G95Cr18轴承钢模铸坯夹杂物及碳化物解析  

Analysis of microstructures,inclusions and carbides of G95Cr18 bearing steel billets by mold casting

作　　者：付宇豪 吴强 朱浩然 季灯平 刘斌 付建勋 Fu Yuhao;Wu Qiang;Zhu Haoran;Ji Dengping;Liu Bin;Fu Jianxun(Advanced Solidification Technology Center,School of Materials Science and Engineering,Shanghai University,State Key Laboratory of Metallurgy and Manufacture of Advanced Special Steels,Shanghai 200444,China;Zhejiang Qingshan Iron and Steel Co.,Ltd.,Lishui 323000,Zhejiang,China;Ansteel Beijing Research Institute,Beijing 102200,China)

机构地区：[1]上海大学材料科学与工程学院先进凝固技术中心,省部共建高品质特殊钢冶金与制备国家重点实验室,上海200444 [2]浙江青山钢铁有限公司,浙江丽水323000 [3]鞍钢集团北京研究院,北京102200

出　　处：《钢铁钒钛》2024年第4期189-197,共9页Iron Steel Vanadium Titanium

基　　金：国家自然科学基金资助项目(52074179)。

摘　　要：基于Thermo-calc软件分析了G95Cr18轴承钢基体组织、相变及碳化物析出情况,用金相显微镜、扫描电镜对模铸坯组织、夹杂物和碳化物进行了解析。研究表明,在G95Cr18轴承钢铸坯中,夹杂物主要成分为Ce、O、Al、Ca等,夹杂物类型主要为稀土氧硫化物Ce-Al-O-Ca-S,同时还发现少量镁铝尖晶石Al-Mg-O,夹杂物密度为31~48 mm^(-2),夹杂物尺寸集中分布在2.2~2.6μm,夹杂物面积占比为0.02%~0.03%;碳化物边部至心部面积占比由3.0%逐渐增加到7.5%,碳化物形貌有块状→棒状→长条状→网状的转变趋势,靠近铸坯心部网状碳化物大多沿晶界分布;碳化物类型为:亮白色富含Nb的MC型碳化物和灰色富含Cr元素的M_(7)C_(3)型碳化物。MC型碳化物的尺寸相较M_(7)C_(3)型碳化物小,在晶内以块状碳化物形式存在,在晶界处以网状碳化物形式存在。Based on Thermo-calc software,the matrix structure,phase transformation and carbides precipitation of G95Cr18 bearing steel were analyzed.Metallographic microscope and scanning electron microscope were used to analyze the mold casting billets structures,inclusions and carbides.The research shows that the main components of inclusions in the casting slab of G95Cr18 bearing steel are Ce,O,Al,Ca and a few other elements.The main type of inclusions is rare earth oxygen sulfide Ce-AlO-Ca-S,and a small amount of magnesia-aluminum spinel Al-Mg-O is also found.The inclusion density is 31-48 mm^(-2),and the average sizes of inclusions are concentrated in a range of 2.2μm to 2.6μm with the inclusion area proportion of 0.02%to 0.03%.The area proportion of carbides from the edge to the core increases from 3.0%to 7.5%,and the morphology of carbides shows a transforming trend of block→rod→strip→network.Most of the network carbides near the core are distributed along the grain boundaries.These types of carbides are composed of bright white Nb-enriched MC carbides and gray M_7C_(3)carbides enriched in Cr,respectively.The sizes of MC carbides are smaller than that of M_7C_(3)carbides,and they present as massive carbides in the matrix and network carbides in the grain boundary.

关 键 词：G95Cr18轴承钢 夹杂物 碳化物 THERMO-CALC软件 

分 类 号：TF76[冶金工程—钢铁冶金]