Tecnologia em Metalurgia, Materiais e Mineração (Oct 2014)

ANALYSIS OF PITTING CORROSION ON AN INCONEL 718 ALLOY SUBMITTED TO AGING HEAT TREATMENT

  • Felipe Rocha Caliari,
  • Elias Felipe da Rosa,
  • Maria Auxiliadora da Silva,
  • Danieli Aparecida Pereira Reis

DOI
https://doi.org/10.4322/tmm.2014.028
Journal volume & issue
Vol. 11, no. 3
pp. 189 – 194

Abstract

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Inconel 718 is one of the most important superalloys, and it is mainly used in the aerospace field on account of its high mechanical strength, good resistance to fatigue and creep, good corrosion resistance and ability to operate continuously at elevated temperatures. In this work the resistance to pitting corrosion of a superalloy, Inconel 718, is analyzed before and after double aging heat treatment. The used heat treatment increases the creep resistance of the alloy, which usually is used up to 0.6 Tm. Samples were subjected to pitting corrosion tests in chloride-containing aqueous solution, according to ASTM-F746-04 and the procedure described by Yashiro et al. The results of these trials show that after heat treatment the superalloy presents higher corrosion resistance, i.e., the pitting corrosion currents of the as received surfaces are about 6 (six) times bigger (~0.15 mA) than those of double aged surfaces (~0.025 mA).

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