Experimental investigation of spring-go and spring-back in V die bending process of AISI 430 stainless steel

In this study, the spring-go and spring-back behaviour of AISI 430 ferritic stainless steel was investigated in V-bending process, which is one of the methods of sheet metal forming. The usage of this type of stainless steel is increasing in the world market due to its formability, being usable in extreme temperatures, excellent corrosion resistance, aesthetic appearance, and surface quality. In this context, 180 sheet metal specimens with dimensions of 40x120x1 mm were prepared by laser cutting method in 0°, 45°, 90° rolling directions. Punch and die were prepared at 60°, 90° and 120° with CNC milling machine from block steel. Punch and die radii were selected as 5 and 4 mm respectively. Specimens were divided into three groups. Heat treatment was not applied on the first group. The second group were subjected to normalizing heat treatment, while the third group were nomalized and then tempering heat treatment was applied. Each group was bent in three different die angles and rolling directions according to holding punch on metal sheet for 30 seconds on the first half, but not at all on the second half. All bending processes were repeated three times. After the bending process, the angle measurements of the specimens were made with angle meter followed by CMM (Coordinate Measuring Machine) and recorded. Afterwards, hardness measurements and metallographic analysis were carried out for each group. In the light of the physical experiments and the analysis made, the spring-go and spring-back behavior of AISI 430 ferritic stainless steel was interpreted.