Development for a 610MPa Class Q&T High Strength Steel Plate B610E for Large Oil Storage Tanks

Baosteel group has recently developed a 610MPa class high strength steel plate B610E with thickness 12–45 mm. Through optimized microalloying and processing parameters, such steel plate can be successfully produced via quenched and tempered process. The industrial trial test results show that B610E steel plate has a yield strength of 525–585 MPa and a tensile strength of 620–660 MPa. Besides, it has excellent toughness, being higher than 239J at −40°C. Of vital importance is its excellent weldability. The charpy impact energy for HAZ at −40°C is around 160J for the high heat input up to 100 KJ/cm. Such excellent toughness and good weldability are attributed to the alloy design and processing parameters leading to multi phase microstructures consisting of acicular ferrite plus bainite.