The Influence of Cold Work and Processing Parameters on the Sensitization Behavior of Nickel Based Alloys

Abstract Important construction materials in the O&G as well as in the CPI are characterized by high strength and sufficient corrosion resistance against different aggressive atmospheres. Taking into account the economic point of view, stainless steels are very attractive and are therefore considered in a first approach. Stricter regulations, the endeavor to increase process efficiency and the more and more challenging well exploration lead to stricter application conditions. In critical components, this requires the use of materials with higher corrosion resistance such as Ni-based alloys. Due to their more noble composition, these alloys have a high resistance to corrosive media, but show reduced mechanical properties when compared to steels and this backdrop can be a barrier for their usage. In these cases, Ni-based alloys can take advantage of the cold work-hardening mechanism with the aim of increasing their mechanical strength. If so, sensitization of the microstructure must be avoided in order not to impair the original corrosion resistance. This paper uses the example of UNS N08034 to analyze the influence of various cold working degrees on mechanical properties and its possible effects on the sensitization of the microstructure, exploring localized corrosion results and the metallographic evolution with different degrees of cold work.