Stainless steels, carbon steels and non-ferrous materials are annealed to trigger the relaxation of internal stresses and give a softer product. Our ALNAT atmosphere solutions for annealing are mainly based on mixtures of nitrogen, hydrogen and hydrocarbon or nitrogen and cracked methanol. Benefits include improved safety, reliability low-maintenance operation and low capital cost.
Brazing processes can be manual or automatic. They are used for heat exchangers in air conditioning, taps, sanitary equipment and compressor parts. Fuel gases include acetylene, hydrogen and Air Liquide’s FLAMAL™ brand gas mixtures.
During carburizing (carbonitriding) operations, carbon and nitrogen is brought to the surface of steel components and diffused to produce a hard martensitic surface layer after quenching. Traditionally, the carbon comes from a hydrocarbon, natural gas or propane, partly oxidized in an endogas generator to produce a carbon/hydrogen atmosphere. For nitriding, the nitrogen agent comes from ammonia cracking at the surface. Nitrogen accelerates the diffusion of carbon into the treated parts. The ALNAT solution offers you an active and reproducible heat treatment under nitrogen and methanol. Either in a batch or in a continuous furnace, the methanol is cracked and represents the carbon agent, which is sprayed with nitrogen in the hot zone of the furnace, around 900°C for carburizing and 880°C for carbonitriding.
Cryo-grinding, or freeze-grinding, involves cooling a material to low or very low temperatures with a cryogenic fluid – typically liquid nitrogen or liquid carbon dioxide – in order to produce particles with a narrow size distribution. Cryogenic technology makes it possible to process soft or heat-sensitive products more efficiently without the risk of degradation. In addition, cryo-grinding can increase productivity and lower power costs. By embrittling the material, fine powder can be obtained easily and with a minimum expenditure of energy. In general, this technique allows greater amounts of substance to be treated, however, overall quantities usually remain relatively small, around several kilograms per hour.
Carbon dioxide, an environmentally friendly blowing agent able to control all the properties of your foamed polymers with accurate carbon dioxide dosing and high reliability, can be used for expanded polystyrene, polyolefin or polyurethane foam. Carbon dioxide has proven to be the best blowing agent for foaming because it is safe to use and low-cost as compared to traditional blowing agents. Carbon dioxide is available in large quantities and, as a recycled product, is environmentally conscious. Air Liquide experts have developed accurate, bubble-free carbon dioxide supply systems that will allow you to produce cellular plastic parts while you control the properties of your final products.
Weight reduction and material savings
Improved insulation properties
Management of your products’ final properties
Safety and Reliability:
High safety standards
No fire/explosion hazards
Continuous availability of carbon dioxide at the necessary temperature and pressure
Gas quenching is an environmentally friendly alternative to oil or salt bath quenching applications. Associated with low-pressure processes such as carburizing, nitriding, annealing and others, gas quenching offers better control of distortion and limits post operations such as rectification. Primarily developed for high performance materials, gas quenching can be performed with nitrogen, argon, hydrogen or helium. Pure or gas mixtures may be used depending on the material specifications. More recently, the development of vacuum carburizing applications in the automotive industry has required high-pressure gas quenching furnaces with pressure up to 20 bars. Air Liquide has built expertise in the development of dedicated solutions.
For laser cutting, a laser beam is focused on the base metal, and a cutting jet ejects molten metal. This process is used mainly on thin metals requiring high precision and high productivity. Air Liquide provides optimized and innovative gas installations and gas equipment to meet your flowrate and pressure needs for carbon dioxide lasing gas.