Residual Compressive Stresses and Defects of Layers Hardened by Chemical Heat Treatment

Metallurgist ◽  
2013 ◽  
Vol 57 (7-8) ◽  
pp. 629-632
Author(s):  
I. P. Banas ◽  
L. V. Morozova ◽  
E. N. Korobova ◽  
O. V. Sedov
Keyword(s):  
Heat Treatment ◽  
Chemical Heat Treatment ◽  
Chemical Heat ◽  
Compressive Stresses

Comparative Analysis of Novikov and Involute Gearing in the ANSYS Workbench Software Package

2021 ◽  
pp. 16-21
Author(s):  
S.I. Karatushin ◽  
D.A. Khramova ◽  
N.A. Bildyuk
Keyword(s):  
Heat Treatment ◽  
Comparative Analysis ◽  
Software Package ◽  
Strain State ◽  
Gear Ratio ◽  
Geometric Parameters ◽  
Chemical Heat Treatment ◽  
Chemical Heat ◽  
Additional Hardening ◽  
Ansys Workbench

The paper introduces the results of studying the stress-strain state of the Novikov gearing in comparison with the involute gearing, similar in geometric parameters. In both versions, the wheel and gear are selected in size and gear ratio in accordance with the most common recommendations without additional hardening by chemical heat treatment. The zone of multiple contact of mated profiles is analyzed: changes in the geometry of contacts, pressure in the contact and stresses in various phases of gearing.

Chemical-heat treatment influence on thermal stability of microstructure, mechanical properties and fracture features of V-Cr-Ta-Zr alloy

2021 ◽  
pp. 36-42
Author(s):  
I.V. Smirnov ◽  
◽  
K.V. Grinyaev ◽  
A.N. Tyumentsev ◽  
A.D. Korotaev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Thermal Stability ◽  
Structural Phase ◽  
Strength Properties ◽  
Chemical Heat Treatment ◽  
Chemical Heat ◽  
High Level ◽  
Fracture Features ◽  
Zr Alloy

A study of the features of structural-phase state, thermal stability, mechanical properties characteristics and fracture features of V-Cr-Ta-Zr alloy after chemical-heat treatment by the method of nonequilibrium internal oxidation has been carried out. It has been established that, in contrast to chemical-heat treatment in a defect state, the effect of oxygen when introduced into a material with a stabilized structure is observed only at high concentrations. At such oxygen concentrations, which ensure the maximum binding of Zr into particles based on ZrO2, the alloy under study demonstrates a high level of thermal stability and strength properties. These effects are associated with the implementation of disperse strengthening according to the Orowan mechanism by nanosized ZrO2 particles characterized by high thermal stability. The concentration and nature of the distribution of oxygen predetermine the spatial distribution of nanosized ZrO2 particles formed during chemical-heat treatment, which manifests itself in fracture features of the material at different temperatures.

THE ANALYSIS OF THE SELECTED PROCESSES OF THERMO-CHEMICAL HEAT TREATMENT OF 20MnCr5 STEEL IN THE CONTEXT OF ABRASIVE WEAR

Tribologia ◽  
2016 ◽  
Vol 269 (5) ◽  
pp. 183-193
Author(s):  
Wojciech TARASIUK ◽  
Mariusz LISZEWSKI ◽  
Bazyli KRUPICZ ◽  
Ewa KASPRZYCKA
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Thin Layer ◽  
Abrasive Wear ◽  
Abrasive Wear Resistance ◽  
Chemical Heat Treatment ◽  
Chemical Heat ◽  
Chrome Plating ◽  
Pin On Disc ◽  
Machine Parts

This paper presents the results of tribological tests performed on a T-11 pin-on-disc type, which made it possible to determine the intensity of abrasive wear of steel 20MnCr5 subjected to selected thermo-chemical heat treatments. The tested steel, after the hardening and tempering process, is characterized by high endurance parameters and is used on heavily loaded machine parts. It is frequently used for elements subjected to intense abrasion. The analysis involved the following: carburizing, boronizing, and various methods of diffusion chromizing. For large loads, it is advisable to apply boronizing or carburizing with hardening. Chrome plating entails a very thin layer of increased hardness, which is characterised by a low abrasive wear resistance at high loads.

scholarly journals CHOICE OF TEMPERATURE AND TIME CONDITIONS OF HEATING FOR THE COMBINED PROCESS OF BORATING AND VOLUME TRAINING OF LARGE STAMPS OF 5KhNM STEEL

2019 ◽  
Vol 62 (9) ◽  
pp. 681-685
Author(s):  
K. A. Minkov ◽  
A. N. Minkov ◽  
A. A. Khlybov
Keyword(s):  
Heat Treatment ◽  
Impact Strength ◽  
Hot Deformation ◽  
Mechanical Characteristics ◽  
Hold Time ◽  
Chemical Heat Treatment ◽  
Chemical Heat ◽  
High Hardenability ◽  
Repeated Heating ◽  
Operational Characteristics

The stamps for hot deformation are widely adopted in industry. In use they are affected by high temperatures, tension (close to a fluidity limit) and variable thermal loadings. High-hardenability tool steels with high mechanical characteristics are used for stamps production. In this article, the possibility of use of 5KhNM steel for this goal is considered. One of technological operations at production of stamps is training in oil. It is rational to apply volume and superficial hardening, in particular chemical heat treatment, to improve operational characteristics of stamps, including wear resistance. The way of superficial hardening by the combined heating under chemical and thermal and heat treatment is presented. As a superficial way of hardening of largesize stamps of hot deformation, it is offered to use borating. Optimum temperature and time parameters of heating under the combined heat treatment are chosen and confirmed. The offered mode of chemical heat treatment allows receiving the necessary thickness of the borated layer providing high hardness and corrosion resistance in the working range of temperatures of a stamp. Also the influence of heat treatment on structure and grain size of the samples has been researched. It is shown that with increase in temperature and hold time, the size of grain increases. It leads to decrease in strength, fluidity, hardness and impact strength that can negatively influence operational properties of stamps. For definition of mechanical characteristics, the samples (in the studied range of temperatures and excerpts) have been tested for stretching and impact strength. All tests were carried out according to the existing state standard specifications. On the basis of these results, temperature and time of borating are chosen providing high mechanical properties and thickness of a borated layer. The offered approach has allowed reducing economic costs of stamps production from 5KhNM steel by exception from technological process of repeated heating for training with saving the required operational characteristics of largesize stamps.

scholarly journals CHEMICAL HEAT TREATMENT OF DUMPED NICKEL SLAGS TO RECOVER NICKEL AND IRON

2017 ◽  
Vol 17 (4) ◽  
pp. 22-31
Author(s):  
A. A. Veselovskiy ◽  
◽  
V.E. Roshchin ◽  
S.A. Lajhan ◽  
◽  
...  
Keyword(s):  
Heat Treatment ◽  
Chemical Heat Treatment ◽  
Chemical Heat

scholarly journals Effect of Rare Earth Element La on Corrosion Resistance of Powder Zinc Coating: Experiment and First Principle Calculation

2021 ◽  
Vol 2101 (1) ◽  
pp. 012058
Author(s):  
J P Xin ◽  
S Y Zhang ◽  
S P Hu
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Salt Spray ◽  
Zinc Coating ◽  
Chemical Heat Treatment ◽  
Chemical Heat ◽  
The Rare Earth

Abstract Using a combination of first-principles calculations and experimental studies to study the effect of La on the corrosion resistance of Powder sherardizing layer in metal structures. Compared to other sherardizing rare earth elements (Re), La has better adsorption with the iron matrix and has the lowest binding energy on the adsorption surface (111) of the Fe matrix. Therefore, the rare earth element La is added to the powder sherardizing process for the rare earth chemical heat treatment to reduce the defects of the powder sherardizing faults formed, improve the surface uniformity and the quality of the permeation layer. On the basis of calculation, La element was added in the process of powder sherardizing, and the corrosion performance of the formed powder galvanizing layer was studied. After alternating salt spray experiments, the degree of corrosion of the layer is relatively small and the corrosion products are predominantly layered and spherical. Electrochemical tests of the layer show that the corrosion resistance of the layer after the rare earth chemical heat treatment has improved.

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