skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: CORROSION RESISTANCE OF STRUCTURAL AMORPHOUS METAL

Abstract

Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The potential advantages of amorphous metals have been recognized for some time [Latanison 1985]. Iron-based corrosion-resistant, amorphous-metal coatings under development may prove important for maritime applications [Farmer et al. 2005]. Such materials could also be used to coat the entire outer surface of containers for the transportation and long-term storage of spent nuclear fuel, or to protect welds and heat affected zones, thereby preventing exposure to environments that might cause stress corrosion cracking [Farmer et al. 1991, 2000a, 2000b]. In the future, it may be possible to substitute such high-performance iron-based materials for more-expensive nickel-based alloys, thereby enabling cost savings in a wide variety of industrial applications. It should be noted that thermal-spray ceramic coatings have also been investigated for such applications [Haslam et al. 2005]. Thismore » report focuses on the corrosion resistance of a yttrium-containing amorphous metal, SAM1651. SAM1651 has a glass transition temperature of {approx}584 C, a recrystallization temperature of {approx}653 C, and a melting point of {approx}1121 C. The measured critical cooling rate for SAM1651 is {le} 80 K per second, respectively. The yttrium addition to SAM1651 enhances glass formation, as reported by Guo and Poon [2003]. The corrosion behavior of SAM1651 was compared with nickel-based Alloy 22 in electrochemical polarization measurements performed in several highly concentrated chloride solutions.« less

Authors:
; ;
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
895719
Report Number(s):
UCRL-TR-220476
TRN: US0702412
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALLOYS; CERAMICS; CHLORIDES; COATINGS; CONTAINERS; CORROSION; CORROSION RESISTANCE; HEAT AFFECTED ZONE; MELTING POINTS; NUCLEAR FUELS; RECRYSTALLIZATION; STRESS CORROSION; SURFACE AREA; TRANSITION TEMPERATURE; US DOD; YTTRIUM ADDITIONS

Citation Formats

Lian, T, Day, S D, and Farmer, J C. CORROSION RESISTANCE OF STRUCTURAL AMORPHOUS METAL. United States: N. p., 2006. Web. doi:10.2172/895719.
Lian, T, Day, S D, & Farmer, J C. CORROSION RESISTANCE OF STRUCTURAL AMORPHOUS METAL. United States. doi:10.2172/895719.
Lian, T, Day, S D, and Farmer, J C. Mon . "CORROSION RESISTANCE OF STRUCTURAL AMORPHOUS METAL". United States. doi:10.2172/895719. https://www.osti.gov/servlets/purl/895719.
@article{osti_895719,
title = {CORROSION RESISTANCE OF STRUCTURAL AMORPHOUS METAL},
author = {Lian, T and Day, S D and Farmer, J C},
abstractNote = {Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The potential advantages of amorphous metals have been recognized for some time [Latanison 1985]. Iron-based corrosion-resistant, amorphous-metal coatings under development may prove important for maritime applications [Farmer et al. 2005]. Such materials could also be used to coat the entire outer surface of containers for the transportation and long-term storage of spent nuclear fuel, or to protect welds and heat affected zones, thereby preventing exposure to environments that might cause stress corrosion cracking [Farmer et al. 1991, 2000a, 2000b]. In the future, it may be possible to substitute such high-performance iron-based materials for more-expensive nickel-based alloys, thereby enabling cost savings in a wide variety of industrial applications. It should be noted that thermal-spray ceramic coatings have also been investigated for such applications [Haslam et al. 2005]. This report focuses on the corrosion resistance of a yttrium-containing amorphous metal, SAM1651. SAM1651 has a glass transition temperature of {approx}584 C, a recrystallization temperature of {approx}653 C, and a melting point of {approx}1121 C. The measured critical cooling rate for SAM1651 is {le} 80 K per second, respectively. The yttrium addition to SAM1651 enhances glass formation, as reported by Guo and Poon [2003]. The corrosion behavior of SAM1651 was compared with nickel-based Alloy 22 in electrochemical polarization measurements performed in several highly concentrated chloride solutions.},
doi = {10.2172/895719},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Apr 10 00:00:00 EDT 2006},
month = {Mon Apr 10 00:00:00 EDT 2006}
}

Technical Report:

Save / Share:
  • New corrosion-resistant, iron-based amorphous metals have been identified from published data or developed through combinatorial synthesis, and tested to determine their relative corrosion resistance. Many of these materials can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in some very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Two Fe-based amorphous metal formulations have been found that appear to have corrosion resistance comparable to, or better than that of Ni-based Alloy C-22, based on breakdown potential and corrosion rate. Both Cr and Mo providemore » corrosion resistance, B enables glass formation, and Y lowers critical cooling rate (CCR). SAM1651 has yttrium added, and has a nominal critical cooling rate of only 80 Kelvin per second, while SAM2X7 (similar to SAM2X5) has no yttrium, and a relatively high critical cooling rate of 610 Kelvin per second. Both amorphous metal formulations have strengths and weaknesses. SAM1651 (yttrium added) has a low critical cooling rate (CCR), which enables it to be rendered as a completely amorphous thermal spray coating. Unfortunately, it is relatively difficult to atomize, with powders being irregular in shape. This causes the powder to be difficult to pneumatically convey during thermal spray deposition. Gas atomized SAM1651 powder has required cryogenic milling to eliminate irregularities that make flow difficult. SAM2X5 (no yttrium) has a high critical cooling rate, which has caused problems associated with devitrification. SAM2X5 can be gas atomized to produce spherical powders of SAM2X5, which enable more facile thermal spray deposition. The reference material, nickel-based Alloy C-22, is an outstanding corrosion-resistant engineering material. Even so, crevice corrosion has been observed with C-22 in hot sodium chloride environments without buffer or inhibitor. Comparable metallic alloys such as SAM2X5 and SAM1651 may also experience crevice corrosion under sufficiently harsh conditions. Accelerated crevice corrosion tests are now being conducted to intentionally induce crevice corrosion, and to determine those environmental conditions where such localized attack occurs. Such materials are extremely hard, and provide enhanced resistance to abrasion and gouges (stress risers) from backfill operations, and possibly even tunnel boring. The hardness of Type 316L Stainless Steel is approximately 150 VHN, that of Alloy C-22 is approximately 250 VHN, and that of HVOF SAM2X5 ranges from 1100-1300 VHN. These new materials provide a viable coating option for repository engineers. SAM2X5 and SAM1651 coatings can be applied with thermal spray processes without any significant loss of corrosion resistance. Both Alloy C-22 and Type 316L stainless lose their resistance to corrosion during thermal spraying. Containers for the transportation, storage and disposal of spent nuclear fuel (SNF) and high-level radioactive waste (HLW) with corrosion resistant coatings are envisioned. For example, an enhanced multi-purpose container (MPC) could be made with such coatings, leveraging existing experience in the fabrication of such containers. These coating materials could be used to protect the final closure weld on SNF/HLW disposal containers, eliminate need for stress mitigation. Integral drip shield could be produced by directly spraying it onto the disposal container, thereby eliminating the need for an expensive titanium drip shield. In specific areas where crevice corrosion is anticipated, such as the contact point between the disposal container and pallet, HVOF coatings could be used to buildup thickness, thereby selectively adding corrosion life where it is needed. Both SAM2X5 & SAM1651 have high boron content which enable them to absorb neutrons and therefore be used for criticality control in baskets. Alloy C-22 and 316L have no neutron absorber, and cannot be used for such functions. Borated stainless steel and G« less
  • Two separate studies are reported. In the first, titanium, stainless alloy AL-6X, Alclad 3003, aluminum alloy 5052, C70600, C72200 and Cu-10Ni-8Sn sheet materials were exposed to ambient temperature, low velocity seawater for 6 months and crevice corrosion and metal-ion concentration cell corrosion evaluations were conducted. Conditions were sufficiently critical to initiate crevice attack on control samples of Type 316 stainless steel. While no evidence of corrosion was detected for titanium and AL-6X, the five aluminum and copper base alloys all exhibited varying degrees of general and/or localized attack. In the second study, laboratory tests in low velocity, filtered seawater atmore » 30/sup 0/C resulted in initiation of crevice attack for 12 of the 13 stainless alloys included in the evaluation. For the most part, evidence of crevice corrosion initiation was detected within the first 30 days of exposure, although considerable variation in the observed time to initiation of crevice corrosion was noted. (LEW)« less
  • These tests were conducted to determine the corrosion and mass transport resistance of various structural materials to liquid sodium in a dynamic test loop operating at a temperature differential. (auth)