Effects of quenchants on microstructures and mechanical properties ofsteel gradeAISI 5160

Authors

Pattama APICHAI

Publication Date

2020-09-01

Abstract

This research aims to study the effects of the quenchants in hardening process on microstructures and mechanical properties of alloy steel grade AISI 5160. The heat treatments include hardening at 900 (Q1), 870 (Q2), 840 (Q3), 810 (Q4) and 780°C (Q5),respectively, followed by quenching into water, oil and brine solution. Microstructures were measured scanning electron microscopy and energy dispersive X-ray spectroscopy.For each condition, hardness and tensile testing were measured. It was found that the microstructure in the as-sheetcondition consisted of ferrite and pearlite. The observed microstructures after quenching process were martensitewith a small amount of retained austainite. The hardening at 810°C for 30 min (Q4) showed carbide distribution in martensite matrix. The coarse ferrite grains were occurredafter hardening at 780°C for 30 min (Q5). The hardness of as-sheet condition was 40 HRC.Highest hardness was obtainedafter hardening follow by water quenching. The ultimate tensile strength in as-sheet conditionwas about 510 MPa. As hardening at all conditions, the maximum ultimate tensile strength was after hardening at 810°C for 30 min (Q4). Heat treatment conditions increased the hardness and ultimate tensile strength comparedwith the as-sheet condition while %elongation gradually decreased. For heat treatment conditions, however, water quenching is more suitable.

First Page

15

Last Page

23

Recommended Citation

APICHAI, Pattama (2020) "Effects of quenchants on microstructures and mechanical properties ofsteel gradeAISI 5160," Journal of Metals, Materials and Minerals: Vol. 30: No. 3, Article 3.
Available at: https://digital.car.chula.ac.th/jmmm/vol30/iss3/3