NEW DRAWING TECHNICS OF LARGE FORGES

REN Yunlai¹  NIE Shaomin¹  NIU Longjiang¹  CHEN Ying²

(1. College of Mechanical Engineering, Yanshan University, Qinhuangdao 066004;
2. School of Mechanical Engineering, Tsinghua University, Beijing 100084)

Abstract: Based on the analysis of the influence of hard-to-deform region on the distribution of stress and strain on forgings in current upsetting and drawing, a new drawing technology named concave anvil drawing is put forwards. By means of numerical simulation and physical simulation, different effects of conventional flat anvil and concave anvil, conventional V-shape anvil and concave V-shape anvil on the equivalent deformation, status of hydrostatic pressure and voids crushing in forgings during drawing are compared. It shows that as far as statuses of stress are concerned, on the condition that the de-formations are same, concave flat anvil forging(CFAF) increases hydrostatic pressure by 30% , concave V-shape anvil forging(CVAF), 50%; as far as deformations are concerned, on the condition that the hydrostatic pressures are same, CFAF decreases reduction by 33.5%, CVAF, 26.5%; as far as void is concerned, by employing concave anvil the ovality of the void is 10% smaller than that by employing conventional anvil. Compared with other special methods, concave anvil drawing methods are more convenient to use and don’t need complicated auxiliary tools.

Key words: Large forgings  Forge  Drawing

CLC No: TG316

Received 20061120, received in revised form 20070720