石油学报 ›› 2003, Vol. 24 ›› Issue (5): 108-112.DOI: 10.7623/syxb200305023

• 石油工程 • 上一篇    

管线钢断裂和疲劳裂纹扩展特性研究

赵新伟1,2, 罗金恒2, 路民旭2, 李鹤林2, 郭万林3   

  1. 1. 西安交通大学材料科学与工程学院, 陕西西安, 710049;
    2. 中国石油天然气集团公司管材研究所, 陕西西安, 710065;
    3. 南京航空航天大学飞机工程系, 江苏南京, 210016
  • 收稿日期:2002-03-25 修回日期:2002-09-16 出版日期:2003-09-25 发布日期:2010-05-21
  • 作者简介:赵新伟,男,1969年11月生,1995年毕业于西北工业大学获硕士学位,现任中国石油天然气集团公司管材研究所研究开发中心主任,工程师,西安交通大学在读博士生.
  • 基金资助:
    中国石油天然气集团公司"九五"重点应用基础研究项目(980704-01).

Characteristics of fracture toughness and fatigue crack growth of steel pipeline

ZHAO Xin-wei1,2, LUO Jin-heng2, LU Min-xu2, LI He-lin2, GUO Wan-lin3   

  1. 1. Institute of Material Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China;
    2. Tubular Goods Research Center of CNPC, Xi'an 710065, China;
    3. Department of Aircraft Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
  • Received:2002-03-25 Revised:2002-09-16 Online:2003-09-25 Published:2010-05-21

摘要: 对厚度分别为3mm、6mm、9mm、12mm、1mm的紧凑拉伸(CT)试样进行了断裂韧性试验,研究了X60管线钢的断裂特性.研究结果表明,由于试件厚度与分层裂纹间有强烈的耦合效应,表观断裂韧性不随厚度的变化而变化,靠增加试样厚度无法获得材料的平面应变断裂韧性,应用穿透裂纹的表观断裂韧性数据进行管道的安全评定不可靠;考虑塑性区修正的有效应力强度因子Ke与弹塑性J积分参量KJ在失稳扩展前保持了良好的等效性.对厚度分别为2mm、4mm和14mm的CT试样的疲劳裂纹扩展试验表明,高韧性管道钢的疲劳裂纹扩展存在显著的厚度效应,厚度效应敏感区在4 mm以内.

关键词: 管线, 试样厚度, 分层裂纹, 断裂韧性, 疲劳裂纹扩展, 三维应力约束

Abstract: The fracture characteristics of X 60 steel pipeline were investigated experimentally by using CT specimens with thickness of 3mm, 6mm, 9mm, 12 mm and 15mm.The results indicate that the appearance toughness of X 60 steel is independent on the thickness of specimen due to the couple effect of delamination cracks and out-of-plane stress constraint in direction of specimen thickness.It is impossible to attain plane strain fracture toughness by increasing specimen thickness.The safety assessment on cracked pipeline by using test data of thickness of penetrated crack is not reliable.The plasticity modified stress intensity factor Ke and Jintegral were found to be equivalent in description of the crack growth on steel pipeline.The effects of thickness on the fatigue crack growth rates of X 60 pipeline steel were investigated experimentally by using CT specimen with thickness of 2mm, 4mm and 14 mm.The results indicate that effect of thickness on the fatigue crack growth rates is notable.The effect of thickness on fatigue crack growth rate is obvious when the thickness of specimen is less than 4mm.

Key words: pipeline, specimen thickness, lamination crack, fracture toughness, fatigue crack propagation, 3-D stress constraint

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