摘要
试验研究高应力比 (R =0 .9)载荷下X70管线钢的裂纹扩展行为。结果表明 ,在加载频率f =10Hz ,应力比R =0 .9时 ,环境介质对X70管线钢裂纹扩展门槛值没有明显影响 ,其值在 2 .3 7MPa·m1/2 ～ 2 .5 1MPa·m1/2 范围内变动 ,对应最大应力强度因子为 2 3 .7MPa·m1/2 ～ 2 5 .1MPa·m1/2 。在模拟碱性和近中性土壤介质中 ,X70管线钢裂纹扩展门槛值保持不变 ,为 2 .45MPa·m1/2 ～ 2 .48MPa·m1/2 ;环境对裂纹扩展的加速作用表现为在近中性介质中的裂纹扩展系数高于碱性土壤介质裂纹扩展系数。在近中性土壤介质中 ,随着加载频率的降低 ,裂纹扩展门槛值略有下降 。
The crack propagation behavior of X70 pipeline steel under high stress ratio (R=0.9) fluctuation loading is investigated. Results indicate that the corrosion medium has not evidential effect on the threshold value of X70 pipeline steel under loading frequency f=10?Hz and stress ratio R=0.9, and the threshold value is in the range from 2.37?MPa·m 1/2 to 2.51?MPa·m 1/2, corresponding to the maximal stress intensity factor 23.7?MPa·m 1/2～25.1?MPa·m 1/2. The crack propagation threshold valve remains unchanged in the range 2.45?MPa·m 1/2～2.48?MPa·m 1/2 in the synthetic alkaline and near-neutral soil solutions. And the crack propagation rate accelerated effect shows the crack propagation factor value in the near-neutral soil solution higher than in the alkaline solution. The threshold value slightly decreases when the loading frequency decreases in the near-neutral soil medium, however, it presents distinct threshold characteristic.
出处
《机械强度》
CAS
CSCD
北大核心
2004年第3期313-316,共4页
Journal of Mechanical Strength
基金
中国石油天然气集团公司石油管力学和环境行为重点实验室基金 (ZYT 0 0 8)资助~~
关键词
X70管线钢
模拟土壤介质
裂纹扩展
门槛值
X70 pipeline steel
Synthetic soil solution
Crack propagation
Threshold value
