316L+Q345R双金属复合板压力容器的点蚀  

Pitting of 316L+Q345R Bimetallic Composite Plate Pressure Vessel

作　　者：陈庆国 谭川江[1] 童根 宋成立 王瑶[1] CHEN Qingguo;TAN Chuanjiang;TONG Gen;SONG Chengli;WANG Yao(PetroChina Tarim Oilfield Company,Koral 841000,China;State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment Materials,CNPC Tubular Goods Research Institute,Xi'an 710077,China)

机构地区：[1]中国石油塔里木油田分公司,库尔勒841000 [2]中国石油集团工程材料研究院有限公司石油管材及装备材料服役行为与结构安全国家重点实验室,西安710077

出　　处：《腐蚀与防护》2025年第3期43-47,共5页Corrosion & Protection

摘　　要：通过在316L不锈钢+Q345R碳钢双金属复合板上预制不同深度的点蚀坑,探讨在典型CO_(2)腐蚀条件下点蚀坑的发展。结果表明:预制的点蚀坑处于不锈钢层时,腐蚀较轻微,未萌生新的点蚀;当点蚀坑底部触及碳钢层时,碳钢优先发生腐蚀,形成孔洞,点蚀速率达到3.911 mm/a,点蚀坑底部附着了一层不均匀且较薄的腐蚀产物,其成分主要为FeCO_(3);当点蚀坑完全穿透至碳钢层时,碳钢层优先发生腐蚀并向周围不断扩大,形成凹凸不平的金属损失形貌,点蚀速率达到4.954 mm/a,点蚀坑底部附着了一层较厚且相对紧密的腐蚀产物,其成分主要是FeCO_(3)。由此表明,该双金属复合板表面一旦形成穿透至不锈钢层的点蚀,将会引发显著的电偶腐蚀,碳钢层优先腐蚀并向周围快速扩展,从而危及复合板的承压性能。By prefabricating pitting pits of different depths on 316L stainless steel+Q345R carbon steel bimetallic composite plates,the development of pitting pits under typical CO_(2) corrosion conditions was discussed.The results show that when the prefabricated pit was in the stainless steel layer,the corrosion was slight and no new pit was generated.When the bottom of the pit just touched the carbon steel layer,the carbon steel preferentially corroded,forming a hole,and the pitting rate reached 3.911 mm/a,and a layer of uneven and thin corrosion products was attached to the bottom of the pit,and its composition was mainly FeCO_(3).When the pit was completely penetrated to carbon steel layer,carbon steel layer preferentially corroded and then expanded to the periphery,forming an uneven metal loss morphology,with a pitting rate of 4.954 mm/a,and a thick and relatively tight corrosion product was also attached to the bottom of the pit,which was mainly composed of FeCO_(3).It is shown that once the surface of the bimetallic composite plate was pitted and penetrated into the stainless steel layer,it will cause significant galvanic corrosion,and the carbon steel layer will preferentially corroded and propagate to the surrounding areas,which will directly endanger the pressure-bearing performance of the composite panel.

关 键 词：316L不锈钢 双金属复合板 点蚀 电偶腐蚀 

分 类 号：TG174.4[金属学及工艺—金属表面处理]