Effect of quenching media on microstructural evolution, mechanical and wear properties of AISI4135 steel

Abstract

The aim of this work is to study the effect of various quenching media on the microstructural evolution and properties enhancement of AISI 4135 alloy steel. The formation of dual microstructures and their effect on mechanical and wear properties are investigated in this work. An attempt is made to correlate the microstructure-properties relation based on the quenching method used. Steel is heated above the austenitic temperatures (A3) and subsequently cooled down through various quenching media to obtain the variations in microstructures and related properties. The heat treated samples were investigated for microstructural evolution through optical microscopy and scanning electron microscope; mechanical characterization through microhardness study, tensile testing and impact testing; and wear characterization through pin on disc tribometer. It was observed that increased cooling rates increased the volume fraction of martensitic structures whereas oil quenching enhanced fine pearlite and bainite formation. The air cooling led to the formation of fine pearlite along with ferrite structures. Strength, hardness and wear resistance is favored with martensite formation but toughness decreases.

Effect Nickel and Quench-Temper Process on Mechanical and Corrosion Properties of Astm A588 Waethering Steel

“…The water and oil quenchant leads to rising in cooling rate more than air cooling and accelerates the austenite decomposition into martensite form (tetragonal structure) with diffusion-less transformation. But, slow cooling within the materials leads to the laminar phases of pearlite, bainite, and ferrite [19]. In lower C concentration (0.17 wt.%C), tempering 400 °C will improve the ductility and young modulus due to the different shear modulus of tempered martensite, which simultaneously leads to generating the prevalent unstable martensite structure, ferrite, cementite, and a carbide precipitate, which associated with the change in lattice distortion (BCT to BCCbody centered cubic lattice).…”