摘要
本文用膨胀分析法测定了45V非调质钢热变形后在奥氏体区在20℃/s和20℃/min冷却条件下再结晶奥氏体的CCT曲线,用光学金相和电子显微镜分析了转变产物的显微组织。结果表明:热变形后在奥氏体区快速冷却,转变前奥氏体晶粒尺寸减小,从而铁素体和珠光体的转变温度提高、先共析铁素体的数量增加,热变形后在奥氏体区慢速冷却,在奥氏体区有碳氮化钒析出,析出物也能促进γ/α相变;并随相变区冷却速度的增加,碳氮化钒以相间沉淀方式析出的倾向减小,析出物数量也减小。
The kinetics of continuous cooling transformation of recrystallized austenite and the structures of transformed products in 45V steel were investigated by the use of Gleeble-1500 testing machine, optical microscope and transmission electron microscope. The cooling rate after hot deformation but before γ/α transformation used was 20C/s and 20 C/min. It has been found that cooling at 20 C/s the recrystallized austenite grains are much fine, hence the γ/α transformation temperatures are higher and the volume fraction of transformed pro euteo-toid ferrite is greater. Cooling at 20 C/min vanadium carbonitrides precipitate in austenite which promote γ/α transformation. The tendency for interphase precipitation of vanadium carbonitrides decreases with increase of the cooling rate during transformation.
出处
《钢铁》
CAS
CSCD
北大核心
1991年第4期51-54,18,共5页
Iron and Steel
