Influence of the heat treatment path on the martensite phase and dry reciprocating wear behavior of dual-phase steels

Department of Materials Engineering, Karaj branch, Islamic Azad University, Karaj 3148635731, Iran
e-mail: abouei@iust.ac.ir

Received: 11 June 2015
Accepted: 17 December 2015

Abstract

In order to explore the tribological potential of dual-phase (DP) steel as a wear-resistant material, the wear and friction characteristics of this steel, which consists of soft ferrite and hard martensite phases, was investigated. A low-carbon (0.11% C) steel was subjected to three different annealing heat treatments in order to develop different martensite percentages and morphologies, i.e., island types, a bulky and interconnected network, and fibrous (fine, needle-like), respectively. Dry reciprocating wear tests were performed under atmospheric conditions of 25 °C using a pin-on-disk apparatus at different loading conditions ranging from 18.9 N to 43.6 N and at a constant sliding velocity of 0.22 m/s. The lowest wear rate was obtained for the DP steel with an ~87% volume fraction (V_F) of martensite, reflecting the effect of hardness imparted by the increasing amount of martensite, which is a hard and load-bearing phase, while the highest wear rate was for the DP steel with a ~36% martensite V_F. The analysis of the surface, subsurface and wear debris of specimens using a scanning electron microscope (SEM) showed that the wear mechanism was mainly mild oxidative wear. The friction and wear rate of the steels are explained with respect to the microstructure and the wear mechanism.