DWTT DROP WEIGHT TEAR TEST OF 600 MPa GRADE PIPELINE STEEL
Pipeline steel is an important energy steel,and the toughness of its material is one of the important technical indicators for the safe operation of oil and gas pipelines.In view of the inconsistency of the drop weight tear test results in the early stage of 600 MPa pipeline steel production in a steel mill,the relationship between the metallographic structure,inclusions,and ribbon structure at the tear fracture position of the drop weight specimen and the cold temperature of the strip steel layer was further analyzed by investigating the production process of the test steel and comparing the drop weight tear test results at different layers of cold temperature.The results showed that the DWTT drop weight tear test of 600 MPa grade pipeline steel was inconsistent because the cold temperature of the strip layer at the sampling location of the drop weight test sample was high,resulting in a large amount of carbides precipitated in the microstructure of the area,which reduced the toughness and increased the brittleness of the strip.The layer cooling temperature is 200～400 ℃,the microstructure is stable,the carbide precipitation is significantly reduced,the toughness performance and drop weight tear performance of the test steel are stable,which can meet the product requirements,and the layer cooling temperature is above 400 ℃,with the increase of the layer cooling temperature,the toughness performance of the steel and the drop weight tear are gradually reduced.
pipeline steelDWTT drop weight tear testtoughnesslayer cooling temperature
万方数据
维普
