2205双相不锈钢中氧化物夹杂的成分和尺寸对点蚀萌生的影响  

Effect of Composition and Size of Oxide Inclusions on Pitting Initiation of 2205 Duplex Stainless Steel

作　　者：张耀华 刘静[1] 黄峰[1] 胡骞[1] 卢赛文 ZHANG Yaohua, LIU Jing, HUANG Feng, HU Qian, LU Saiwen(The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, Chin)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,武汉430081

出　　处：《腐蚀科学与防护技术》2018年第2期105-112,共8页Corrosion Science and Protection Technology

基　　金：国家科技基础条件平台建设项目(2005DKA10400-Z12)~~

摘　　要：利用恒电位脉冲方法、毛细管微电极技术结合扫描电镜等研究了夹杂物对2205双相不锈钢点蚀萌生的影响。结果表明:2205双相不锈钢中夹杂物均为氧化物,且为2205双相不锈钢点蚀萌生的主要因素;氧化物夹杂通过影响其周围钢基体的点蚀电位从而影响点蚀的萌生,且点蚀是沿夹杂物而不是金属基体扩展。不仅氧化物夹杂的化学成分,其尺寸也会影响该不锈钢点蚀的萌生,其中Al_2O_3-CaO-SiO_2和Al_2O_3-MgO-CaO-SiO_2型夹杂物易引起点蚀,且尺寸越大越易萌生点蚀,而Al_2O_3-MgO夹杂物不易引起点蚀。Effect of composition and size of inclusions on the pitting initiation of 2205 duplex stainless steel was studied by means of potentiostatic pulse technique, capillary microelectrode technique and scanning electron microscope. Results showed that the inclusions in 2205 duplex stainless steel were all oxides, and the pitting of duplex stainless steel is mainly triggered by inclusions. The oxide inclusion influences the initiation of pitting corrosion by affecting the pitting corrosion potential of the surrounding matrix, while pitting extends along the inclusions rather than the metal matrix. Not only the chemical composition but also the size of oxide inclusions will affect the pitting corrosion initiation. Pitting initiated preferentially on the inclusions of Al2O3-CaO-SiO2 and Al2O3-MgO-CaO-SiO2 but the inclusions of Al2O3-MgO, of the former the greater the size is the easier the pitting initiation is.

关 键 词：2205双相不锈钢 夹杂物 点蚀 恒电位脉冲方法 毛细管微电极技术 

分 类 号：TG174[金属学及工艺—金属表面处理]