Brazing is a process that heats filler metal to its fluid temperature and evenly distributes it between two close-fitting parts by capillary action. The molten filler metal bonds with the base metal to form a strong sealed joint. If oxides are present on the joints, they can hinder the process. Praxair can provide a reducing atmosphere that consists of hydrogen and nitrogen to minimize oxide formation and reduce existing oxide, ultimately resulting in higher quality joints.
Carburizing is a case hardening process in which carbon diffuses into the surface layer of a steel part at a temperature high enough to change the steel grain structure into its austenitic state, allowing it to absorb carbon. The result is a strong, wear-resistant surface layer, which makes carburizing an ideal process in the production of strong, safe components.
Our nitrogen-methanol atmospheres provide a consistent carbon level in the steel surface. Control of the carburizing process is measured to industry specifications, enabling consistent process control batch after batch to save you money. In certain cases, we can make alterations to the atmosphere, accelerating the carburizing speed and increasing efficiency. Our suspended carburizing process eliminates the need for pusher furnaces to be emptied for weekend shutdowns — resulting in minimum delays and increased productivity.
Hermetic Sealing -
Hermetic seals are used in a variety of applications in the automotive industry. By providing a vacuum-tight seal, they can protect electronic components from dirt and dust, and work to insulate and channel electricity. Praxair nitrogen and hydrogen provide the right atmosphere for this process to prevent metal oxidation and ensure bonding between glass, ceramic and metal pieces.
Neutral Hardening -
Neutral hardening and tempering produces strength and toughness on automotive parts that will be highly stressed. The strength and toughness can be adjusted to different levels by choosing different temperatures. Praxair’s nitrogen and methanol technology, combined with a precise atmosphere control system, provides the ideal conditions for better control and repeatability.
Sintering is a process that uses compressed metal or ceramic powders to form various shapes. It allows manufacturers to make complex automotive parts that require little to no downstream machining. Our nitrogen and hydrogen-based atmospheres sweep lubricants from the furnace while protecting sintered parts from oxidation and decarburization. The result? Finished parts that look brighter and cleaner. Plus, soot formation and oxidation are virtually eliminated. Size and hardness are reproducible time after time, and production can be increased by faster start-ups, fewer process interruptions and less idle furnace time.
Vacuum Carburizing -
More and more, vacuum carburizing is used in the production of power train components in the automotive industry. Our chemically generated acetylene provides the right carbon source for a vacuum carburizing atmosphere due to its high reactivity and small molecular structure. Our nitrogen, helium, argon and hydrogen are used as the quenchant in High Pressure Gas Carburizing.
Annealing is a process to relieve stress caused by prior operations. The process is done by heating and maintaining a suitable temperature, followed by controlled cooling. The correct atmosphere is key to a successful, reproducible annealing process. So, whether you’re working with ferrous or non-ferrous metals, Praxair’s nitrogen/hydrogen-based systems can improve the quality of your results.