Corrosion Performance of Additively Manufactured (AM) Alloy 625

As the usage of additive manufacturing (AM) expands into more critical applications, the need to establish confidence in the expected performance and reliability of AM components also becomes more critical. However, very little information has been presented with regard to the use of AM within the chemical process industry (CPI). The harsh and demanding environments of chemical process industries present unique and challenging conditions for AM components to withstand. To help address this lack of information, a case study AM component was created to showcase the types of features that can be created using the AM process while designing for chemical process conditions.

An Alloy 625 laser powder bed fusion printed component was created and analyzed via a Finite Element Model (FEM), and was then statically load tested and fatigue tested to simulate typical oil-field conditions. Various properties, including hardness, were documented along with the microstructure.

Immersion corrosion testing of Alloy 625 AM and wrought Alloy 625 bar were performed in a reducing inorganic acid, an oxidizing inorganic acid, and an organic acid. Immersion tests were also performed in a ferric chloride solution to compare the critical pitting temperature of the Alloy 625 AM material to a traditional wrought Alloy 625 material.

Corrosion rates of AM alloy vs wrought alloy 625 in above mentioned conditions and effect of microstructure due to exposure to the acids and salts will be presented.

Key words: Additive Manufacturing, Alloy 625, Corrosion Resistance