates companies to develop processes that are as efficient as possible in their production. Ringsvets AB is a company that produces pipe and ring blanks from a flat stock by rolling and welding the piece to make it stay in its desired form. The direct benefit of the method is the minimizing of material loss, and it has thereby both environmental and economical advantages. The downside of the method is that the processes involved changes the mechanical behavior of the ring, locally around the weld zone. The focus of this master thesis is the processes and how they affect the material, both microstructure and behavior. The processes involved are; rolling, welding, shaping, brushing, forging, heat treatment, and calibration.

The purpose of this work was to elevate the knowledge and understanding of the processes at Ringsvets. The goals were to give a theoretical description of them along with practical test results and explanations of how and why they function in reality.

A literature study has been conducted which provided a theoretical basis on how the material reacts on certain processes. Practical examination of samples from current production has been done to get evidence of how well the processes are used, and how well they function, in today's production. Lastly, the main focus of the thesis, an evaluation has been made; do theory and practice correlate, and should anything be changed to correlate better?

The results showed that the first operations do not alter the material behavior to an unacceptable extent. Forging, on the other hand, gives the material a very high hardness in the weld zone, and that needs to be corrected. The following heat treatment should compensate for that in a perfect world, but does not in reality. The finished ring shows good properties in general but with places where the heat treatment has failed to correct the uneven behavior induced by earlier operations.

The heat treatment requires some adjustments before it functions as intended. Some grainshas not been recrystallized which makes them very hard and non-ductile. Future tests using a higher temperature or a longer heat treatment time would reveal the best way to adjust the heat treatment to obtain the desired properties. Other changes in the processes could also be benecial. Interesting things to try and change would, for example, be the degree of deformation in the forging, which affects the recrystallization temperature.

Notes should be taken that this examination is done on just one sample of just one size. Analyses of different samples of different sizes should be done to ensure of the accuracy of the examination.

Place, publisher, year, edition, pages
2019. , p. 63
Keywords [en]
FBW, flash butt welding, low alloy steel, metallurgy
National Category
Mechanical Engineering
Identifiers
URN: urn:nbn:se:kau:diva-74578OAI: oai:DiVA.org:kau-74578DiVA, id: diva2:1347080
External cooperation
Ringsvets AB; Camatec Industriteknik AB
Subject / course
Mechanical Engineering
Educational program
Engineering: Mechanical Engineering, spec. in Materials Engineering (300 ECTS credits)
Presentation
2019-06-03, Karlstad, 08:16 (Swedish)
Supervisors
Examiners
Available from: 2019-09-03 Created: 2019-08-30 Last updated: 2019-09-03Bibliographically approved

Open Access in DiVA

fulltext(28068 kB)6 downloads
File information
File name FULLTEXT01.pdfFile size 28068 kBChecksum SHA-512
3af9fb349957f8bbd4df23858692a270fc3243762344d225237fee59af7d6526cbb0ecd8dab3011d09c7db480cc7d9098a53044e0ebdadcc59d1a41efa29171c
Type fulltextMimetype application/pdf
Arkivfil(28068 kB)1 downloads
File information
File name FULLTEXT02.pdfFile size 28068 kBChecksum SHA-512
3af9fb349957f8bbd4df23858692a270fc3243762344d225237fee59af7d6526cbb0ecd8dab3011d09c7db480cc7d9098a53044e0ebdadcc59d1a41efa29171c
Type fulltextMimetype application/pdf

By organisation
Faculty of Health, Science and Technology (starting 2013)
Mechanical Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 7 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 35 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf