材料期刊网

<正> 一、前言 在铸造上应用土高炉生产的高硫生铁有着很多困难。首先是它能够促使铸铁铸态成为硬而脆的白口组织,不能加工和应用;其次它使铸铁铸造性能恶化,铸造废品率大大增加。为了解决土铁在铸造上应用的问题,通常采取二种办法: (一)利用高硫:当铸铁的S/Mn>1时,将铸态所得的白口胚件,经过短时间的退火,使自由渗碳体分解石墨化,而得到球状石墨的所谓球墨可锻铸铁; (二)去硫:使铸铁中含硫量降到0.10％左右,以符合一般铸铁含硫量的标准。 第一种方法应视为一种不得已的措施,因为它并没有能够彻底的解决问题。首先它并没有能解决高硫铸铁的铸造性能不良的问题;其次采用退火的办法增加了燃料、工时及

In the present communication, a method for desulfurizing cast iron by electrolyzing slag wasdescribed. Experimental results obtained with this method warranted the following conclusions: (1) Among the various methods used for desulfurization of cast iron, the method describedin the present communication is the most effective and cheap one, especially for cast iron withsulfur content higher than one percent. (2) The percentage of sulfur reduction increases with the basicity (CaO/SiO_2) of the slag.For example, for slag with basicity of 0.5, the percentage of sulfur reduction is 72; while for slagwith basicity of 1.4, the percentage of sulfur reduction is 97.5. (3) The initial sulfur and carbon content of cast iron has an obvious effect on the processof desulfurization. As the sulfur and carbon content increases, the process of desulfurization pro-ceeds more completely. (4) There is a critical current density of the cathode (molten cast iron). At the criticalpoint, the percentage of sulfur reduction is the highest. As the current density exceeds the criticalvalue, the percentage of desulfurization decreases. (5) The percentage of desulfurization increases with the voltage of electrolysis. (6) If it is possible to prolong the process of electrolysis, the percentage of sulfur reductionincreases with the time of electrolysis. The mechanism of desulfurization by electrolyzing slag was also briefly discussed.