Microstructure Transformation Behaviour of 610 MPa HSLA Steel Plate for 150000 m3 Oil Storage Tank Construction

Static and dynamic continuous cooling transformations (CCT) of 610 MPa HSLA steel plate for 150000 m3 oil storage tank construction were measured by using an MMS200 thermomechanical simulation system. It was found that with the increase in cooling rate, the proeutectoid ferrite, pearlite, granular bainite, and lath bainite appeared in the transformed microstructure. Compared with those of static CCT, the transformation points of acicular ferrite, granular bainite, and lath bainite in the dynamic CCT curve were shifted to the left, resulting in an increased acicular ferrite and bainite transformation area.