Seamless aluminum tube leveling and annealing combined with experimental conditions, the occurrence mechanism of trenches and non-continuous pits and the influence of Al2O3 particles were analyzed, and the ablation rate of seamless aluminum tubes under this experimental condition was obtained. Study on the Mechanism of Carbide Formation in Ultra-Low Carbon Ductile Cast Iron Through the investigation of crystallographic microscope and scanning electron microscope, the composition of two types of carbides, granular carbides and network carbides, of ultra-low carbon ductile iron in metal casting has been studied. mechanism. The results show that the granular carbides are potential nucleation centers formed on the basis of the residual products produced by the inoculants, metamorphic agents, and spheronization agents, which may be melted or reverberated. Nucleation grows at this center, and its distribution is due to the crystallization. When the dendrite's preferential orientation influences, a certain directionality appears; the networked carbides are precipitated from the primary austenite and eutectic austenite and adhere to the two austenite grain boundaries.
After the straight leveling can not reach flatness less than 5mm, the seamless aluminum tube leveling annealing process discusses continuous casting and rolling seamless aluminum tubes. The flatness after uncoiling and blanking is 10~12mm. This paper seeks stress relief annealing and incomplete annealing. Process leveling. The results show that the use of 650 °C stress relief annealing leveling, flatness of 7.5 ~ 8.2mm, leveling effect is not aspiration. The flatness of 2.8~3.4mm after flattening at 740°C incompletely meets the requirement of flatness. The metallographic arrangement is uniform equiaxed grain; the tensile strength is 470~480MPa; the yield strength is 348~350MPa; the elongation rate is 30%~32.5%; its function is satisfactory, and the application of the technology has good application value. In view of the fact that the computer cannot simulate the ablation effect of the solid rocket engine's tail flame, the ablation experiment of the seamless aluminum tube used for the diffuser is commonly used.