engleski

Application of JM® -test in 3D Simulation of Quenching

Purpose: Simulation of hardness distribution in quenched steel specimen has been investigated using 3D numerical formulation. Structural mesh has been used in numerical simulation. Numerical calculations of hardness distribution in specimen made of high hardenability steel have been performed in order to define appropriate steel for manufacturing of machine part. Possibility of application of numerical model based on experimental results in steel quenching has been investigated. Methodology: Numerical simulation of the steel quenching is consisted of computation of cooling curve during the quenching and prediction of hardness at specimen points after the quenching. Hardness at specimen points is estimated by the conversion of cooling time results to hardness. Conversion is provided by the relation between cooling time and distance from the quenched end of Jominy-specimen. In this way the numerical simulation has been combined with experimental Jominy-test. Findings: Structure transformation and hardness distribution can be successfully estimated based on time, relevant to structure transformation. Relevant time for quenching results for most structural steels is cooling time from 800 to 500  C (t8/5). Research limitations: Since high hardenability of investigated steel there are limits in application of original Jominy-specimen in simulation of quenching of steels. The modified Jominy-test enables cooling time, t8/5 higher than Jominy-test. Practical implications: The simulation of quenching based on modified Jominy-test can be applied for steels with higher hardenability. This method of simulation is especially suitable for tools and dies steels. 3D numerical simulation of quenching is more confident in practical implementation and provides more information than 2D formulation. Originality: Using the results of simple experimental test, i.e., modified Jominy-test in numerical modeling of steel quenching it is possible to achieve better results of hardness simulation.

analysis and modeling; numerical techniques; 3D modeling; steel quenching

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