Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
FIRST RESULTS OF THE CAVITATION EROSION BEHAVIOR FOR LOW-TEMPERATURE PLASMA CARBURIZED MARTENSITIC STAINLESS STEEL
Submission Author:
Fabiane Severo , PR
Co-Authors:
Fabiane Severo, Rodrigo Perito Cardoso, Silvio Francisco Brunatto, Cristiano Scheuer
Presenter: Fabiane Severo
doi://10.26678/ABCM.COBEM2017.COB17-2687
Abstract
This work presents first results of the investigation regarding the cavitation erosion resistance of a plasma carburized martensitic stainless steel (MSS). AISI 420 MSS was DC plasma carburized at 350 °C for 12 h using a gas mixture of 99.5% (80% H2 + 20% Ar) + 0.5% CH4. Samples were characterized by X-ray diffractometry and microhardness measurements. Cavitation erosion tests were performed on treated (carburized) and untreated (quenched and 220 °C tempered) samples, according to the ASTM G32-10 standard (ultrasonic vibratory apparatus). The characteristics of the damaged surfaces were analyzed by means of scanning electron microscopy, in order to identify the main wear mechanisms. XRD results evidence the formation of a layer composed by carbon-expanded martensite (α’C) and cementite (Fe3C) phases, which exhibits hardness about 1.3 times higher to the untreated material. These first results of cavitation tests demonstrated that the superficial increase on carbon content, using the plasma technique, leads to the improvement on the cavitation erosion resistance of the treated material, since it promotes the hard carburized layer formation that enhances the material’s capacity in responding to cavitation. Nominal incubation periods of 7.8, and 17.9 h for the untreated, and carburized samples were observed, respectively.
Keywords
Cavitation erosion, AISI 420 martensitic stainless steel, low temperature plasma carburizing, carbon-expanded martensite
