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

Abstract

a b s t r a c tThermodynamic and kinetic modeling were 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 intergranular cracking/intergranular stress corrosion cracking (IGC/IGSCC) 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.

Evaluation of minimum quantity lubrication effects by cutting force signals in face milling of Inconel 182 overlays

“…It shows recrystallized features with extensive grain boundary migration (MGB) where the recrystallized grain boundaries cut across the solidification substructures (Bao et al, 2009). During the solidification phase of the welding, re-distribution of the solutes occurs, as a result, two types of precipitates have distributed on the dendritic grain boundaries during the cooling phase after solidification.…”

Microstructures and machinability of the Inconel 182 overlays at different overlay thickness deposited by shield metal arc welding

“…The depletion of chromium will, in some extent, reduce the micro-hardness of Inconel 182 overlays. 17 Meanwhile, due to the relative high welding temperature, a small amount of carbon in substrate can in turn diffuse into Inconel 182 overlays and forms small round Si carbide and Ti carbide precipitates around grain boundaries, strengthening the hardness. The Si carbide and Ti carbide precipitation in Inconel 182 overlays depends strongly on the heat treatments of the material and the environmental temperature during the solidification phase in welding process.…”

Laser surface melting of nickel-based alloy reduces nickel release in the primary cooling system of a nuclear power plant

“…Analysis of this chromium enriched surface layer has revealed a significant amount of Cr 2 O 3 on laser melted surfaces of Fe-based alloys [35] and Ni-based alloys [36]. Bao et al [37,38] compared LSM and classical heat treatment on Ni-based alloys to produce controlled oxidation. They proved that laser treatment could reduce the subsurface chromium depletion and provide better healing properties to the oxide layer than classical heat treatment.…”