高碳工具钢75Cr全流程夹杂物的演变规律  

INCLUSION EVOLUTION OF HIGH CARBON TOOL STEEL 75Cr IN THE WHOLE PROCESS

作　　者：吴飞鹏 杨晓江 贾宁 张红奎 刘志卫 张岩 Wu Feipeng;Yang Xiaojiang;Jia Ning;Zhang Hongkui;Liu Zhiwei;Zhang Yan(Technology Center of HBIS Group Tangsteel Company,Tangshan 063210,Hebei;Chief Engineer Office of HBIS Group Tangsteel Company,Tangshan 063210,Hebei)

机构地区：[1]河钢集团唐钢公司技术中心,河北唐山063210 [2]河钢集团唐钢公司总工办,河北唐山063210

出　　处：《河北冶金》2024年第7期41-46,共6页Hebei Metallurgy

摘　　要：通过全流程取样,研究了75Cr工具钢全流程夹杂物的演变规律以及钢水的全氧和氮含量;利用自动扫描电镜对非金属夹杂物的组分、尺寸、数密度等变化特征进行了分析;制作了2类典型非金属夹杂物Al_(2)O_(3)-MgO-CaO和SiO_(2)-Al_(2)O_(3)-MgO-CaO的三元相图,并分析了夹杂物的熔点。结果表明,钢中非金属夹杂物的数密度在全流程中整体呈降低趋势,从LF进站到热轧品夹杂物去除效果显著,成品中夹杂物数量密度为5.1个/mm^(2)。非金属夹杂物尺寸均值变化不大,范围为4.5~6.5μm;全流程分析共发现4种类型的夹杂物,其中两种主要夹杂物为Al_(2)O_(3)-MgO-CaO型、SiO_(2)-Al_(2)O_(3)-MgO-CaO型。与上述夹杂物复合的MnS只在铸坯和热轧卷中被检测出,并与之形成两种新的夹杂物。同时计算了Al_(2)O_(3)-MgO-CaO型夹杂物的熔点,熔点大于1600℃,属于高熔点夹杂物;SiO_(2)-Al_(2)O_(3)-MgO-CaO型夹杂物基本位于低熔点区域,熔点小于1400℃。In order to study the evolution law of inclusions in 75Cr Tool steel in the whole process,the total oxygen and nitrogen contents of molten steel were analyzed by sampling in the whole process.In addition,ternary phase diagrams were prepared for two typical non-metallic inclusions,Al_(2)O_(3)-MgO-CaO and SiO_(2)-Al_(2)O_(3)-MgO-CaO,and the melting point of the inclusions was analyzed.The results show that the number density of non-metallic inclusions in steel decreases in the whole process,and the inclusion removal effect is significant from LF station to hot rolled product,and the number density of inclusions in finished product is 5.1/mm^(2).The mean size of nonmetallic inclusions has little variation,ranging from 4.5 to 6.5μm.Four types of inclusions were found in the whole process analysis,among which two main inclusions were Al_(2)O_(3)-MgO-CaO type and SiO_(2)-Al_(2)O_(3)-MgO-CaO type.MnS compounded with the above inclusions were detected only in the billet and hot-rolled coil,with which two new inclusions were formed.At the same time,the melting point of Al_(2)O_(3)-MgO-CaO type inclusions is calculated,and the melting point is greater than 1600℃,which belongs to high melting point inclusions.The inclusion of SiO_(2)-Al_(2)O_(3)-MgO-CaO is basically located in the low melting point area,and the melting point is less than 1400℃.

关 键 词：高碳工具钢 75Cr 夹杂物 铝镁尖晶石 MNS 数密度 熔点 

分 类 号：TG142.4[一般工业技术—材料科学与工程]