Abstract: Phase transformation of 0. 13Nb microalloying low carbon steel with deformation in non-crystallization temperature zone(as deformation≥50%,crystallization occurred)and continuous cooling with cooling rate0.1～50 ℃/s has  been studied by using thermecmastor-Z thermal simulation test machine and the effect of thermal deformation parameters on phase transformation structure was analyzed. Results indicated that with deformation in non-crystallization temperature zone,in continuous cooling with cooling rate larger than5℃/s,more than 90% of structure was granular bainite,and at same deformation temperature,with increasing deformation the amount of procutectoid ferite increased and the amount of bainite decreased.

Key words: Low C Steel,Nb Microalloying,Thermal Deformation,Phase Transformation

摘要： 利用Thermecomastor-Z热模拟试验机,研究了含铌0.13%微合金低碳钢奥氏体未再结晶区(超过50%、发生再结晶)变形、并以0.1～50℃/s的冷却速度连续冷却过程的相变。研究了热变形参数对相变组织的影响。结果表明,在未再结晶区变形,在连续冷却条件下,冷却速度≥5℃/s时,90%以上组织为粒状贝氏体;在相同变形温度情况下,随着变形量的增加,先共析铁素体的量增加,贝氏体的量随之减少。

关键词: 低C钢, 铌微合金, 热变形, 相变