高级检索

Inconel 625熔敷金属抗Cl腐蚀行为分析

Analysis of Cl corrosion resistance of Inconel 625 deposited metal

  • 摘要: 为了分析Inconel 625熔敷金属在Cl腐蚀液中的腐蚀行为,采用静态浸没腐蚀和慢应变速率拉伸的方法,研究了不同温度下熔敷金属浸没在熔盐中的腐蚀行为以及室温应力腐蚀开裂行为. 通过X-ray diffractiong(XRD),S-3400N扫描电子显微镜系统地研究了熔敷金属的腐蚀产物物相组成、腐蚀形貌和元素分布. 结果表明,在静态浸没腐蚀时,两种温度下熔敷金属腐蚀失重均呈现出递增的变化趋势,但是不同时间区间的增加幅度有所不同. 前10 h熔敷金属的腐蚀失重缓慢增加,10 ~ 60 h腐蚀失重激增,可以发现10 h是腐蚀行为的分界点. 700 ℃下熔敷金属的耐蚀性优于900 ℃,其原因在于700 ℃时熔敷金属表面出现致密MgO壳层,能够阻碍腐蚀反应进行;而900 ℃时,由于CrCl3的存在,出现“破壳效应”,破坏MgO壳层,使其耐蚀性下降. 对于慢应变速率拉伸而言,腐蚀介质中试样的抗拉强度比在空气介质中降低22.97%,应力腐蚀开裂敏感性指数为30.39%,说明腐蚀介质中的Cl会增大试样的应力腐蚀开裂敏感性.

     

    Abstract: In order to study the corrosion behavior of Inconel 625 deposited metal in Cl- corrosive solution, the corrosion behavior of deposited metal immersed in molten salt and room temperature stress corrosion cracking behavior at different temperatures were studied by means of static immersion corrosion and slow strain rate tension. X-ray diffraction (XRD) and S-3400N scanning electron microscope were used to systematically study the phase composition, corrosion morphology and element distribution of the deposited metal. The results show that: in the static immersion corrosion, the corrosion weight loss of deposited metal shows an increasing trend at both temperatures, but the increasing range is different in different time intervals. The corrosion weight loss of deposited metal increases slowly in the first 10 h, and increases sharply in the 10 ~ 60 h. It can be found that 10 h is the dividing point of corrosion behavior. The corrosion resistance of the deposited metal at 700 ℃ is better than that at 900 ℃, because the dense MgO shell appears on the surface of the deposited metal at 700 ℃, which can hinder the corrosion reaction; At 900 ℃, due to the existence of CrCl3, the "shell breaking effect" appears, which destroys the MgO shell and reduces its corrosion resistance. For slow strain rate tensile test, the tensile strength of specimens in corrosive medium is 22.97% lower than that in air medium, and the susceptibility index of stress corrosion cracking is 30.39%, which indicates that Cl- in corrosive medium will increase the susceptibility of specimens to stress corrosion cracking.

     

/

返回文章
返回