2205双相不锈钢在水溶液中的疲劳裂纹扩展行为  

Corrosion Fatigue Crack Propagation Behavior of 2205 Duplex Stainless Steel in Aqueous Medium

作　　者：杨斌[1,2] 陈吉 耿越[1] 崔萧[1] 桂王林 YANG Bin, CHEN Ji, GENG Yue, CUI Xiao, GUI Wanglin(1 School of Mechanical Engineering, Liao Ning Shihua University, Fushun 113001, China 2 NCS Testing Technology Co., Ltd., Shanghai 201103, Chin)

机构地区：[1]辽宁石油化工大学机械工程学院,抚顺113001 [2]钢研纳克检测技术股份有限公司,上海201103

出　　处：《腐蚀科学与防护技术》2018年第2期182-186,共5页Corrosion Science and Protection Technology

摘　　要：对2205双相不锈钢(DSS)在空气、去离子水和3.5%(质量分数)NaCl溶液中进行疲劳裂纹扩展实验,结果表明,水溶液环境可显著提高2205 DSS疲劳裂纹扩展速率,降低其疲劳寿命,疲劳裂纹扩展速率顺序为:(da/dN)_(deionized water)>(da/dN)_(NaCl)>(da/dN)_(atmosphere),疲劳裂纹扩展寿命顺序为:N_(atmosphere)>N_(NaCl)>N_(deionized water)。断口观察表明,氢致开裂是双相不锈钢材料在水溶液介质中疲劳性能弱化的主要原因。与去离子水相比,Cl^-具有更强的腐蚀作用,在主裂纹前端可诱发更多的缺陷并发展成二次裂纹,使有效裂纹长度更长,裂纹扩展的驱动力更小。Experiments of fatigue crack propagation were performed of 2205 dual stainless steel（2205 DSS） in the deionized water, 3.5%（mass fraction） NaCl solution and atmosphere respectively. It found that in the aqueous solutions the crack growth rate and the fatigue life of the steel was greatly enhanced and reduced respectively. Correspondingly, the influencing degree of the three media can be described respectively as the following two rankings：（da/dN）（deionized water）（da/dN）（NaCl）（da/dN）（atmospherefor） fatigue crack propagation rate and N（atmosphere）N（NaCl）N（deionized water） for fatigue crack propagation life. The fracture morphology revealed that hydrogen induced cracking is the main reason for the deterioration of the fatigue performance of the duplex stainless steel in aqueous medium. Compared with the deionized water, Clhas a stronger corrosion effect, and more defects can be induced in the front of the main crack, therewith which develop into secondary cracks, resulting in the longer the effective crack length and the smaller the driving force of crack propagation.

关 键 词：双相不锈钢 去离子水 3.5%NaCl溶液 腐蚀疲劳 裂纹扩展 

分 类 号：TG174[金属学及工艺—金属表面处理]