The effect of heat-to-heat variations in metallurgy and hydrogen-metal interactions on the hydrogen embrittlement of Monel K-500

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:703

Article

Troconis, B. C. Rincon¹  Harris, Z. D.¹  Ha, H.¹  Burns, J. T.¹  Scully, J. R.¹ 

[1] Univ Virginia, Dept Mat Sci & Engn, Ctr Electrochem Sci & Engn, 395 McCormick Rd, Charlottesville, VA 22904 USA

关键词: Nickel alloys;    Hydrogen embrittlement;    Thermal desorption spectroscopy;    Hydrogen diffusion;    Hydrogen trapping;    Sulfur embrittlement;   

DOI  :  10.1016/j.msea.2017.07.019

来源: Elsevier

【 摘 要 】

The influence of heat-to-heat variations on the hydrogen embrittlement susceptibility of age-hardened Monel K-500 (UNS N05500) was evaluated through detailed characterization of metallurgical attributes and hydrogen interactions, coupled with notched tensile specimen embrittlement metrics. Four nominally peak-aged material heats of Monel K-500 were assessed using slow strain rate tensile (SSRT) testing while immersed in 0.6 M NaCI solution and exposed to cathodic polarization levels ranging from -0.850 to -1.1 V-SCE. Despite each of the four heats meeting the US Federal Procurement Specification QQ-N-286G, the hydrogen embrittlement susceptibility was found to vary extensively between the tested material heats. Characterization of microstructural features, composition, and hydrogen-metal interactions were performed to facilitate correlation between material property and susceptibility trends. Results suggest that subtle differences in grain boundary chemistry and H uptake behavior may contribute to heat-to-heat variations in hydrogen embrittlement susceptibility of Monel K-500. Conversely, parameters including yield strength, hydrogen diffusivity, hydrogen production rate, grain boundary character, and grain size do not independently control the observed variations in susceptibility. Based on these experimental results, a macroscale framework for assessing the degradation in fracture stress as a function of applied potential is proposed and possible avenues for framework improvement are suggested.

【 授权许可】

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