Process technology and steel development in press hardening
Over the last decade press hardening process has become a key lightweight technology for the automotive industry worldwide because it offers ultra - high strength up to 1 500 MPa for the safety components;adopts the modern manufacturing technology to form the ultra - high steels and finally gives carmakers new opportunities to achieve the lightweight design.Today to use press hardening steel up to 26% in the car body is the state of art and it could reach 40% in the future.However the alloying concept of the standard press hardening steel 22MnB5 was not originally designed for automotive application.Due to the martensitic microstructure and the high strength level the crash performance of press hardening steel is highly dependent on its toughness,bendability ( 3 - point - bending test) and resistance to delayed hydrogen induced cracking.Based on this consideration the potential problems of the conventional alloying concept will be discussed and some latest research results,which are related to the improvement of press hardening steels for a better crash performance,will be presented.Finally this paper will introduce the novel alloying designs for high strength steels which are tailored for press hardening process and suitable for automotive application.The key of the new alloying concept is to adopt Nb microalloying and to remove boron from the concept.
press hardening steel martensite grain refinement grain boundary cohesion toughness delayed cracking
Bian Jian Hardy Mohrbacher WANG Li
Niobium Tech Asia,068898 Singapore NiobelCon bvba,2970 Schilde,Belgium Research Institute,Baoshan Iron & Steel Co.,Ltd.,Shanghai 201900,China
国内会议
上海
英文
1-9
2013-06-01（万方平台首次上网日期，不代表论文的发表时间）