Springback Analysis and Prediction of Automotive Steel Sheets Used in Compression Bending.

Springback is still one of the most challenging issues in sheet metal forming, especially in the automotive industry, where hundreds of pressings made of different types of materials are joined together by various methods. In this study, springback evaluation was conducted on three types of steel that are commonly used in the automotive industry. Transformation induced plasticity (TRIP), micro-alloyed and deep-drawing steel sheets were used in compression bending, which is largely used in bending hollow tubes. The impact of die diameter and anisotropy on the springback was studied and evaluated. A numerical prediction of springback was conducted using Simufact Forming 2022 software. Based on the experimental results, it was found that steels with higher yield and tensile strength experience more springback than steels with lower strength properties. Additionally, the use of larger die diameters (30 mm and 25.4 mm) in compression bending results in higher springback compared to smaller ones (10 mm and 15 mm). The impact of anisotropy on the springback was mostly evident in pressings made of deep-drawing steel.