应力-溶解氧耦合对Ni-Cr-Mo-V高强钢腐蚀行为的影响  

Combined Effect of Stress and Dissolved Oxygen on Corrosion Behavior of Ni-Cr-Mo-V High Strength Steel

作　　者：孙佳钰 彭文山 邢少华 SUN Jiayu;PENG Wenshan;XING Shaohua(Institute for Research of Urumqi Petrochemical Company,Urumqi 830019,China;National Key Laboratory of Marine Corrosion and Protection,Luoyang Ship Material Research Institute,Qingdao 266237,China)

机构地区：[1]中国石油乌鲁木齐石化公司研究院,乌鲁木齐830019 [2]中国船舶集团有限公司第七二五研究所、海洋腐蚀与防护全国重点实验室,青岛266237

出　　处：《中国腐蚀与防护学报》2024年第3期755-764,共10页Journal of Chinese Society For Corrosion and Protection

摘　　要：在实验室模拟环境中,通过四点弯曲装置向Ni-Cr-Mo-V高强钢施加不同应力,并结合电化学测试、腐蚀形貌和产物分析,研究了溶解氧与应力耦合对Ni-Cr-Mo-V高强钢在低温海水环境中腐蚀行为的影响及规律。结果表明:溶解氧含量的增加会加快Ni-Cr-Mo-V高强钢的腐蚀产物生成,施加外加应力会使应力集中部分的腐蚀情况进一步加剧;低温海水中溶解氧的增加,协同试样上所施加的应力,致使腐蚀产物层中的Cr、Ni减少,从而降低腐蚀产物层对基体的保护作用;当溶解氧含量和外加应力均增加时,会进一步使Ni-Cr-Mo-V高强钢发生伪钝化现象,导致其自腐蚀电流密度增大。在低温海水环境中,应力与溶解氧对Ni-Cr-Mo-V高强钢存在协同作用,促进Ni-Cr-Mo-V高强钢腐蚀反应的进行,致使该材料表面腐蚀情况加剧,腐蚀产物对基体的保护作用下降。In fact,Ni-Cr-Mo-V high strength steel is widely used as engineering structure material of ships-and equipment-building for the exploration of polar resources.However,high strength steel will suffer from corrosion in low temperature seawater environment.In case when the structure component of Ni-Cr-Mo-V high strength steel is subjected simultaneously to stress and corrosive seawater in this polar low temperature environment,its corrosion failure probability will be greatly aggravated.Therefore,it is of significance to clarify the service performance of Ni-Cr-Mo-V high strength steel in this environment.As thus,the corrosion behavior evolution of the steel in simulated low temperature seawaters with variation of dissolved oxygen contents was assessed in lab,while a four-point bending device was adopted as a means of applying stress on the testing steel.Results show that while a stress was applied on the test steel through banding in low temperature seawater,the increase of dissolved oxygen content will acceler-ate the formation of corrosion products on Ni-Cr-Mo-V high strength steel;correspondingly,Cr and Ni in the corrosion product layer decrease,which reduces the protective effect of the corrosion products layer on the substrate;when the dissolved oxygen content and the applied stress increase simultaneously,the Ni-Cr-Mo-V high strength steel will be further pseudo-passivated,resulting in an increase in its free-corrosion current density.It follows that in low temperature seawater environment,the applied stress and dissolved oxygen have a synergistic effect on the corrosion of Ni-Cr-Mo-V high strength steel,which promotes the corrosion reaction of Ni-Cr-Mo-V high strength steel,resulting in the aggravation of surface corrosion and the decrease of the protective effect of corrosion products on the steel substrate.

关 键 词：低温海水 高强钢 溶氧量 应力 腐蚀 

分 类 号：TG172.5[金属学及工艺—金属表面处理]