氮在非调质钢中的作用

介绍了氮在非调质钢中的有益作用。非调质钢中增氮，改变了钒在相间的分布，促进Ｖ（Ｃ，Ｎ）析出，使析出相的颗粒尺寸明显减小，从而增强了钒的沉淀强化作用、大幅度提高钢的强度。氮通过促进Ｖ（Ｃ〉Ｎ）析出，有效地钉扎奥氏体－－铁素体昌细化了铁素体晶粒。增氮还可促进晶内铁素体的形成，进一步细化了铁素体组织。对微钛处理非调质钢，增氮提高了ＴｉＮ颗粒的稳定性，更有效地阻止奥氏体晶粒长大，充分利用廉价的氮元素，在保

THE ROLE OF NITROGEN IN MICROALLOYED FORGING STEEL

This paper reviews beneficial effects of nitrogen in microalloyed forging steels. An enhanced nitrogen content promotes the precipitating of V(C,N) and decreases the particles size of V(C,N) precipitates, hence increases precipitation strengthening effect of vanadium. Nitrogen also refines the ferrite grain by promoting the intragranular ferrite nucleation and retarding the ferrite grain boundaries motion due to the precipitation of V(C,N) in the interior of austenite and on the austenite ferrite boundary. In the steels processed with the technology of TiN dispersion, enhanced nitrogen content makes TiN particles more stable and efficient in pinning the austenite grain boundaries. For a given strength level, the vanadium content can be reduced by 20 %~40 % by making fully use of cheap nitrogen. So, nitrogen is a very cost effective alloy element for microalloyed forging steels.