Development and Applications of V-N Microalloyed Steels in China


This paper reviews the recent development of V-N microalloying technologies and its applications in HSLA steels in China. Enhanced-nitrogen in V-containing steels promotes precipitation of fine V(C,N) particles, and improves markedly precipitation strengthening effectiveness of V(C,N), therefore, there is a significant saving of V addition in a given strength requirement. V-N microalloying can be used effectively for ferrite grain refinement as well by the nucleation of intra-granular ferrite promoted by VN precipitates in Austenite in V-N steels. Compared with Nb-Ti steels, V-Ti-N steels show superior weldability under large heat input welding due to the ideal ferrite-based microstructure with relatively fine ferrite grain size in CGHAZ. V-N microalloying process is a cost-effective way which has been widely used for high strength rebars, section steels, forging steels, seamless pipes, and CSP strip steels in China.


 V-N microalloyed steels, precipitation strengthening, intra-granular ferrite nucleation, ferrite grain refinement, weldability


Yang Caifu, Pan Tao, Chai Feng, Wang Ruizhen, Chen Xuehui


 Central Iron and Steel Research Institute, No. 76 Xueyuan Nanlu, Haidian District, Beijing 100081, China


Vanadium Microalloyed Steels: A Symposium in Memory of Michael Korchynsky, MS&T14, 12-16 October 2014, Pittburgh, PA, USA.