流动3.5%NaCl溶液中显微组织及Cr元素含量对低合金钢腐蚀初期耐蚀性的影响  

Influence of Microstructure and Cr Content on Corrosion Resistance of Low Alloy Steel Exposed to Flow 3.5% NaCl Solution in Initial Corrosion Stage

作　　者：李灏[1] 姜杉[1] 柴锋[1] 杨才福[1] LI Hao;JIANG Shah;CHAI Feng;YANG Caifu(Department of Structural steel,Central Iron and Steel Research Institute,Beijing,100081)

机构地区：[1]钢铁研究总院工程用钢研究所

出　　处：《热加工工艺》2018年第20期80-86,共7页Hot Working Technology

摘　　要：利用光学显微镜、扫描电镜以及动电位极化曲线等方法,研究了流动3.5%NaCl溶液中,珠光体含量及铁素体晶粒尺寸不同对含Cr低合金钢在腐蚀初期耐蚀性的影响。并分析了Cr元素对该低合金钢在流动加速腐蚀初期耐蚀性的影响。结果表明,钢中C元素含量的提高使显微组织中珠光体的相对含量上升,试验钢的腐蚀失重随钢中珠光体含量的上升而提高。铁素体晶粒尺寸不同的试验钢腐蚀失重基本相同。腐蚀过程中珠光体内的渗碳体并未发生腐蚀,所以渗碳体作为电化学反应的阴极材料,其含量的变化是影响低合金钢流动加速腐蚀初期腐蚀速率的重要因素。Cr元素含量的提高,使试验钢显微组织中珠光体的含量相应提高,加速了腐蚀。The influences of relative amount of pearlite and average grain size of ferrite on the corrosion resistance of Cr containing low alloy steels in the initial corrosion stage were investigated in flowing 3.5% NaCl solution by optical microscope, scanning electron microscope and potentiodynamic polarization curve. The effects of Cr element on the flow accelerated corrosion resistance of low alloy steels were analyzed in the initial corrosion stage. The results show that the increase of C content in the steel can lead to the increase of relative amount of pearlite in the microstructure. The corrosion mass loss of the experimental steels increases with the increase of pearlite content. There is no significant difference in the mass loss of the experimental steels with various average grain size of ferrite. The corrosion of cementite in the pearlite cannot occur in the corrosion process. Therefore, the amount of cementite which is used as the cathodic material in the electrochemical reaction, is the main impact factor on the corrosion rate of the low alloy steel in the initial stage of flow-accelerated corrosion. The increase of Cr content in the steel results in the increase of the content of pearlite in the microstructure, thereby, accelerating the corrosion.

关 键 词：显微组织 CR元素 流动加速腐蚀 低合金钢 

分 类 号：TG113.231[金属学及工艺—物理冶金]