A preliminary study on the microstructural characteristics and stress corrosion cracking susceptibility of a friction stir welded (FSW) 304L stainless steel plate was carried out. The weld examined was characterized by several typical microstructural features of friction stir welds including a gradient of dynamically recrystallized microstructure with distinct material flow patterns reflective of the complex distribution of thermomechanical histories. Evidence of process-induced microstructural sensitization was lacking Immersion testing of the friction stir welded plate in boiling magnesium chloride solution indicated the FSW region was more susceptible to SCC than the base 304L material, especially along the weld toes. The microstructural origins of this SCC susceptibility are not clear, but it is likely driven by residual stress imparted by the welding process. Future work will focus on direct examination of the SCC damaged microstructure and residual stress of the weld zone to further clarify the operative characteristics controlling SCC susceptibility.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2019

Identification of Twin Formation in Additively Manufactured Stainless Steel by In-Situ EBSD.

Abstract not provided.

Dickens, Sara↗

DOE OSTI2019

Round Robin Tensile Testing of 50% cold worked Nitronic 60

This report documents recent experiments on the structural properties of Nitronic 60, Level 5 (cold worked to approximately 50% reduction in diameter). Material from two different vendors was examined. Different cold working approaches by the two vendors resulted in inhomogeneous material properties that varied as a function of distance from the center of the rod. Measurements were compared to Sandia specifications (7343200-7343207). The effect of several parameters on structural properties was examined, including lot-to-lot variability, lot diameter, radial location of tensile bars, tensile bar size, and cold working method. Most significantly, the apparent tensile strength, yield strength, and ductility were found to all vary with radial distance from the center of the bar.

36 MATERIALS SCIENCE↗

DOE OSTI2019