钒含量对不同冷速冷却后高碳珠光体钢显微组织的影响

Effect of Vanadium Content on Microstructure of High-carbon Pearlitic Steels at Different Cooling Rates

将高碳SWRS82B盘条钢进行钒元素微合金化后，采用盐浴等温处理和不同冷速的风冷条件进行冷却，研究钒含量对试验钢显微组织的影响。结果表明：钒含量的加入能细化SwR$82B盘条钢奥氏体晶粒，当钢中钒含量大于0．16％（质量分数，下同）、在低于16℃·S叫冷速风冷时，晶界会明显出现铁素体；而钒含量控制在小于0．08％、风冷冷速在10～16℃·S叫时均可避免铁素体的形成；其原因是钒促进了碳化物在晶界富集，在晶界附近特定区域形成了贫碳区，促进了铁素体形成，并且钒元素的加入会使高碳钢共析点右移，使先共析铁素体相区增大。

The microstructure changing of SWRS82B wire rod steel with vanadium microalloying after aircooling at different cooling rates and salt bath cooling were invistigated. The results show that vanadium refined the austenite grains in SWRS82B wire rod steel. When the vanadium content was more than 0. 16wt, ferrites along crystal boundary grew obviously after air-cooling below 16 ℃ s 1. When the vanadium content was less than 0.08wt%, and the aicooled rate was between 10 16 ℃ S 1 , the ferrites did not apperared in the specmens. Vanadium element encouraged the segregation of carbide along grain boundary, and the formation of carbon-poor zone in some areas promoted the appearance of ferrite. And by addition of vanadium element the eutectoid point of high carbon steel moved to the right, which enlarged the area of pro-eutectoid ferrite.