Tensile tests at 77 K and 4 K on 316L stainless steel welded plates

Abstract

Based on the collaborative framework established between ASME, NASA, and NIST, quasi-static tensile tests were performed in liquid nitrogen (77 K) and liquid helium (4 K) on tensile specimens extracted from the centers of four welded 316L stainless steel plates, each produced by a different vendor. Relatively large differences in strength, elongation, and reduction in area were observed between the welds with the strongest two welds (W4 and W2) exhibiting a nearly 20 % difference in 4 K ultimate tensile strength when compared to the welds with the lowest 4 K tensile strength (W1 and W3). As the testing temperature decreases from 77 K to 4 K, all welds exhibit an increase in yield strength, plus an attenuation in total elongation and reduction in area. Serrated yielding was observed at every test conducted at 4 K. The tensile properties reported in this work will be used during analysis of future fracture toughness (single edge notch bending) testing conducted at 77 K and 4 K on the same four sets of welded plates.

Fracture toughness tests at 77 K and 4 K on 316L stainless steel welded plates

“…In all the fracture toughness tests conducted at liquid helium temperature (4 K), visible serrations were observed on the force-CMOD diagrams of the tested specimens. These serrations appeared as small force drops, accompanied by CMOD increases, and had been already observed during the tensile tests performed at 4 K [19]. These serrations did not occur in tensile or toughness tests performed at liquid nitrogen temperature (77 K), as can be seen in Figure 11.…”

“…The framework of this study is a collaborative project between the American Society of Mechanical Engineers (ASME), the National Aeronautics and Space Administration (NASA), and the National Institute for Standards and Technology (NIST). The results presented in this report include quasi-static fracture toughness (as opposed to impact toughness, measured from Charpy tests in [18]) measured on Charpy-type specimens [18] at 77 K and 4 K, extracted from the same four lots of welded 316L plates previously investigated through Charpy impact testing at 77 K and tensile testing at 77 K and 4 K [19]. These results can be applied in energy and aerospace industries.…”

Fracture toughness tests at 77 K and 4 K on 316L stainless steel welded plates

“…In all the fracture toughness tests conducted at liquid helium temperature (4 K), visible serrations were observed on the force-CMOD diagrams of the tested specimens. These serrations appeared as small force drops, accompanied by CMOD increases, and had been already observed during the tensile tests performed at 4 K [19]. These serrations did not occur in tensile or toughness tests performed at liquid nitrogen temperature (77 K), as can be seen in Figure 11.…”

“…The framework of this study is a collaborative project between the American Society of Mechanical Engineers (ASME), the National Aeronautics and Space Administration (NASA), and the National Institute for Standards and Technology (NIST). The results presented in this report include quasi-static fracture toughness (as opposed to impact toughness, measured from Charpy tests in [18]) measured on Charpy-type specimens [18] at 77 K and 4 K, extracted from the same four lots of welded 316L plates previously investigated through Charpy impact testing at 77 K and tensile testing at 77 K and 4 K [19]. These results can be applied in energy and aerospace industries.…”