Microstructure and Properties of Q420 30^# Large Channel Steel Used for Transmission Towers

A Q420 grade 30^# large gauge channel steel was developed via vanadium micro-alloying. The microstructure and properties of tested steel were systematically investigated by using optical microscope,tensile test and impact test. The results show that the microstructure of test steel is mainly composed of banded ferrite and pearlite. The microstructures difference at different positions result in difference in properties.Under the low temperature condition,tested steel has stable mechanical properties,and with excellent impact toughness,which meets the E-level regulated by national standards.