超快冷终冷温度对含Nb-V-Ti微合金钢组织转变及析出行为的影响

发布时间：2018-02-09 23:46

  本文关键词： Nb-V-Ti微合金钢 超快冷 硬度 析出强化　出处：《金属学报》2015年07期 　论文类型：期刊论文

【摘要】：以复合添加Nb,V和Ti的低碳微合金钢为研究对象,采用热模拟试验机模拟高温轧制+超快速冷却+缓冷工艺,采用OM,HRTEM和显微硬度计等对超快冷至不同温度实验钢的组织转变和析出规律进行研究.结果表明,随着超快冷终冷温度的升高,显微组织由贝氏体向珠光体和铁素体转变,碳化物形核位置从贝氏体转变为铁素体,铁素体中的析出物密度大于贝氏体中的,且在620℃达到最大.超快冷至不同温度时析出物的尺寸均小于10 nm,纵横比均接近于1,即析出物形态更接近于球形,且随终冷温度的降低,析出物尺寸逐渐减小.利用Orowan机制计算了析出强化增量,得出在620℃析出强化对屈服强度的贡献最大,可达到25.6%.
[Abstract]:Taking low carbon microalloyed steel with NB V and Ti as the research object, the super fast cooling slow cooling process of high temperature rolling was simulated by thermal simulation testing machine. The microstructure transformation and precipitation of ultrafast cooling to different temperatures were studied by means of OMW-HRTEM and microhardness tester. The results show that the microstructure changes from bainite to pearlite and ferrite with the increase of the final cooling temperature. The nucleation position of carbides changed from bainite to ferrite, and the density of precipitates in ferrite was higher than that in bainite. At 620 鈩，

本文编号：1499148