Impact Strength Comparison with Carburization Case Depth Variation for Gear Steel by Instrumented Charpy, Izod and Brugger Tests

Impact strength of gear steel assist in estimating the sudden load bearing capacity of the steel. Traditional Charpy and Izod tests provide qualitative assessment of impact strength of steel. Brugger method is evaluated in this paper for case hardened steel. The instrumented impact test results are compared by all the methods for case hardened EN353 steel. The impact results are also compared by varying case depth to assess its influence on test methods. New co-relation is proposed for verification of Brugger impact strength. Fracture surface of impact specimens were characterized using SEM to analyze the associated failure modes and mechanisms. Compared to traditional methods, Brugger method found effective for quantitative impact strength determination of case hardened steels.