Posted on 02 Jun 2012
JFE Steel has developed high performance H-shapes applying an advanced thermo-mechanical control process (TMCP). To obtain high strength H-shapes with excellent toughness, it is important to obtain refined bainite microstructure, through suitable alloy design, hot rolling under the optimum rolling conditions, and accelerated cooling after hot rolling. This paper introduces examples of recently developed high performance H-shapes, such as 520 MPa grade (in tensile strength) H-shapes for high-rise building construction application with excellent toughness, weldability and earthquakeresistant properties, and 490 MPa grade (in tensile strength) H-shapes with superior low temperature toughness. Alloy designing to obtain refined microstructure under the specific hot rolling conditions to H-shapes, and the accelerated cooling facilities for shapes (Super-OLAC S: On-line Accelerated Cooling for Shapes. OLAC is a registered trademark in Japan.) are essential for the development of high performance H-Shapes.
