氮含量对SWRH82B盘条组织和性能的影响

为了研究不同含氮量的SWRH82B盘条在组织和性能等方面的差异，利用液压万能试验机对盘条进行拉伸试验，利用扫描电镜（SEM）和透射电镜（TEM）观察盘条的微观组织、拉伸断口及第二相析出情况。结果表明：增氮使索氏体组织的层片间距更细小；增加1.38×10-4的氮可使盘条的屈服强度提高8 MPa、抗拉强度提高28 MPa、延伸率降低1.8%、断面收缩率降低5.8%；高氮盘条比低氮盘条的拉伸断口上有更多的夹杂物；高氮盘条中的析出物更多且分布较弥散，析出物主要集中在位错线或原奥氏体晶界上，经标定，析出物中含有细小的V(C,N)颗粒。

Effect of nitrogen on microstructure and properties of SWRH82B wire rod

The microstructure, mechanical properties, tensile fractures and the precipitation of the second phase of vanadium microalloyed wire rods with different nitrogen contents are studied by hydraulic universal testing machine, scanning electron microscopy(SEM) and transmission electron microscopy(TEM) . The results show that the interlamellar spacing of pearlite is smaller in high nitrogen steel; the high nitrogen steel has higher yield strength, tensile strength and lower elongation and reduction of area; there are more inclusions on the tensile fracture surfaces of the high nitrogen steel; and in high nitrogen steel, the size of precipitation, mainly precipitating at dislocation or the boundary of austenite, is finer than that of low nitrogen steel, what is more, fine V(C,N) particles are concluded in the precipitations.