Forming and microstructural behaviors of high strength low alloy 420 steel sheets formed by single point incremental forming process

In this work, the forming behavior of the High Strength Low Alloy (HSLA) 420 steel sheet during the Single Point Incremental Forming (SPIF) process was investigated. The formability is enhanced by increasing the spindle rotational speed, reducing the tool feed and reducing the incremental step-down. A numerical simulation was also performed and the results were compatible with experimental results. The studies are further extended to microstructural analyses. A large dislocation density was obtained due to a high swiveling effect. Therefore, the possibilities of high-angle grain boundaries were increased, which caused an increase in the percentage of ultra-fine grain formation. Hence, the strong texture was obtained by increasing the swiveling effect and the texture components were favored to enhance the formability.