Development of A 610 MPa Class QT High Strength Steel Plate B610E for Large Oil Storage Tanks

摘要

Baosteel group has recently developed a 610 MPa class Q&T 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 microstructure s consisting of acicular ferrite plus bainite.