Properties of Low-Carbon Steel With Various Microalloying Additions After Particular Thermomechanical Processing

摘要

The article deals with production of the micro alloyed steel forged products for oil industry. Customer requires high toughness in lowered temperatures, guaranteed weldability and also relatively high yield strength. Applied heat of steel has 0.1 of carbon content and 1.5 percent of manganese. Conventional alloying with conventional heat treatment not always lead to consistency in mechanical properties. Application of usual heat treatment (quenching and subsequent tempering) ensures only close compliance of requirements in yield strength. It is also complicated to meet adequate toughness at -46℃ by applying conventional heat treatment. New heats with combination of several microalloying elements (Ti, V, Nb, Zr) were prepared. Physical simulation of forging on real specimens was done on unique device with possibilities of temperature and deformation controlling. The main goal of this experiment was to assess mechanical and microstructural properties of steel after addition of various amounts of various microalloying elements.