Method of obtaining X80 steel grade two phase organization large deformation pipeline steel

Abstract

The invention belongs to the large deformation pipeline steel machine technical field, and provides a method of obtaining X80 steel grade two phase organization large deformation pipeline steel. The method of obtaining X80 steel grade two phase organization large deformation pipeline steel comprises the following steps: firstly conducting design of pipeline steel component, obtaining steel component meeting standard requirement; determining CCT curve of designed steel; determining a critical zone (Ar3,Ar1) of the designed steel when cooling rate is 0.2-0.5 degree / second; choosing cooling rate ranged conforming to forming bainite structure requirement in the CCT curve; determining beginning accelerated cooling temperature and cooling speed in manufacture of the steel according to phase transformation point and cooling rate range, and conducting production of steel plates. The method of obtaining X80 steel grade two phase organization large deformation pipeline steel obtains a two phase organization composed of the bainite and territe through critical zone accelerated cooling, the pipeline steel has large deformation capability, large uniform elongation, high strain strengthening index and low yield ratio, practical use requirement of large deformation pipeline steel is met, practicability if strong, and strong population and application value are possessed.

Description

technical field [0001] The invention belongs to the technical field of large-deformation pipeline steel processing, and in particular relates to a method for obtaining large-deformation pipeline steel with a dual-phase structure. Background technique [0002] Large-deformation pipeline steel is a new type of pipeline structure material that is suitable for oil and gas long-distance pipelines when they pass through geologically complex areas (landslides, earthquakes, frozen soil, etc.), in order to reduce the possible deformation damage to the pipeline caused by stratum movement. The typical structure of this new type of pipeline steel is composed of a soft matrix phase and a hard second phase. Larger uniform elongation (>8%) and lower yield ratio (<0.8), so it has the ultimate deformation ability to resist buckling, instability and ductile fracture in a large strain environment, meeting the needs of large deformation. With the rapid growth of energy demand in the deve...

AI Technical Summary

Problems solved by technology

[0003] At present, in the world, large deformation pipeline steel is only produced in a small amount in Japan, the United States and other countries, but there is no public report on its production method and process

Relevant units in China have also carried out research, but the disclosed content only involves the composition and the final test performance, and neither provides a specific manufacturing process plan nor a dual-phase structure photo and stress-strain curve. The direct evidence of large deformation duplex structure

Images