Improving mechanical properties of carbon and tool steels via chromizing

Abstract

Steels are commonly used in high-performance demanding applications due to their favourable mechanical properties. Various surface engineering techniques have been developed for steels, among which chromizing is an affordable high-throughput casehardenig process for improved surface hardness and wear resistance while retaining the substrate ductility and toughness. In this work, tribological testing along with nano-and micro-indentation and morphological and composional characterisation were used to understand the effects of the chromizing process on the AISI 1095 carbon steel, 52100 bearing steel and A2, D2 and M2 tool steels. The results of this study demonstrate that the chromizing treatment of low-cost 1095 and 52100 steels significantly improves their wear and hardness properties to a level comparable to the more costly tool steels. While chromizing also increased the hardness of the tool steels, it had little improvement on the wear resistance for the D2 and M2 tool steels.

Tribological Analysis of Steels in Fuel Environments: Impact of Alloy Content and Hardness

“…The Raman spectra indicated the presence of characteristic carbon D and G bands, at approximately 1350 cm −1 and 1580 cm −1 , respectively. These Raman signatures have frequently been associated with the formation of carbon-based tribofilms [37][38][39][40][41][42][43][44][45]. The acquired series of Raman maps, spectra, and energy-dispersive x-ray spectroscopy (EDS) maps demonstrated the formation of carbon films during the sliding process.…”

“…The Raman spectra indicated the presence of characteristic carbon D and G bands, at approximately 1350 cm −1 and 1580 cm −1 , respectively. These Raman signatures have frequently been associated with the formation of carbon-based tribofilms [37][38][39][40][41][42][43][44][45]. Figure 7a shows how the steel samples behaved in terms of friction when they were paired with alumina as the counterbody material.…”

Improved Wear Resistance of Nitro-Chromized Carbon Steel Using an Additional Carburizing

“…Chromium-containing compounds attract widespread attention [1][2][3] in the field of surface modification due to their good thermal stability [1,4], high hardness [1,[5][6][7][8][9], and excellent antioxidant properties [9][10][11]. The surface modification layer composed of chromium-containing compounds always exhibits good wear [4,[12][13][14] and corrosion resistance [5,6,[8][9][10][11]15], thereby prolonging the service life of components in aircraft, automobiles, and ships [16][17][18][19].…”

“…Chromizing [4][5][6][7][8][9][10][11][12][13][14][15]20] is one of the most commonly used surface treatment techniques for forming chromium-containing compounds on the surface of workpieces. During the chromizing process, external active chromium atoms penetrate into the lattice of the substrate through thermal diffusive phase transformation and lead to a chromizing layer composed of chromium carbides/nitrides.…”

“…The conventional direct chromizing [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] operates at high temperatures above 900 • C and results in a chromium-containing compound layer mainly composed of chromium carbides, i.e., Cr 7 C 3 , Cr 23 C 6 . Usually, the conventional chromizing layer has a high hardness value in the range of 1200-1800 HV [1,[5][6][7][8][9] and good wear resistance [4,[12][13][14]. Nonetheless, the conventional direct chromizing process faces two limitations in modern industrial applications.…”