Sensitization of Austenitic Stainless Steels: Current Developments, Trends, and Future Directions

Abstract

In this manuscript, the latest developments pertaining to sensitization are discussed. Sensitization leads to intergranular corrosion and intergranular stress corrosion cracking. The advantages and disadvantages of conventional methods to combat sensitization are elaborated. Emerging/newer techniques such as grain boundary engineering, creation of orientation gradients, and high density of twinning to improve resistance to sensitization are also covered. Detection and monitoring of deleterious phase precipitation such as carbides, nitrides, and other intermetallic phases during operation necessitate making use of nondestructive testing (NDT) methods. Possible information that we get from NDT is for material characterization includes the size, shape, and location of a defect. Herein, the significant developments for monitoring and detection of phases concerning sensitization by NDT are discussed. These range from magnetic methods to ultrasonic techniques. The multi-physics approach is essential to fully utilize NDT to ensure/predict the lifetime of the components used in the industry. Further, proper selection of suitable NDT for defect detection can avert accidents, catastrophic failures, and economic losses due to corrosion degradation. For this, the corrosion engineer/corrosionist properly apply the suitable techniques (prevention, monitoring, and assessment) to address the issues of sensitization among the wide choice available.

Failure analysis of low-pressure steam superheater in a purification device

“…Sometimes there are mechanisms such as cracking in a hydrogen sulfide environment and hydrogen embrittlement cracking [13][14][15]. In addition, sensitization-intergranular corrosion is also a major cause of stainless steel cracking [16][17][18].…”

A Review: Sensitization in stainless steel

“…That chromium form Cr2O3 passive film on the surface of steel and makes it corrosion resistant (Fig. 1) [27], [28] As the chromium carbide further grows along grain boundary & chromium content keeps on depleting in the adjacent region of grain boundary & making poor corrosion resistance zone as shown in Fig. 2.…”

Impact of austenite nanograins induced by sliding friction on interfacial strength during ultrasonic welding

“…2 Particularly, low bonding temperature can prevent issues that occur with high temperatures, such as grain coarsening 3 or the formation of deleterious secondary phases, 4 which contributes to a decrease in mechanical strength or the corrosion resistance of joints, 5,6 particularly in the welding of stainless steels (SS). 7…”

“…2 Particularly, low bonding temperature can prevent issues that occur with high temperatures, such as grain coarsening 3 or the formation of deleterious secondary phases, 4 which contributes to a decrease in mechanical strength or the corrosion resistance of joints, 5,6 particularly in the welding of stainless steels (SS). 7 USW is widely adopted in joining soft metals, such as Al, [8][9][10][11][12][13][14][15] Mg, [16][17][18] or Cu [19][20][21] alloys, and soft/hard metal combinations (e.g. steel/Al 22 ), by inducing localised severe plastic deformation (SPD), 23 recrystallisation [24][25][26] or intermetallic phase formation.…”