TY - GEN
T1 - Post-mortem study of fractured surface of Cr12 blade used in a steam turbine
AU - Sari, Nur Mala
AU - Anawati, Anawati
AU - Wibowo, Tri
N1 - Funding Information:
This research was financed by Hibah Publikasi Terindeks Internasional (PUTI) Prosiding with contract no. NKB-931/UN2.RST/HKP.05.00/2020.
Publisher Copyright:
© 2021 Author(s).
PY - 2021/8/10
Y1 - 2021/8/10
N2 - One of the turbine blades made of carbon steel Cr12 used at Suralaya Power Station experienced failure after being used for 33 years. The cause of such failure was studied in this work based on post-mortem data of the chemical composition, fracture morphology, and mechanical properties of the fractured section. The composition analysis by an x-ray fluorescence spectrometer (XRF) showed a slightly higher Cr and Ni content of 16.1 wt% in the fractured material, which probably due to the accumulation of scale deposit on the surface. The XRD analysis detected only the martensite phase indicating no phase transformation occurred during the long period of exposure to elevated temperature. Many fine cavities were observed in the cross-section material. The cavities were likely formed as a result of the absorption of hydrogen gas from the environment. The material was exposed to H2S gas during operation. Infiltration of hydrogen in the material contributed to increasing the material hardness to 324 HB and lowering the tensile strength to 95 MPa. The standard material has a mechanical hardness and tensile strength value of 240 HB and 530 MPa. The cavities became the initiation site for cracks. Under the cyclic load during operation, a crack was inevitably occurred, leading to material failure. The existence of beach marks in the fractured surface confirmed that the material experienced fatigue failure.
AB - One of the turbine blades made of carbon steel Cr12 used at Suralaya Power Station experienced failure after being used for 33 years. The cause of such failure was studied in this work based on post-mortem data of the chemical composition, fracture morphology, and mechanical properties of the fractured section. The composition analysis by an x-ray fluorescence spectrometer (XRF) showed a slightly higher Cr and Ni content of 16.1 wt% in the fractured material, which probably due to the accumulation of scale deposit on the surface. The XRD analysis detected only the martensite phase indicating no phase transformation occurred during the long period of exposure to elevated temperature. Many fine cavities were observed in the cross-section material. The cavities were likely formed as a result of the absorption of hydrogen gas from the environment. The material was exposed to H2S gas during operation. Infiltration of hydrogen in the material contributed to increasing the material hardness to 324 HB and lowering the tensile strength to 95 MPa. The standard material has a mechanical hardness and tensile strength value of 240 HB and 530 MPa. The cavities became the initiation site for cracks. Under the cyclic load during operation, a crack was inevitably occurred, leading to material failure. The existence of beach marks in the fractured surface confirmed that the material experienced fatigue failure.
UR - http://www.scopus.com/inward/record.url?scp=85113922513&partnerID=8YFLogxK
U2 - 10.1063/5.0059985
DO - 10.1063/5.0059985
M3 - Conference contribution
AN - SCOPUS:85113922513
T3 - AIP Conference Proceedings
BT - Proceedings of the 4th International Seminar on Metallurgy and Materials, ISMM 2020
A2 - Khaerudini, Deni Shidqi
A2 - Darsono, Nono
A2 - Rhamdani, Ahmad Rizky
A2 - Utomo, Muhammad Satrio
A2 - Thaha, Yudi Nugraha
A2 - Kartika, Ika
A2 - Nugraha, Ahmad Ridwan Tresna
PB - American Institute of Physics Inc.
T2 - 4th International Seminar on Metallurgy and Materials: Accelerating Research and Innovation on Metallurgy and Materials for Inclusive and Sustainable Industry, ISMM 2020
Y2 - 19 November 2020 through 20 November 2020
ER -