The effect of accelerated air cooling on microstructures and mechanical properties of mi- croalloyed steel

Abstract

The microstructures and mechanical properties of the 38MnVS6 microalloyed steel under accerelated air cooling conditions were investigated.
Compared to conventional cooling, accelerated air cooling (AAC) makes it possible to significantly increase strength properties without lowering impact toughness. The microstructure consisted of ferrite which formed at prior austenite grain boundaries and large amounts of pearlite.
The cooling rates had an important effect on impact energy. The microstructure was characterized by optical microscopy and SEM analysis; the
mechanical behavior was studied by hardness, tensile and instrumented Charpy V-notch impact tests carried out at 50°C, room temperature and
-18°C. The observed microstructure was consistent with the continuous cooling transformation diagram. Continuous cooling transformation
(CCT) diagrams, phase fractions and particle sizes have been calculated by means of JMATPro which is the best-practice tool for the calculation of temperature-dependent materials properties for a variety of technical alloys.