Abstract
Although the austenitic stainless steel grades are
commonly considered to be quite easily weldable, there
are certain applications which make exception to the
above statement. As an example, which has also attributed
to this study, it could be mentioned a welded assembly
which forms a very rigid structure. In above mentioned
structure, a risk of solidification cracking (i.e. hot
cracking) in produced welds could be a significant
problem, if necessary precautions are not taken into
account well in advance. It is generally known that hot
cracking of austenitic stainless steel during welding is
very much coupled to chemical composition and the strains
formed during solidification stage of the weld. The level
of strains is dependent on e.g. a groove design, used
welding parameters and the rigidity of the structure to
be welded. In this work the main objective was to find a
method for studying hot cracking susceptibility when a
thick section austenitic stainless steel is welded using
laser hybrid welding process (3 kW Nd:YAG-laser + GMAW)
and multi pass technique. The tested parent material was
a specially customized heat: AISI 316L(N)-IG ITER-grade
austenitic stainless steel. During this study the test
system was first developed and tested. It consists of a
very rigid clamping system and specially designed 60 mm
thick test piece which was planned to be rigid as itself.
The test welds were evaluated with macroscopic and
microscopic examination. In addition NDT was used as
well. The results of welding tests showed that the
developed test set-up can produce strains high enough to
promote hot cracking in produced test welds. According to
welding test results, hot cracking occurred in these
rigid weld arrangements. The test set-up is described and
the results of hot cracking tests are reported. The
effect of chemical composition of the used parent/filler
material and prevailing micro structure of weld metal on
the risk of hot cracking susceptibility is discussed as
well. (10 refs.)
| Original language | English |
|---|---|
| Title of host publication | Proceedings |
| Subtitle of host publication | 27th International Congress on Applications of Lasers and Electro-Optics, ICALEO 2008 |
| Publisher | Laser Institute of America |
| Pages | 535-544 |
| ISBN (Print) | 978-0-9120-3512-3 |
| Publication status | Published - 2008 |
| MoE publication type | A4 Article in a conference publication |
| Event | 27th International Congress on Applications of Lasers and Electro-Optics, ICALEO 2008 - Temecula, CA, United States Duration: 20 Oct 2008 → 23 Oct 2008 |
Conference
| Conference | 27th International Congress on Applications of Lasers and Electro-Optics, ICALEO 2008 |
|---|---|
| Abbreviated title | ICALEO 2008 |
| Country | United States |
| City | Temecula, CA |
| Period | 20/10/08 → 23/10/08 |
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Cite this
Karhu, M., & Kujanpää, V. (2008). Experimental test set-up for studying hot cracking in multi pass laser hybrid welding of thick section austenitic stainless steel. In Proceedings: 27th International Congress on Applications of Lasers and Electro-Optics, ICALEO 2008 (pp. 535-544). Laser Institute of America.