The Reasons of Steam Pipeline Elbow Rupture

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In the paper the reasons for steam pipeline’s elbow material rupture, made of steel 13CrMo4-5 (15HM) that is being used in the energetics. Based on the mechanical properties in the ambient temperature (Rm, Rp0,2 and elongation A5) and in the increased temperature (Rp0,2t) it was found, that the pipeline elbow’s material sampled from the ruptured area has lower Rp0,2 i Rp0,2t by around 2% than it is a requirement for 13CrMo4-5 steel in it’s base state. The damage appeared as a result of complex stress state, that substantially exceeded the admissible tensions, what was the consequence of considerable structure degradation level. As a result of the microstructure tests on HITACHI S4200 microscope, the considerable development of the creeping process associates were found. Also the advances progress of the microstructure degradation was observed, which is substantial decomposition of bainite and multiple, with varied secretion size, and in most cases forming the micro cracks chains. With the use of lateral micro sections the creeping voids were observed, that creates at some places the shrinkage porosities clusters and micro pores.

[1] Dobosiewicz, J. (1999). Investigations of thermal and mechanical energy. Warsaw: Gamma.

[2] Dobosiewicz, J. (1984). Problems extend the life of the plant. Power Engineering. 7.

[3] Trzeszczyński, J. (2010). Assessment of and life prediction for the critical components of thermo-mechanical power equipment intended to be operated beyond 300 000 hours. Power Engineering. 2(Pro Novum), 806-812.

[4] Trzeszczyński J. (2008). Material Diagnostics on-line of thermal-mechanical power. Power Engineering. 1(Pro Novum), 279-283.

[5] PN-EN 10216-2 (2009).

[6] Trzeszczyński, J. (2008). Remote diagnostic systems for the evaluation of the technical condition of thermal-mechanical Power In Real time. Power Engineering. 836-839.

[7] Trzeszczyński, J. & Stanek, R. (2013). Management the maintenance of the technical condition of boilers on the basis of risk analysis. Technical Supervision. 269(6), 136-141.

[8] Trzeszczyński, J. & Stanek, R. (2013). Failure Frequency Analysis of a 200 MW Power unit critical elements as an Important Component of a Service Life Prediction Methodology. Power Engineering. 6, 505-508.

Archives of Foundry Engineering

The Journal of Polish Academy of Sciences

Journal Information

CiteScore 2016: 0.42

SCImago Journal Rank (SJR) 2016: 0.192
Source Normalized Impact per Paper (SNIP) 2016: 0.316


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