Effect of Quenching Heat Treatment Temperature on Al-Si Coating of Hot Stamped Steel

In order to study the effect of quenching heat treatment temperature on Al-Si coating of hot stamped steel, the phase structure of Al-Si coating on hot stamped steel with three kinds of thicknesses and the variation of coating thicknesses were analyzed by DIL805A/D quenching dilatometer, scanning electron microscopy and energy dispersive spectroscopy. The results show that under the same quenching heat temperature, different phase structures are formed in coatings with different thickness. The thinner the coating is, the shorter the path of iron to the coating direction and aluminum to the steel substrate direction is, the less saturation time of Fe and Al and alloying time are. After austenitizing, cracks and voids appear in the coating, and the number and size of voids increase with the increase of temperature. The total thickness of coating and the thickness of interdiffusion layer increase with the increase of temperature, and the thicknesses of interdiffusion layer of three kinds of coatings are the same at the same heating temperature.