Experimental Investigation of Process Forces and Part Quality for Fine Blanking of Stainless Steel with Inductive Heating

Andreas Feuerhack,Ingo Felix Weiser,Robby Mannens,Thomas Bergs

doi:10.25518/esaform21.2575

Abstract

Fine blanking is a highly productive process of industrial mass production with which high quality components in particular but not exclusively for the automotive industry are produced. The manufacturing process faces its limits at elevated tensile strengths of the materials to be processed. Consequently, high-strength steels can currently only be fine blanked to a limited extent. This can be overcome by lowering the flow stress of high-strength steels by means of inductive heating. A steel of high importance especially for industries with high hygiene standards such as medical and nutrition production is the stainless steel X5CrNi18-10 (1.4301). As a metastable austenitic steel which can initiate cutting impact on the press through martensitization, fine blanking of stainless steel is a challenge. X5CrNi18-10 is not a high-strength steel per se but becomes difficult to process due to the high hardness of the martensite phase, known as transformation-induced plasticity (TRIP) effect. Thus, in order to combine the possible advantages of the fine blanking process with inductive heating and the important properties of stainless steel, fine blanking of this steel was investigated with inductive heating prior to the fine blanking. The process forces and product quality properties such as die roll were investigated and found to be advantageous in comparison to non-heated fine blanking specimens of the same steel. The process forces and the die roll height decreased due to the heating.

Highlights

Stainless steel is crucial for many application fields as an alternative for corrosive applications, showing a growing volume of 3 – 5 % p.a. [1]
One of the first developed stainless steels (Krupp Company, Germany, 1912) is up to now amongst the most frequently used stainless steel alloys [3]. It is known under the compositional name X5CrNi18-10 (AISI 304) or the material number 1.4301, which is the first number in the class of stainless steels
The objective of this research is the experimental investigation of process forces and part quality for fine blanking of stainless steel with inductive heating

Summary

Introduction

Stainless steel is crucial for many application fields as an alternative for corrosive applications, showing a growing volume of 3 – 5 % p.a. [1]. The objective of this research is the experimental investigation of process forces and part quality for fine blanking of stainless steel with inductive heating. The specimens do consist of X5CrNi18-10, correspond to the standard and are suitable for forming as a consequence of the relatively high portion of austenite stabilizing elements Cu and Ni. It has to be considered that the results of optical emission spectroscopy are in general less accurate than the results of the melt composition analysis. They are unusual for a steel material: corrosion-resistant, non-ferromagnetic and not hardenable by heat treatment [3]. Cutting impact is not expected to a greater extend, as the peril of martensitization is comparatively low and not enforced by the servomechanical press

Objectives

Results

Discussion

Conclusion