碲处理控制Y15易切削钢中MnS夹杂物形貌  

Morphology of MnS inclusions in Y15 high sulfur free-cutting steel by tellurium treatment

作　　者：张硕[1] 杨树峰[1] 李京社[1] 王林珠[1] 

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083

出　　处：《钢铁》2017年第9期27-33,41,共8页Iron and Steel

基　　金：国家自然科学基金资助项目(51674023)

摘　　要：为了研究碲对钢中MnS夹杂物形貌的影响,针对Y15高硫易切削钢,利用SEM-EDS扫面电镜,结合FactSage热力学计算,分析了不同碲质量分数对钢中MnS夹杂物形貌、尺寸、长宽比的影响,同时探讨了稀散金属碲对MnS夹杂物形貌控制的机理。研究结果表明,钢液中加碲后,在MnS夹杂物的外环形成了碲、锰、铁的复合相。钢中加碲后MnS夹杂物的形貌和分布大幅度改变,当碲硫比为0.05时,链状MnS夹杂物大幅度减少,球状MnS夹杂物数量增加;当碲硫比增加到0.2时,链状MnS夹杂物基本消失;当碲硫比增加到0.5时,MnS夹杂物形貌的变化不再明显。钢中加碲显著降低了MnS夹杂物的长宽比,控制MnS夹杂物长宽比最合适的碲硫比为0.2。FactSage计算结果表明,MnTe的生成温度为1900℃,在MnS的析出温度下,MnTe是作为液态夹杂物存在的。在凝固过程中,MnTe和MnS发生固溶现象,由于MnTe为液态,两者形成的固溶体会趋于球形生长。For the purpose of investigating tellurium on the morphology of MnS in steel,aiming at Y15 high sulfur freecutting steel,using scanning electron microscopy,combined with Fact Sage thermodynamic calculation,the effect of tellurium on morphology,size and aspect of MnS inclusions in steel was studied and the controlling mechanism of scattered metals tellurium in the morphology of MnS inclusions was discussed.The results show that,after tellurium added into liquid steel,the compound which is identified as complex phase containing Fe,Mn and Te by elementmapping forms. The morphology and distribution of MnS changes significantly by adding Te into liquid steel.MnS inclusions of chain shapearegreatly reduced and quantities of globular MnS inclusions increase when the ratio of Te content to S content reaches 0.05. MnS inclusions of chain shape almost entirely disappear when the ratio of Te content to S content reaches 0.2,andthe change of MnS inclusions morphologyis no longer obvious when w（Te）/w（S） reaches 0.5. The aspect of MnS inclusions reduces significantly by adding Te into liquid steel and the best ratio to control MnS inclusions is 0.2.Fact Sage calculation shows that the formation temperature of MnTe is 1 900 ℃.Solid solution occurs between MnS and MnTe during solidification. Solid solution growsspherical because of liquid MnTe.

关 键 词：碲处理 MnS夹杂物 Y15易切削钢 MnTe 

分 类 号：TG142.1[一般工业技术—材料科学与工程]