热顶铸造铝合金空心铸锭内孔漏铝及其改进方法  

Aluminum Leakage from Inner Hole of Hot Top Casting Aluminum Alloy Hollow Ingot and Its Improvement Method

作　　者：杜新宇[1] DU Xinyu(School of Intelligent Manufacturing,Nanyang Institute of Technology,Nanyang 473003)

机构地区：[1]南阳理工学院智能制造学院,南阳473003

出　　处：《特种铸造及有色合金》2024年第10期1431-1435,共5页Special Casting & Nonferrous Alloys

基　　金：河南省重点研发与推广专项(科技攻关)资助项目(202102240002)。

摘　　要：热顶铸造铝合金空心铸锭时,由于内孔表面结晶的凝壳较薄,在拉力的作用下凝壳容易产生裂纹甚至发生漏铝问题。通过显微观察发现漏铝部位多数具有拉痕和断裂特征,但也有突发漏铝的情况。结合生产实际,分析了空心锭内孔拉痕拉裂漏铝以及无拉裂突发漏铝产生的原因。指出为避免拉裂漏铝,需要从铸造结晶器结构、铸造参数和操作工艺等方面采取措施。通过控制半连续铸造时铝液放热和冷却水吸热的热平衡来控制内腔凝壳厚度和所受拉力;无拉裂突发漏铝主要是由于铸管内腔压力过大所致,从而研制出加装了内孔排气装置的热顶铸造结晶器,并采取优化铸造温度、铸造速度、冷却速度、冷却均匀性等措施。生产表明,加装内孔排气装置的结晶器可有效降低铸管内气体压力,解决无拉裂突发漏铝产生的问题,而其他工艺措施能够很好地控制凝壳厚度,从而解决了拉裂漏铝的问题。With hot top casting aluminum alloy hollow ingot,due to the thin crystalline shell on the inner hole surface,crack is easily occurred on the shell under the action of force and even leak the molten alloy.Through microscopic observation,it is found that there are stretch marks and cracks in the ingot where the molten liquid is leaken,and sud⁃den leakage often occurs.Combined with the actual production,the causes of tensile leakage and non-tensile leakage in hollow aluminum alloy ingot were analyzed.It is pointed out that some measures should be taken from the structure of casting mould,casting parameters and operation technology to avoid molten alloy liquid leakage.The thickness and ten⁃sion of the inner cavity shell are controlled by achieving a thermal balance between the heat release of aluminum alloy melt and heat absorption of cooling water during semi-continuous casting.The non-tensile leakage is mainly caused by excessive pressure in the cavity of cast pipe.Therefore,a casting mold equipped with an internal hole exhaust device was developed,and measures were taken to optimize the casting temperature,casting speed,cooling speed and cool⁃ing uniformity.The production reveals that the gas pressure in the mold cast pipe is effectively reduced by using the internal hole exhaust device,and the non-tensile leakage is eliminated,while other measures can well control the thick⁃ness of crystalline shell to avoid tensile leakage.

关 键 词：铝合金空心铸锭 热顶铸造 裂纹 应力 

分 类 号：TG245[金属学及工艺—铸造] TG249.7[一般工业技术—材料科学与工程] TG146.21[金属学及工艺—金属材料]