Nitriding Behavior and Strengthening Mechanism of Ti Added Steels in a Rapid Nitriding Process

Precipitation of nanosized nitrides in plasma nitrided Fe–M (M = Al, Cr, Ti, V) alloys

“…Therefore, alloying of strong nitride forming elements, such as Ti, Al, V, Cr and so on, is necessary to obtain substantial surface hardening, and precipitation behaviours of alloy nitrides have been studied so far. [1][2][3][4][5][6][7][8][9][10][11][12][13] Equilibrium alloy nitrides for these elements are TiN, VN and CrN of NaCl (B1) structure and AlN of wurtzite (ZnS type) structure in usual steels. On the other hand, Jack 7 and Rickerby et al 8,9 investigated the microstructure of various gaseous nitrided Fe-Ti alloys and reported the formation of metastable mixed substitutional (M)-nitrogen (N) atom cluster based on indirect experiments.…”

On the determining role of acicular ferrite in V-N microalloyed steel in increasing strength-toughness combination

“…It also appeared that after the initial nucleation events at the intragranular heterogeneities (i.e., precipitates, inclusions, and deformation bands), small platelets subsequently form "sympathetically" at the austenite/ferrite interface [31,35]. The critical nuclei for uniform-sized precipitates is increased with increase in the degree of supercooling [36], and the coarsening rate was remarkably reduced because diffusion coefficient decreases with decrease in holding temperature [37][38][39]. As a result, there were high fractions of 3-5 nm precipitates in steel C (Fig.…”

Present Status and Future Prospects of Simulation Models for Predicting the Microstructure of Cold-rolled Steel Sheets

“…Recent research 72) indicates that the formation of a surface layer hardened by nitriding provides highly dent-resistant steel sheets. Figure 8 shows the hardness distribution in such a surface layer of samples with various Ti contents nitrided at 750°C for 40 min in an NH 3 atmosphere.…”