Al、Ti含量对锻态Incoloy825合金组织和耐腐蚀性能的影响  

Effect of Al,Ti Contents on the Microstructure and Corrosion Resistance of As-forged Incoloy825 Alloy

作　　者：孙楠[1] 温宸 刘子利[1] 刘希琴[1] Sun Nan1, Wen Chen1,2, Liu Zili1, Liu Xiqin1(1. Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China） （2. Changshu Liony Metals Co. Ltd, Changshu 215517, China)

机构地区：[1]南京航空航天大学,江苏南京211106 [2]常熟市良益金属材料有限公司,江苏常熟215517

出　　处：《稀有金属材料与工程》2018年第3期860-866,共7页Rare Metal Materials and Engineering

基　　金：江苏省六大高峰人才项目(2014-XCL-005);江苏高校优势学科建设工程资助项目

摘　　要：在热力学模拟Incoloy825合金成分范围内研究不同Al、Ti含量对合金析出相析出规律的基础上,采用光学显微镜(OM)、扫描电镜(SEM)观察了合金显微组织和腐蚀试样的表面形貌,采用电化学工作站和静态失重法测试了合金在1、3 mol/L HCl溶液中的动电位极化曲线、电化学阻抗谱和腐蚀速率。结果表明,终锻温度下Incoloy825合金由基体γ相和少量Ti(C,N)析出相组成。随着Al、Ti含量提高,块状Ti(C,N)析出量增加,组织细化;锻态Incoloy825合金的腐蚀电流密度增大,耐蚀性下降,发生点蚀的倾向增大。合金的腐蚀优先从组织中块状Ti(C,N)部位出现点蚀。随着Al、Ti含量提高,合金表面的腐蚀产物逐渐由致密变得疏松多孔,对基体的保护作用下降。Effect of varying Al and Ti contents of Incoloy825 alloy on the phase transformations was simulated by a thermodynamic modelling tool.The microstructure and corrosion morphology of Incoloy825 alloy were investigated by the optical microscope（OM）,and scanning electron microscope（SEM）.The Potentiodynamic polarization curves,electrochemical impedance spectroscopy and corrosion rate of the tested alloy were investigated by electrochemical workstation and static weight-loss method in 1,3 mol/L HCl solutions.The results indicate that the microstructure of as-forged Incoloy825 is composed of γ substrate and a small quantity of Ti（C,N）at the final forging temperature.With the increase of Al,Ti contents,precipitation volume of blocky Ti（C,N）increases gradually,and the grain is refined;corrosion current density increases gradually,corrosion resistance decreases significantly,and pitting of the tested alloy is easier to occur.Large,faceted Ti（C,N）particles in Incoloy825 alloy provide preferred sites for pit initiation in the chloride environments.With the increase of Al,Ti contents,corrosion products on the surface of the alloy become more porous,and the protection ability to matrix decreases.

关 键 词：锻态Incoloy825合金 Al、Ti含量 组织 耐腐蚀性能 

分 类 号：TG146.15[一般工业技术—材料科学与工程]