Annealing is a process that softens metal, causing changes in its strength and hardness. 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 anneal ferrous or non-ferrous metals, our nitrogen-based systems can improve the quality of your results.
Case Study: Atmosphere Conversion for Annealing (1.0MB)
Case Study: Globe Products Heat Treating (1.2MB)
N2-H2 Atmosphere Control to Exothermic Gas Atmospheres (120KB)
Precise Reproducible and Traceable Atmospheres (506KB)
Brazing is a joining process that heats filler metal to a 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. Oxides on joints can hinder the process. That’s why we 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 / Vacuum Carburizing / Hardening -
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, which allows it to absorb carbon. The result is a wear-resistant surface layer that makes carburizing an ideal process in the production of strong, safe metals.
Control of the carburizing process is measured to industry specifications, enabling consistent process control batch after batch. And best of all, our atmosphere technology saves 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.
Today’s low pressure carburizing process, like many thermal treating processes, demands an atmosphere that is highly reproducible and highly controllable. The right carbon source for this process has been available for use since well before the vacuum heat treating process was developed. Neutral hardening and tempering produces strength and toughness on 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 ideal conditions for better control and repeatability.
Gas Quenching / Inerting -
Typically used in vacuum furnace applications, gas quenching can provide a variety of advantages over traditional polymer or oil-based quenching approaches. Using gas quenching, residue can be eliminated which is an unwanted byproduct in many types of liquid quench processes. Also, due to temperature uniformity in the gas chamber, distortion of parts may be reduced as well. Praxair offers, nitrogen, helium and hydrogen for gas quench applications and has a large variety of supply systems that can meet process requirements.
Many conventional heat treatment furnaces have purge or inerting requirements. Praxair offers nitrogen, argon and other gases that can provide an inert atmosphere that prevents reaction between air and components.
Sintering is a process that uses compressed metal or ceramic powders to form various shapes. Using nitrogen and hydrogen-based atmospheres results in consistent performance for your sintering operation. Our atmospheres sweep lubricants from the furnace while protecting sintered parts from oxidation and decarburization. The result? Finished parts look brighter and cleaner, and 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.