40CrMnSi多元低合金钢的稀土净化研究

Effect of Varying Rare-Earth Content on 40CrMnSi Alloy Steel

采用金相显微镜、扫描电镜、温度记录仪等分析测试手段研究了不同稀土加入量对40CrMnSi多元低合金钢的纯净度、过冷度以及晶粒度的影响。研究结果表明,稀土夹杂物以Ca、Al高熔点氧化物为核心聚集长大。适量稀土加入后,钢中夹杂物含量减少,纯净度提高,过冷度增加,晶粒明显细化,当稀土加入量为0.85%时,过冷度达到最大值27.6K。

The effects of varying rare-earth content on cleanness, undercooling and grain size of 40CrMnSi alloy steel have been investigated by using metallographic microscope, scan electron microscope, temperature recorder, etc. The results showed that RE inclusions accumulate and grow in refractory Al-, Ca-rich oxides core regions. Right amount of rare-earth added into steel, inclusions in steel reduce obviously and degree of undercooling increases because of refining and purifying action of RE elements. When the addition of rare-earth is 0.85%, degree of undercooling of alloy remarkably increases with a peak value of 27.6 K.