The Paton Welding Journal, 2007, №06

2007 №06 (05)

2007 №06 (07)

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The Paton Welding Journal, 2007, #6, 28-32 pages

Evaluation of technical state of welded joints on hps steam lines allowing for hydrogen-induced degradation of metal in operation

G.N. Nikiforchin¹, O.Z. Student¹, S.M. Stepanyuk², A.D. Markov²

¹G.V. Karpenko Physico-Mechanical Institute, NASU, Lvov, Ukraine
²E.O. Paton Electric Welding Institute of the NASU. 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine.

Abstract
Loss of performance of degraded metal from different zones of real (~2105 h) and model (repair) welded joints on live steam lines of heat power stations (HPS) was evaluated. It is established that current state of the base metal in operation can be evaluated only from local (short-time crack resistance) mechanical properties, whereas that of the weld metal can be evaluated also from integrated (strength, ductility, hardness) properties. It is shown that mechanical properties of the weld metal in operation are deteriorated more intensively, compared with the base metal. It is recommended to allow for the revealed peculiarities of degradation of metal of welded joints in evaluation of the current state of the weld metal and estimation of the remaining life of welded structures.
Keywords: arc welding, HPS steam line, degradation of metal, hydrogen-induced embrittlement, welded joint, weld metal, short-time crack resistance, integrated mechanical properties

References

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Suggested Citation

G.N. Nikiforchin, O.Z. Student, S.M. Stepanyuk, A.D. Markov (2007) Evaluation of technical state of welded joints on hps steam lines allowing for hydrogen-induced degradation of metal in operation. The Paton Welding J., 06, 28-32.

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