熔速对电渣重熔GH4169合金凝固组织的影响

EFFECT OF MELTING RATE ON SOLIDIFICATION STRUCTURE OF GH4169 IN ELECTROSLAG REMELTING PROCESS

为研究熔速对GH4169合金在电渣重熔过程中凝固组织的影响,以Φ300 mm结晶器为例,在2. 5 kg/min、3 kg/min、3. 5 kg/min、4 kg/min四种熔速下进行试验,检测分析了铸锭的结晶形貌、二次枝晶间距、Laves相分布等。研究发现:随着电渣重熔速率的增加,中心部位和R/2处二次枝晶间距先减小后增大,而其边部是逐渐增大的;Laves相析出随着熔速的增加而增加;熔速≤3. 5 kg/min时,铸锭会得到较为理想的凝固组织。

In order to study the effect of melting rate on solidification structure of GH4169 alloy in electroslag remelting process,in this paper,taking the 300mm mold for example,experiments were carried out at four melting rates of 2.5kg/min,3kg/min,3.5kg/min and4kg/min,and the crystal morphology,dendrite arm spacing and distribution of Laves phase of ingot casting were examined and analyzed.It is found that with the increasing of the melting rate,the secondary dendrite arm spacing at the center and R/2 decreased first and then increased thereafter,and that increased gradually at the edge;the concentration of Laves phase precipitates were more populated with the increasing of melting rate;the ingot would get more ideal solidification structure when the melting rate was not higher than 3.5kg/min.