王正
,
徐向俊
,
任晨星
中国腐蚀与防护学报
采用A002，A132和A302三种焊条以及（600，800和1050）℃×6h 三种焊后热处理方式，研究了304钢不同焊缝的环境断裂行为。试验是用悬臂梁弯曲试样在室温0.5mol/L NaCl+2.5mol/L H2SO4溶液中进行的.测定了各种焊缝的da/dt～K1 曲线,并作了浸蚀试验\腐蚀电化学试验和断口分析.结果表明:焊缝的 K ISCC 为30～38MPam 1/2 ,按A002,A302和A132顺序递增,只及母材的(62～79)%;其裂缝扩展速率da/dt达(5-7)×10-6mms-1, 为母材的2.8～3.9倍.随焊后热处理温度升高,da/dt下降,K ISCC 升高.304母材的环境断裂受应变产生活性通道机理控制;在焊缝中,铁素体呈阳极而优先溶解,其数量越多,越易呈半连续或连续的网状,意味着预存活性通道越通畅,环境断裂敏感性越高.焊缝成分和焊后热处理的影响,实际上都是通过改变铁素体的数量和形态而起作用的.
关键词:
304钢焊缝
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environmental fracture
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threshold stress intensity
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crack growth rate
裴鸿勋
,
杨京俊
,
柯伟
金属学报
本文用海洋平台结构钢A537CL1的单边裂纹样品,在空气和3.5％ NaCl水溶液中进行了腐蚀疲劳短裂纹扩展实验,比较不同裂纹长度及环境介质对疲劳短裂纹扩展行为的影响。结果表明,在门槛值附近,对于相同的应力强度因子范围,短裂纹扩展速率比长裂纹扩展快。短裂纹扩展的门槛值随裂纹长度的减小而减小。与空气介质相比较,盐水对疲劳短裂纹扩展加速的程度远大于长裂纹。
关键词:
疲劳短裂纹
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offshore platform steel
,
environment medium
,
threshold stress intensity
PEI Hongxun YANG Jingjun KE Wei Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang
,
China PEI Hongxun Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang
,
China
金属学报(英文版)
The effects of environmental media,both in atmosphere and in 3.5% NaCl aqueous solution, on the growth of short cracks in comparison with the long ones have been investigated under fatigue loading on the specimens of single-edge crack about 0.05—0.15 mm for A537CLI steel.The growth rate of short cracks is faster than those of long ones around the threshoht stress intensity.The threshold stress intensity for short crack growth decreases with de- creasing crack length.The acceleration effect of the salt water,as compared with atmosphere environment,on the growth of short cracks under fatigue is much greater than that on the growth of long cracks.
关键词:
short fatigue crack
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null
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null
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