Studies on Galling Behavior in Square Cup Drawing of High Tensile Strength Steel

Abstract

In this study, galling behavior in macro-scale is investigated in the square cup drawing of a high tensile strength steel in semi-dry and dry condition on laboratory experiments. The drawing dies are set two types: the non-coated (SKD11, ADI and SLD) and coated (TiC and DLC-Si). When using the non-coated dies in semi-dry, the macro-scale galling can clearly observed on die and drawn cup surface after a few drawing cycles. As a result, the galling on the die surface occurs at the bottom point of the boundary between the straight and corner edge, and grows upward with the drawing cycles; on the drawn cup, the galling starts at the top of the same boundary and grows downward. Simultaneously, the finite element method (FEM) with DEFORM-3D was used to simulate the square cup drawing process with the respect to the drawing force distribution and volume change analysis, which gave us a rational interpretation of the galling phenomena and illustrated the galling behavior and seizing tumour theoretically. Furthermore, a continued experiment with coated dies for TiC (CVD) and DLC-Si (DC -PACVD) was carried out to seek a anti-galling tool material for the high tensile strength steel.