Analysis And Research On The Properties Testing For X80Grade Pipeline Steel

Contemporary transportation of gas and oil has boosted the development of steel pipeline products. From21th century, the application of X80grade pipeline steel has become worldwide, while the manufacturing technology and product quality have also been improved. On the convetional items of mechanical properties testing for X80pipeline steel, there is a well-documented resesrch and recognization at home and abroad. However, for the testing of DWTT, HIC and hydrostatically, there are no common methods to be adopted. Presently, we just only use US standards or enterprises rules and have no systematic or universile testing methods. For this reason, the aim of this thesis is to get a deep investigation of how to test DWTT, HIC and hydrostatically in order to meet the requirement of UOE products manufactured in BAOSTEEL.Firstly, an investigation has been made in this thesis on the properties requirement and testing methods for X80pipeline steel and the items to be examined and standards to be used have been elucided. Secondly, concerining the actual situation of BAOSTEEL, a sampling method was studed to determine the sampling scheme. Finally, we combined the in-site experiments, a comprehensive investigation has been made on the tensile and impact behaviors, DWTT, optical microstructures, hydrostatic testing and anti-HIC ability for the X80pipeline steel. The influencing factors and failure mechanism have also been analyzed.This thesis can provide a technological basis for the development, production and properties examination of X80pipeline steel.