碲处理对20CrMnTi齿轮钢中MnS夹杂物改性效果

 为了研究碲处理对钢中MnS夹杂物形貌的影响,利用SEM-EDS扫描电镜,研究了20CrMnTi钢中添加高纯碲粉后MnS夹杂物的改性效果。试验结果表明,碲处理使钢中夹杂物的平均长宽比由3.17降至1.83,球化效果较为明显;当碲硫比控制在0.33时,不同硫含量的钢中夹杂物形貌有明显差异,硫质量分数为0.21%的钢中,形成了MnS镶嵌在碲化物中的大型夹杂,而在硫质量分数为0.11%的钢中,形成了碲化物包裹MnS的复合夹杂;当碲硫比为3.21时,发现钢中出现了单独存在的高碲相,MnS外层的碲化物层也较厚,改性率仅为8.75%,这表明高碲硫比并不能提高硫化物改性的数量。

Effect of tellurium treatment on modification of MnS inclusion in 20CrMnTi gear steel

In order to study the influence of tellurium treatment on the morphology of MnS inclusions in steel, the modification effect of high purity tellurium powder added to 20CrMnTi steel was studied by SEM-EDS scanning electron microscope. The results show that the average aspect ratio of inclusions in the steel decreases from 3.17 to 1.83, and the spheroidization effect is obvious. When the tellurium-sulfur ratio was controlled at 0.33, the inclusions in steels with different mass percent of sulfur had obvious differences in morphology. In steels with the mass percent of sulfur of 0.21%, large inclusions embedded in tellurides were formed in MnS, while in steels with the mass percent sulfur of 0.11%, complex inclusions encrusted with tellurides were formed. When the tellurium-sulfur ratio was 3.21, it was found that there was a single high tellurium phase in the steel, the tellurium layer on the outer layer of MnS was also thicker, and the modification rate was only 8.75%, which indicated that the high tellurium-sulfur ratio could not increase the amount of sulfide modification.