Effect of Ti-V-Nb-Mo addition on microstructure of high chromium cast iron

作     者：Ma Youping Li Xiulan Liu Yugao Zhou Shuyi Dang Xiaoming 

作者机构：School of Metallurgic EngineeringXi'an University of Architecture&TechnologyXi'an 710055China School of Mechanical and Electrical EngineeringQingdao Agricultural UniversityQingdao 266109China 

出 版 物：《China Foundry》 (中国铸造（英文版）)

年 卷 期：2012年第9卷第2期

页      面：148-153页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by the Education Department of Shaanxi Province(No.2010JK49) 

主　　题：high chromium cast iron microstructure alloying thermodynamics kinetics 

摘      要：The effects of trace additions of multi-alloying elements （Ti, Nb, V, Mo） on carbides precipitation and ascast microstructure of eutectic high chromium cast iron containing 2.85wt.%C and 31.0wt.%Cr were investigated from thermodynamic and kinetic considerations. The thermodynamic calculations show that Ti and Nb exist in the multi-alloying system in the forms of TiC and NbC. The formation of VC during the solidification is not feasible from the thermodynamic consideration. XRD analysis shows that the V exists in alloy compounds （VCr2C2, VCrFes）. The first precipitated high melting point particles （TIC, NbC） can act as the heterogeneous substrate of M7C3 carbides, which results in significant refinement of the M7C3 carbides. After the addition of alloying elements, C atom diffusion is hindered due to the strong affinities of the strong carbide forming elements for carbon, which decreases the growth rate of carbides. The combined roles of the increase of nucleation rate and the decrease of carbides growth rate lead to the finer microstructure.