稀土镁对高铬铸铁变质效果的研究

Study on the Effect of RE-Mg Modification Treatment on the High Chromium Cast Iron

为了研究RE-Mg对Cr15Mo3高铬铸铁铸态及热处理态组织、冲击韧性、硬度、耐磨性等性能的影响规律,提出RE-Mg变质处理工艺的改进方案,通过对比实验的方法,验证了改进方案的可行性.结果表明:铸态未变质的高铬铸铁组织中,奥氏体含量大,碳化物呈粗大网状分布,基体被撕裂;变质后碳化物的网断裂,变细成为鱼骨状,对基体的割裂作用大大减小,基体的连续程度增加.RE-Mg变质处理可使Cr15Mo3高铬铸铁的硬度、冲击韧性、耐磨性都得到提高.本实验条件下,当变质剂加入量wRE-Mg=1.5%时变质效果最好,材料的综合性能最佳.

The effect of the addition RE-Mg on structure, impact toughness, hardness, and wear ability of high chromium cast iron （Cr15% , Mo3% ） was investigated with method of compare experiments. The results show that modified affect was obvious; the comprehensive performance of the material is improved greatly. High chromium cast iron without modification contain lot of austenite and big net carbide, the base body is torn. In modified high chromium cast iron by RE-Mg, big net carbide was smashed, became more isolated and round, much austenite was replaced by mart site. RE - Mg alloy can make the hardness, impact toughness, wear ability of the high chromium casting iron of Crl5Mo3 all improved to deal with going bad, the comprehensive performance of the material is the best when adding quality fraction for RE-Mg was 1.5%.