低碳马氏体不锈钢凝固冷却过程中的夹杂物特征  

Characteristics of inclusion in low carbon martensitic stainless steel during solidification and cooling process

作　　者：黄日清 任英[3] 张立峰 HUANG Riqing;REN Ying;ZHANG Lifeng(Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China;Technology Center,Guangxi Beigang New Material Co.,Ltd.,Beihai 536000,Guangxi,China;School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;School of Mechanical and Materials Engineering,North China University of Technology,Beijing 100144,China)

机构地区：[1]武汉科技大学钢铁冶金及资源利用省部共建教育部重点实验室,湖北武汉430081 [2]广西北港新材料有限公司技术中心,广西北海536000 [3]北京科技大学冶金与生态工程学院,北京100083 [4]北方工业大学机械与材料工程学院,北京100144

出　　处：《钢铁》2024年第1期117-123,共7页Iron and Steel

基　　金：国家自然科学基金资助项目(U22A20171)。

摘　　要：低碳马氏体不锈钢有着优良的综合性能,广泛应用于经济和社会发展的各个行业。钢中非金属杂物直接影响低碳马氏体不锈钢的性能,已有研究主要为钢液中夹杂物的生成、去除、改性等控制方法,对于钢液凝固和冷却过程中低碳马氏体不锈钢中夹杂物的相关研究很少。因此,有必要研究低碳马氏体不锈钢凝固冷却过程中的夹杂物特征,为最终低碳马氏体不锈钢产品中夹杂物的控制奠定基础。以S400低碳马氏体不锈钢中夹杂物为研究对象,通过高温共聚焦显微镜试验,以1、10、20和50℃/s的不同冷却速率对样品进行冷却,从而研究冷却速率对低碳马氏体不锈钢中夹杂物成分转变的影响。在钢的凝固和冷却过程中,夹杂物中Al_(2)O_(3)含量明显增加,CaO含量略有增加,而MgO和SiO_(2)含量先增加后下降,凝固和冷却过程中温度变化引起的夹杂物与钢基体之间的热力学平衡移动是夹杂物成分转变的主要驱动力。冷却速率为50℃/s样品中的夹杂物主要成分为21%Al_(2)O_(3)-12%MgO-35%CaO-29%SiO_(2)。随着冷却速率的降低,夹杂物平均成分中SiO_(2)含量呈降低趋势,Al_(2)O_(3)含量逐渐增加。冷却速率越小,发生转变的有效反应时间就越长,最终夹杂物成分就越接近平衡态成分。当冷却速率较大时,低碳马氏体不锈钢很快从高温区域冷却至低温区域,夹杂物在有效反应时间内的保持时间更短,不利于元素在钢中的快速扩散,导致夹杂物成分发生的转变很小。Low carbon martensitic stainless steels were widely used in various industries of economy and social development due to their excellent comprehensive properties.Non-metallic inclusions in steel have an obvious influence on the performance of low carbon martensitic stainless steel.Previous studies mainly focused on the formation,removal,modification,and other control methods of inclusions in the liquid steel.The characters of inclusions in low carbon martensitic stainless steel during the solidification and cooling process of the liquid steel was rarely studied.Therefore,it is necessary to study the inclusion characteristics in the solidification and cooling process of low carbon martensitic stainless steel to lay a foundation for the control of inclusions in the final low carbon martensitic stainless steel products.Inclusions in S400low carbon martensitic stainless steel were investigated in the current study.Steel samples were cooled at different cooling rates of 1,10,20and 50℃/s by high temperature confocal microscopy.The effect of cooling rate on the composition transformation of inclusions in low carbon martensitic stainless steel.During the solidification and cooling process of steel,the Al_(2)O_(3)content in inclusions increased obviously,the CaO content of increased slightly,and MgO and SiO_(2)content increased first and then decreased.The change of thermodynamic equilibrium between inclusions and the steel matrix caused by the change of temperature was the main driving force for the composition transformation of inclusions during in the solidification and cooling process.At a cooling rate of 50℃/s,the main composition of inclusions was 21%Al_(2)O_(3)-12%MgO-35%CaO-29%SiO_(2).With the decrease of the cooling rate,the content of SiO_(2)decreased and the content of Al_(2)O_(3)increased gradually.With a higher cooling rate,the low carbon martensitic stainless steel was quickly cooled from the high temperature to the low temperature,the inclusion in the effective reaction time was shorter,which retarded th

关 键 词：低碳马氏体不锈钢 夹杂物 热力学计算 凝固冷却 高温共聚焦显微镜 

分 类 号：TG142.71[一般工业技术—材料科学与工程]