As more industries look toward additively manufactured (AM) components to combat lead times, re-design, cost of complexity, etc., those industries are faced with re-evaluating the performance of AM-based materials as compared to their well-documented wrought or machined counterparts. A particular alloy of interest to many industries including aerospace and energy/power generation is Inconel 718 due to its resistance to oxidation and high temperature degradation [1]. Additively manufactured Inconel 718 parts typically receive a series of post-build heat treatments prior to deployment. If not properly controlled, these post-build treatments may introduce secondary precipitates and other inhomogeneities that will affect the parts’ mechanical properties and susceptibility to corrosion. This is specifically true of susceptibility to localized corrosion mechanisms that may lead to crack initiation, accelerated crack growth and ultimately premature failure. By utilizing electrochemical parameter testing to analyze for localized breakdown potentials, this work investigates the variation in tolerance to localized corrosion that results from common post-build heat treatment steps and the secondary phase precipitation that can ensue in Inconel 718 AM parts.

Press hardening steel (PHS) applications predominately use 22MnB5 AlSi coated in the automotive industry. This material has a limited supply chain. Increasing the tensile strength and bendability of the PHS material will enable light-weighting while maintaining crash protection. In this paper, a novel PHS is introduced, and properties are compared to 22MnB5. The new Coating Free PHS (CFPHS) steel, 25MnCr, has increased carbon, with chromium and silicon additions for oxidation resistance. Its ultimate tensile strength (UTS) of 1.7 GPa with bending angle above 55° at 1.4 mm thickness improves upon the 22MnB5 grade. This steel is not pre-coated, is oxidation resistant at high temperature, thus eliminating the need for AlSi or shot blasting post processing to maintain surface quality. Microstructural mechanisms used to enhance bendability and energy absorption are discussed for the novel steel. Performance evaluations such as: weldability, component level crush and intrusion testing and e-coat adhesion, are conducted on samples from industrial coils.

Aluminide diffusion coatings enhance carburization and oxidation resistance of iron and nickel based alloys by formation of iron and nickel aluminides which extends the life of furnace alloys and fixtures. As a part of a large project in the Center for Heat Treating Excellence (CHTE), an aluminized coating on RA330 was studied by a hot dip process followed by diffusion heat treatment. Samples of RA330 steel were dipped in pure liquid aluminum at 700 °C for 10 minutes. After dipping, four samples were given an additional diffusion treatment. To predict the developed phases, computational analysis was used and the results were compared with the experimental data.

An advanced nickel alloy with a specially designed chemistry to provide maximum oxidation resistance at the most extreme temperatures and controlled precipates to maximize creep strength. A leading vacuum furnace supplier has selected this alloy as a suitable material for bar baskets in their most demanding application, 2300 F and pressure quenching. Baskets fabricated from all other alloys tested lasted between 5 and 10 cycles before requiring extensive, labor intensive straightening. The new alloy baskets have been used for over 30 cycles, with minimal distortion. This extended life eliminates several straightening cycles and the high labor costs associated with manual straightening and reassembly.

RA 602 CA (also known as 602 CA and NiCroFer 6025, which are trademarks of VDM) is one of the best heat resistant alloys. It has excellent creep strength even at high temperatures, and oxidation resistance up to 2250°F. It is being used in an increasing number of new applications in the toughest of high temperature environments with success.

The use of high hardness surface layers can extend the life of components such as molds and dies by increasing their wear resistance. However, corrosion and oxidation resistance are also important to improve the durability of the components, especially for those that work under more demanding environments. In this work, samples of AISI H13 tool steel for hot work were borided by the pack cementation process, producing uniform and high hardness layers (1400-1800 HV). Afterwards the samples were subjected to a quasi-isothermal oxidation testing at 550 °C, the same working temperature of H13 steel in aluminum extrusion dies. Throughout the test, the mass gain of the untreated substrate, used for comparison, was 100%, while the borided sample treated at 900 °C for 2 hours had mass gain of 83% and the sample treated at 1000 °C for 4 hours presented a mass gain of 43%. The oxidation coefficients of the borided samples were similar, indicating similar oxidation kinetics but different from the untreated substrate.