作　　者： ; ; ; ;

机构地区： 东北大学材料与冶金学院轧制技术及连轧自动化国家重点实验室

出　　处： 《机械工程学报》 2010年第16期131-135,共5页

摘　　要： Nb+V和V微合金非调质钢常应用于汽车的结构件与保安件,疲劳断裂是其主要的失效形式,因此有必要对其疲劳断裂行为进行深入研究。利用LEICA Q550 IW型光学显微镜、AG-25TA型电子拉力试验机和DYNATUP 9250HV型落锤式冲击试验机等试验设备,考察仅含V与Nb和V复合添加的两种微合金非调质钢的组织与性能,利用FTM-100型液压伺服疲劳试验机对其三点弯曲疲劳性能进行比较研究,绘制S-N曲线,用FEIQUANTA600型扫描显微镜观察疲劳试样的断口特征。结果表明,在微合金元素质量分数基本相同时,Nb-V复合添加的微合金非调质钢具有良好的强韧性配合,并且其三点弯曲疲劳极限要远高于仅含V的微合金非调质钢;其原因是Nb-V复合添加的微合金非调质钢具有细小的晶粒组织。 Nb＋V and V microalloyed forging steels are usually applied to structural parts and security parts of automobiles,and fatigue fracture is their main failure mode,so it is necessary to investigate in depth their fatigue fracture behaviors.By using LEICA Q550IW optical microscope,AG-25TA electronic tensile testing machine and DYNATUP 9250HV floor-type impact testing machine,the microstructures and mechanical properties of a Nb-V microalloyed forging steel and a V microalloyed forging steel are studied,the three-point-bending fatigue behaviors of them are compared and studied by using FTM-100 hydraulic servo fatigue testing machine,and S-N curves are obtained.The fracture characteristics of the fatigue specimen are observed by using FEI QUANTA600 scanning electron microscope.The results show that when the mass fractions of microalloying elements are basically the same,Nb-V microalloyed forging steel has superior strength and toughness,and its three-point-bending fatigue limit is far higher than that of V microalloyed forging steel because Nb-V microalloyed forging steel has finer grain structures.

关 键 词： 非调质钢 铌 钒微合金化 疲劳极限 微观组织 力学性能

领　　域： [金属学及工艺] [金属学及工艺]