Hardening of a quick-speed steel tool through nitration process with nitrogen controlled potential

The study of the gas nitriding method, which allows obtaining high-quality diffuse layers in high-speed steel P6M5 on the basis of an internal nitrogen hardening zone with no brittle nitride zone, has been viewed. Research results of phase composition of nitrided steel with a change in the nitrogen potential of the atmosphere during dilution of ammonia are presented. Nitrided tool increased resistance during drilling constructional steel and titanium alloy, which is due to precipitation hardening treatment of the internal nitrogenization zone using tungsten nitrides, is given.

Nitriding of High Speed Steel for Improvement of Tools Resistance

The article is devoted to the study of the gas nitriding process, which makes it possible to obtain high-quality diffusion layers in high-speed steel M2 on the basis of an internal nitriding zone without a brittle nitride zone. The results of studies of the nitrided steel phase composition with a change of the saturating atmosphere during dilution of ammonia by hydrogen are presented. An increase in the resistance of the nitrided tool when drilling structural steel is shown, which is associated with the dispersion hardening of the internal nitriding zone with tungsten nitrides.

Analysis of Multiple Indicators of Ion Nitrided Layers of BH11 Steel

In modern scientific and engineering expertise there are a few methods for graphical computational analysis related to decision making. However, few of them are devoted to materials science and the determination of the complex of properties separately and simultaneously. This research proposes a decision analysis approach tested for the basic properties of BH11 steel. With the help of the approach the tendencies as technological regimes in the change of the microhardness Hv, the relative wear resistance Kv and the connected nitride zone δnz are established. A model for the phase composition is derived, which interprets all observed trends and technological regimes for the relatively minimal and relatively maximal studied values. Thus, the efficiency of the technology in processing the considered steel is associated with the structure and properties of ion nitrided layers, which as a research is the main task of materials science.

Structure and properties of the modified diffusion nitride-oxide surface layer

To combine the processes of gas nitriding and oxidation in water vapor, the effects of the atmospheric nitrogen potential in dissociated ammonia on the formation of surface diffusion nitride phases are studied. Modification of the surface nitride layer with oxygen was carried out by oxidation of the nitride zone at the second stage of obtaining an oxycarbonitride layer. The corrosion and wear-resistant properties of the nitride-oxide layer t of the lowest nitride layer are investigated, depending on the phase changes in the nitride layer after oxidation. The distributions of the elements in the nitride-oxide layer are determined, and the nature of the formation of the modified surface layer under the combination of gas nitriding with subsequent oxidation in water vapor is established.

Viscosity Controlled Interdiffusion in Nitriding

This works presents new approach to model formation of expanded austenite (S-phase) during nitriding in plasma conditions. Diffusion saturation of the substrate (iron or austenite steel) is treated as interdiffusion of nitrogen and iron that involves stresses and plastic deformation and is based on the Darken scheme. It is argued that S-phase growing at nitriding behaves as elasto-viscous Maxwell solid. During the process, in the nitride zone, the dynamic pressure appears, which is related to Darken drift and depends on metal viscosity. Basic equations are formulated and discussed. The formula for drift is derived. Exemplary results, i.e. concentration profiles, dynamic pressure and dilatation of the sample during the process, are presented. Concentration profiles confirm existence of characteristic plateau like zone in the surface adjacent zone.