Open AccessCORROSION BEHAVIOUR OF TEMPERED 42CrMo4 STEEL
Author(s) -
Sunčana Smokvina Hanza,
Lovro Štic,
Lovro Liverić,
Vedrana Špada
Publication year - 2021
Publication title -
materiali in tehnologije
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.27
H-Index - 25
eISSN - 1580-3414
pISSN - 1580-2949
DOI - 10.17222/mit.2021.014
Subject(s) - tempering , materials science , metallurgy , quenching (fluorescence) , corrosion , microstructure , hardening (computing) , alloy steel , carbon steel , ultimate tensile strength , austempering , alloy , martensite , composite material , bainite , physics , layer (electronics) , quantum mechanics , fluorescence
Low-alloy 42CrMo4 steel (AISI 4140) is a medium carbon steel, commonly used as a quenched and tempered steel. Because of its good mechanical properties, high tensile strength and toughness, 42CrMo4 is one of the widely used and investigated steels. In order to increase ductility even more, in addition to standard quenching and tempering, steel is often hardened by double quenching and tempering and austempering. The aim of this paper was to investigate the corrosion behaviour of 42CrMo4 steel after quenching and tempering, double quenching and tempering and austempering. For this purpose, microstructural characterization and electrochemical investigation after different hardening processes were performed. Microstructure of specimens was observed using optical microscopy and scanning electron microscopy. Open circuit potential and potentiodynamic polarization measurements of tempered specimens were carried out using computer-controlled potentiostat with three electrode set-up in 0.6 M NaCl naturally aerated solution. It was concluded that applied heat treatment processes increase the corrosion resistance of 42CrMo4 steel in comparison to normalized steel. In comparison to quenched and tempered steel, double quenching and tempering, as well as austempering, do not significantly change corrosion resistance of steel.