S30408不锈钢无缝管泄露原因分析  

Analysis of Reasons for Leakage of S30408 Seamless Stainless Steel Tube

作　　者：陶亚平 TAO Yaping(Jiangsu Xinchang Special Steel Pipe Co.,Ltd.,Taixing 225400,China)

机构地区：[1]江苏鑫常特材有限公司,江苏泰兴225400

出　　处：《钢管》2024年第5期51-54,共4页Steel Pipe

摘　　要：针对S30408不锈钢无缝管表面点腐蚀坑缺陷,对其表面形貌、化学成分、腐蚀坑附近金相组织及腐蚀产物、晶间腐蚀性能等进行检验,并对点腐蚀坑产生的机理及原因进行分析。结果表明:发生点腐蚀坑主要是因为在设备运行过程中折流板与钢管接触摩擦导致表面钝化膜受损,暴露出基层金属,而在水中较高浓度Cl-的诱导下与金属阳离子结合发生腐蚀小点并成为点蚀核,继而发展成为蚀孔,孔内介质相对孔外介质呈滞流状态,从而使Cl-浓度不断增加,随着时间的推移,蚀孔不断向深处发展形成腐蚀坑。Addressing the surface pitting corrosion of the S30408 seamless stainless steel tube,relevant inspections are conducted to the said tube in terms of surface morphology,chemical composition,metallographic structure near the corrosion pit and the corrosion products as well as intergranular corrosion performance,etc.And the occurrence mechanism of and reasons for the pitting corrosion are also analyzed.As a result,it is revealed that occurrence of pitting corrosion is mainly due to the contact friction between the baffle and the steel pipe during operation,which causes damage to the surface passivation film of the pipe and gets its base metal exposed,and then with the induction of the relatively high concentrations of Cl-in water,the base metal combines with the metal cations to form small corrosion points which then develop into pitting corrosion core,and continuously develop into corrosion holes.The medium inside the hole is in a stagnant state relative to the medium outside the hole,resulting in a continuous increase of the Cl-concentration.With the passage of time,the pits continue to develop deeper and deeper,and inevitably become corrosion pits.

关 键 词：无缝管 S30408不锈钢 点腐蚀 泄露 

分 类 号：TG142.71[一般工业技术—材料科学与工程] TQ050.9[金属学及工艺—金属材料]