铸造工艺参数对半连续铸造A390合金管坯宏微观组织的影响

采用半连续铸造方法制备了A390合金管坯.研究了铸造速度和铸造温度对A390合金管坯宏微观组织的影响.结果表明:随着铸造速度由90 mm/min提升至120 mm/min、铸造温度由800℃增加至850℃,管坯中初生Si宏观分布趋于均匀,初生Si颗粒的平均尺寸逐渐减小.截面尺寸为164 mm/60 mm的半连续铸造A390合金管坯的最佳铸造工艺参数为:铸造速度110 mm/min、铸造温度850℃,可以获得初生Si宏观分布均匀、初生Si颗粒平均尺寸不超过26μm的管坯,管坯内侧的抗拉强度为264 MPa,延伸率为0.5%.

Effects of Casting Process Parameters on Macrostructure and Microstructure of A390 Alloy Hollow Billet Produced by DC Casting

DC casting was used to produce A390 alloy hollow billet. The effects of the casting speed and temperature on the macrostructure and microstructure of A390 alloy hollow billets were studied. The results showed that the distribution of primary Si in the hollow billet became more even and the average size of primary Si particle decreased gradually with the increase of the casting speed from 90mm/min to 120mm/min and casting temperature from 800℃ to 850℃，respectively. The optimum casting process parameters for the A390 alloy hollow billets of 164mm/60mm were obtained with the casting speed of 110mm/min and casting temperature of 850℃. The primary Si particles uniformly distributed with their average size less than 26μm obtained under the optimum casting process parameters. The ultimate tensile strength and elongation at the inner wall of the hollow billets were 264MPa and 0.5%， respectively.