Numerical Simulation And Microstructure Study Of TC4 Titanium Alloy Bar Cross Rolling

Titanium as the 21 st century’s most promising new materials, widely used in aerospace, marine vessels, medical equipment, metallurgical equipment, and other industries. Titanium alloy has low density, high specific strength, high specific stiffness, high temperature mechanical properties and corrosion resistance,etc., outstanding overall performance. And the big titanium rod as an important raw material needs of the increasing quality requirements are also increasing, how to solve the uniformity and stability of large-scale organized bar has become an important focus of attention at home and abroad.Therefore,this paper according to the requirements of a company of big size TC4 titanium alloy bar rolling production and microstructure,with large-size TC4 titanium alloy bars as the research object, obtained by three roll cross rolling production, by calculating the won the corresponding roller type parameters and rolling parameters, and by using the finite element software was numerically simulated. To verify the correctness of the rolling model.A further comparison of the damage bar core under different reduction, the design of large bar rolling process parameters are explored from the macro; in order to verify the reliability of theoretical research, experiments by the rolling process parameters set in the microstructure, the microstructure good;And the microstructure of the experiment was compared with that of the simulation, the results were in good agreement. So that the design of the parameters of the rolling process and the correctness of the model. Key technologies are as follows:(1) Cross rolling theory based on the existing of pass design for 300 mm diameter large bar rolling to determine the specific parameters for the reduction of 30 mm,41mm,50 mm,to the rolling angle of 3 degrees and feed angle of 15degrees;(2) According to the determination of process parameters in DEFORM-3D modeling and Simulation for 30 mm, 41 mm, 50 mm, diameter 300 mm bar rollingprocess of amount of pressure. The simulation results verify the accuracy of the process parameters and the rationality of the pass design. Final results showed that: increase the value of the strain and damage reduction when rolling 50 mm maximum may cause internal damage to the bar of cracks.(3)Select the 50 mm reduction is the case, the use of such as the proportion of the existing rolling mill on the rolling mill for bar rolling experiment and the samples collected before and after rolling the microstructure observation. To verify the above conjecture. The results show that the rolling bar after the roundness is good, no micro crack damage core.(4) To simulate the microstructure of the rolling process based on metallographic experiment on the comparison between the simulation and experiment of bar microstructure morphology analysis, microstructure simulation during the evolution process and the phase transformation. The results show that the reduction in 50 mm when rolling within the dynamic recrystallization takes place, but the degree of crystallization is not sufficient and there is no crack. In the pressure range of 30mm~50mm, can be rolling,rolling bar will not damage the obvious defects.