The influence of micropurity on the failure of the steel reinforcement in the production process

Abstract

During the production of the car structure, even the smallest defects and production errors, which could negatively affect the function of the given components are prohibited. Such defects could cause traffic accident or pose risk to the passenger's health. This paper focuses on conducting a material study of the reinforcing element in a dynamically stressed car component and aims to determine the causes of defects occurring during its production process. The examined component is manufactured from structural fine-grained microalloy steel using sheet metal cold forming technology. Although only one type of steel was used, there were two material deliveries, with one of them showing a significant error rate, evidenced by extensive surface cracks in the edge areas of the sheet metal part. These microcracks were located in places where extensive reshaping of the sheet blank occurs. The methods of optical microscopy, scanning electron microscopy and energy-dispersive spectroscopy were employed in the material analysis. Furthermore, a static tensile test and the Vickers hardness test were performed to determine changes in the mechanical properties of the examined material.