Tungsten Sheet Rolling

Tungsten plate rolling can be divided into hot rolling, warm rolling and cold rolling. Due to the large deformation resistance of tungsten, ordinary rolls cannot fully meet the requirements of tungsten sheet rolling. Rolls made of special materials should be used. During rolling, the rolls should be preheated. According to different rolling conditions, the preheating temperature is 100-350°C. The blank can be processed only when its relative density (the ratio of actual density to theoretical density) is greater than 90%, and the processing performance is good when the blank density is 92-94%. The blooming temperature of hot rolling is between 1350 and 1500 ℃, and the deformation process parameters of the blooming are not properly selected, and the billet will be stratified. The starting temperature of warm rolling is 1200°C and the thickness of the hot-rolled sheet is 8mm, which can reach 0.5mm after warm rolling. Due to the large deformation resistance of the tungsten plate, the roll body is bent and deformed during rolling, resulting in uneven thickness of the plate in the width direction. When changing rolls or mills, the plate may crack due to uneven deformation of various parts. The plasticity-brittle transition temperature of the 0.5 mm thick sheet is still room temperature or above, and the sheet is brittle. The sheet should be rolled to 0.2 mm at 200-500°C. In the later stage of rolling, the tungsten sheet is thin and long. In order to ensure the uniform heating of the sheet, graphite or molybdenum disulfide is often coated, which not only facilitates the heating of the sheet, but also has a lubricating effect during processing.