The welding of C-Mn steels using the pulsed current MIG welding
process was investigated. Following initial work on the basic fusion
characteristics, the process was applied to the production of closed
butt joint linepipe welding and narrow gap welding (in the flat and
H-V positions).
The initial stage of the work covered the determination of pulse
parameters for controlled metal transfer with a variety of wires and
shielding gases. Basic bead-on-plate fusion characteristics were
investigated 1n all welding positions and quantified in terms of the
major welding variables of current and travel speed. Welding position
was shown to have no effect on fusion behaviour.
Successful full penetration closed butt root welds were produced in
all welding positions. Heat input was shown to be the factor
controlling bead dimensions. Close control over welding parameters
are needed to maintain consistent bead sizes. Complete joint
simulations were also made. The vertical-up technique was shown to
give superior fusion characteristics with the process producing
excellent quality results in all positions.
Narrow gap MIG welding was shown to be feasible without wire manipulation
at gap widths below 12 mm in the flat position. A wire manipulation
technique gave excellent fusion characteristics with gap
widths greater than 12 mm. A computer program was devised as a guide
to the selection of process parameters and possible fusion behaviour.
Modelling considerations showed that H-V position narrow gap welding
would be feasible only with gap widths less than 10 ... A short
experimental programme validated the predictions of fusion behaviour
by the model and indicated the direction for future development work.
| Identifer | oai:union.ndltd.org:CRANFIELD1/oai:dspace.lib.cranfield.ac.uk:1826/11111 |
| Date | 03 1900 |
| Creators | Foote, W. J. |
| Contributors | Apps, R. L. |
| Publisher | Cranfield University |
| Source Sets | CRANFIELD1 |
| Language | English |
| Detected Language | English |
| Type | Thesis or dissertation, Doctoral, DBA |
| Rights | © Cranfield University, 1986. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder. |
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