Corrosion Resistances of Iron-Based Amorphous Metals with Yttrium and Tungsten Additions in Hot Calcium Chloride Brine Natural Seawater: Fe{sub}48Mo{sub}14Cr{sub}15Y{sub}2C{sub}15B{sub}6 and W-Containing Variants

摘要

Yttrium-containing SAM1651 (Fe{sub}48.0Cr{sub}15.0Mo{sub}14.0B{sub}6.0C{sub}15.0Y{sub}2.0) has a critical cooling rate (CCR) of approximately 80 Kelvin per second, while SAM2X5 (Fe{sub}49.7Cr{sub}17.7Mn{sub}1.9Mo{sub}7.4W{sub}1.6B{sub}15.2C{sub}3.8Si{sub}2.4) with no yttrium has a higher critical cooling rate of approximately 600 Kelvin per second. SAM1651's low CCR enables it to be rendered as a completely amorphous material in practical materials processes. Chromium (Cr), molybdenum (Mo) and tungsten (W) provide corrosion resistance; boron (B) enables glass formation; and rare earths such as yttrium (Y) lower CCR. The passive film stability of these Fe based amorphous metal formulations have been found to be superior to that of conventional stainless steels, and comparable to that of Ni-based alloys, based on electrochemical measurements of the passive film breakdown potential and general corrosion rates.