SS304和Q235异种钢搅拌摩擦焊接头腐蚀有限元模拟
Finite element simulation of corrosion of SS304 and Q235 dissimilar steel friction stir welded joints
王洪铎 1常素腾 1路永新 1刘彦明1
作者信息
摘要
针对异种金属焊接接头易于发生电偶腐蚀,基于腐蚀电化学原理,将动电位极化曲线参数和金相组织面积比例等作为边界条件,采用有限元分析软件COMSOL对Q235 低碳钢和 304 不锈钢(SS304)异种钢FSW接头不同区域腐蚀行为进行了预测,研究了焊接接头不同区域宏观和微观电偶腐蚀电位分布和电流密度的变化规律.结果表明,在宏观电偶腐蚀中,腐蚀深度的最大值位于SS304 后退侧(RS304)与搅拌区(SZ)的交界处,约为Q235 低碳钢母材(BMQ235)的 5 倍,各区电流密度随腐蚀时间的增长而增大;在微观电偶腐蚀中,腐蚀深度的最大值位于SS304 侧搅拌区(SZ304)与Q235 侧搅拌区(SZQ235)的交界处,约为BMQ235 的 1.2 倍,并且珠光体组织面积比例越大,耐蚀性越差.采用该有限元模型可以预测异种钢搅拌摩擦焊接头不同区域的腐蚀行为.
Abstract
In view of galvanic corrosion of dissimilar metal welded joints,based on principle of corrosion electrochemistry,parameters of potentiodynamic polarization curve and area ratio of metallographic structure were used as boundary conditions.Finite element analysis software COMSOL was used to predict corrosion behavior of FSWed joints of Q235 low-carbon steel and 304 stainless steel(SS304)dissimilar steel in different zones,and variation law of macroscopic and microscopic galvanic corrosion potential distribution and current density in different zones of welded joints was studied.The results showed that in macroscopic galvanic corrosion,the maximum corrosion depth was located at the junction of retreating side of SS304(RS304)and stirring zone(SZ),which was about 5 times that of base metal of Q235 low carbon steel(BMQ235).Current density of all zones increased with the increase of corrosion time.In microscopic galvanic corrosion,the maximum corrosion depth was located at the junction of stirring zones on both the SS304 side(SZ304)and the Q235 side(SZQ235),which was about 1.2 times that of BMQ235.Moreover,the larger the area proportion of pearlite was,the worse the corrosion resistance was.The finite element model could be used to predict corrosion behavior of friction stir welded joints of dissimilar steels in different zones.
关键词
304不锈钢/Q235低碳钢/搅拌摩擦焊接头/有限元模拟Key words
304 stainless steel/Q235 mild steel/friction stir welded joints/finite element simulation引用本文复制引用
出版年
2024
NETL
NSTL
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