The Paton Welding Journal, 2015, №12



2015 №12 (04)

DOI of Article 10.15407/tpwj2015.12.05

2015 №12 (06)

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The Paton Welding Journal, 2015, #12, 24-28 pages
 

Structural changes in metal of welded joints of steam pipelines in operation

V.V. Dmitrik¹, O.V. Sobol¹, M.A. Pogrebnoj¹, A.V. Glushko¹ And G.I. Ishchenko²

¹NTU «Kharkov Polytechnic Institute». 21 Frunze Str., 61022, Kharkov, Ukraine. E-mail: svarka126@ukr.net
²OJSC «Turboatom». 199 Moskovsky Ave., Kharkov, Ukraine. E-mail: office@turboatom.com.ua
 
 
Abstract
Extension of service life of steam pipelines is a relevant task. Investigation of peculiarities of structural state in metal of welded joints of long-lasting operation steam pipelines allows evaluating a level of their damageability and grounding residual life. This study determined that structural changes of welded joints from 15Kh1M1F and 12Kh1MF steels are caused by diffusion processes, formation of intergranular segregations, carbide reactions, nucleation and propagation of creep pores. The ways are outlined for regulation of structural state of metal of HAZ areas, which are directed at reduction of structural inhomogeneity and extension of service life. 10 Ref., 10 Figures.
 
Keywords: heat-resistant steels, steam pipeline welded joints, structure, carbides, pores, damageability, diffusion, deformation, heat-affected zone
 
 
Received:                20.05.15
Published:               21.01.16
 
 
References

1. SO 153-34.17.456-2003 (2005): Procedural recommendations on assessment of service life of heat power plants. Moscow: ORGRES.
2. OST 34-70-690-96: Metal of steam-power equipment of power plants. Methods of metallographic analysis in service conditions. Moscow: VTI.
3. SO 153-34.17.455-2003: Instruction on extension of service life of steam pipelines from centrifugal-cast pipes at heat power plants. Moscow: ORGRES.
4. RD 153-34.1-17.467-2001: Express method for evaluation of residual life of welded joints of boiler and steam pipeline collectors according to structural factor. Moscow: ORGRES.
5. Khromchenko, F.A. (2002) Life of steam pipeline welded joints. Moscow: Mashinostroenie.
6. Elpanova, N.V., Berezina, T.G. (1989) Influence of structure on fracture kinetics of 12Kh1MF steel at creep. Metallovedenie i Termich. Obrab. Metallov, 7, 36-39.
7. Dmitrik, V.V. (2013) Welded joints of steam pipelines. Kharkov: Majdan.
8. Dmitrik, V.V., Bartash, S.N. (2014) Peculiarities of degradation of metal of welded joints of steam pipelines of heat power plants. The Paton Welding J., 6/7, 29-30. https://doi.org/10.15407/tpwj2014.06.05
9. Dmitrik, V.V., Bartash, S.N. (2010) Features of damageability of steam pipeline welded joints by the creep mechanism. Ibid., 6, 19-21.
10. Butyagin, P.Yu. (2006) Chemical physics of solids. Moscow: MGU.

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