High dew points in endothermic generated sintering atmospheres are a common reason for decarburisation. This problem can be overcome by using a controlled nitrogen-diluted endothermic atmosphere or, better still, a controlled nitrogen-hydrogen atmosphere.

Nitrogen-based atmospheres have been used for sintering carbon steel components for a number of years. These atmospheres are produced and supplied by using an endothermic generator or by blending pure nitrogen with hydrogen. The use of nitrogen-hydrogen atmospheres has been shown to produce parts with consistent quality and properties. However, there are still a number of powder metal parts manufacturers who, anticipating high hydrogen costs, continue to utilize endothermically generated atmospheres for sintering carbon steel components. To help these parts manufacturers increase product quality and consistency without substantially increasing overall atmosphere cost, Air Products initiated a comprehensive experimental program to study sintering of carbon steel components in endothermic and nitrogen-diluted endothermic atmospheres under similar operating conditions in production furnaces.  

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