On dissimilar welding: a new approach for enhanced decision-making
Tasalloti Kashani, Hamed (2017-07-07)
Väitöskirja
Tasalloti Kashani, Hamed
07.07.2017
Lappeenranta University of Technology
Acta Universitatis Lappeenrantaensis
Julkaisun pysyvä osoite on
https://urn.fi/URN:ISBN:978-952-335-094-6
https://urn.fi/URN:ISBN:978-952-335-094-6
Tiivistelmä
Demand for dissimilar welding has shown continuous growth in a wide variety of
industrial fields, including power generation, petrochemical plants, oil and gas
exploration, transportation and aerospace manufacturing. Dissimilar welding enables the
desirable properties of different materials to be combined in a single welded joint.
Although dissimilar welding is advantageous in many applications, it is usually a more
difficult and problematic operation than similar metals welding. The challenges stem
from disparity in the physics, mechanics and metallurgy of the constituent materials in
the welded joint.
The objective of the current thesis is to provide a critical literature review and
experimental study of a number of dissimilar welds with different combinations of base
metals and welding processes. Additionally, the study aims to utilize the findings from
the experiments and review in design of a novel decision-making method to improve the
design and reliability of welded structures.
This dissertation is an article-based study that includes the outcome of seven articles
presented in the second part of the work. The results of the experimental studies and
review show the consequential alterations in the microstructure and mechanical properties
of the welds focusing on their relation to the process parameters and techniques used. The
results testify to the critical role of selection of the materials, welding process and
parameters in achieving a quality weld with appropriate metallurgical and mechanical
characteristics.
A new database-driven and application-based selection method is presented that aims to
reduce the risk of failure in manufacture or during service. To this end, a modified design
for manufacturing and assembly (DFMA) approach for welding is utilised to introduce
an application-based selection method with a built-in expertise feature in agreement with
the concurrent engineering (CE) concept into dissimilar welding decision-making. To
realise the benefits of CE and enable effective adoption of the approach in manufacturing
companies, integration of the new DFMA-based model into product data management
(PDM) systems is proposed. An application is devised as a proof of principle and is tested
with offshore conditions as the nominated service conditions. The proposed approach can
facilitate the design of weldments and accelerate decision-making in weld design as its
use demands only minimal knowledge of welding and metallurgy.
industrial fields, including power generation, petrochemical plants, oil and gas
exploration, transportation and aerospace manufacturing. Dissimilar welding enables the
desirable properties of different materials to be combined in a single welded joint.
Although dissimilar welding is advantageous in many applications, it is usually a more
difficult and problematic operation than similar metals welding. The challenges stem
from disparity in the physics, mechanics and metallurgy of the constituent materials in
the welded joint.
The objective of the current thesis is to provide a critical literature review and
experimental study of a number of dissimilar welds with different combinations of base
metals and welding processes. Additionally, the study aims to utilize the findings from
the experiments and review in design of a novel decision-making method to improve the
design and reliability of welded structures.
This dissertation is an article-based study that includes the outcome of seven articles
presented in the second part of the work. The results of the experimental studies and
review show the consequential alterations in the microstructure and mechanical properties
of the welds focusing on their relation to the process parameters and techniques used. The
results testify to the critical role of selection of the materials, welding process and
parameters in achieving a quality weld with appropriate metallurgical and mechanical
characteristics.
A new database-driven and application-based selection method is presented that aims to
reduce the risk of failure in manufacture or during service. To this end, a modified design
for manufacturing and assembly (DFMA) approach for welding is utilised to introduce
an application-based selection method with a built-in expertise feature in agreement with
the concurrent engineering (CE) concept into dissimilar welding decision-making. To
realise the benefits of CE and enable effective adoption of the approach in manufacturing
companies, integration of the new DFMA-based model into product data management
(PDM) systems is proposed. An application is devised as a proof of principle and is tested
with offshore conditions as the nominated service conditions. The proposed approach can
facilitate the design of weldments and accelerate decision-making in weld design as its
use demands only minimal knowledge of welding and metallurgy.
Kokoelmat
- Väitöskirjat [1037]