Fatigue and Environmentally Assisted Cracking Behavior of Wrought and Additively Manufactured 316L Stainless and HY-80 and LA-100 Steel
Committee:
Dr. Robert Kelly (Chair)
Dr. Ji Ma (MSE, UVA)
Dr. Sean Agnew (MSE, UVA)
Dr. Peter Alonzi (Data Science, UVA)
Dr. James Burns (Advisor)
Abstract
Metal additive manufacturing (AM) is an attractive technology that can directly produce complex part geometries with just feedstock material and an AM machine. The 316L stainless steel alloy has received significant attention as an AM feedstock material for its combination of moderate strength and high corrosion resistance. To date, research on AM 316L has focused on microstructure and first order properties like strength and ductility with limited studies on environmental degradation. Three research tasks are proposed to evaluate the effect of environment on the corrosion fatigue and stress corrosion cracking (SCC) performance of AM 316L, produced using the laser powder bed fusion (LPBF) AM process, through comparison with its traditional, wrought counterpart. A fourth task is proposed to compare HY-80 a wrought steel used for naval construction to Directed Energy Deposition (DED) LA-100. Mechanical properties, and deformation behavior in the as built and the hot isostatic pressed (HIP) condition are evaluated in Task 1. Using a linear elastic fracture mechanics (LEFM) paradigm, Task 2 compares the SCC performance of wrought and AM 316L in 4.5M MgCl2 from room temperature up to 85°C. Task 3 evaluates the corrosion fatigue crack growth behavior of wrought and AM 316 in humid air and 0.6M NaCl at various frequencies. Task 4 establishes baseline environmentally assisted cracking (EAC) behavior of AM LA-100. The results from this research will provide a survey of the EAC performance of AM 316L, HY-80, and LA-100 and identify the microstructural features introduced by AM that control its EAC performance.
All interested persons are invited to attend.
Please contact Michael Roach for Zoom information.