Page 30 - Handbook of Materials Failure Analysis

22 CHAPTER 1 Progressive failures of components

The obtained evidence suggested the operation of SCC as the dominant damage
mechanism. The SCC failure mechanism is also facilitated by other contributing phe-
nomena, such as selective/preferential oxidation and Cr-depletion. The synergy of
aggressive environment, containing corrosive species (such as Cl) at high tempera-
tures, provides an additional driving force supporting the hypothesis of SCC as the
principal failure mechanism. Transgranular cracking with multiple secondary branch-
ing constitutes typical fingerprints of SCC fracture mode in austenitic stainless steels
(see also Figures 1.13 and 1.14). Revision of the operating conditions that foresee pres-
sure attenuation in the inlet fluid stream could be recommended as further corrective
action, reducing the filter operating load and thus the risk of SCC. The installation of a
baffle system or a flow dividing system that could balance the flow more uniformly
could potentially lead to uniform pressure distribution applied on the grid area.
The replacement of the currently used austenitic stainless steel with another alloy
of higher resistance in SCC and enhanced high-temperature microstructure stability,
such as nickel superalloys (Monel or Hastelloy), could be recommended. Addition-
ally, a ferritic stainless steel, such as the AISI 403 (UNS S 40500), with Cr level
within the range 11.5-14.5 wt%, could also constitute an alternative construction
material of selected components in chemical process industry.

REFERENCES
[1] Pantazopoulos GA. A process-based approach in failure analysis. J Fail Anal Prev
2014;14(5):551–3.
[2] Becker WT, Shipley RJ, editors. ASM metals handbook, volume 11: failure analysis and
prevention. Materials Park (OH): ASM International; 1992.
[3] Jones DRH. Engineering materials 3—materials failure analysis. Oxford: Pergamon
Press; 1993.
[4] Benac DJ. Failure avoidance brief: estimating heater tube life. J Fail Anal Prev
2009;9:5–7.
[5] Ilman MN, Kusmomo. Analysis of material degradation mechanism and life assessment
of 25Cr-38Ni-Mo-Ti wrought alloy steel (HPM) for cracking tubes in an ethylene plant.
Eng Fail Anal 2014;42:100–8.
[6] Quickel G, Taske C, Rollins B, Beavers J. Failure analysis and remaining life assessment
of methanol reformer tubes. J Fail Anal Prev 2009;9:511–6.
[7] Fontana MG. Corrosion engineering. 3rd ed. New York: McGraw Hill; 1986.
[8] Traubert TD, Jur TA. Metallurgical analysis to evaluate cracking in a 316 L grade stain-
less steel spiral heat exchanger. J Fail Anal Prev 2012;12:198–203.
[9] Asghar MSA, Tariq F, Ali A. Failure analysis of AISI-304 stainless steel styrene storage
tank. J Fail Anal Prev 2010;10:303–11.
[10] Jin GX, Xie YP, Tian AH. Corrosion failure analysis of the condensate collector vessel
head of evaporation system in ethylene glycol device. Eng Fail Anal 2012;22:113–20.
[11] Shayegani M, Zakersafaee P. Failure analysis of reactor heater tubes SS347H in ISO-
MAX unit. Eng Fail Anal 2012;22:121–7.
[12] Tawancy HM. Failure of hydrocracker heat exchanger tubes in an oil refinery by poly-
thionic acid-stress corrosion cracking. Eng Fail Anal 2009;16:2091–7.