【摘要】 针对镁合金半连续铸造过程中的熔炼过程、半连续铸造工艺以及小直径AZ31B半连续铸造铸锭容易形成的拉裂、夹杂缺陷进行分析。结果表明,为防止拉裂缺陷,应适当降低铸造速度和铸造温度,铸造速度130~140 mm/min,铸造温度710~720℃;适当加大水压使铸锭表面冷却均匀,清理结晶器内水垢以提高铸锭的冷却强度;结晶器工作面保持均匀润滑;正确安装结晶器和分配漏斗防止液流倾斜。精炼过程中采用分层加热,在炉子中形成正温度梯度,利于杂质沉降,铸造过程中及时打渣并避免渣子通过漏斗孔进入熔体,以防止夹杂缺陷的产生。更多还原

【Abstract】 Melting process parameters,semi-continuous casting parameters and casting defects including hot cracks and inclusions of smaller diameter magnesium semi-continuous casting ingots were discussed.The results show that process parameter control should be adopted to avoid hot crack forming,and the low casting speeds of 130~140 mm/min and low casting temperature of 710~720 ℃ should be used individually,increasing the output pressure of water and clearing the scale in the mould thoroughly to increase cooling intensity,keeping the surface of the mould uniformly lubricates,adjusting the position of mould and distributing funnel to avoid the melting inclining resulting in cooling the ingots surface uniformly.Additionally,using the method of layered heating in the furnace in refining process forms a positive temperature gradient from the top part to the bottom part of the furnace,resulting in slag settles in the furnace easily.The slag was removed in time to prevent slag from going through the funnel and to enter into the melt,avoiding inclusion forming.更多还原