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前言用普通砂型铸造方法生产船用螺旋桨,必须有一个很大的冒口,这几乎是世界上有铸造史以来,铸造工作者必须遵守的一条“法律”。在生产船用大型螺旋桨时,冒口重量往往占螺旋桨本体重量的40%左右。能不能采用一种特殊的工艺方法,既能够在铸造过程中就不使用冒口,又能够保证螺旋桨的质量呢?最近几年,国外开始把电热冒口工艺应用到船用螺旋桨上。但在国内还没有先例。我们
Foreword The production of marine propellers using the common sand casting method requires a large riser, which is almost a “law” the foundry workers must obey since the founding of the world. In the production of large marine propellers, riser weight often accounts for about 40% of the propeller body weight. Can we use a special process, both in the casting process will not use riser, but also to ensure the quality of the propeller it? In recent years, foreign countries began to apply electrothermal riser craft on marine propellers. However, there is no precedent in China. we