Técnica de análise não destrutiva por parâmetros magnéticos para identificação da variação microestrutura em um aço 4140

Abstract

Non-destructive testing (NDT) corresponds to techniques used in the inspection of materials and equipment without, however, damaging them and can be used in the manufacturing, construction, assembly, and maintenance stages. These tests consist of one of the main tools of quality control of materials and products. They have applications in the petrochemical, chemical, electromechanical, aeronautical, aerospace, steel, naval, and other fields. In this context, in order to improve the speed and reliability of sample analysis of parts and equipment composed of SAE 4140 steel, which are generally fabricated for applications in high strength machine parts such as connecting rods, crankshafts, steering joints, axles, pump parts, high pressure piping, large industrial gears, machine tool parts, wrenches, and nails. This study proposes to analyze the microstructures modifications promoted by the thermal treatments of hardening and tempering by means of the use of a Non Destructive Test device through magnetic parameters. At the end of the experiments and in possession of all the results, it can be concluded that the used technique was able to detect the microstructural variations caused by the heat treatments operations, allowing the comparison between these results with the hardness results obtained with the durometer, and also the comparison between the used device with the conventional ones.