Empirical Relation between Leeb Rebound Hardness and Tensile strength for Austenitic Ductile Cast Iron

摘要

Rebound hardness is a popular onsite testing method to evaluate the hardness of heavy and massive metal parts and products. It is usually economical to do Leeb rebound testing where only one or very few items are to be produced because it is a non-destructive test. It is not economical to do destructive test such as tensile strength in this case. The aim of this study is to find the relation between leeb rebound hardness and tensile strength of the austenitic ductile cast iron, to rely on the leeb rebound test for measuring tensile strength to avoid the waste of material, and time in destructive tensile test. The tests were performed on a production of three groups of austenitic ductile cast iron covering a wide range of carbon equivalent (3.51 to 5.04%) using; carbon, silicon or nickel as alloying elements. The first group (A) having%CE ranging from 3.51 to 5.04 and the variable element was carbon. The second group (B) having%CE ranging from 3.86 to 4.64 and the variable element was silicon content, and the third group (C) having%CE ranging from 3.90 to 4.8 and the variable element was nickel. A mathematical relation was deduced to relate the tensile strength and Leeb Rebound hardness of austenitic ductile cast iron with regression coefficient R= 0.88.