Residence time and speed before quenching and annealing after high temperature deformation

Residence time after quenching and annealing after deformation

The deformation temperature of high-temperature deformation quenching is higher than the austenite recrystallization temperature, so the stay after deformation will inevitably affect the structure and properties of the steel after deformation quenching. The tensile strength first increases and then decreases with the extension of residence time, while the elongation rate first decreases and then increases. The maximum value of strength and the minimum value of elongation correspond to the same residence time.

Deformation speed

There are not many research results on the effect of deformation speed on the effect of high-temperature deformation quenching of steel, but it is generally believed that under certain deformation temperature and deformation amount conditions, there should be a better deformation and quantity condition that corresponds to better strengthening effect. The strengthening effect should compensate for the influence of two better forms. When the deformation speed is small, as the deformation speed increases, the strength of the steel continues to increase, and the plasticity value is also higher. When the deformation speed is large, due to the accumulation of internal heat, the possibility of recrystallization occurs, the increase in habitat strength slows down, and the plasticity begins to decline. When the deformation speed is larger, the de-strengthening process of steel cannot proceed in time, the strength continues to increase, and the plasticity slowly decreases.

Under actual production conditions, the deformation speed is determined by the rolling and forging equipment used. The rolling speed of various profiles, strips and plates can range from a few tenths of a meter per second to more than ten meters per second. The rolling speed can range from a few tenths of a meter per second to +several meters per second.

Tempering

The carbon content of martensite in high-temperature deformation quenched steel is lower than that in the ordinary quenched state, so it has high strength, high plasticity and toughness, and can be tempered at lower temperatures without worrying about brittle fracture. Due to the formation of a very stable, regularly arranged dislocation substructure pinned by fine and dispersed carbides, high temperature deformation quenched steel has high tempering resistance.