Carburization behavior of AISI 316LN austenitic stainless steel – Experimental studies and modeling

Evaluation of Microstructural, Mechanical Properties and Corrosion Behavior of AISI Type 316LN Stainless Steel and Modified 9Cr-1Mo Steel Exposed in a Dynamic Bimetallic Sodium Loop at 798 K (525 °C) for 16,000 Hours

“…[30] Hence, in Indian sodium containing 25 ppm carbon, of which 2 ppm is in solution, carbon activity would be much higher than in type 316LN austenitic stainless steel containing 0.03 wt pct carbon. [31] A comparison of Figures 5(b) and (c) suggested that the carbon diffusing into type 316LN stainless steel caused extensive precipitation of M 23 C 6 carbides. Hence, carbon that diffused into the steel formed a carburized zone with a high volume fraction of M 23 C 6 type of carbides.…”

LWRS Program - Updates of High-Fluence Induced Microstructural Evolution of Austenitic Stainless Steels under LWR Relevant Conditions

“…It was possible to expect that a modified surface layer exists on the samples due to contact with sodium coolant. For example, as shown in [4], for 16000 hours irradiation at 793K the thickness of carburized zone was found to be ~60 microns. In order to avoid any contamination caused effects, samples were polished mechanically, and layers of ~200 microns thickness were removed from both sides.…”

Modeling of vacuum pulse carburizing of steel

“…When surface carbon concentration is constant then Eq. (1) has an analytical solution given by error function [19,21,22]:…”

“…In such case the carbon surface concentration is determined by carbon activity in the gas [8]. For stationary processing, the Dirichlet type boundary condition can be applied which provides the surface carbon concentration (c C s ) equal to the carbon potential (C p ) in the carburizing atmosphere (c C s = C p ) [21,22].…”