Slow Strain Rate Fracture Characteristics of Steel and Aluminum Alloys Tested in Mercury Environments

Abstract

Slow strain rate tensile tests performed on Type 304 stainless steel, A516 Grade 70 C-Mn steel, and aluminum alloy 5083 revealed that all three materials were susceptible to varying degrees of mercury liquid metal embrittlement (LME) at ambient conditions. Both Type 304 stainless and A516 Grade 70 C-Mn steels exhibited significant strain rate sensitivity to LME, while aluminum alloy 5083 embrittlement was independent of strain rate over the range tested (8.3 × 10−3 to 5.0 × 10−7 s−1). Ductility (reduction in area) and toughness losses for tests in mercury compared to respective tests in air indicated that aluminum alloy 5083 embrittlement was more acute than either steel. Crack arrest (secondary cracking) characteristics and reactions to different mercury species also suggested that Type 304 stainless and A516 Grade 70 C-Mn steels were less susceptible to mercury LME than aluminum alloy 5083.