炉前处理及热处理工艺对ADI阻尼性能的影响

发布时间：2018-03-15 20:35

  本文选题：ADI　切入点：工艺　出处：《哈尔滨理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：等温淬火球墨铸铁(ADI),是公认的综合力学性能优良的材料。由于其组织是由针状铁素体、残余奥氏体和石墨球组成,使其又有良好的减振降噪性,可作为设备的传动部件。以往人们只注重ADI力学性能方面的研究,而对其阻尼性能的研究罕见报道,因此,本文系统的研究和分析了炉前处理及热处理工艺对ADI阻尼性能的影响规律,为研发高阻尼ADI奠定基础。本文采用动态机械分析仪(DMA)对不同炉前处理及热处理工艺下ADI试样的阻尼性能进行测试,利用金相显微镜及X射线衍射仪(XRD)对组织进行分析。不同炉前处理工艺下试样的应变-内耗曲线显示:在应变为0.05%时,一次孕育剂加入量为1.0~1.4%时阻尼性能较优异,内耗值Q-1可达0.02以上;二次孕育剂加入量为0.2%时阻尼性能最佳,内耗值Q-1达到了0.025左右;球化剂加入量为1.1~1.5%时阻尼性能较优,内耗值Q-1超过了0.018;结合组织分析可知:石墨球形状、尺寸及球化率差别不大的情况下,ADI组织中石墨球的数量越多,则越有益于提升ADI的阻尼性能。不同热处理工艺下试样的应变-内耗曲线显示:在应变为0.05%时,奥氏体化温度为900℃时阻尼性能最佳,内耗值Q-1达到了0.017左右;第一步等温淬火温度为240~260℃时阻尼性能较优,内耗值Q-1超过了0.014;第二步等温淬火温度为320℃时阻尼性能最佳,内耗值Q-1超过了0.017;第一步等温淬火时间为10~15 min时阻尼性能优异,内耗值Q-1超过了0.016;第二步等温淬火时间为40~60 min时阻尼性能较优,内耗值Q-1可达0.017以上,完全符合高阻尼合金的标准(Q-10.01);结合组织分析可知:ADI基体中形核数量越多、晶粒尺寸越小,则越有益于提升其阻尼性能,同时,基体中残余奥氏体含量对其阻尼性能也有一定的影响。本文研究发现,ADI的阻尼性能对测试温度和频率较敏感,试验结果表明:随着测试温度的升高,ADI的阻尼性能逐步上升,在180~220℃时达到峰值Q-1为0.029左右,继续升温则阻尼性能逐渐降低;测试频率范围为1~100 Hz时,随着测试频率的提升,ADI的阻尼性能有上升的趋势。
[Abstract]:Isothermal quenched ductile iron is recognized as a material with excellent comprehensive mechanical properties. Its structure is composed of acicular ferrite, residual austenite and graphite ball, which makes it have good vibration and noise reduction. In the past, people only paid attention to the study of mechanical properties of ADI, but rarely reported its damping property. In this paper, the influence of furnace pretreatment and heat treatment on the damping properties of ADI is systematically studied and analyzed. In this paper, a dynamic mechanical analyzer is used to test the damping properties of ADI samples under different furnace pretreatment and heat treatment processes. The microstructure was analyzed by metallographic microscope and X-ray diffractometer (XRD). The strain-internal friction curves of different furnace pretreatment processes showed that when the strain was 0.05 and the amount of inoculant was 1.0 ~ 1.4, the damping property of the sample was better. The internal friction value Q-1 can be more than 0.02, the damping property is the best when the secondary inoculant dosage is 0.2, the internal friction value Q-1 is about 0.025, and the damping property is better when the nodularizing agent dosage is 1.1 ~ 1.5. The internal friction value Q-1 was more than 0.018.The results of microstructure analysis showed that the number of graphite spheroids in ADI was more when the shape, size and spheroidization rate of graphite spheroidization were not different. The strain-internal friction curves of the samples under different heat treatment conditions show that when the strain is 0.05 鈩，

本文编号：1616704