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This work is based in a model of neural and wavelets networks using published experimental data. The objective is to compare a neural and a wavelet network estimating the creep rupture strength based on chemical composition of Fe-2.25Cr-Mo and Fe-(9-12)Cr steels, and on its heat treatment temperature and life time. It will be determined the configuration that provides the best fit of the data.

The rapid cooling in quenching heat treatment results in thermal stresses due to high thermal gradients. Thermal residual stresses can potentially affect the martensitic transformation as well the distortions. Distortion is one of the main problems of manufacturing and heat treatment is the main cause of this phenomena. It is known, that the quenchant agitation is a parameter that influences the cooling rates and consequently the residual stresses and distortions. In this way this work proposes to quench an AISI 5160 steel in three different levels of agitation, a conventional mineral oil at the same temperature. Cooling curves analysis, finite element simulation and metallographic observation support the obtained conclusions. It is found that a moderate agitation rate produces better results in terms of distortion and thermal residual stresses.

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.