Research On The Defects For Horizontal Continuous Casting Of TP2 Copper Tubes

Tubes are one of the products with high economical value and play an important role in national economical construction and social development. Therefore, research and development of the new processes of tubes are extremely important. The copper tubes are widely applied to the air conditioning and refrigeration industry. With the development of air-conditioning industry towards to environmental protection, lower energy consumption and higher efficiency, the needs of high quality air-conditioning and refrigeration copper tubes increase quickly. The extrusion process is a traditional method for the TP2 copper tubes, in which continuous casting solid billet is extruded to hollow tube billet firstly and then drawn to tube. This method for production of copper tubes has the following disadvantages: long period, complicated process and high production cost. So it is not suitable for demands of the copper tube enterprises which pursue for the higher production efficiency and the lower cost. But the new cast & roll process method firstly cast to the horizontal continuous casting hollow tube billet, then roll by three-roller planetary rolling, and then spin to tubes. The copper tubes produced by cast & roll technology has stable performance, high productivity and low cost, it can satisfy user's requirements. Thus, it has widespread applications in the copper tube.In this paper, the horizontal continuous casting process of the TP2 copper tube was investigated. The main work was carried out in the Institute of Metal Research Chinese academy of sciences and Henan Golden Dragon Precise Copper Tube Group. The main contents are as follows:The horizontal continuous casting principle of the TP2 copper tube and the process was summarized and analyzed, and the influencing factors of the quality were studied. By using the scan electron microscope, the spectrum analyzer and the metallographic microscope, the defects of the TP2 copper tube during the process were analyzed. The rule of the defects during the process and the relationship of the defects and the technological condition had been found, and the mechanism of the defects was analyzed, and some effective measures to prevent the defects were proposed. Results indicated that:(1) The cast & roll process of copper tubes has many advantages such as short procedure, high productivity and low cost and equipment investment. The horizontalcontinuous casting process is the first and key process. The quality of horizontal continuous casting tube billet affects the final product quality;(2) Horizontal continuous casting procedure includes four processes: electrolysis copper plate melting, copper fluid solidification, the drawing and cutting of tube billet. The processes of melting and solidification are important processes.(3) Because of the influence of the equipment and the process parameters, the horizontal continuous casting process of TP2 copper tube billet has usually various defects, which reduce the productivity, increase product cost and affect the subsequent processing;(4) According to the process measures taken to prevent from the defects, it can not only increase the productivity but also improve the product quality to choose reasonable process parameters.