51CrV4汽车用弹簧钢基础特性研究
发布时间：2018-10-12 06:49
【摘要】：本课题研究的主要是方大特钢实际生产线上的高强度优质汽车用弹簧扁钢51CrV4,针对51CrV4弹簧钢的基础特性展开相关研究,为生产提供技术上的支持,达到整个工业生产线的集成优化,具体研究内容以及结论如下:利用Gleeble-3800热模拟机研究了51CrV4弹簧钢的高温力学性能,并采用扫描电镜观察了不同温度区间下51CrV4的断口形貌,结合J-Mat Pro软件研究了钢种第二相析出规律,分析了不同区域的断裂机理。结果表明,51CrV4钢存在高温脆性区(1350~1284℃),主要与液膜诱发熔断有关,呈现出熔融断口;低温脆性区(904~600℃),主要与Cr7C3和Fe3C硬质相的析出以及锰硫比的增多降低了高温塑性,表现为典型的沿晶断口。在单一的奥氏体区(1283~905℃),可获得良好塑性,表现为典型的韧窝断口。研究了51CrV4弹簧钢过冷奥氏体连续转变规律,采用热膨胀法得出了其相变临界点,同时得出了51CrV4钢过冷奥氏体在不同冷速下连续转变时的膨胀曲线并绘制了其静态CCT曲线。结合金相-显微硬度法,研究得出了不同冷速时,51CrV4钢各个组织性能的影响。结果表明:过冷奥氏体冷速在0.5℃/s的时候,奥氏体转变的产物是铁素体和珠光体;当冷速增加,达到1℃/s之后,贝氏体开始生成,随着冷速的变大,贝氏体含量也逐渐增多;马氏体转变冷速区间为2~30℃/s;当冷速超过12℃/s之后,过冷奥氏体相变产物只有马氏体。对51CrV4钢使用单道次压缩试验,采用热物理模拟的方法,对不同变形量、变形速率及变形温度下的51CrV4弹簧钢进行真应力-真应变曲线测定同时分析不同试验条件下变形量、温度、应变速率对热变形过程中变形应力的影响。研究结果表明,在相同的变形温度下,真应力值随着变形速率的增加而增加,应变速率越大,真应力值越大。在相同的变形速率下,真应力值随着变形温度的增加而降低,应变温度越高,真应力值越小。
[Abstract]:This research is mainly focused on the high strength and high quality spring flat steel 51CrV4 used in Fangda special steel production line, aiming at the basic characteristics of 51CrV4 spring steel to provide technical support for production. The specific research contents and conclusions are as follows: the mechanical properties of 51CrV4 spring steel at high temperature are studied by Gleeble-3800 thermal simulator, and the fracture morphology of 51CrV4 at different temperature ranges is observed by scanning electron microscope (SEM). Combined with J-Mat Pro software, the precipitation law of the second phase of steel was studied, and the fracture mechanism of different regions was analyzed. The results show that there is a high temperature brittle zone (1350 ~ 1284 鈩，
本文编号：2265177
[Abstract]:This research is mainly focused on the high strength and high quality spring flat steel 51CrV4 used in Fangda special steel production line, aiming at the basic characteristics of 51CrV4 spring steel to provide technical support for production. The specific research contents and conclusions are as follows: the mechanical properties of 51CrV4 spring steel at high temperature are studied by Gleeble-3800 thermal simulator, and the fracture morphology of 51CrV4 at different temperature ranges is observed by scanning electron microscope (SEM). Combined with J-Mat Pro software, the precipitation law of the second phase of steel was studied, and the fracture mechanism of different regions was analyzed. The results show that there is a high temperature brittle zone (1350 ~ 1284 鈩，
本文编号：2265177
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