Edge crack test methods for AHSS steel grades: A review and comparisons

Abstract

Due to the economic efficiency of shear cutting, mechanical cutting is used for almost every sheet metal component processed in large numbers. The process parameters recommended both in the literature and in factory regulations generally apply to low- strength, single-phase steel alloys with low ECS. This does not necessarily apply to current types of high-strength alloys, such as those used in body and chassis components for passenger cars or in frame structures of commercial vehicles. As a result, metal working industries and teaching institutes have developed a range of non-standard testing methods to identify the ECS of metals. The ability to prevent edge cracking by the choice of appropriate cutting parameters eliminate the need for costly and time-consuming testing, which in turn reduces machine, tool, material and labor costs. This paper investigates various edge crack testing methods based on current single and multi-phase steel alloys and objectively evaluates them based on multiple criteria. The findings were then linked to the state of knowledge. A particular aspect of this document as compared to a conventional review paper is that the materials used can be regarded as constant across all test methods. This enables an objective comparison and evaluation of the methods used. A simple discussion or comparison of the recorded parameters of the state of knowledge is not expedient due to the large number of metallic alloy systems per material group and the fact that the alloy composition is generally not explicitly documented.