27th IFHTSE CONGRESS & EUROPEAN CONFERENCE ON HEAT TREATMENT 2022

Within the research work of the transregional collaborative research centre TRR136, the so-called Process Signatures were determined for some processes that result due to an exclusively thermal load for the component surface layer. These Process Signatures represent correlations between material modifications (e.g. residual stress and hardness profile) and characteristic values of the material...

Carburizing and quenching are one of the surface modification treatments to impart mechanical properties to materials. Carburizing is a lengthy process, generally performed at approximately 1203 K. Conventional carburizing (gas carburizing or low pressure carburizing) is processed in batches. Consequently, this creates many in-process inventories, which negatively affects the production...

The wear and fatigue properties of metallic components can be improved by surface heat treatment. The applied process should be chosen depending on the application, because the processes offer specific advantages and disadvantages. Nitriding is suitable for components sensitive to distortion, since due to the low treatment temperature no thorough phase transformation takes place. However, the...

Highly stressed components such as gears are usually case-hardened according to the current state of the art in order to adjust the specific stressability at the tooth flank and root. The heat treatment process typically involves carburization followed by quenching to room temperature in gaseous or liquid media. In most cases, the result is a predominantly martensitic structure with finely...

Carbonitriding has shown great potential to further increase service life of components exposed to contact fatigue. In this project, the rolling contact fatigue properties of case hardened and carbonitrided 18CrNiMo7-6 were investigated. The aim was to qualitatively assess the impact of retained austenite on micropitting damage to further understand the underlying mechanisms of the...

In recent years the use of pushbelt Continuously Variable Transmissions (CVT) in automotive applications has seen a strong worldwide growth. Currently over 75 million pushbelts have been produced by Bosch Transmission Technology, while Bosch continues to respond to market demands regarding electrification, efficiency, NVH, cost, and power density. Power density comprises the transmittable...

In some applications, carbonitriding treatment is used to replace the carburizing treatment thanks to its ability to improve mechanical properties.

The aim of this study is to better understand the role of nitrogen on mechanical properties and microstructure. For this we studied the response of the 27MnCr5 steel to different carbonitriding treatments which target specific carbon and...

In industry, thermochemical carbonitriding treatment is often followed by shot peening. Each of these processes generates surface microstructural modifications and residual compressive stresses which have a direct effect on the fatigue resistance. In the literature, these processes are often studied separately and therefore optimized independently.

This study focuses on these two processes,...

Forming industry is confronted with ever increasing demands on productivity, quality and performance of tools and dies. The main limiting factors are wear and fatigue resistance. Good abrasive wear resistance is obtained by increasing material hardness, which however may hamper toughness and fatigue resistance. Therefore different surface engineering techniques like plasma nitriding are used...

The Böhler K490 MicroClean tool steel was developed for hardening and tempering applications with the possibility of additional nitriding in plasma, gas or salt bath. Its application includes cold working tools and polymer processing tools. The paper analyses the influence of the choice of austenitization temperature, deep cryogenic treatment (DCT), tempering temperature and plasma nitriding...

The active screen plasma nitriding (ASPN) is a nitriding method that avoids the edge effects and arcing that occur during the conventional direct current plasma nitriding (DCPN). Furthermore, applying voltage to a sample during the ASPN increases the nitriding rate (S-DCPN). Although steel is the predominant screen material, there are few reports on non-ferrous material screens. Therefore,...

High temperature solution nitriding (HTSN) of stainless steel was originally introduced in the early 1990s and is in many aspects the “stainless” analogue to carburizing of steels. Instead of introducing carbon to the surface, nitrogen is used. The process is normally carried out at temperatures above, say, 1050°C, using an atmosphere of molecular nitrogen at a fixed pressure in order to...

Solution nitriding is a high temperature nitriding process carried out in a gaseous atmosphere composed of pure nitrogen under various pressure. It is notably used to reinforced stainless martensitic steels while limiting loss of stainless properties due to chromium precipitation. The aim of the study is to propose an approach based on thermodynamics considerations for identifying adequate...

Gaseous nitriding is a thermochemical surface treatment aiming surface strengthening of steels. The diffusion of nitrogen atoms in the ferritic matrix involves the precipitation of nano-scale alloying elements nitrides MN (M = Cr, V, Al…) that leads to secondary phase hardening and the generation of compressive residual stresses. Prior to nitriding, steels are quenched and tempered for...

Rich of more than 60 years development in industrial conditions, Salt bath nitrocarburizing (SBN) has been able to adapt itself to match standards in so different fields (Aeronautics, Energy, Automotive, Construction Equipment, Military…).

Thus, SBN is nowadays an essential surface treatment solution, globally established and recognized with more than 500.000 tons of parts yearly treated...

Titanium is a lightweight highly corrosion resistant material used in industrial applications as diverse as aerospace, biomedical, military and chemical processing. Titanium’s excellent biocompatibility makes it one of the materials of choice for implants and medical devices. Furthermore, titanium is widely used in 3D metal printed applications, which is becoming increasingly popular. However,...

Hydraulic cylinders are one of the main products in the fluid power industry. During their service life, piston rods are exposed to corrosive environments and wear stresses. Thus, a suitable surface treatment for enhancement of corrosion- and wear resistance is of high importance to guarantee a long lifetime of the parts. The main requirements to piston rod coatings include high surface...

A passivation layer is present on the aluminum surface, and Al has a better affinity for oxygen than nitrogen so generation of aluminum oxide is easier than with aluminum nitride (AlN). Therefore, it is difficult to form the AlN on aluminum surface below the melting point. However, gas nitriding of aluminum is possible by using the barrel nitriding in which the oxygen partial pressure in the...

Induction thermal processing is found in modern production lines as it brings benefits in time and energy savings and allows increased reproducibility and integration in a manufacturing chain. Simulation and experimental studies addressing induction hardening have been widely performed in opposition to induction tempering, which has not been extensively studied. However, applying an optimum...

AISI 304 austenitic stainless steel plates were austenitized in Ar or solution nitrided in 0.5 bar N2 gas at 1150 °C for 2 h. Both austenitized and solution nitrided conditions were cold rolled to different engineering strains by 10‒70 % thickness reduction. The most heavily deformed coupons were subsequently annealed at various temperatures for up to 1 hour. Gaseous nitriding of the deformed...

Surface hardening treatments such as nitriding can improve the mechanical properties to extend the applicability of austenitic stainless steel (ASS) fine and precise machining. Improving these characteristics without changing the design and material is highly advantageous, particularly for medical and surgical instruments. In particular, an improved bending rigidity of medical injection...

In the paper, authors explore the possibility of applying convolutional Neural Network (CNN) to the solution of coupled electromagnetic and thermal problem, i.e. the classical modeling of induction heating systems, traditionally solved by resorting to Finite Element Models. In fact, finite Element modeling is widely used for the design of induction heating systems also in industrial...

Almost all components in technical applications experience alternating mechanical stress during their use. This can cause damage to the material, which increases with each load cycle and can ultimately lead to a fracture of the component. With regard to harsh, corrosive environments, austenitic stainless alloys are the material of choice. However, this highly favorable property is often...

In order to avoid distortion of long and thin tools made out of high-speed steels during heat treatment, a continuous inductive heat treatment can be applied. A classical inductive heat treatment device consists of several inductors, which are aligned, in a row with a certain distance to each other. Due to this configuration, the material can undergo temperature variations during heat...

In the present work a new process route for martensitic stainless steel X30Cr13 (AISI 420) is pursued. Conventional austenitization or high temperature solution nitriding is followed by unconventional tempering and ‘ultra-low’ temperature gaseous nitriding. Tempering is performed in high vacuum and at higher temperatures than the recommended ones for X30Cr13. The relatively high tempering...

Electrothermal technologies, in particular induction heating, can play an important role on improving performance and quality in brazing and soldering metal joints. Induction heating, in comparison to other industrial heat treatments for brazing processes that are traditionally based on open flames, allows to induce heat directly inside the workpiece, reducing process time and costs, with...

Lifetime of an induction heating coil is an important factor directly influencing the economic and environmental attractiveness of an induction heating process. A vast majority of the induction coils are complex electrical devices made of pure copper, carrying extreme electrical currents to generate a strong alternating magnetic field, requiring a water-cooling channel to remove excessive heat...

The paper focuses on the calibration of a model of induction hardening of gear wheels. This process requires high precision and cannot be realized without an application of a good mathematical model to adjust the input parameters of heating and subsequent cooling to achieve the desired results, mainly the prescribed distribution of hardness and microstructure in surface layers of the tooth....