In the production and manufacturing of metallic components, there is almost always a step in the process where the product is treated to obtain specific physical, mechanical, and technological characteristics.
There are various types of treatments, among which thermal treatments are common. Typically, these involve a thermal cycle under certain temperature conditions followed by more or less slow cooling depending on the desired results. Among the most common thermal treatments are: quenching, annealing, normalizing, tempering, and aging. Many of these, both for technological reasons and to avoid external contaminations (particularly those due to oxygen present in the air), occur in a controlled atmosphere, either in a vacuum environment or constituted by a gas or gaseous mixture.
In this article, we will explore some of the applications in the processes described above, where the controlled atmosphere consists of nitrogen, hydrogen, or a nitrogen/hydrogen mix, gases that can be produced on-site thanks to ILT Energia generators.
1. Nitrogen Controlled Atmospheres:
Gaseous nitrogen at ordinary pressures and temperatures is chemically inert with most common substances. For this reason, it is widely used in thermal treatments to prevent oxidation and improve the surface hardness of metals. Nitrogen generators from Nitro are capable of providing high-purity nitrogen with flows compatible with almost all machinery related to the heat treatment industry.
2. Hydrogen Controlled Atmospheres:
Gaseous hydrogen acts as a reducing agent when reacting with non-metals. Indeed, it finds application in the formation of controlled atmospheres at high temperatures, the ultimate goal of which is to reduce the surface oxides that deposit on metals. Furthermore, due to its high thermal conductivity, it is useful in processes where it is necessary to remove heat or uniformize temperature. Electrolysers and gas treatment systems (drying systems, rectification systems…) branded ILT Energia provide hydrogen of very high purity, making it one of the best supply systems for applications such as quenching and annealing.
3. Nitrogen/Hydrogen Mix Controlled Atmospheres:
The combination of hydrogen and nitrogen and their respective characteristics (inerting action and reducing action) offers a controlled atmosphere that can be optimized to obtain specific properties of metals. For example, in sintering processes, the mix of hydrogen and nitrogen can improve the density and mechanical resistance of metallic components. This flexibility in adapting controlled atmospheres to the specific needs of heat treatment is a key advantage in the use of gas generators.
4. An Example of ILT Energia Generators Usage: Heat Treatment of Stainless Steel
The ability to customize the composition of controlled atmospheres based on the specific needs of the process, combined with the possibility of applying the logic of producing gas on-site in the quantities and times decided, constitutes a clear advantage from a management and quality perspective in the production processes of metallic components in various industrial sectors.
The application of hydrogen, oxygen, and nitrogen generators is perfectly compatible with the heat treatments of stainless steel. Stainless steel is known for its resistance to corrosion and oxidation, but heat treatment can further improve its properties.
The use of nitrogen or nitrogen/hydrogen mix controlled atmospheres during the annealing process of stainless steel can contribute to maintaining its resistance to corrosion while preserving its crystalline structure.
This is particularly important in sectors where the mechanical resistance and corrosion resistance of stainless steel are fundamental, such as in the chemical and food industries.
