Failure Analysis of a 9–12%Cr Steel Superheater Tube

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
E. Pour saeidi ◽  
M. Aieneravaie ◽  
M. R. Mohammadi Arhani
Keyword(s):  
Failure Analysis ◽  
Chromium Steel ◽  
Steel Tubes ◽  
Steam Power ◽  
Final Fracture ◽  
Superheater Tube ◽  
Load Carrying ◽  
Power Plant Boiler ◽  
Electron Microscopes ◽  
Plant Boiler

The failure analysis of 9–12% chromium steel tubes, containing about 2.5% molybdenum, is discussed in the present study. The component is used in a steam power plant boiler as a high-temperature superheater tube and has been in service for about 100,000 h. The failure occurred without appreciable wall thinning. Specimens were taken from the region beneath the fracture surface and investigated by optical and electron microscopes. The microstructure was composed of ferrite and grain boundary particulate carbides. The results indicated that the fracture was initiated because of the bending of the tube near the anchor and propagation of the crack through the interfaces between massive carbides and matrix (sensitized zone). Final fracture has occurred as a result of an overload due to the decreasing of load carrying section produced by crack propagation.

Numerical Simulation of the Creep Failure of a Steam Reformer Outlet Manifold

2017 ◽  
Author(s):  
Gys van Zyl ◽  
Jan Keltjens ◽  
Ali Al-Shawaf
Keyword(s):  
Failure Analysis ◽  
Theoretical Calculations ◽  
Rupture Life ◽  
Creep Damage ◽  
Damage Mechanism ◽  
Creep Failure ◽  
Element Analysis ◽  
Steam Reformer ◽  
Nickel Base ◽  
A Minor

After eleven years of service, a through-thickness crack developed at a circumferential welded joint in the outlet manifold of a steam reformer. The crack led to a minor fire and controlled shutdown of the reformer. The manifold was fabricated from cast 20Cr-30Ni-Nb material, with welds from Inconel 617 nickel base filler. This paper will present the findings of the failure analysis that was performed to ascertain the cause of the incident. A metallurgical failure analysis was performed to determine the damage mechanism and found clear signs of creep damage, highly localized to the weld. Theoretical calculations and finite element analysis were performed to determine the estimated creep rupture life and found that failure occurred long before the minimum estimated end-of-life. Further numerical simulations were performed to evaluate the effect of an unusually high number of startup/shutdown cycles. The analyses considered elastic-plastic and inelastic (creep) properties of the weld and base materials and simulated a number of operational cycles where thermal and pressure conditions were cycled between ambient and operational. The simulations found clear evidence that operational cycles contributed to a dramatic reduction in life through the action of repeated cycles of plastic strain, due to a mismatch in the thermal expansion of the base and weld metals, and creep relaxation. The study concludes with recommendations that can be implemented at fabrication to mitigate this mode of damage.

scholarly journals Creep failure analysis of heterogeneous steel welded steam pipeline T91-TP347H

2021 ◽  
Vol 1750 ◽  
pp. 012017
Author(s):  
Fan Yi-Lu ◽  
Yu Cao ◽  
Chuan-huai Liu ◽  
Dong-Mei Ji
Keyword(s):  
Failure Analysis ◽  
Creep Failure ◽  
Steam Pipeline

scholarly journals Creep failure analysis for ceramic composites containing viscous interfaces

1998 ◽  
Author(s):  
I.J. Beyerlein ◽  
L. An ◽  
R. Raj
Keyword(s):  
Failure Analysis ◽  
Ceramic Composites ◽  
Creep Failure

scholarly journals The transient heat transfer and Larson-Miller creep failure analysis of severe accident relief pipeline

2020 ◽  
Vol 51 (2) ◽  
pp. 176-184
Author(s):  
ChongYi LIU ◽  
QiongHui TANG ◽  
Rui ZHOU ◽  
GaoFeng WU ◽  
MingYu WANG ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Failure Analysis ◽  
Severe Accident ◽  
Transient Heat Transfer ◽  
Creep Failure

Failure analysis of cracked 2.25Cr–1.0Mo steel tubes of an oil refinery boiler

2020 ◽  
Vol 110 ◽  
pp. 104435 ◽  
Author(s):  
Azin Ahmadi ◽  
Mohmad shayegani Akmal ◽  
Amir Pasha ◽  
Shahram Yareie
Keyword(s):  
Failure Analysis ◽  
Oil Refinery ◽  
Steel Tubes
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