engleski

Systematical analysis of cooling curves for liquid quenchants

This investigation suggests and describes a systematic approach to the analysis of liquid quenchant characteristics using a standard ISO Inconel alloy probe. A new systematic mathematical model for the cooling curve analysis has been developed. The model allows a possibility for a more precise determination of quenching parameters and links certain parameters with a mathematical model for microstructure prediction and properties of quenched work pieces. Besides the usual technological parameters (cooling rate at 700oC, maximum cooling rate, cooling time from 800 to 500 0C, cooling rate at 300 0C, quenching intensity H), heat transfer coefficient is determined using the following methods: lumped-heat capacity method, Kobasko method and inverse heat transfer method according to ''SQIntegra'' software. The results of heat transfer coefficient calculation according to all the mentioned methods are compared and verified with ISO Inconel alloy probe cooling curve analysis for quenching in water, industrial quenching oil and water based PAG polymer solution with concentrations from 5 to 30%vol PAG in water.

quenching; cooling curve analysis; heat transfer coefficient

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