Pitting corrosion behaviour of austenitic stainless steels – combining effects of Mn and Mo additions

The role of titanium in the initiation of localized corrosion of stainless steel 444

“…This is a marked contrast from MnS inclusions observed for austenitic SSs, which dissolve readily. 7 Despite such Mg/Al oxide core inclusion's stability in this study, their role in material fatigue during wear testing has been documented. 16 The role these inclusions play in localized corrosion is an unintentional consequence of the presence of Ti in the alloy, which is intentionally added to ferritic SS to inhibit CrC precipitation and decrease IGC.…”

“…[3][4][5] Despite the successful reduction of IGC in alloyed ferritic SS, its mechanical strength can still be greatly reduced by pitting corrosion, usually associated with some discontinuity over the metal surface, such as a grain boundary, a defect/scratch, or an inclusion within the metal's microstructure. 6 Among the typical corrosion initiators, manganese sulfide (MnS) inclusions in austenitic SSs have been identified as pitting corrosion initiation sites and have been extensively investigated using macro-scale [7][8][9][10] and micro-scale 11,12 techniques. More recently, Ti and Nb rich carbide and nitride inclusions have been found in SS resulting from the preferential precipitation of stabilizing agents, as previously described.…”

Coloración de aceros inoxidables AISI 304 y AISI 316L para uso biomédico

“…Este comportamiento, en el caso del acero AISI 304, continúa observándose para los mayores tiempos de tratamiento (60 minutos). Sin embargo, para el caso del acero AISI 316L, por encima de los 55 minutos de tratamiento de coloración, su espesor no se ve incrementado, hecho que se podría asociar a una tercera etapa o periodo de estabilización de la película de óxido: es bien conocido que el molibdeno como elemento aleante del acero AISI 316L, incrementa la estabilización de las películas de óxido de cromo y dificulta su crecimiento de forma continua [13].…”

“…Finalmente, para tiempos de 60 minutos la superficie muestra de forma clara indicios de una corrosión intergranular previa producida probablemente durante el tratamiento de coloración. Se observa que para el acero sin recubrimiento, la zona de pasividad del material se extendió por alrededor de 750mV, aproximadamente 3 veces más amplia que para el acero AISI 304, hecho asociado a la presencia de molibdeno que estabiliza la película pasiva e incrementa su resistencia a la corrosión [13].…”

Tensile properties of the modified 13Cr martensitic stainless steels

“…In case of chemical modification, Mo has a beneficial effect to increase corrosion resistance of the stainless steel [7][8][9]. The addition of Ni into martensitic stainless steel also gives beneficial effect by avoiding formation of delta ferrite during cooling and increases the corrosion resistance.…”