Using Fractography for Determining of Technological Reasons of Defect and Brittle Fractures Occurrence in Steels

Abstract

The paper describes practical examples of identification of rupture defect on steel components and its connection with the violating of the production process. Every violation of optimal production technology causes irreversible changes in the material that are visible on the fracture after breaking. Characteristics of the fracture allow the backward identification of specific technological reasons for defect fracture origin and consequent degradation of utility properties of the component. Documented examples include wide spectrum of production technologies where defective fractures can occur as are casting, forming, heat treatment or surface treatment. Wider notice is dedicated to the brittle fractures caused by non-optimal heat treatment. Presented fractures are documented by macroscopical as well as microscopical study using SEM microscope and they represent handy atlas of defects fractures with usage in real industrial practice.