The Paton Welding Journal, 2020, №01



2020 №01 (02)

DOI of Article 10.37434/tpwj2020.01.03

2020 №01 (04)

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The Paton Welding Journal, 2020, #1, 24-30 pages
 
Journal                    The Paton Welding Journal
Publisher                 International Association «Welding»
ISSN                      0957-798X (print)
Issue                       #1, 2020 (February)
Pages                      24-30

Impact of spatial position in laser welding on quality level of welded joints of AISI 321 steel

A.V. Bernatskii, V.D. Shelyagin, O.V. Siora, V.M. Sydorets and O.M. Berdnikova

E.O. Paton Electric Welding Institute of the NAS of Ukraine 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua

The objective of the study was determination of the impact of spatial position in laser welding of corrosion- heat-resistant austenitic steel AISI 321 on the microstructure and quality level of welded joints. Penetration beads were made in plates of 3 mm thickness at different angles of inclination to the horizontal plane. «Uphill» and «downhill» laser welding was performed both in the continuous and pulsed modes of laser generation. Results of visual and radiographic testing and analysis of the data of metallographic examinations were used for evaluation of quality level of the produced specimens for compliance with the requirements of valid standards. In «uphill» and «downhill» welding in the continuous mode of laser generation no inner defects in the form of cracks, pores and inclusions were found at all the angles of inclination. A tendency to increase in both the quantity as well as in the size of pores at reduction of the angle of inclination from 90 to 0° was found in «downhill» and «uphill» welding in the pulsed mode of laser generation. By the data of metallographic examinations, no significant differences were observed in the structure of welded joints made in different spatial positions on steel AISI 321 of 3 mm thickness. At different values of the angle of inclination, the microhardness and dimensions of the crystallites differ by approximately 10 %. Contrarily, the shape of welds in the produced penetration beads differs quite significantly. Dependencies of quality characteristics of welded joints of AISI 321 steel in laser welding were derived for the first time for different spatial positions. The derived dependencies provide determination of tendencies of changing the shape and quality of welded joints at the change of position or technological parameters of laser welding process. 13 Ref., 2 Tables, 6 Figures.
Keywords: laser welding; corrosion-resistant steel; heat-resistant steel: austenitic steel; technological parameters; spatial position; quality; structure; porosity
 
Received:                25.10.19
Published:               21.02.20

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