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.

Resistance of Aluminide Coatings on Austenitic Stainless Steel in a Nitriding Atmosphere

A new slurry cementation method was used to produce silicide-aluminide protective coatings on austenitic stainless steel 1.4541. The slurry cementation processes were carried out at temperatures of 800 and 1000 °C for 2 h with and without an additional oxidation process at a temperature of 1000 °C for 5 min. The microstructure and thickness of the coatings were studied by scanning electron microscopy (SEM). The intention was to produce coatings that would increase the heat resistance of the steel in a nitriding atmosphere. For this reason, the produced coatings were subjected to gas nitriding at a temperature of 550–570 °C in an atmosphere containing from 40 to 60% of ammonia. The nitriding was carried out using four time steps: 16, 51, 124, and 200 h, and microstructural observations using SEM were performed after each step. Analysis of the chemical composition of the aluminide coatings and reference sample was performed using wavelength (WDS) and energy (EDS) dispersive X-ray microanalysis, and phase analysis was carried out using X-ray diffraction (XRD). The resistance of the aluminide coatings in the nitriding atmosphere was found to depend strongly on the phase composition of the coating. The greatest increase in resistance to gas corrosion under nitriding atmosphere conditions was achieved using a manufacturing temperature of 1000 °C.

The effect of stadial nitrogenization on the structure and properties of martensitic steel 13X11N2V2MF

A new method of gas nitriding is presented, which produces obtaining high-quality diffusion layers that meet the requirements of the use for various purposes, including aviation ones. Peculiar properties of highly alloyed martensitic steel nitriding after stadial thermo-gas-cyclic nitrogenization under partially dissociated ammonia with air additives have been examined. The results of metallographic studies, diagnostic leach, tests for wear resistance, impact hardness and corrosion stability, depending on the test mode are presented.

Investigation of Gas Nitriding Effect on Damping Ratio of Steel 1.7225 and Cutting Vibration of Indexable End Mill Made from It During the Straight Groove

End-milling is a cutting technology that removes material from machined workpieces by end mill and is widely used to manufacture parts. Moreover, this process is prone to vibration due to low stiffness. Also, nitriding is a surface hardening process with lots of effects on mechanical properties. This study investigated the effect of gas nitriding on a nitrided end mill in comparison with an unnitrided end mill and showed significant improvement in vibration peak and RMS during end milling. To clarify the reason for this improvement this article carried out a modal test to show how nitriding affected the natural frequency and damping ratio of the nitrided and unnitrided samples and showed that tool rigidity remained the same while damping ratio increased so we claimed nitriding improved damping ratio without change of tool rigidity. For verifying this claim we modeled, meshed, and analyzed for obtaining tool natural frequency both for nitrided and unnitrided tool and compared with extracted natural frequencies from each tool FFT diagram during straight grooving. We showed that the natural frequencies were the same with less than 3 percent change so we concluded that nitriding led to better tool performance by increasing the damping ratio without any significant change in the tool stiffness.

Stress and Deformation Analysis of Batch Plates using Finite Element Method

The aim of the paper is to check the load-bearing capacity of batch plates. The batch plates are used for coating process of ball joints in a gas nitriding furnace. The plates have circular shape with two types of circular holes, the first type of holes are used for gas flow and the second type of holes are used for ball joints. The plates are laid on the supporting frame. The frame is supported in four suspension eyes, it is loaded by the actual weight of the plate and the plate is loaded by the weight of the stored ball joints. From the results is clear that adjustments need to be made on the supporting frame for the safe operation.

Calculation of the main parameters of the ultrasonic oscillatory system for the intensification of gas nitriding processes

The paper studies the matters of designing an ultrasonic oscillatory system taking into account the peculiarities of the impact on the gas environment. Calculations of the elements of an ultrasonic oscillatory system are presented. The types of membrane emitters for influencing the saturating medium during gas nitriding are analyzed.

Application of technical nitrogen during gas nitriding austenitic steels

The possibility of using technical nitrogen including 0,2% O2 for activation austenitic steels surfaces during gas nitriding were investigated. By changing mole fraction of technical nitrogen i NH3 /N2t mixture one can regulate oxygen potential of gas atmosphere during heating the steel to nitriding temperature and sometimes during nitriding process. Four representative austenitic steels were nitrided with good results at 570°C and under 450°C. New method can be alternative to regulating oxygen potential by air and allows avoiding installing of firing mechanism and safety control.