X65级别海底管线钢低温CTOD性能研究

Study on CTOD performance of X65 grade submarine pipeline steel at low temperature

由于恶劣的海洋环境,要求海底管线钢具有较高的低温断裂韧性。CTOD性能是海底管道低温断裂韧性的重要评价指标。本文通过对不同厚度实验钢在0℃、-20℃、-40℃、-60℃、-80℃试验温度下进行CTOD试验。试验结果表明,本文实验钢的CTOD性能存在厚度规格效应的影响,20.6 mm厚度实验钢的CTOD值随着试验温度降低而降低,在0~-40℃之间,其CTOD性能均保持在较高水平,其CTOD值均在1.30 mm以上,在-60℃以下,其CTOD值大幅度降低,CTOD值降低为0.11 mm。而14.3 mm厚度实验钢随着试验温度的降低变化不大,其CTOD性能均保持在较高水平,在-80℃下,其CTOD值仍达到1.63 mm。

Due to the harsh marine environment,the submarine pipeline steel is required to have high low-tempera-ture fracture toughness.CTOD performance is an important evaluation index for low temperature fracture toughness of submarine pipelines.This article conducts CTOD tests on experimental stel with different thicknesses at experi-mental temperatures of o℃,-20℃,-40℃,-60℃,and-80℃.Theexperimental resultsindicatethat there is a thickness specification effect on the CTOD performance of the experimental steel in this paper.The CTOD value of the experimental steel with a thickness of 20.6 mm decreases as the test temperature decreases.Between O and-40℃,itsCTOD performanceremainsat ahighlevel,withCTOD valuesabove1.30mm.After beingbelow-60 C,its CTOD value significantly decreases,with a CTOD value of 0.11 mm.However,the 14.3 mm thick ex-perimental steel showed little change with the decrease of test temperature,and its CTOD performance remained at a high level.At-80℃,itsCTOD valuestill reached 1.63mm.