Research On Microstructure And Oxidation Behavior Of High Speed Steel Hot Rolling Work Rolls

Roller is one of the main consumables steel production process.The main failure form of roller is wear and tear,which is the dynamic equilibrium process of the formation and wear of the oxide film on the surface of the roller.The mechanical properties of the oxide film will be decreased,it wear and tear consumption increased even flake into pieces,under the combined action of mechanical stress and thermal stress,when the oxide film is not uniform or the oxide film thickness exceeds a certain value.The quality of the oxide film on the roller greatly affects the price and quality of the steel.In oxide film on the surface of the roller control technology,the technology level of our country is far behind the international advanced level.in order to solve this problem,microstructure and oxidation behavior of high speed steel hot rolling working roll material were studied systematically in this project study by Thermo-Calc,metalogra-phic microscope,scanning electron microscope,XRD,TGA and other tools and equipment.The microstructure of high speed steel for roller is the matrix of martensite and carbide such as MC、M6C、M23C6.M6 C carbide is mainly formed by Mo,M6 C and part of MC derived from the decomposition reaction of M2 C.it was a long strip,carbide rods,honeycomb,uneven distribution in the matrix;MC carbide is mainly formed by V,it is mainly formed in the high speed steel solidification stage and distributed evenly in the matrix;M23C6 type carbide are mainly separate out from too cold austenite and it is metal atoms are Cr and Fe.In this paper,the relationship between the oxidation weight gain and the temperature and time of the high speed steel in the dry air condition is obtained by the calculation method,the veracity of the formula is verified by experiment.In this paper,the oxide films of high speed steel rolls formed at different atmosphere and different temperature,different time were studied.The results show: The temperature increase can accelerate the oxidation rate of high speed steel and affect the properties of oxide film.In a short time,the uniformity and the compactness of the oxide film formed at 600 ℃ is better than the oxide film formed at 550 ℃ and 650 ℃.The study also shows that the steam atmosphere can accelerate the oxidation rate of the high speed steel and make the oxide film more compact and have better mechanical properties.The actual production can take advantage of this law,proper adjustment of the cooling water pressure and the amount,reasonable control roll surface temperature can extend the service life of the roll.