Experimental Research And Numerical Calculation For T10Steel Quenched By Atmosphere-pressure High-velocity Nitrogen-water Spray

As a new type of quenching process, atmosphere-pressure high-velocity nitrogen-water spray quenching has caught the attention of the quenching field at home and abroad. Because it has the advantages, such as, economy, high efficiency, no pollution, and the quenching cooling rate can be controlled, etc. However, the parameters of aerosol medium quenching process are still not clear so far.In order to study the performances and characteristics of this new type of quenching process atmosphere-pressure high-velocity nitrogen-water spray quenching, the research combined with a new aerosol spray quenching experiment device that is invented recently, analyzed the influence factors of atmospheric aerosol high-speed quenching process and prepared related experimental conditions. For the study, three periods of experiments are carried out, and what’s more the experimental programs are designed, such as the water quenching, oil quenching, oil quenching after water quenching, aerosol quenching in quenching tank, etc.(1) Nitrogen pressure, water flow and jet distance’s influences on quenching cooling time are studied, and the responses from two impact factor include nitrogen pressure, water flow are analyzed;(2) The mechanical properties and microstructure are overall analyzed;(3) Specimen apparent after quenching experiments are compared and evaluated, the maintenance of a working environment are discussed, and the cost of experiments under a variety of operating conditions are analyzed and evaluated combined the quenching effects.In this research, combing with the theory of heat transfer calculation model of the quenching process, quenching experiments are studied and analyzed with Software and program. The studies include the following aspects:(1) The surface integrated heat transfer coefficient of the specimen during the quench process is reverse solved with FEM software DEFORM and FORTRAN program based on nonlinear estimation method respectively;(2) Corresponding composite model is established for T10steel, and the temperature field, the stress field, the organization field under different conditions are forecasted and analyzed;(3) The causes of error for numerical simulation are explored and identified.In this paper, the experimental results and numerical results are summarized and analyzed. The contact of spray cooling process and specimen quenching effect is built. The main conclusions are:(1) The water flow is the most important influencing factors to the quenching cooling capacity, the interaction between nitrogen pressure and water flow is significant.(2) The quenching cooling speed is high when the nitrogen pressure is in low level and the water flow is in high level. And what’s more, the cost for experiment can be effectively controlled;(3) DEFORM software based on FEM does not have general applicability for calculate the surface integrated heat transfer coefficient.(4) When quenched, the phase transition of T10steel specimen is uneven. The influences of phase change to temperature and stress can not be ignored.These conclusions can be used to guide the subsequent research work. It is also of great importance to the future aerosolized quenching in the field of industrial heat treatment and even the establishment of the expert system.