Charpy impact energy, fracture toughness and ductile–brittle transition temperature of dual-phase 590 Steel: Fid-Bau Portal

Charpy impact energy, fracture toughness and ductile–brittle transition temperature of dual-phase 590 Steel

Chao, Y.J. / Ward, J.D. Jr. / Sands, R.G.

AbstractAdvanced high strength steels (AHSS) have been introduced and gradually adopted in vehicle structures as lightweight materials in the past years. Engineering performance of AHSS in many areas have shown that they are superior to the conventional steels. In this paper, we present the results from Charpy V-Notch impact tests on dual phase 590 (DP590) steel, which belongs to the family of AHSS. Tests were conducted at temperatures ranging from −120°C (−184°F) to 90°C (194°F). Specimens oriented in both L–T and T–L directions were tested. Due to its reduced thickness relative to the ASTM testing standards, specimens from a medium low carbon steel AISI-1018, having both standard and reduced thickness, were tested as well to justify the correction method for the DP590 data. The results show that the ductile–brittle transition temperature (DBTT) based on 20.4J (15 ft-lb) absorbed energy is about −95°C (−139°F) for DP590 which is far below the 5°C (41°F) of the AISI-1018 steel. In addition, fracture toughness values of DP590 steel were obtained from correlation with the Charpy impact energy. It is shown that that the fracture toughness of DP590 is in the range of 160–200MPam^1/2 (146–182 ksiin.^1/2) in the upper shelf region, which includes the room temperature.