基于感应-脉冲电流复合熔覆的气缸套再制造机理及性能研究

With the improvement of the technical indexes of marine diesel engines, cylinder liner wear and corrosion also will be accelerated, that leads to the premature failure of the cylinder and great waste of natural resources and energy. The induction cladding coating has metallurgically bonding, excellent wear resistance and corrosion resistance, and thus has a wide application ranges in the surface strengthening and the components repairing. However, the poor surface quality and metallurgical flaws in cladding layer has restricted its applications in many fields. Therefore, an innovative method named induction-pulse current hybrid cladding is proposed in this project, aiming to reduce the metallurgical defects and enhance the surface performance. With the study on waste engine cylinder liners, the wettability of coating materials, the behavior and mechanisms of interface in the electrically, magnetically, thermally and mechanically coupled field, and the wear resistance and the corrosion resistance are studied in depth. The induction-pulse current hybrid cladding remanufacturing mechanism of used cylinder liners will be illustrated and the high quality cladding layer preparation process will be optimized. The study results provide supports on theories and methods of cylinder liner recycling with high value and high efficiency, which also has great significance in environmental conservation, resource cyclic utilization, cost reduction and life extension of cylinder liners of marine engine.

随着船用柴油机技术指标的提高，气缸套磨损、腐蚀等也随之加快，致使气缸过早失效报废，造成了能源和资源的巨大浪费。感应熔覆技术制备的覆层具有冶金结合、耐磨、耐蚀等优点，在零部件的表面强化与修复领域具有广阔的应用前景。但在普通环境下制备的熔覆层表面质量差，易产生气孔、裂纹、夹生等缺陷，严重阻碍了感应熔覆技术的工业化进程。为此，本项目提出感应-脉冲电流复合熔覆的新方法，旨在降低熔覆层的冶金缺陷，提高其表面性能。本项目以船用柴油机废旧气缸套为主要研究对象，深入研究在电、磁、热、力耦合作用下熔覆层材料的润湿性、界面键合/扩散行为及机理与熔覆层的耐磨损、耐腐蚀性能，阐明基于感应-脉冲电流复合熔覆技术的气缸套再制造的机理，并优化高质量再制造覆层制备工艺。本项目研究成果为实现船用柴油机废旧气缸套的高值高效循环使用提供理论与方法基础，对环保、资源的循环利用、以及提高气缸套使用寿命，都具有重大意义。

随着船用柴油机技术指标的提高，气缸套磨损、腐蚀等也随之加快，致使气缸套过早失效报废，造成了能源和资源的巨大浪费。感应熔覆技术制备的熔覆层具有冶金结合、耐磨、耐蚀等优点，在零部件的表面强化与修复领域具有广阔的应用前景。本项目以船用柴油机废旧气缸套为主要研究对象，深入研究了电、磁、热、力耦合作用下熔覆层成形的电磁学与热力学机理、熔覆层的耐磨损、耐腐蚀行为与性能，并优化了高质量再制造熔覆层制备工艺。. 在深入研究感应熔覆机理基础上，搭建了超音频感应熔覆试验平台，结合实时采集的电磁场、温度场特征物理量，分析了感应熔覆的电磁学、热力学机理；采用材料测试手段，分析了熔覆层与基体界面的元素扩散/键合行为，熔覆层的织构特征和物相组成，结果表明，熔覆层与基体为冶金结合，界面处无明显裂纹、孔隙缺陷，且基体对熔覆层的稀释率较低。熔覆层组织沿温度场梯度方向呈现明显分层结构，孔隙率显著低于激光熔覆层；模拟船用柴油机气缸套高温腐蚀和摩擦工况，制定了感应熔覆层耐蚀和耐磨性能研究试验方案，分析了感应熔覆层腐蚀和磨损行为和机理；以熔覆层组织形貌、孔隙率、界面质量、稀释率作为熔覆层质量评价指标，在大量试验研究基础上，系统分析了工艺参数对熔覆层质量的作用规律。针对高含碳量铸铁零件，探索了基于能量梯度输入的多步感应熔覆工艺，实现了在铸铁基体上制备界面无明显缺陷的镍基、铁基和钴基熔覆层。. 通过项目研究，已发表学术论文10篇，学位论文2篇：其中SCI/EI论文4篇，ISTP论文1篇；培养研究生3名（其中已毕业硕士研究生2名）。该项目的研究为延长船用柴油机气缸套使用寿命和提高其环境效益，开辟了再制造的新途径。