72A高碳钢的热成形性能

Hot forming properties of high carbon steel 72A

用Gleebe-1500热模拟试验机对国内钢厂生产的72A钢热轧盘条的热塑性进行研究,利用扫描电镜及光学显微镜分析高温脆化原因。结果表明,72A钢的第Ⅲ脆性温度区为700~850℃,断面收缩率均低于60%。72A钢在823~850℃时的脆化机理为晶界处细小第二相粒子TiN的析出;在823℃以下时的脆化机理是晶界处铁素体薄膜的析出。

Hot ductility of high carbon 72A steel domestically produced was tested with Gleeble 1500 simulation test machine and the reason of high temperature brittleness was analyzed by SEM and optical microscopy .The results show that the third brittle temperature range is 700-850 ℃, the percentage reduction of area is less than 60%.The embrittlement of the steel at 823-850 ℃ and below 823 ℃ is due to the precipitation of fine particles TiN at the grain boundary and the ferrite film presented at the austenite grain boundary , respectively.