Horn net punching deviation cause and remedy method
Blank out of shape when horn net punching. That is, the metal under the punch is squeezed to the four sides, the height of the billet decreases, the diameter increases, the upper end face concave, the lower end face convex. The out-of-shape degree is related to billet diameter D0, height H0 and aperture d1 before punching. The smaller D0/d1 is, the more serious the out-of-shape degree is.
Correction of eccentricity when punching: when punching due to the uneven anvil surface, punch two end faces skew and billet heating inequality, will produce aperture eccentricity. Correction method can be used by immersion method: operation will be the thin side of the hole wall immersed in water, so that the temperature is reduced, and then use the punch to expand the hole, the wall thickness of the side due to high temperature, good plasticity and thinning, so that the entire forging wall thickness is uniform, eccentric is corrected. This method is suitable for plastic materials. Correction method is: should control D0/d1≥ 2.5 ~3 is good. If the diameter of the hole is large, such as D0/dl< When 2.5, generally, the hole is punched first, and then the hole is reamed to obtain the required aperture.
