The Jetq-Family - New Highly Ductile AHSS Steel Grades with Improved Technological Properties

Abstract

<div class="section abstract"><div class="htmlview paragraph">New highly ductile AHSS steel grades with tensile strength greater than 980 MPa have been developed with the aim of combining high strength and excellent formability. The new jetQ-Family offers high local and global ductility while still fulfilling standards for resistance towards hydrogen embrittlement and weldability. These improved properties are based on their specifically engineered microstructure, which utilize the TRIP-mechanism in a strengthened matrix. This work shows how the microstructure plays a significant role for the tensile testing as well as hole-expansion. Based on the increased yield strength a better crash performance compared to conventional DP steel grades can be attained. The local ductility is demonstrated with excellent hole expansion ratios and high resistance to sheared edge failure. In combination with improved bending angles and thickness strain at fracture a robust process for manufacturing of components can be achieved. The results are completed by the characterization of resistance spot welding and the resistance towards hydrogen embrittlement. The jetQ-Family with its optimized property profile will contribute to greater safety and efficiency in vehicle bodies.</div></div>