V的析出对中碳锰非调质钢热塑性及组织的影响

Influence of vanadium precipitation on hot ductility and microstructure of medium-carbon manganese non-quenched and tempered steel

通过热模拟试验,对比分析不加V和加V两种中碳锰非调质试验钢的高温力学性能和组织,探讨V的析出对热塑性及组织的影响。结果表明,高温形变诱导析出的V(C、N)可抑制动态再结晶行为、提高变形抗力并促进晶内铁素体转变,使热塑性降低、高塑性温度区变窄、低塑性温度区变宽,而VC主要在奥氏体向铁素体转变时沿γ/α界面的形核析出,并有利于铁素体向晶内长大。不加V和加V的试验钢经1280℃固溶处理后,高温变形分别在900~1100℃和1000~1130℃时,可获得高的热塑性。

High temperature mechanical properties and microstructure of two medium-carbon and manganese non-quenched and tempered steels without and with vanadium addition were comparatively analyzed by thermal simulation test,and then the influence of V precipitation on the hot ductility and microstructure was studied.The results show that high temperature deformation induced V(C,N)precipitates can inhibit the dynamic recrystallization behavior and increase deformation resistance,and promote intragranular ferrite transformation;and therefore causing that the hot ductility is decreased,the temperature range of high ductility is narrowed,and the temperature range of low ductility is widened.On the other hand,VC phase precipitates mainly along theγ/αinterface during the transformation from austenite to ferrite,and is beneficial to the ferrite growing toward the austenite grain insides.After solution treating at 1280℃and then deforming at temperature range of 900-1100℃and 1000-1130℃respectively,both the tested steels without and with vanadium addition can obtain high hot ductility.