Springback Characteristics of the Tailor-Welded 18g2a-E355 Steel Strips

Abstract

Recently many industry companies are trying to form different products by using tailor-welded blanks. A tailor-welded blank consists of two or more sheets that have been welded together in a single plane prior to forming. And the sheets joined by welding can be identical, or they can have different thickness, mechanical properties or surface coatings. Various welding processes, i.e. laser welding, mash welding, electron-beam welding or induction welding, can join them. Many studies presented a wide range of information about the formability and failure patterns of tailor-welded blanks and the springback of non-welded sheet metal parts. However, accurate prediction of the springback remains elusive, especially in the case of thick sheet metal. The purpose of this study was to predict the springback of the tailor-welded 18G2A-E355 steel strips. Especially, it was focused on comparing the differences of the mechanical properties and springback between the tailor-welded strips and non-welded ones under the same experimental conditions. The set-up mounted on the testing machine, instrumentation and process control system allows the rig to operate in displacement as well as load control. The MAG method with the Argon + CO 2 atmosphere was used for strips welding.

Influence of Technological Parameters on the Springback Angle of High-Strength Steels

“…Some theoretical and experimental research studies have considered the influence of blankholder force (BHF) and die geometry upon the springback and side wall curl [9], whereas, other studies have ignored the above effect [10]. Some studies were devoted to the influence of the tool geometry to the springback amount [11], material properties [12], die gap [13], die radius [14], bending radius [15,16] etc. Also friction condition on the springback can be considered from the same point of view with blankholder force since higher friction condition increases the tension applied to the sheet and decreases the DOI required bending moment for a given curvature [17], therefore, friction condition influence the springback.…”