A Study on the Failure of AISI 304 Stainless Steel Tubes in a Gas Heater Unit

Abstract

This paper investigates a failure in convection section tubes of a gas heater unit in a petrochemical plant. Tubes are made of AISI 304 stainless steel. The failure is reported after 5 years of service at working temperature 500 °C. The failure is in the form of circumferential cracks in the vicinity of the weld. Various characterization techniques, including optical and electron microscopes as well as energy-dispersive X-ray spectroscopy (EDS), were used to study the failure. Results showed that that the damage has initiated in the heat affected zone (HAZ) area parallel to the weld/base metal interface. Cracks have propagated alongside grain boundaries, resulting in an intergranular fracture. The main cause of failure was concluded to be attributable to the grain boundary sensitization and intergranular grain boundary attack due to improper welding and long time exposure of tubes to high temperature. Possible mitigation strategies to minimize similar failures will be discussed.

Corrosion-Fatigue Failure of Gas-Turbine Blades in an Oil and Gas Production Plant

“…This certainly has positive implications for the system reliability and service life of a gas turbine. Lessons learnt from a failure study will certainly be useful in planning failure mitigation strategies in similar plants/set-ups [21][22][23][24][25][26][27][28][29][30]. It will be shown that the failure, reported in this study, is a corrosion-fatigue failure.…”

Influence of V and Heat Treatment on Characteristics of WMoNbTaV Refractory High-Entropy Alloy Coatings by Mechanical Alloying

“…On the other hand, Figure 10 exhibits the variation of hardness in the three model RHEA coatings milled for 24 h. The WMoNbTaV HEA coating has the highest average hardness value of 1205 HV 0.025; however, the coating after annealing shows a relatively low hardness value (967 HV 0.025 on average). It should be pointed out that 304 stainless-steel substrates are intrinsically subject to embrittlement due to precipitation of second phases when exposed to high temperature for a long time [37]. However, annealing of the substrate is not a primary goal and beyond the scope of this study.…”

Failure Mechanisms in Alloys

“…(i) Casting and Metal Forming [6,7,11,13,15,19,[24][25][26] (ii) Machining [12,16,20] (iii) Chemical/Petrochemical [3,17,21,23] (iv) Heat Treatment [22] (v) General Plant Machinery [1,9,18,24] b. Fatigue and Cyclic Loading [8,9,18]; c. Corrosion and Environmentally Assisted Cracking [3,5,11,21]; d. Wear and Surface Degradation [1,24,27].…”

“…(i) Casting and Metal Forming [6,7,11,13,15,19,[24][25][26] (ii) Machining [12,16,20] (iii) Chemical/Petrochemical [3,17,21,23] (iv) Heat Treatment [22] (v) General Plant Machinery [1,9,18,24] The metal component manufacturing industry (casting, metal forming, and machining) seems to be highly involved, as one of the primary industrial component production sectors, in highlighting the efforts in understanding material behavior and taking actions for failure prediction and prevention.…”