镁钛对包晶钢凝固过程中包晶转变收缩的影响  

Effect of Mg-Ti on Peritectic Transformation and Shrinkage During Solidification of Peritectic Steel

作　　者：曹磊 杨依铭 王国承[1,2] CAO Lei;YANG Yiming;WANG Guocheng(School of Materials and Metallurgy,University of Science and Technology Liaoning,Anshan 114051,Liaoning,China;Liaoning Provinceial Key Laboratory of Metallurgy Engineering,Anshan 114051,Liaoning,China)

机构地区：[1]辽宁科技大学材料与冶金学院,辽宁鞍山114051 [2]辽宁省高校冶金工程重点实验室,辽宁鞍山114051

出　　处：《材料导报》2024年第24期218-223,共6页Materials Reports

基　　金：国家自然科学基金(52174318)。

摘　　要：采用高温共聚焦激光扫描显微镜对包晶钢和含镁钛的包晶钢凝固过程中包晶转变现象进行原位观察。结果表明,在L→δ相变过程中,含镁钛的包晶钢从L相中析出的δ相的数量和尺寸均小于不含镁钛的包晶钢。在包晶反应阶段,含镁钛的包晶钢包晶反应开始温度比不含镁钛的包晶钢降低了12.3℃,降低了γ相的生成温度,抑制了γ相的长大。包晶转变收缩会导致表面粗糙度增大,通过表面粗糙度测定发现,含镁钛的包晶钢比不含镁钛的包晶钢表面粗糙度降低了10%。凝固收缩特性指数(R V)计算发现,平衡凝固和非平衡凝固条件下含镁钛的包晶钢的凝固特性指数比不含镁钛的包晶钢分别降低2.79%和3.25%。因此,镁钛处理是一种能有效降低包晶转变收缩,从而减轻表面裂纹发生的策略。Using a high-temperature confocal laser scanning microscope,in-situ observation of the peritectic transformation phenomenon during the soli-dification process of peritectic steel and peritectic steel containing Mg-Ti was carried out.During the phase transition from L toδ,the number and size ofδphase precipitated from the L phase in peritectic steel containing Mg-Ti were smaller than those in peritectic steel without Mg-Ti.In the peritectic reaction stage,the starting temperature of the peritectic reaction of peritectic steel containing Mg-Ti was 12.3℃lower than that of peritectic steel without Mg-Ti,which reduced the formation temperature of phaseγand inhibited its growth.The shrinkage of peritectic transformation should lead to an increase in surface roughness.Through surface roughness measurement,it was found that the surface roughness of peritectic steel containing Mg-Ti was reduced by 10%compared to peritectic steel without Mg-Ti.The solidification shrinkage characteristic index(R V)calculation found that under equilibrium and non-equilibrium solidification conditions,the solidification shrinkage characteristic index of peritectic steel containing Mg-Ti decreased by 2.79%and 3.25%compared to peritectic steel without Mg-Ti,respectively.Therefore,Mg-Ti treatment is an effective strategy to reduce peritectic transformation shrinkage,and thus alleviates the occurrence of surface cracks.

关 键 词：包晶钢 包晶相变 原位观察 镁钛处理 

分 类 号：TG142.33[一般工业技术—材料科学与工程]