Progress and Prospect for Development and Application ofMicroalloying Press-Hardening Steel

Ultra-high strength steels are important materials for the lightweight and safety of motor vehicles. The development and application of 1.5 GPa and above grade high-performance press-hardening steel are the key. In recent 10 a, the manufacturing technology of microalloying press-hardening steels and their parts have developed rapidly, achieving the performance such as high bending angles, hydrogen embrittlement resistance, high toughness and high hardenability; therefore the passive safety performance and lightweight of vehicles are improved. The development and application status of microalloying press-hardening steels are summarized, including the development and application of 1.5-2.0 GPa grade Nb microalloying, V microalloying, Nb-V composite microalloying and Nb-V(Mo) composite microalloying press-hardening steels, and the effects of microalloying on the nanoscale second phase precipitation and grain refinement; the hydrogen embrittlement resistance and its mechanism of microalloying press-hardening steels; the sharp corner cold bending property of microalloying press-hardening steels and its influence on the collision safety performance; the fracture failure performance of microalloying press-hardening steels. The manufacture and application of microalloying press-hardening steels in the future are also prospected.