Heat Treating Process Improvement

Most heat treating and other industrial processes require mixtures of reactive, reducing or inert gases supplied to furnaces to protect or change the surfaces of parts or material being processed at high temperatures.

Such atmospheres are used widely in heat treating operations including

carburizing (gaseous case hardening) annealing powdered metal sintering nitriding

Typically heat treating atmospheres consist of four to eight significant gas constituents. One of two gas supply sources typically provide the atmosphere gases: customer-owned thermal catalytic reactors ("generators") that crack fuel and air mixtures, or liquified gas and liquid supplied by industrial vendors.

Most heat treating furnaces measure only a single gas (oxygen or water vapor) to control atmosphere quality. This approach always characterizes the atmosphere imprecisely and part quality suffers. Additional processing costs such as increased scrap and rework often result.

As a consequence many furnace operations consider adding three-gas infrared (IR) analyzers to improve processing accuracy and part quality. However, IR technology does not monitor many of the most important heat treating gases. These gases include hydrogen, nitrogen and oxygen which can't be measured. Also not measured are ammonia, most organic compounds and water vapor, which are too expensive to measure with industrial IR equipment.

ARI's LGA technology allows the cost-efficient complete atmosphere control that has been desired, but unavailable until now. This control not only provides the process information needed to improve part quality, but also enables new ways of gas processing that increase furnace production rates and significantly lower production and operating costs.