生产2A70铝合金A级探伤制品用铸锭的熔铸工艺研究

Study on melting and casting process to produce 2A70 billets with quality of grade A flaw detection

生产2A70铝合金A级探伤制品用的铸锭,要求具有高的纯洁度和更好的冶金质量。通过按化学成分内部标准配料,采用在电炉内投固体料进行熔炼,用一号熔剂覆盖保护熔体;通过炉前化学成分分析控制合金熔体的成分在内标范围内,尤其是w(Fe):w(Ni)≈1,w(Fe)或w(Ni)>1.25%时必须对熔体冲淡,以防止成分偏析和生成粗大化合物一次晶体;加强除气除渣,除在熔炼炉中精炼熔体外,在静置炉中再用Ar气精炼,在铸造过程中用ALTECH装置在线除气,用陶瓷片在线过滤熔体,并在线播种Al-Ti-B丝细化晶粒;采用合适的铸造工艺参数。这样生产出的Φ270 mm 2A70铝合金铸锭质量,能满足生产高质量的A级控伤制品的要求。

In order to produce 2A70 billets with quality of grade A flaw detection,which requires high purity and better metallurgically quality,the internal standard has been settled.The chemical composition has been controlled accurately by the standard.The solid elements have been put into the electric furnace directly for melting.The chemical elements are analyzed by microanalyzer for controlling the chemical composition,in order to make it conforming to the internal standard.The melting should be diluted to prevent segregation and producing gross chemical compounds crystal when the w（Fe） ：w（Ni）≈1∶ 1,w（Fe）or w（Ni）l.25.Degassing is enhanced.The refining has been done in the melting furnace and the Ar gas refining has been used in the standing furnace.The ALTECH and ceramic plates have been used on the casting line for filtrating the melt.The Al-Ti-B has been used for refining the grain size.The suitable casting technology has been used as well.So the 2A70 aluminum alloy billet with diameter of 270mm has been produced and the quality reached to grade A flaw detection which can be meet the requirement of the production.