西南石油大学学报(自然科学版) ›› 1999, Vol. 21 ›› Issue (2): 65-67.DOI: 10.3863/j.issn.1000-2634.1999.02.18

• 钻采工艺与设备 • 上一篇    下一篇

盐水泥浆中碳钢的腐蚀疲劳断裂

傅朝阳1 郑家燊1 姚安林2 李健2

  

  1. 1.华中理工大学化学系,湖北 武汉 430074; 2.西南石油学院,四川 南充 637001
  • 收稿日期:1998-10-30 修回日期:1900-01-01 出版日期:1999-04-20 发布日期:1999-04-20

CORROSION FATIGUE OF CARBON STEEL IN SALTS DRILLING FLUIDS

Fu Chao-yang1 Zheng Jia-shen1 Yao An-lin2 Li Jian2   

  1. Department of Chemistry,Huazhong University of Science and Technology
  • Received:1998-10-30 Revised:1900-01-01 Online:1999-04-20 Published:1999-04-20

摘要: 钻井液中钻具因受到各种作用应力,加上井下高温高压的腐蚀环境,使其易发生腐蚀疲劳断裂。为探讨钻具的断裂过程以期能找到有效的防护措施,实验室内建立了模拟试验装置。针对盐水泥浆中45钢的腐蚀疲劳断裂行为,通过自制的旋转弯曲腐蚀疲劳试验机,模拟钻具的运转受力情况,研究了不同泥浆介质、应力、载荷频率和温度对45钢腐蚀疲劳断裂行为的影响,并结合动态腐蚀试验和断口分析,讨论了各影响因素的作用。结果表明,盐水泥浆的pH值、Cl-含量等对45钢的疲劳寿命有直接影响,腐蚀疲劳寿命与与局部腐蚀的程度大小有密切关系;随着加载频率的增大,45钢的腐蚀疲劳寿命有较大提高;在15~80℃温度范围内,45℃左右时45钢的腐蚀疲劳寿命最短。

关键词: 碳素钢, 腐蚀, 疲劳, 断裂, 钻井液, 载荷频率

Abstract:

Under load stresses and corrosion environment with high temperature and pressure , drill pipes occur corrosion fatigue crack easily in drilling mud. A simulated testing apparatus was used to study the crackprocessof drillpipes so as to find an efficient protection method in laboratory. Corrosion fatigue behaviors of steel 45 are studied using self - made rotary type bending corrosion fatigue testing apparatus in salt drilling fluids, as well the effect of some mechanics factors and medium factors, such as cyclic stress, load frequency, temperature , on the corrosion fatigue crack of steel 45 . Results showed that corrosion fatigue crack of steel45 was depended on the corrosion rate of steel 45,especially the extent of pitting corrosion. The corrosion fatigue life of steel 45 increased with the increase of load frequency.While temperature reached 45 C or so , the corrosion fatigue crack of steel 45 was the most quickly.

Key words: Carbon steel, Corrosion fatigue, Crack, Drilling fluid, Load frequency

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