Precipitation and Cr depletion profiles of Inconel 182 during heat treatments and laser surface melting

Baoa Gang

Yamamoto Motomichi

Shinozaki Kenji

Journal of Materials Processing Technology

Thermodynamic and kinetic modeling was conducted to simulate Cr depletion profiles near grain boundaries in Inconel 182 during heat treatments and laser surface melting (LSM) using Thermo-Calc and DICTRA code. The effect of Nb addition was also considered in the modeling. Based on the good agreement with Cr concentration distributions during the heat treatments measured experimentally, Cr depletion profiles adjacent to grain boundaries during the heat treatments and the LSM process were modeled. The Cr depletion profiles were evaluated using the Cr depletion area below the critical Cr concentration for IGC/IGSCC (Intergranular Cracking/Intergranular Stress Corrosion Cracking) susceptibility (12 mass%). Compared with the result of the Streicher test, the calculated Cr depletion areas showed good agreement with IGC/IGSCC susceptibilities. The sample after stress relief (SR) treatment had the largest Cr depletion area and showed the poorest IGC/IGSCC resistance. Cr depletion showed some recovery during subsequent low temperature sensitization (LTS). The sample after the LSM process had the smallest Cr depletion area and showed the best IGC/IGSCC resistance.

Cr depletion

IGC/IGSCC susceptibility

Inconel 182

LSM

precipitation

Metal and mining engineering [ 560 ]

eng

Elsevier Science S.A.

Copyright (c) 2008 Published by Elsevier B.V.

[ISSN] 0924-0136

[DOI] 10.1016/j.jmatprotec.2008.02.021

[NCID] AA10748601

[DOI] http://dx.doi.org/10.1016/j.jmatprotec.2008.02.021