Investigation of deep drawbility of DP500 and DP600 sheet metals

In automotive sector, thick steel sheets were used for the high security components. However, these components are replaced by the use of thinner but high strength materials.Drawing die radius, punch radius, punch velocity and lubrication are the most important die parameters that effect the quality of the produced cups.The goal of this thesis is to determine the suitable die parameters which are used to shape the high strength steels before die production. Therefore, it is expected to produce proper dies with these parameters and get cups with desired production quality.The parameters affecting the deep drawing process have been experimentally investigated in this work. At experimental studies, cylindrically deep drawing processes were carried out by using different parameters. The experiments were applied to DP500 and DP600 quality high strength sheets of 0.9 mm thick. All tests were realized by using Hounsfield tension-compression test device. Effects of die radius (2,3,4 and 6 mm), punch radius (2,3,4 and 6 mm), punch velocity (60, 150, 250 and 350 mm/min) and lubrication (without lubricant, stretch film and mineral oil) parameters on drawing process were investigated. It was analyzed that wrecking, sheet thinning, molding forces, cup height and earring in samples. It was observed that the sheet material was wrecked in small die radius. Furthermore, it was observed that molding force decreased with increasing the punch velocity and die radius. The same relationship was determined when the present lubricant is replaced with other oil. The smallest molding force was obtained and it is observed that the sheet thicknesses changed also while a thin film used as lubricant. And also, it was obtained that sheet thicknesses changed with changing die radius.