钙镁复合处理顺序对AH36船板钢中夹杂物改性效果的对比研究

Comparative Study on Modification Effect of Inclusions in AH36 Steel Plate for Ship-building Based on Ca-Mg Complex Treatment Sequences

利用真空感应炉,以过程取样的方式研究了钙镁复合处理顺序对AH36船板钢中夹杂物的改性效果。结果表明,在本实验条件下,两种处理方式(即先镁后钙、先钙后镁)虽然导致了夹杂物性质的不同演变路径,但最终都形成了以镁铝尖晶石为核心、外部为铝酸钙的分层结构。并且两种处理方式下,当硅钙合金加入后,夹杂物中均出现了中间产物CaS,但随后数量迅速下降。相对于先钙后镁加入方式,先镁后钙加入方式最终形成的夹杂物数密度和尺寸均更大,其边缘形成的铝酸钙更趋向于液相区。与原始样相比,两种处理方式均有效增加了氧化物数密度,降低了其长宽比,从而改善了氧化物形态。

The modification effect of the inclusions in the AH36 steel plate for ship-building based on the Ca-Mg complex treatment sequences(adding Mg before Ca,and adding Ca before Mg)was studied by using a vacuum induction furnace,together with the method of intermediate sampling.The study results showed that under the experimental conditions mentioned in this paper,the different two addition methods led to the different evolution paths of inclusion properties,but finally all of them formed the layering structure with the core of magnesium aluminate spinel and calcium aluminate at the exterior.And what's more,it should be pointed that for each addition method,CaS formed after adding Si-Ca alloy and then intermediately reduced.Both the number density and size of oxides through the method of adding Mg before Ca were larger than these values through the method of adding Ca before Mg and the calcium aluminate formed at the edge of inclusions tended to the liquid phase.Compared to original samples,both addition methods increased the number density of oxides,and decreased the length-width ratio,which helped to modify the form of oxides.