V和Ti在高碳钢中的应用

Application of vanadium and titanium in high carbon steel

研究了V、Ti在预应力钢绞线及钢丝用高碳钢线材中的应用。高碳钢盘条中加入微量的V、Ti,在降低了珠光体相变温度的同时使珠光体相变与贝氏体相变温度区间发生分离;V的加入可以在细化珠光体片层间距的同时,抑制晶界连续渗碳体的形成。V、Ti在高碳钢中主要以复合碳氮化物的形式在晶界铁素体及珠光体片层间弥散析出,同时有部分V以合金碳化物的形式存在于渗碳体片层中。高温区析出的Ti(C,N)对奥氏体晶粒的长大具有显著的抑制作用,V主要在低温区以碳氮化物的形式起到析出强化的作用,另有部分V原子与Cr类似,与渗碳体结合形成合金碳化物,起到了强化渗碳体的作用。

Addition of vanadium and titanium to high carbon steel wire rod was studied. The results show that the phase transformation temperature of pearlite decreases and the temperature ranges of phase transformation for pearlite and bainite are separated due to adding of vanadium and titanium. The adding of vanadium decreases the spacing of pearlite lamella and also suppresses the formation of continuous cementite on grain boundary. Vanadium and titanium mainly precipitate as carbonitride at ferrite on grain boundary and between pearlite lamellas in the high carbon steel. Part of vanadium exists in cementite lamella as alloying cementite. The carbonitride of titanium precipitating in high temperature zone inhibits growth of austenite grains obviously and the carbonitride of vanadi- um precipitating at low temperature strengthens ferrite in the steel. Otherwise, some vanadium atoms, as chromi- um, combine with cementite to form alloying cementite, which strengthens cementite.