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This paper describes the use of computational simulation to examine the heat transfer properties and resulting residual stress obtained by quenching a standard probe into various quench oils. Cooling curves (time-temperature profiles) were obtained after immersing a preheated 12.5 mm dia. × 60 mm cylindrical Inconel 600 (Wolfson) probe with a Type K thermocouple inserted into the geometric center into a mineral oil quenchant. Different quenching conditions were used, as received (“fresh”) and after oxidation. Surface temperatures at the cooling metal - liquid quenchant interface and heat transfer coefficients are calculated using HT-Mod, a recently released computational code. Using this data, the temperature distribution was calculated. The corresponding residual stresses were calculated using ABAQUS. This work illustrates potential benefits of computational simulation to examine the expected impact of different quenchants and quenching conditions on a heat treatment process.

One of the most important heat treating processes is steel carburizing. However, the relatively long process times makes carburizing (and related thermochemical processes) a particularly energy consumptive and expensive process. Thus, if significant reductions in process times or temperatures can be achieved, this would result in substantial product cost savings and reduced energy consumption. Various methods of accelerating the carburizing process have been reported previously including: the use of rare earth metals, optimization by computer control of endo gas composition, use of superficial nitriding and others. In this paper, an overview of a new process using a hydrocarbon decomposition reaction catalyst that results in substantial diffusion rate acceleration and/or the potential use of significantly lower carburization temperatures will be discussed.