Strength of self-piercing riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel

Benedikt Uhe,Clara-Maria Kuball,Gerson Meschut,Marion Merklein

doi:10.25518/esaform21.1911

Abstract

The use of high-strength steel and aluminium is rising due to the intensified efforts being made in lightweight design, and self-piercing riveting is becoming increasingly important. Conventional rivets for self-piercing riveting differ in their geometry, the material used, the condition of the material and the coating. To shorten the manufacturing process, the use of stainless steel with high strain hardening as the rivet material represents a promising approach. This allows the coating of the rivets to be omitted due to the corrosion resistance of the material and, since the strength of the stainless steel is achieved by cold forming, heat treatment is no longer required. In addition, it is possible to adjust the local strength within the rivet. Because of that, the authors have elaborated a concept for using high nitrogen steel 1.3815 as the rivet material. The present investigation focusses on the joint strength in order to evaluate the capability of rivets in high nitrogen steel by comparison to conventional rivets made of treatable steel. Due to certain challenges in the forming process of the high nitrogen steel rivets, deviations result from the targeted rivet geometry. Mainly these deviations cause a lower joint strength with these rivets, which is, however, adequate. All in all, the capability of the new rivet is proven by the results of this investigation.

Highlights

A further reduction in fuel consumption and CO2 emissions in traffic can be achieved through lightweight design
Driven by the advantages of rivets made of stainless steel, a concept for the use of high nitrogen steel as a rivet material was elaborated in previous papers
The present investigation focusses on the strength of self-piercing riveted joints with conventional rivets and rivets made of high nitrogen steel 1.3815

Summary

Introduction

A further reduction in fuel consumption and CO2 emissions in traffic can be achieved through lightweight design. This is resulting in an increasing proportion of high-strength steel and aluminium in car bodies. To join these materials, self-piercing riveting (SPR) is a well-established technique. A punch presses a semi-tubular rivet into the sheets. The rivet pierces the sheet on the punch side before flaring in the sheet on the die side. This creates an interlock [2]

Methods

Results

Conclusion