Study On Welding Process Of Girth Weld For Transportation Gas Pipeline

The present paper is a study project of Pipeline Bureau of CNPC. In this paper, focused on researching on welding process of anti-SSCC X60 pipeline steel for ZHONG-WU pipeline. The contents of research include: Make the weld property test for the X60 pipeline steel, as a result from it that is temperature before starting weld to prevent delay crack;Choose excellent welding materials on sale at present to meet requirements of engineering; Designe the welding process according to data, engineering experience and technology requirements of ZHONG-WU pipeline. Under simulating field bad welding condition, carry out weld process test as per the pre-finished process design documents, at same time, evaluating welding materials operation property. Make the visual examination and x-ray test in accordance with API 1104 standard after finishing welding, then conduct the destructive test after qualified; Study mechanical properties of girth joint, including general mechanical properties test, low temperature charpy-notch test, microstructures etc. highlights on SSSC,HIC and COD property research. Evaluate every item results whether meet the requirements of the relevant standards and codes or not by the tests. Compare, analyze and evaluate the test results in theory; Evaluate synthetically different welding process, recommend excellent welding process for ZHONG-WU pipeline.The fruits of this paper are directly used in ZHONG-WU pipeline construction, it provides technology data and support for the pipeline construction.