液固两相流高速冲蚀条件下的复合热效应研究

Service condition of flowing-passed component is becoming more and more rigorous in liquid-solid two-phase flow fields such as petroleum, metallurgy and chemical industry of China.Especially,self-growing friction heat resulted from high impact velocity should aggravate corrosion and wear loss rate of target material. It is very urgent to carry out the research on friction thermal effect and the related basic theory with material damage mechanism under high impact velocity condition. In the project, the characterization method of friction heat will be carried out by using self-made erosion wear (erosion-corrosion）experiment apparatus with temperature detection system, produce and transfer laws as well as affecting factors of friction heat will be studied under liquid-solid two-phase flow erosion wear condition，the influence law of friction thermal effect on erosion wear property of target material will be researched, the temperature field model of target material and slurry system will be also established by means of combined computer simulation and experiment. Particularly, the project would focus on self-growing friction thermal effect and its mechanism on erosion wear region of the target material. The material damage mechanism coupled with erosion-corrosion-thermal effect will be revealed, and the material design method to control the negative effect will be proposed, the purpose of the project is to provide theory basis and technical support for material design and application of erosion wear equipment parts with high reliability and long service life in the key engineering field.

随着我国石油、冶金、化工等液固两相流领域中过流部件服役条件的日益苛刻化，高速冲蚀自生摩擦热使材料的腐蚀与磨损流失速度加快，开展高速冲蚀（冲蚀磨损）热效应及材料损伤机制相关基础理论的研究非常迫切。本项目采用自行研制的带有温度测试系统的冲蚀磨损试验装置对摩擦热进行表征，探讨液固两相流冲蚀磨损条件下自生摩擦热的产生、传递规律及影响因素，研究摩擦热效应对材料冲蚀磨损性能的影响规律；通过试验及计算机模拟相结合的方式，建立冲蚀磨损过程中靶材和料浆液系统温度场模型；重点考察液固两相流条件下冲蚀磨损自生摩擦热效应及其对材料磨损微区的作用机制，揭示冲刷磨损-腐蚀-热效应耦合作用下材料的复合损伤机制；提出控制热效应负面影响的材料设计方法，为关键工程领域中高可靠性长寿命冲蚀磨损设备构件材料的设计和应用提供理论依据和技术支撑。

在液固两相流高速冲蚀磨损条件下，摩擦热效应的影响应引起高度重视。针对目前液固两相流冲蚀磨损试验装置缺乏试样温度实时测试的问题，本项目首先自行研制了一种带有测温系统和电化学测试系统的旋转式冲蚀磨损试验装置。在被冲蚀试样表面附近、中心和背面附近位置开孔，插入热电偶，通过导线与温度传感器和计算机联接，在线测试并绘制冲蚀磨损过程中试样不同部位的温度变化曲线，分析测试冲蚀磨损过程中摩擦热量在试样中的产生、传递及其对试样冲蚀磨损特性的影响。经试验测试表明，该装置具有结构简单、操作便利、数据稳定可靠、直观性好的特点。随着料浆冲击速度的增大，料浆和试样温升显著增大，料浆冲击速度对料浆和试样温升的影响最大，表明冲蚀磨损过程中摩擦热量随着料浆冲击速度的增大而增加，试样冲蚀磨损量增大。同时，采用Fluent软件对冲蚀磨损过程中料浆和试样体系的温度场进行了模拟分析，探讨液固两相流冲蚀磨损条件下自生摩擦热的产生、传递规律及影响因素，建立了冲蚀磨损过程中料浆液和试样靶材系统的温度场模型，模拟结果得到试验测试结果的验证；采用正交试验方法，研究了料浆冲击速度、料浆温度和料浆酸浓度等因素对不锈钢材料冲蚀磨损性能的影响规律，分析了各因素的显著性，揭示了冲刷磨损-腐蚀-热效应耦合作用下材料的复合损伤机制；最后，采用单因素方法试验研究了不同料浆液温度对不锈钢材料冲蚀磨损性能的影响规律。重点考察了料浆液温度等因素及其交互作用对材料磨损量的影响，分析其对材料表面微区的作用机制，提出控制热效应负面影响的材料设计方法，为关键工程领域中高可靠性长寿命冲蚀磨损设备构件材料的设计和应用提供理论依据和技术支撑。