Abrasive Wear Behaviour of Heat Treated En31 Steel

Abstract

Ni-Cr-Mo steels are widely used in machine part members, gears and shafts. Steels with higher carbon content (~1%) are used for heavy machine parts and bearings. Abrasive wear resistance is often a very important requirement for these high carbon steels, apart from sliding wear properties. In the present study, En31 steel was subjected to varying heat treatments to generate different microstructures. An attempt has been made to correlate the two body abrasive wear resistance with the bulk hardness and microstructures. The microstructures were studied through a combination of scanning electron microscopy (SEM), energy dispersive spectrometer attached to SEM (i.e. SEM-EDS) and X-ray diffraction (XRD). The bulk hardness decreased with increase in tempering temperature from 423 K to 848 K. The precipitation of Cr7C3 after 598 K tempering did not cause an appreciable increase in the hardness. At higher tempering temperatures (848 K), the martensite decomposed to give ferrite and cementite. The abrasive wear tests were carried out on hardened and tempered specimens. The abrasive wear mass loss increased with increase in the tempering temperature. Hardness had a direct correlation with the two body abrasive wear behaviour in En31 steel -increase in hardness increased the abrasive wear resistance. The important material removal mechanism were micro cutting and micro ploughing, the relative contribution of each to total wear loss was influenced by abrasive wear test conditions.

Microstructure evolution and abrasive wear behavior of D2 steel

“…At higher tempering temperatures, precipitation of iron rich carbides indicates the decomposition of martensite into ferrite and Fe 3 C, which is slightly enriched with Cr. A similar sequence has been reported for a study on En31 steel [40]. The XRD patterns of the as-quenched, quenched-tempered 523 K, quenched-tempered 723 K and quenched-tempered 923 K D2 steel samples are shown in Fig.…”

“…Reduction in the size of the crystallites/coherently diffracting domains and increase in the micro-strain lead to the broadening of the peak profiles. The presence of dislocations in the structure induces micro-strains, which results in the broadening of the diffraction peaks [40,41]. After tempering at 523 K, 723 K and 923 K, the broadening reduced due to reduction in the dislocation density as well as decomposition of martensite into ferrite.…”

Microstructure Evolution and Abrasive Wear Behavior of Ti-6Al-4V Alloy

“…Though this law gives a very rough and general approximation of wear behavior, it has been successful in describing a first estimate of wear behavior for various materials ( Ref 15). There are numerous studies on steels, which indicate that an increase in hardness results in an increase in the wear resistance (Ref [16][17][18][19]. However, contradictory opinions also exist in the published literature.…”

“…Some authors (Ref 20,21) have reported a drop in wear resistance with increase in hardness in steels. These studies (Ref [16][17][18][19][20][21], particularly on the two-body abrasive wear behavior, are mostly confined to steels and Al alloys. A systematic study relating abrasive wear behavior of Ti64 alloy to hardness (and heat treatment) is not available in the domain of published literature.…”

Simplified Simulation Method of Round Steel Bar Cooling

“…Application of heat treatment during manufacturing process is one of the most effective ways to improve main service properties of hypoeutectoid low alloy steel products: fire resistance, 1) susceptibility to hydrogen induced cracking and sulfide stress cracking, 2) abrasive wear resistance, 3) strength and toughness. 4) Depending on the cooling intensity of the metastable austenite even before its phase transformation different microstructures with different properties are obtained, 5) especially throughout the cross-section of the products with large diameters.…”