The Paton Welding Journal, 2004, №12

2004 №12 (09)

2004 №12 (02)

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The Paton Welding Journal, 2004, #12, 2-8 pages

Role of segregation of oxygen in welding of Invar type alloys

K.A. Yushchenko, V.S. Savchenko, T.M. Starushchenko

E.O. Paton Electric Welding Institute of the NASU 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine.

Abstract
It has been found that cracks in welding of Fe-36 % Ni alloy are formed primarily at temperatures that are much lower than solidus temperature, i.e. within the ductility-dip temperature range. Conditions causing enrichment of weld metal with oxygen are formed in a joint during the welding process. Subsequent cooling leads to enrichment of high-angle grain boundaries with oxygen due to thermal-deformation processes occurring in metal, which leads to decrease in ductility and embrittlement. Investigations by the Varestraint test method have shown existence of quantitative relationship between the effect of oxygen and ductility dip in the weld metal.
Keywords: Invar type alloy, ductility, segregation, enrichment with oxygen, brittle fracture, solidus, hot cracks, grain boundaries, welded Joint, Auger spectroscopy

References

1. Yushchenko, K.A., Starushchenko, T.M., Savchenko, V.S. (1983) Mechanism of formation of hot cracks induced by oxygen during welding of Invar alloy. Avtomatich. Svarka, 8, 5–7.
2. Yushchenko, K.A., Starushchenko, T.M. (1981) Role of oxygen in crack formation during welding of Invar alloy. Ibid., 8, 21–24.
3. Savage, W.F., Lundin, G.D. (1977) The Varestraint test. Welding J., 44(10), 433–442.
4. Matsuda, F., Nakagawa, FL, Ogata, S. et al. (1978) Fractographic investigation on solidification crack in the Varestraint test of fully austenitic stainless steel – studies on fractography of welded zone (III). Transact, of JWRI, 7(1), 59–70.
5. Khirt, J., Lote, I. (1972) Theory of dislocations. Moscow: Atomizdat

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Suggested Citation

K.A. Yushchenko, V.S. Savchenko, T.M. Starushchenko (2004) Role of segregation of oxygen in welding of Invar type alloys. The Paton Welding J., 12, 2-8.

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