高强耐候钢YQ450NQR1钒氮微合金化

V-N microalloying of high strength weathering steel YQ450NQR1

钒氮微合金化是高强耐候钢YQ450NQR1强化屈服强度的重要途径。钒氮微合金化对高强耐候钢YQ450NQR1性能的影响主要由钒和氮两部分构成,其中钒产生晶粒细化、析出强化的主要作用,氮强化钒的作用。通过高强耐候钢YQ450NQR1的钒氮积w(V)·w(N)研究,发现钒和氮质量分数的增加均可提高钢的屈服强度,同时钒和氮也呈乘积的方式对屈服强度产生影响。为保证高强耐候钢YQ450NQR1的屈服强度达到465 MPa,要求钒氮积w(V)·w(N)达到0.001 44以上。为提高连铸坯的高温塑性,降低铸坯裂纹发生的敏感性,氮质量分数需控制为0.012%~0.014%。

V-N microalloying is a main method to improve the yield strength of weathering steel YQ450NQR1. The per- formance of high strength weathering steel YQ450NQR1 microalloyed with vanadium and nitrogen is mainly influenced from vanadium and nitrogen, i.e., the vanadium mainly plays a part of the grain refinement and precipitation strengthening, and the main function of nitrogen is to strengthen the role of vanadium. Through the research of the product of vanadium and nitrogen w（V）-w（N） in high strength weathering steel YQ450NQR1, it is found that with the increase of vana- dium content and nitrogen content, the yield strength of the steel is improved, and the yield strength is influenced by the product of vanadium and nitrogen w（V）. w（N）. In order to guarantee the yield strength of weathering steel YQ450NQR1 up to 465 MPa, the product of vanadium and nitrogen w（V）. w（N） should be over 0.001 44. In order to improve the ductility of the continuous casting slab at high temperature and reduce the cracking sensitivity of the cast slab, the nitrogen should be controlled in the range of 0.012%-0.014%.