X70海洋管阻力曲线的测定研究

为了测定X70海洋管的阻力曲线,并以此来描述材料的断裂行为,采用多试样法对X70海洋管焊接接头进行低温CTOD试验,分别在0℃测试焊缝、热影响区和母材的断裂韧性并拟合阻力曲线,得到启裂韧度δ_(0.2)。通过类比法,确定最小允许值为0.2 mm较为妥当。X70海洋管焊接接头启裂韧度δ_(0.2)均值大于0.2 mm,显示韧性良好。结果表明,其具有良好的抗开裂性能,可免除焊后热处理,节约成本,试验结果为有效评价X70级直缝埋弧焊海洋管焊接接头提供了可靠依据。

Detection Research of X70 Marine Pipe Resistance Curve

In order to detect the resistance curve of X70 marine pipe, so as to describe the fracture behavior of materials. In this article, it used multi-sample method to conduct low temperature CTOD test for X70 marine pipe welded joints. The fracture toughness of weld, HAZ and base metal was tested respectively at 0 ℃, resistance curve fitting, and the start crack toughness δ0.2 was obtained. Through the analogy method, it determined the minimum allowable value of 0.2 mm was more appropriate. The start crack toughness δ0.2 average value of X70 marine pipe welded joint is greater than 0.2 mm, showed good toughness. Results showed that it is with good cracking resistance, can be exempted from heat treatment after welding, cost savings. The test results provided a reliable basis for effective evaluation X70 longitudinal submerged arc marine pipe welded joint.