Ce对曲轴钢49MnVS3中硫化物形态的影响

Effect of Ce on morphology of sulfides in crankshaft steel 49MnVS3

曲轴是一种极为重要的机械零部件,通常应用于各种发动机中,是内燃机将直线运动转化为旋转运动的重要部件。针对曲轴钢49MnVS3中硫化物形态控制问题,通过Olympus金相显微镜、Zeiss扫描电子显微镜以及OTS钢铁夹杂物自动分析系统对不同Ce含量铸锭中硫化物形态、尺寸、分布及数量进行统计和分析,通过电解侵蚀的方法对硫化物的三维形态进行观察,并通过热压缩试验评价不同种类硫化物的变形能力。研究结果表明,随着钢中Ce含量的增加,钢中的大尺寸长条状MnS夹杂物逐渐转变为弥散分布的小尺寸球状(Ce,Mn)S复合夹杂物。钢中硫化物夹杂的长宽比和密度均发生了较大变化,夹杂物尺寸从4.6μm降到2.3μm,长宽比由2.9降到1.8,单位面积(mm2)夹杂物数量由32个增加到65个,铸锭中夹杂物的球化率显著提高。热压缩后,未添加Ce的试验钢中MnS夹杂物尺寸为20μm左右,呈垂直压缩方向的长线状,而加入Ce的试样中含Ce夹杂物未发生明显变形,仍保持了良好的弥散分布特征,这为高品质非调质钢制备技术的发展提供理论指导与技术支撑。

The crankshaft is an extremely important mechanical component,commonly used in various engines,and is an important component for converting linear motion into rotational motion in internal combustion engines.Focused on the control of sulfide morphology in crankshaft steel 49MnVS3,the morphology,size,distribution,and quantity of sulfides in ingots with different Ce contents were statistically analyzed using Olympus metallographic microscope,Zeiss scanning electron microscope,and OTSInca steel inclusion automatic analysis system.Three-dimensional morphology of sulfides through electrolytic erosion was observed and the deformation ability of different types of sulfides through thermal compression experiments was evaluated.The research results indicate that large-sized elongated MnS inclusions gradually transform into dispersed small-sized spherical(Ce,Mn)S composite inclusions with the increase of Ce content in steel.The aspect ratio and density of sulfide inclusions in steel have undergone significant changes,the size of inclusions in steel decreases from 4.6μm to 2.3μm,the aspect ratio decreases from 2.9 to 1.8,and the number of inclusions per unit area increases from 32 to 65.The spheroidization rate of inclusions in the ingot significantly increases.After thermal compression,the size of MnS inclusions in the experimental steel without Ce addition is around 20μm,it presents a long linear shape in the vertical compression direction,while the sample containing Ce inclusions in Ce added are not undergone significant deformation and maintaine good dispersion distribution characteristics.The results provide theoretical guidance and technical support for the development of high-quality non quenched and tempered steel preparation technology.