用容量为10公斤的真空感应炉研究了在电熔氧化鎂坩堝中熔炼純鉄时熔池中碳和氧的反应,以及坩堝在这个反应中所起的作用。証实在熔炼过程中坩堝不断向熔池供氧,因此熔池的含氧量在降低到最低值后重新回升。 在10~(-4)(及10~(-1))毫米汞柱的炉压下,发現熔池中的[％C]·[％O]乘积都达到6×10~(-6)至3.5×10~(-5)之間的数值。当配料含碳0.03—0.05％而含氧为其一半时,可以得到含碳0.006％以下、含氧0.003％以下的高純度铁。 坩堝对熔池的影响随着使用次数的增长而減弱。 熔池的氧浓度对最終含氮量有显著影响。含氧量越高,脫氮就越慢。
Reaction between carbon and oxygen in melts of iron was studied, using crucibles made of electrically prefused magnesia, in a medium-frequency induction furnace of 10kg. capacity. It was found that the melts continually absorbed oxygen from the crucible, so that during the heat its oxygen content dropped to a minimum and then rose again. Under a furnace pressure of 10-4 (and in a few cases 10~(-1) mm Hg, the [％C].[0％] product fell between 6×10~(-6) and 3.5×10~(-5). By limiting the carbon content of the charged iron to 0.03—0.05％, with a C:O ratio of 2, a high-purity product containing less than 0.003％ oxygen and less than 0.006％ carbon was satisfactorily obtained. The melt-crucible reaction became less pronounced with each heat after a new crucible had been put into use. The oxygen content of the melt had a marked effect on its final nitrogen content. A high oxygen concentration retarded de-nitrogenation.