Investigation of effective geometrical parameters on wear of hot forging die

Abstract

The hot forging process has better formability than cold forging, however, the hot forging die sustains higher temperature and coupled pressure and temperature effect. The die wear is faster than those of cold forging. The objective of this research is to combine the previous experimental techniques in wear coefficients, numerical method, and wear model to predict the wear behavior of hot forging die in 3D, obtain the most critical wear points and geometry types on the die surface and investigate the effect of these geometrical parameters on the most critical wear points of the die surface. These investigations are done based on the combined effects of the pressure, temperature, and velocity as functions of step time and contact geometry. DEFORM FEM code is used to analyze the hot forging die in 3D and Archard wear model is applied to obtain the wear surface of the die. To deeply investigate the geometrical effects of the surface slope angle of the contact surface and fillet radius, a 2D FE model is implemented in ABAQUS commercial code and a velocity field distribution on the die surface is defined and contact temperature effect in wear coefficient and contact pressure for each node at each step time is considered to obtain the final wear depth. Although increasing the surface slope angle from 0° to 45° usually moderates the highest amount of wear and the corresponding position on the die, the surface slope angle of 30° shows a reverse trend. A statistical analysis based on the Taguchi method is carried out and an empirical model to predict the wear on hot forging dies is presented.