The phenomenon of double necking during hot tensile tests is discussed
in this work. The investigation was carried out on high-carbon steel
using a tensile testing machine equipped with an integral heating syst
em. Tensile tests were performed in a large temperature range to obtai
n the mechanical characteristic of the material. Microstructure evolut
ion was observed by light microscopy and hardness measurements to dete
rmine the position of double zones of necking, A significant increase
in flow stress of as-transformed austenite was found to be at the orig
in of the double necking behaviour.