The main scope of this work is to explore different process configurations to understand the corrosion response of additive manufactured alloys and to suggest the parameters to be controlled for future qualification in sour environment.

Alloy 718 is a common oilfield material for permanent and service equipment in need of high-mechanical ratings and resistance to corrosion especially environmentally-assisted cracking in sour gas wells. In past decade Alloy 718 production from traditional and newer mills has greatly increased in response to global demands; independently yet driven by similar market growth additive manufacturing (AM) has expanded beyond rapid prototyping to become an industrial production process namely in the aerospace. Today 718 bar stocks as per API6CRA are produced by over a dozen mills worldwide;similarly 718 powder products are increasingly offered by both traditional and newer mills with intents to servea multitude ofAM technologies. Due to the rise of new economic forces in the O&G there are today needs for evaluating (ultimately qualifying) newer 718 producing mills as well as 718 powders in combination with various AM technologies. Due to concerns overraw-material properties a study was conducted to analyze 718 materials from these various origins utilizing (1) mill cert big-data analyses (2) third-party recertified mechanical test data (3) a multitude of sour service test results outside the traditional NACE MR0175/ISO15156 operational service limits among others. The later raw-material test implemented in the early 2010s for screening and qualification purposes aims at quantitatively comparing 718 production heats of various origins and with additive manufacturing also generating interests since the early 2010sthe same tests have also beenextended to determine how layer-by-layer deposited materials compare to bar stock materials.

Precipitation hardenable nickel alloys are commonly used in oil and gas offshore structures where requires outstanding mechanical strength and corrosion resistance. In seawater galvanic coupling to steel or cathodic protection promotes the formation of atomic hydrogen on the surface of Inconel 718. Hydrogen atoms further dissolve into the metal matrix and cause hydrogen embrittlement. The unconventional Additive Manufacturing (AM) process generates fine microstructure and alters surface finish that affect hydrogen intake process and the subsequent hydrogen embrittlement. The effects of hydrogen embrittlement are investigated on different build orientations and surface finish of AM Inconel 718 by slow strain rate (SSR) testing in seawater environment under cathodic protection. The susceptibility of AM 718 to hydrogen embrittlement is discussed based on the SSR results and metallography analysis with respect to its wrought counterpart.