How to control the temperature and atmosphere of heat treatment in a multi-purpose furnace?

How are the temperature and atmosphere controlled during heat treatment in a multi-purpose furnace?
Multi-purpose furnaces are highly flexible and automated heat treatment equipment, widely used in a variety of heat treatment processes, including carburizing, carbonitriding, quenching, and tempering. Accurate control of temperature and atmosphere is crucial for ensuring heat treatment quality.
For temperature control, multi-purpose furnaces typically utilize a multi-zone automatic temperature control system, using high-precision thermocouples and PID temperature controllers to precisely regulate the furnace temperature. The system can program heating, holding, and cooling curves required for different processes, ensuring stable operation within the specified temperature range. Temperature differential control typically achieves ±1-2°C, effectively preventing structural abnormalities or uneven hardness caused by temperature fluctuations.
For atmosphere control, multi-purpose furnaces are typically equipped with automatic control systems for shielding or carburizing gases. Gases such as nitrogen, ammonia decomposition gas, methanol, and propane can be introduced according to process requirements. Gas flowmeters and proportional control valves ensure precise flow adjustment. Oxygen probes or infrared analyzers monitor furnace gas composition (such as carbon and oxygen potentials) to provide real-time feedback and automatic adjustments. This closed-loop control technology ensures consistent and controllable performance of indicators such as carburized layer depth and hardness distribution.
Through coordinated control of temperature and atmosphere, the multi-purpose furnace meets the demands of high-precision heat treatment processes and is widely used in applications requiring stringent performance, such as automotive parts, gears, bearings, and high-strength fasteners.