Source: AZO Sensors
Many heat treat processes require protective or process gases. These gases often require careful monitoring. One of the protective and/or process gases used in many heat treat applications is an endothermic atmosphere which is made up largely of CO, CO2, H2, and N2. This article is about the creation and proper monitoring of endothermic atmospheres.
In an atmosphere furnace, the proper mix of these gases can help facilitate changes in the metal such as proper hardness and strength, resistance to temperature, or improved tensile strength to mention a few. Without careful control of temperature, time and atmosphere, metals can experience unwanted changes in properties such as hydrogen embrittlement, surface bluing, soot formation, oxidation, and decarburization. With such critical outcomes in the balance, it is necessary to control the endothermic gas.
An excerpt:
“In order for the required metal treatment to be a success, you must control and monitor the gas composition with extreme care. The concentrations of gases, CO₂, H₂O, CH₄, N₂, H₂ and CO, that make up the endothermic gas atmosphere should be measured in order to aid the prevention of unwanted reactions and ensure that the endogas generator and the furnace are operating normally.”
Read more: “CO and CO2 Control of Endothermic Gas in Heat Treatment Furnaces”
