Bulk glassy Fe-Cr-Mo-C-B alloys with high corrosion resistance

Abstract

The preparation of bulk glassy alloys with high glass-forming ability and high corrosion resistance in Fe-based system was succeeded by means of copper-mold casting. The temperature interval of supercooled liquid region (ΔTx) is as large as 53-62 K and the reduced glass transition temperature (Tg/Tm) is as high as 0.62-0.63 for the cast a diameter of 1.2 mm were in the range of 10-3-10-2 mm year-1 in 1, 6 and 12 N HCl solutions at 298 K. The bulk glassy alloys are spontaneously passivated in 1 and 6 N HCl solutions with wide passive region and low passive current density. They do not suffer pitting corrosion even when polarized anodicly in 12 N HCI solution up to 1.0 V (Ag/AgCl). The high corrosion resistance is due to the formation of chromium-rich passive films during immersion in HCI solutions. In addition, the increase of boron content in alloys improves the corrosion resistance of the bulk glassy alloys within the composition range examined. © 2002 Elsevier Science Ltd. All rights reserved.