不锈钢板翅结构蠕变的有限元分析

基于有限元软件ABAQUS,利用Norton蠕变本构关系及镍基钎料BNi-2和不锈钢母材SS304在600℃的蠕变参数,对不锈钢板翅结构进行蠕变有限元分析,预测其在高温环境下服役105h的应力、应变分布规律和危险位置.利用有限元分析获得了板翅结构在钎焊过程中产生的残余应力的分布规律,讨论了残余应力对蠕变变形的影响.结果表明,由于钎料和母材力学性能参数的不匹配以及钎焊夹具的约束作用,产生了较大的残余应力,对板翅结构的蠕变变形产生较大影响,故在板翅结构的高温强度设计中,残余应力不可忽略.钎角处蠕变应力和应变集中,易萌生裂纹,成为最薄弱的环节.

Finite Element Analysis of Creep for Micro Stainless Steel Plate-fin Heat Exchanger

According to Norton Creep Constitutive Equation and creep parameters of as-cast Ni-based BNi-2 filler and 0Cr18Ni9 stainless steel, 100 thousand hours creep analysis for Micro Plate-fin Heat Exchanger made of stainless steel was carried out by ABAQUS finite element code. The creep strain and stress distribution of overall Micro Plate-fin Structure was obtained. The creep deformation and the most dangerous position at high temperature were predicted. Due to the mismatch of mechanical property between brazing filler metal and base metal, the welding residual stress was generated inevitably during the brazing process, which has great influence on the creep deformation and life. Especially in the fillet, the creep strain and stress distribution is inhomogeneous and concentrated. In the interface, the stress and strain show discontinuous and uncoordinated, which have great effect on creep failure.