【摘要】 高铬铸铁的韧性强烈依赖于枝晶间共晶硅化物的数量与分布。通过定向凝固试样,考察了稀土合金对亚共晶及共晶成分高铬铸铁组织的影响,测定了奥氏体(r)一次臂的横截面积(D_r)、共晶曲域直径(E_w)及碳化物间距(Fs~C—共晶区域中心碳化物间距;Fs~B—共晶区域边界碳化物间距),以及力学性能。结果表明,稀土合金对高铬铸铁的共晶组织有明显的细化作用,对其韧性也有一定的贡献。本文还对稀土的作用机理进行了讨论。更多还原

【Abstract】 The toughness of high chromium cast iron depends stronglyupon the amount and the distribution of carbides within interdendritic regions.Through unidirectionally solidifying samples, the effect of RE alloy was invest-igated on the eutectic structure of high chromium cast iron with hypoeutecticand eutectic composition. Such variables were measured as the section area ofaustenite dendrite arm (D_r), the diameter of eutectic region (E_w), the spacingof carbides (F_s~C in the centre and F_s~B in the boundary of eutectic region). Itis shown that the RE alloy contributes to the refining of eutectic structure andto the increase of toughness.更多还原