LOW CYCLE FATIGUE PROPERTY AND LIFE OF COILED TUBING UNDER LARGE DEFORMATION
Fatigue test has been performed in constant total strain amplitude conditions, low cycle fatigue(LCF) behavior and cycle strain-stress properties of coiled tubing treated by incomplete normalizing process has been investigated, and the model of cycle fatigue life is established in this paper. The results show that: the cyclic softening occurs at the tow strain amplitudes of 0.4％ ,0.6％ and 0. 8％. However, when strain amplitude increased to 1.2％ or 1.5％ ,cyclic hardening appeared. Critical strain (εc) lies between 0.8 and 1.0％ .The cyclic saturation stress elevates as strain amplitude rises. The excellent fatigue behavior is due to the interactions of softening and hardening during cycle. TEM observations reveal that the structure of matrix was composed of ferrite + minor pearlite and M-A constituents with grain size rating 12.0, remained dislocation were found in microstructure of the specimens. Results show that the low cycle fatigue properties of coiled tubing are improved benefit from the microstructure after the treatment of incomplete normalizing progress.
Coiled tubing low-cycle fat igue strain-stress property fatigue model incomplete normalizing treatment
Bi Zongyue Xian Linyun Jing Xiaotian
School of Materials Science and Engineering,Xian University of Technology Institute of steel pipes, Institute of Steel pipes,Baoji Petroleum Steel Pipe Co.Ltd,Baoji,Shannxi,China School of Materials Science and Engineering,Xian University of Technology Xian,Shannxi,China
国际会议
The 3rd World Conference on Safety of Oil and Gas Industry(第三届世界石油天然气工业安全会议 WCOGI 2010)
北京
英文
592-599
2010-09-27（万方平台首次上网日期，不代表论文的发表时间）